Maquet Servo 900c User manual

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SERVO VENTILATOR 900 C OPERATING MANUAL

CRITICAL CARE

Important

▲

General information

• Servo Ventilator 900 C must be operated only by authorized personnel who are well trained in its use. It must be operated according to the instructions in this Operating Manual.

• After unpacking, the ventilator must be checked and, if necessary, calibrated.

• All data on pressures for Servo Ventilator 900 C are given in cm H2O. 1 kPa (kilopascal) ≈ 10 cm H 100 kPa = 1 bar ≈ 1 atm ≈ 1 kgf/cm 100 kPa ≈ 15 psi

• Responsibility for the safe functioning of the equipment reverts to the owner or user in all cases in which service or repair has been done by a non-professional or by persons who are not employed or authorized by MAQUET, and when the equipment is used for other than its intended purpose.

•A full technical description – including circuit diagrams, parts list and service data – is contained in the service documentation, copies of which are held by your supplier.

(kp/cm2)

Connection

• When connected to a patient, the ventilator must never be left unattended.

•A check on functions must be done before a patient is connected to the ventilator.

• When anaesthetic gas is metered via a flow meter on the low pressure inlet, compressed air must not be connected at the same time.

• To avoid explosion hazards, flammable agents such as ether and cyclopropane must not be used in this machine. Only agents which comply with the requirements on nonflammable agents in the IEC standard “Particular requirements for electrical safety of anaesthetic machines” are suitable in this machine.

• As this machine is not suitable for use with flammable agents such as ether and cyclopropane, the use of antistatic breathing tubes and face masks is not necessary. The use of antistatic or electrically conductive breathing tubes when using high frequency electric surgery equipment, may cause burns and is therefore not recommended in any application of this machine.

• Never connect or disconnect auxiliary equipment to the outlet on the rear of the ventilator when the ventilator is connected to mains.

• All gases must fulfill the specifications for medical grade gas. The gases supplied must be dry and free from oil and dust. Air H2O< 5 g/m

Oxygen H2O< 20 mg/m Nitrous oxide/gaseous phase) H2O< 58 ppm

Oil < 0.5 mg/m

Operation

• The APNEA ALARM is not intended to and will not monitor for disconnections.

• The APNEA ALARM is not functional in VOL. CONTR., VOL. CONTR. + SIGH, PRESS. CONTR. or MAN.

• In the case of a power failure, manual ventilation using a Servo Ventilator 900 C is possible only with the help of power supply from external battery. A resuscitator should always be available, however, as an extra safety measure.

• The SV 900 C is certified, with regard to safety, to be compatible with electromagnetic environments complying with IEC 601-1-2. It is the responsibility of the user to take necessary measures in order to ascertain that the specified limits are not exceeded as this may impair the safety of the ventilator.

Such measures should include, but are not limited to: – normal precautions with regard to relative humidity and

conductive characteristics of clothing in order to minimize the build-up of electrostatic charges.

– avoiding the use of radio emitting devices in close

proximity of the ventilator, such as high-frequency surgery apparatus or cordless (mobile) telephones, resulting in a field level exceeding 3 V/m (IEC 601-1-2).

Magnetic fields of MR equipment having flux densities above 20 mT may cause deactivation of the ventilator functions and may result in permanent damage to the Servo Ventilator.

• To protect the patient against high pressures, the WORKING PRESSURE and UPPER PRESS. LIMIT must always be set at suitable values.

• Do not forget to set the manual ventilation valve to position AUT after completed manual ventilation. Otherwise the patient may be hypoventilated without any alarm from the ventilator. (Not applicable to manual ventilation accessory with motor).

• When mains supply is switched off or in the case of a mains power failure, the inspiratory and expiratory valves will automatically open. This may also occur in the case of an internal electronic failure. Thus, if the WORKING PRESSURE is set too high and the gas supply through the gas supply unit continues, this may result in increased airway pressure.

• When excess gas is being scavenged, the scavenging system must meet the following requirements: – At the point at which the scavenging system is connected to the ventilator, the sub-atmospheric pressure must not exceed 0.5 cm H the breathing system greater than 0.5 l/min. – With continuous air flows of 30 l/min and 90 l/min for not less than 5 seconds at the inlet of the anaesthetic gas scavenging system, the resistance in the system shall not exceed 0.25 cm H

The Servo Evac 180 basic evacuation unit meets these requirements.

• If the ventilator is equipped with electronic gas supply unit, the following applies: When mains supply is switched off or in the case of power failure, the gas supply is automatically blocked.

O or cause an induced flow from

O and 2.5 cm H2O, respectively.

Cleaning

• The ventilator must not be gas sterilized.

• The flow transducers must not be cleaned in a dish washing machine, by ultrasonic methods or by using agents that contain aldehydes.

• Agents used for cleaning must have a pH value between 4–8.5.

• Complete cleaning should be done after every 1000 hours of operation or, at the latest, after every six months.

Service

• The Servo Ventilator 900 C must be serviced at regular intervals by specially trained personnel. Any maintenance must be noted in the log book provided for that purpose, in accordance with national regulations. We recommend that service is done as a part of a service contract with MAQUET.

• The 1000 hours overhaul shall be done after every 1000 operating hours or, at the latest, every six months. In addition, the ventilator shall undergo a technical safety check twice a year, at six months intervals, according to national regulations.

• Service and repairs on the ventilator may be done only by MAQUET authorized personnel.

• Only original parts from MAQUET must be used in the ventilator.

Equipment combinations

• Only MAQUET-approved accessories and auxiliary equipment may be connected to the ventilator.

• In order to maintain system safety and integrity only accessories complying with IEC 601-1, or the safety of which has been verified in another way must be connected to the signal outputs on the rear of the ventilator. For details on connections and allowed voltages, please see Circuit Diagram.

Product information program

This Operating Manual is a part of a comprehensive information program for Servo Ventilator 900 C. The program is planned to contain the following:

Promotional and Scientific Publications

Brochure Servo Application Product Leaflet Reprints

Ventilator Brochures:

Concept

Operating and Service Instructions

Operating Brief Wall Diagram Service Manual Circuit Diagram

Manual Operating with Cleaning

Instructions Instructions

Intensive Care

Anesthesia

Transportation

Product Training Material

Training Advisory Slide Series “I am breathing The Patient’s

Instructions Booklet including through a ABSee

for Instructors Textbook ventilator” Cards

Film and and Poster

Booklet

Front Panel Panel Block Trainee’s set Video programs

Flip-chart Video guide

Video news

Servo Ventilator 900 C-Front

Operating instructions

Servo Ventilator 900 C is simple to operate. Operating instructions are found:

On the ventilator in the form of a panel and cleaning instructions on the lid of the pneumatic unit.

“Normal” settings are indicated in green on the front panel. Settings indicated in red should be used with caution, since these settings may involve a certain risk for the patient.

In the Brief Operating Instructions in the drawer under the ventilator.

A log sheet is available with the Brief Operating Instructions. After certain routines, e. g. cleaning etc., the person responsible for the work should complete and sign the log sheet. The log sheet can then be filed.

On a separate wall poster with cleaning instructions.

In this Operating Manual.

The inside of the cover shows a picture of the ventilator. This picture can be used as a foldout when reading the manual.

The following information is found in the corresponding chapters:

Description ............................................ 1-3

Operating............................................... 4-9

Maintenance......................................10-13

Technical specifications ......................... 14

Contents

1. Arbetsprincip

1. Basic principles

2. Kontrollpanel och ventilationssätt

2. Control panel and ventilation modes

3. Patientsäkerhet

3. Patient safety

4. Uppställningar

4. Set-ups

5. Förberedelser

5. Preparations

6. Funktionskontroll

6. Check on functions

7. Anslutning till patient

7. Connection to patient

8. Klinisk bedömning och felsökning

8. Clinical judgement and troubleshooting

9. Registrering

9. Recording

10. Rutinrengöring

10. Routine cleaning

11. 1000-tim.-översyn med fullständig rengöring

11. 1000 hours overhaul with complete cleaning

12. Utbyte av O2-cell

12. Replacement of O

13. Kalibrering

13. Calibration

14. Tekniska specifikationer

14. T echnical specifications

cell

Chapter 1

Basic principles

In this chapter:

General design .................1:2

Pneumatic unit..................1:3

Rear ...................................1:4

General design

Pneumatic unit

The pneumatic unit comprises the gas conduction system, pressure and flow transducers and control valves.

The control of flow and pressure is done by a feed-back system. The transducers continually measure the flow and pressures. The information is compared with the panel settings and a difference between the actual and the preset values results in correction signals to the control valves.

For detailed description, see chapter “Basic principles” in the Training Instructions.

Low pressure

High pressure

Electronic unit

The electronic unit contains a number of plugin PC-boards with the circuits for regulation, alarms and monitoring.

The unit effects the electronic control of the

pneumatic unit.

Servicing of the ventilator is facilitated by the spare parts exchange system. The faulty parts are replaced by factory trimmed exchange parts.

Service on the electronic unit must be done by MAQUET, or by MAQUET authorized personnel only.

Pneumatic unit

Gas connection. The upper inlet, not visible in the picture, is used for low pressure gas and the lower inlet is used for high pressure gas. For anaesthesia, a gas supply unit with three inlets is available.

The gas supply is regulated by a valve so that a constant pressure is maintained in the bellows.

The O2 cell measures the O2 concentration in the gas.

The gas flows through a bacteria filter.

The respiratory gases are mixed and stored at a constant pressure in the bellows.

The working pressure is set with an adjustment screw.

A manometer shows the working pressure.

A safety valve opens if the bellows is overfilled, or if the pressure exceeds approx. 120 cm H

(

The flow transducer on the inspiration side measures the gas flow to the patient.

The inspiration valve regulates the inspiratory gas flow. It is closed during the pause and expiratory parts of the respiratory cycle.

The pressure transducer on the inspiration side measures the airway pressure.

The flow transducer on the expiration side measures the gas flow from the patient.

To prevent condensation, the transducer is

heated to approx. 60°C.

The pressure transducer on the expiration side measures the airway pressure.

The expiration valve is closed during inspiration. During the expiratory phase it is either fully open or regulating the PEEP level.

The flap valve prevents a back flow of exhaled gases. It is also necessary for the trigg function.

Rear

Operating time meter

Equipotential socket On/Off switch

Fuse holders

Outputs for auxiliary equipment

Control terminal

Recorder output

Rear of Servo Ventilator 900 C

To the right on the electronic unit are the mains inlet socket, fuse holders, On/Off switch, voltage rating, equipotential socket and operating time meter.

To the left on the electronic unit are three

15-pole sockets for auxiliary equipment.

The 37-pole socket is used for recording of

pressure and flow curves.

There are labels with the serial number of the apparatus on both the pneumatic unit and the electronic unit.

Mains inlet socket

Control terminal

Under the secured lid, there is a connector for external control of ventilation.

For details see separate Operating Manual.

Chapter 2

Control panel and ventilation modes

In this chapter: Panel design

and symbols ................... 2:2

Panel functions............... 2:3

Working pressure........... 2:3

Mode selection ............... 2:3

Respiratory pattern ........ 2:4

I:E ratio............................ 2:5

Expired minute volume.. 2:6

Special functions............ 2:7

Airway pressure ............. 2:8

SIMV ................................ 2:10

alarm........................... 2:11

Parameter selection ....... 2:11

121

Controlled ventilation .... 2:12

Supported ventilation .... 2:13

Spontaneous ventilation. 2:15

Manual ventilation .......... 2:16

Panel design and symbols

For easy operation, the panel is divided into fields. Each field is described in this chapter.

“Normal” settings are indicated in green on the front panel. Settings indicated in red should be used with caution since these settings may involve a certain risk for the patient.

A number of knobs and the EXPIRED MINUTE VOLUME meter have dual scales.

The blue scale is always to be used when the low range is selected.

Power on is indicated by a green lamp.

A yellow lamp is either an indication of a certain setting or a reminder to set an alarm limit.

A red lamp always indicates an alarm.

! Working Pressure @ Mode Selection # Respiratory Pattern $ Expired Minute Volume % Special Functions ^ Airway Pressure & SIMV * O

Concentration Alarm

( Monitoring

Panel functions

Working pressure

The working pressure is set with an adjustment screw and is read on the manometer WORKING PRESSURE.

The working pressure must always be set at a value somewhat higher than the highest airway pressure.

Mode selection

The Servo Ventilator 900 C can be operated in 8 different modes, which are selected by means of the mode selector.

The modes are described in special sections in this chapter.

Controlled ventilation

Volume controlled ventilation (VOL. CONTR.) Volume controlled ventilation + sigh (VOL. CONTR. + SIGH) Pressure controlled ventilation (PRESS. CONTR)

Supported ventilation

Pressure supported ventilation (PRESS. SUPPORT) SIMV (Synchronized Intermittent Mandatory Ventilation) SIMV + Pressure support (SIMV + PRESS. SUPPORT)

Spontaneous ventilation

CPAP (Continuous Positive Airway Pressure)

Manual ventilation

MAN

Panel functions

PRESET INSP. MIN. VOL./min

100 110

120

25 50

INSP. TIME %BREATHS/min

PAUSE TIME 10 %

(INSP. PAUSE)

Respiratory pattern

Preset inspiratory minute volume

The inspiratory minute volume is set with the knob PRESET INSP. MIN.VOL. l/min. The knob has a locking button on the underside.

A suitable initial value can be calculated by, for instance, using a Radford nomogram. The minute volume can be readjusted after indication from a CO auxiliary equipment for the Servo Ventilator.

The setting range is 0.4-40 l/min. The tidal volume = PRESET INSP. MIN. VOL. l/min

BREATHS/min

The tidal volume can be read on the digital display.

At extremely high flows it may be necessary to increase the working pressure in order to obtain the desired minute volume.

Flow pattern switch

During VOL. CONTR. and VOL. CONTR. + SIGH, a constant or an accelerating inspiratory flow can be selected. Constant flow gives a lower peak pressure and is the pattern normally used.

A decelerating flow will be obtained in PRESS. CONTR.

Breaths per minute

The respiratory rate is steplessly adjustable within the range of 5 to 120 BREATHS/min.

Analyzer 930, which is

Inspiration time %

There are 6 fixed inspiration times, 20, 25, 33, 50, 67 and 80% of the breathing cycle.

Pause time %

There are 5 fixed pause times, 0, 5, 10, 20 and 30% of the breathing cycle.

Panel functions

I:E ratio

Insp. Pause I:E ratio

time time

20 0 1:4 20 5 1:3 25 0 1:3 20 10 1:2.3 25 5 1:2.3 33 0 1:2 25 10 1:1.9 33 5 1:1.6 20 20 1:1.5 33 10 1:1.3 25 20 1:1.2 20 30 1:1 50 0 1:1 33 20 1.1:1 25 30 1.2:1 50 5 1.2:1 50 10 1.5:1 33 30 1.7:1 67 0 2:1 50 20 2.3:1 67 5 2.6:1 67 10 3.4:1 67 20* 4:1 80 0 4:1

* Reduced to 13%

To the left is a conversion table for INSP. TIME % and PAUSE TIME % to I:E ratio for those who are more used to working with the latter.

On the basis of an I:E ratio, i.e. the relation of inspiration time to expiration time, the pause is allocated to inspiration time.

For example, insp. time 25% and pause time 10% = I:E ratio 35/65 = approx. 1:1.9.

If the ventilator has been set so that insp. time + pause time exceeds 80%, then expiration automatically begins when 20% of the respiratory cycle remains (safety function). The pause time is then reduced.

Example 1:

Preset insp. time = 67% ➞ 67% inspiration Preset pause time = 20% ➞ 13% pause

20% expiration

Example 2:

Preset insp. time = 80% ➞ 80% inspiration Preset pause time = 30% ➞ 0% pause

20% expiration

The settings are independent of changes in the patient’s compliance and resistance.

Inspiration time settings of 33%, 67% or 80% should be avoided in volumecontrolled respiration with accelerating flow patterns. With these settings patient triggering may cause the temporary partial blocking of the inspiration valve which, however, would be indicated by a minute volume alarm. Should the valve be blocked, the situation can be remedied immediately by switching over to a constant flow.

Inspiratory flow

In mode VOL. CONTR. (constant flow) or SIMV the inspiratory flow is calculated by:

PRESET INSP. MIN. VOL. l/min

INSP./TIME %

Example:

PRESET INSP. MIN. VOL. l/min = 8 l/min INSP. TIME % = 25% Results in an inspiratory flow: = 8 × 100/25

Adjustment of INSP. TIME% (use reverse value) 20% = 1/5= 5 25% = 1/4= 4 33% = 1/3= 3 50% = 1/2= 2 67% = 2/ 80% = 4/

× PRESET INSP. MIN. VOL = inspiratory flow (l/min)

1.5

1.25

= 1.5 = 1.25

= 32 l/min

Panel functions

Expired minute volume

EXPIRED MINUTE VOLUME is indicated on a meter which has dual scales: 0-40 l/min and 0-4 l/min.

The scale 0-4 l/min is intended for use when

greater accuracy, e. g. for infants, is needed.

The knobs for LOWER ALARM LIMIT and UPPER ALARM LIMIT also have the same dual scales.

The end stop positions for the knobs do not coincide with the end positions on the scale. This is correct and no attempt should be made to alter the range.

The desired scale is selected with the switch INFANTS/ADULTS.

The alarm limits for expired minute volume must always be set. If either of the knobs has been set in end position (out of scale), the yellow lamp SET MIN. VOL. ALARM flashes. The alarm limits are normally set at approx. 20% below and above the selected minute volume. The upper limit may be set at approx. 30% above the selected minute volume in the mode VOL. CONTR. + SIGH.

The APNEA ALARM is activated with audible signals and flashing light if the time between any two consecutive breaths, spontaneous or mandatory or a combination of the two, is greater than approximately 15 seconds (4 breaths per minute or less). The APNEA ALARM is not intended to and will not monitor for disconnections. The APNEA ALARM is operative in CPAP, PRESS. SUPPORT, SIMV and SIMV + PRESS. SUPPORT.

Failure of gas supply to the ventilator will result in visual and audible GAS SUPPLY ALARM signals. The GAS SUPPLY ALARM is not operative at respiratory rates over 80 breaths/min., and INSP. TIME % 20 or 25.

Panel functions

INSP. EXP. GAS PAUSE PAUSE CHANGE HOLD HOLD

Special functions

Under the small hood below the UPPER ALARM LIMIT knob are three pushbuttons for special functions.

Inspiratory pause hold

When the pushbutton INSP. PAUSE HOLD is depressed, the valves close after inspiration and the pause is prolonged as long as the pushbutton is depressed.

This provides an exact measurement of the end inspiratory lung pressure. It may also give time for an equilibration of the blood gas and alveolar pressures.

Expiratory pause hold

The valves are closed, after the expiration, as long as the pushbutton EXP. PAUSE HOLD is depressed, i.e. a prolonged expiratory pause. This provides an exact measurement of the end expiratory lung pressure.

EXP. PAUSE HOLD must not be used in

SIMV or SIMV + PRESS. SUPPORT mode.

Two inspirations may occur at the same

time. However, the UPPER PRESS. LIMIT

is still functional.

Gas Change

The pushbutton GAS CHANGE is used, for instance, when it is desirable to rapidly alter the gas mixture to the patient. The concentration setting on the vaporizer/gas mixer/flowmeters must be altered first.

The inspiration and expiration valves open so that the pressure in the patient circuit is max. 20 cm H2O.

During the gas changing time, the EXPIRED MINUTE VOLUME meter is zeroed automatically.

Panel functions

Airway Pressure

Airway pressure meter

The meter continually indicates the airway pressure reading.

Upper pressure limit

The knob UPPER PRESS. LIMIT is used to set the upper limit for airway pressure. When this pressure limit has been reached, inspiration is immediately discontinued and there is a change over to the expiratory phase. Visual and audible alarms are activated.

Since the inspiration is discontinued, the complete tidal volume will not be delivered and, consequently, the LOWER ALARM LIMIT for EXPIRED MINUTE VOLUME may be activated.

Upper pressure limit is connected in all modes.

There are safety catches on the knob at 80 and 100 cm H

PEEP

PEEP is the setting of a Positive End Expiratory Pressure, e.g. used to counteract the formation of atelectasis.

The PEEP range is from 0 to 50 cm H2O. There are safety catches on the PEEP knob at 0 and at 20 cm H

In case of a leakage, e.g. if a tracheal tube without cuff is being used, the PEEP-setting may cause self-triggering. To avoid this, the TRIG. SENSITIVITY should be set at a somewhat lower value.

The PEEP knob is prepared for NEEP (Negative End Expiratory Pressure). In order to use NEEP, it is necessary to connect auxiliary equipment to the expiration outlet. The NEEP range is from 0 to -10 cm H

Panel functions

Trig. sensitivity

The knob TRIG. SENSITIVITY is used to set the value of negative pressure that the patient must produce in order to trigger a breath.

The TRIG. SENSITIVITY is relative to PEEP.

For instance, PEEP +10 and TRIG. SENSITIVITY -2 cm H2O mean that the patient must produce a pressure of -2 cm H to the setting to trigger a breath.

This corresponds to a pressure of +8 cm H

relative to atmospheric pressure in the patient’s airways.

The airway pressure, measured on the

expiration side, is compared with the preset TRIG. SENSITIVITY + PEEP. If the airway pressure drops below TRIG. SENSITIVITY + PEEP, a breath is triggered.

If it is desirable for the patient to be able to

easily trigger the ventilator, the knob is set at green value.

If it is undesirable for the patient to be able to

trigger the ventilator, the knob is set at

-20 cm H Trig. sensitivity is connected in all modes

except MAN. For further details, see description on different modes.

O relative

Inspiratory pressure level

The knob INSP. PRESS. LEVEL is used to set the constant inspiratory pressure, relative to PEEP, when any of the following modes of ventilation are used: PRESS. CONTR., PRESS. SUPPORT, SIMV + PRESS. SUPPORT.

A safety catch is located at 30 cm H2O.

The total inspiratory pressure level also includes PEEP. This is why there is a marking under the PEEP knob leading to the INSP. PRESS. LEVEL knob. At a PEEP of +5 cm H LEVEL of +15 cm H pressure level would be +20 cm H relative to atmospheric pressure.

O and an INSP. PRESS.

O, the total inspiratory

Panel functions

SIMV

SIMV (Synchronized Intermittent Mandatory Ventilation) means that the patient gets mandatory breaths controlled by the ventilator, and that he also has the possibility of breathing spontaneously.

The mandatory breaths are synchronized with the breaths of the patient so that he need not breathe against the ventilator.

SIMV-rate (SIMV BREATHS/min) is the rate of the mandatory breaths per minute. The rate is set between 0.4 and 4 breaths per minute on the LOW RATE scale, and between 4 and 40 breaths/min on the HIGH RATE scale. The desired rate is selected by means of a switch. There are two indicating lamps, one for each rate.

The tidal volume and the frequency can be read on the digital display.

Minute volume, respiratory rate, inspiration time and pause time must be set for the SIMV mode. These functions determine the respiratory pattern of the mandatory breaths. The BREATHS/min must always be set higher than the SIMV BREATHS/min to allow time for the spontaneous period.

The SIMV cycle is divided into SIMV period and spontaneous period. See page 2:14.

Panel functions

O2 alarm

Alarm limits for O2 concentration are set with the knobs UPPER ALARM LIMIT and LOWER ALARM LIMIT. The SET O alarm limits have not been set.

The end stop positions for the knobs do not coincide with the end positions on the scale. This is correct and no attempt should be made to alter the range.

The alarm limits are set as follows:

• Set O2 concentration on the gas mixer/

flowmeters.

• Set the parameter selector at O

and read the value.

• Set the alarm limits at approx. 6% by volume

(3 scale divisions) below and above the O

concentration reading on the digital display.

Visual and audible alarms are activated when any of the alarm limits is exceeded.

If the O the ventilator, the O If not, the LOWER ALARM LIMIT will activate alarm.

If no O2 cell is mounted, neither digital displays nor alarm is activated when the parameter selector is set at O2 CONC. %.

cell is expended but still mounted in

ALARM flashes if the

CONC. %

cell has to be disconnected.

Parameter selection

A digital display of the O2 concentration is given when the selector is set in position O

Other displayable parameters are:

INSPIRED TIDAL VOLUME ml—the volume provided by the ventilator at each breath.

EXPIRED TIDAL VOLUME ml—the volume produced by the patient at each breath (with no leakage in the patient circuit).

EXPIRED MINUTE VOLUME l/min—(also indicated on the EXPIRED MINUTE VOLUME meter).

PEAK PRESSURE cm H2O—the pressure at the end of the inspiration phase.

PAUSE PRESSURE cm H the end of the pause. This pressure normally corresponds to the maximal alveolar pressure in the lungs.

MEAN AIRWAY PRESSURE cm H2O—the mean value in the patient circuit, continually measured.

BREATHS/min—the respiratory rate of the patient. In controlled ventilation, this value equals the set respiratory rate plus eventual patient triggered breaths. In the SIMV mode, it is the sum of the spontaneous and the mandatory breaths. In the CPAP and PRESSURE SUPPORT modes, the value represents the spontaneous breaths/min of the patient.

O—the pressure at

CONC. %.

Controlled ventilation

Insp. Exp.

l/s cm H

Flow Pressure

WORKING PRESSURE and UPPER PRESS. LIMIT must always be set at adequate values. This is extremely important when treating infants.

Pause

Sigh

Volume controlled ventilation

Volume controlled ventilation (VOL. CONTR.) ensures that the patient receives a certain preset tidal volume.

Servo Ventilator 900 C delivers a specific tidal volume at a specific rate during a specific time (preset values).

If the patient makes inspiratory efforts so that the airway pressure falls below the triggering level, a preset tidal volume will be delivered earlier and the expired minute volume will increase.

A constant or an accelerating flow can be selected.

A patient trigg initiates a breath with the preset values.

Volume controlled ventilation + sigh

In this mode of operation, the Servo Ventilator 900 C delivers a sigh every hundredth breath. At sigh, double tidal volume is delivered since the flow is constant and the inspiration time is doubled.

The first sigh will occur at the second inspiration after setting the mode selector to VOL. CONTR. + SIGH.

The UPPER ALARM LIMIT for EXPIRED MINUTE VOLUME may have to be set somewhat higher in this mode.

Pressure controlled ventilation

In the mode PRESS. CONTR., gas is delivered at a constant pressure during the set inspiration time.

The pressure is set with the knob INSP. PRESS. LEVEL.

The flow is decelerating in this mode.

The set inspiratory pressure, respiratory rate, and inspiration time determine the volume the patient will receive.

Servo Ventilator 900 C works with a constant pressure during the entire inspiration.

The minute volume can be read on the EXPIRED MINUTE VOLUME meter.

Tidal volume can be read on the digital display with the parameter selector in position INSP. TIDAL VOLUME or EXP. TIDAL VOLUME.

In case of leakage in the system, e.g. due to the use of a tracheal tube without cuff, a pause time of 0% is recommended to ensure that the measurement of the expired minute volume will be as correct as possible.

A patient trigg initiates a breath with the preset values.

Supported ventilation

Trig.

Flow Pressure

Pressure supported ventilation

PRESS. SUPPORT is a spontaneous breathing mode in which the patient must trigger breaths.

Some applications for PRESS. SUPPORT are: weaning, patients suffering from asthma or, in post-operative use, when the patient’s own breathing efforts are insufficient.

When the patient triggers the ventilator, an inspiration pressure support is given at a preset constant pressure.

The ventilator regulates the pressure during inspiration so that it corresponds to preset INSP. PRESS. LEVEL + PEEP.

The pressure during expiration drops to 0 cm H

occurs when the flow decreases to 25% of the peak inspiratory flow.

change from inspiration to expiration, for instance in the case of a leakage.

has closed the inspiratory valve and the airway pressure has increased to +3 cm H the preset INSP. PRESS. LEVEL + PEEP or after 80% of the preset respiratory cycle. Because of this safety function the respiratory rate should always be set with the knob BREATHS/min.

O, or alternatively to PEEP-level.

The change from inspiration to expiration

There are also safety functions to control the

Expiration will then start when the step motor

O above

Supported ventilation

SIMV cycle 10 s SIMV cycle 10 s

SIMV period 4 s Spontaneous period 6 sSpontaneous period 6 sSIMV period 4 s

Flow Pressure

A patient trig. during the SIMV period initiates a mandatory breath. After that, spontaneous breathing.

SIMV

SIMV (Synchronized Intermittent Mandatory Ventilation) means that a preset number of breaths are ventilator controlled, mandatory breaths (SlMV BREATHS/min). The patient may breathe spontaneously between those breaths.

Breathing pattern and tidal volume for the mandatory breaths are selected with the knobs PRESET INSP. MIN. VOL., BREATHS/min, INSP. TIME % and PAUSE TIME %.

The time in seconds for one SIMV cycle is calculated from the formula

preset SIMV freq.

The SIMV cycle is divided into SIMV period and spontaneous period.

The spontaneous period consists of spontaneous breathing time if the patient has triggered a mandatory breath during the previous SIMV period.

If the patient has insufficient spontaneous breathing, the maximum time between two mandatory breaths is just over one SIMV cycle, (cp 1 to 2 in the picture above).

During the SIMV period no breath has been triggered. The next period begins with a mandatory breath. After that, spontaneous breathing.

To ensure adequate ventilation, apnea alarm is activated if the time between two breaths exceeds approx. 15 sec., and the minute volume alarm is activated if any of the preset alarm limits is exceeded.

Either of these alarms is a command to take the necessary action (e.g. clinical judgement of the patient, increased SIMV frequency, altered trig. sensitivity).

The SIMV period is approx. equal to one respiratory cycle.

The spontaneous period is calculated as SIMV cycle-SIMV period.

Example:

BREATHS/min 15 ➞ SIMV period = SIMV BREATHS/min 6 ➞SIMV cycle = Spontaneous period ➞10-4 = 6 s

A patient trig during the SIMV period initiates a breath with the preset values. A patient trig during the spontaneous period opens the inspiratory valve, and the patient can breathe through the ventilator.

60 = 4 s

60 = 10 s

Supported and spontaneous ventilation

SIMV cycle 10 s

SIMV

period 4 s

Flow Pressure

These settings determine the SIMV period. This setting determines the SIMV cycle.

SIMV cycle

SIMV period Spontaneous period

Spontaneous

period 6 s

SIMV + pressure support

The main difference between this mode and the SIMV mode is that the spontaneous, triggered breaths are pressure supported.

The level of support is set with the control INSP. PRESS. LEVEL. The level also includes PEEP.

See also description of pressure support on page 2:13.

INSP. PRESS. LEVEL

0 or PEEP-level

TRIG. SENSITIVITY

Flow Pressure

Mandatory breath Pressure supported

spontaneous breaths

TRIG. SENSITIVITY

Flow Pressure

PEEP

Care should be taken in setting the preset

BREATHS/min, so that the spontaneous

pressure-supported breaths are not

prematurely time-cycled rather than flow-

cycled to expiration.

Spontaneous ventilation CPAP

In this mode, CPAP (Continuous Positive Airway Pressure), the patient breathes spontaneously through the ventilator at an elevated pressure level. The positive pressure is set with the PEEP control.

The TRIG. SENSITIVITY control must be set at a position which allows the patient to trigger the ventilator. Upon triggering, the inspiration valve opens, and the patient can inspire through the ventilator and control the tidal volume and respiratory rate.

To avoid self-triggering due to leakage, the trig. level should be set at a low value.

If CPAP (PEEP) = 0, it will be possible to check the patient’s ability to breathe spontaneously without help from the ventilator.

The minute volume, tidal volume and respiratory rate can be monitored.

Manual ventilation

Electronic unit

MAN

AUT

Mode selector

If the breathing bag becomes overfilled, the expiratory valve in the ventilator may go to a locked position.

To unlock the valve:

• Set UPPER PRESS. LIMIT below 20 cm

• Squeeze the breathing bag and check that

the pressure in the bag is lowered.

• Set UPPER PRESS. LIMIT back to the

lowest possible value for normal operation.

If the breathing bag becomes overfilled with the manual ventilation valve in posotition AUT:

• Remove the breathing bag.

• Exchange the manual ventilation valve.

Motor/

valve unit

Manual ventilation

The Manual Ventilation Accessory with Motor consists of two units:

• Electronic unit

• Motor/valve unit

With this accessory switching between manual ventilation and other modes is done with the mode selector.

The valve is automatically set to the correct position by a motor. The switch-over time is about 5 seconds. An alarm with audible signals and red light is activated if the positions of the valve and mode selector are not the same.

In position pressure of about 4 cm H valve closes.

When the breathing bag is squeezed, the gas flows to the patient via a non-return valve.

Always set UPPER PRESS. LIMIT at the lowest possible value for normal operation.

The APNEA alarm is inoperative during

manual ventilation.

In the case of a power failure, manual ventilation is not possible unless an external power pack is connected.

PEEP cannot be used in manual ventilation mode.

Set the mode selector to VOL. CONTR. immediately before connecting the ventilator to a patient. The reason is to zero the gas flow reading.

At spontaneous breathing during manual ventilation the following readings will be incorrect. – the displayed values for BREATHS/min.,

EXP. TIDAL VOLUME and EXP.

MINUTE VOLUME. – the alarm monitoring instrument

EXPIRED MINUTE VOLUME.

The accuracy of the EXPIRED MINUTE VOLUME meter reading decreases. After about 5 minutes, the accuracy is about ±2 l/min. To get a correct meter reading, the breathing bag should be squeezed at least every 5 minutes.

For spontaneous breathing, the PRESSURE SUPPORT mode is recommeded. The INSP. PRESS. LEVEL should be set at zero or at a low value. This enables continuous monitoring of pressure and volume.

MAN., the breathing bag is filled to a

O, then the inspiratory

Chapter 3

Patient safety

In this chapter:

Protective devices......... 3:2

Alarm schedule.............. 3:4

131

Protective devices

Alarms

There are a number of alarms on the ventilator which protect the patient by alerting ward personnel to any malfunctions. Alarms are given with audible signals and flashing red lights. An audible signal only is given as alarm for power failure and certain technical malfunctions.

Some audible alarms can be switched off for a period of approximately 2 minutes. For details see the alarm schedule on page 3:4.

In addition there are panel indicators with fixed or flashing yellow lights.

Examples are given in chapter 8, Troubleshooting, regarding actions for various alarms.

The patient is protected against high pressure by an electronic limiter, which is controlled by the knob UPPER PRESS. LIMIT.

If the value set with this knob is too high or if the limiting function should fail, the pressure is limited to the set WORKING PRESSURE.

The WORKING PRESSURE is prevented from exceeding the set value by a safety valve and cannot be set at values exceeding 120 cm H

As an extra patient safety protection against too high an airway pressure, there is a HIGH PRESSURE PROTECTION circuit incorporated when either of the modes CPAP, PRESS. CONTR. or PRESS. SUPPORT is selected. This protection circuit functions when the airway pressure in the inspiration channel for some reason, e.g. coughing, exceeds 30 cm H level.

O above INSP. PRESS. LEVEL/PEEP

Important!

The SV 900 is not designed to withstand severe negative pressures, which, if applied to the system may damage the internal pressure transducers rendering the unit inoperable.

Transducer pressure range

SV 900 up to and including SIN 188499 are factory equipped with pressure transducers that will tolerate pressures down to -100 cm H20(mbar), whereas units from S/N 188500 are factory equipped with pressure transducers that will tolerate pressures ranging from -500 cm H20(mbar) to +500 cm H20(mbar).

Earlier units may have been retrofitted with Transducer Upgrade EM12102/l featuring the same pressure tolerance as units with S/N ≥188500. Uppgraded units are identified with a label !Upgrade EMO12/02/l’ attached to the inside of the pneumatic unit lid.

If closed system suctioning is applied, the following must be considered:

A suctioning flow exceeding the flow delivered by the ventilator will result in a negative pressure affecting the patients airways as well as the ventilators breathing system.

Do not use the “Pause hold” function during the procedure.

All audible alarms, with the exception of upper pressure limit for airway pressure and alarm for mains power failure, are switched off for a period of 2 minutes when the button

2 min is depressed, while the red light

continues flashing. This means that no new audible alarm will be possible during approximately 2 minutes.

To switch off the power failure alarm, the button must be depressed until the audible alarm stops.

The APNEA ALARM is not intended to and will not monitor for disconnections.

Protective devices

Set minute volume alarm

Indicates that the alarm limits for expired minute volume have not been set.

Mains power failure

The green lamp for POWER ON goes out. Slow audible signals which stop after 5-10 minutes.

Set O2 alarm

Indicates that the alarm limits for O concentration have not been set.

Alarm limit, O2 concentration

Upper or lower alarm limit has been exceeded.

If no O2 cell is mounted, neither digital

displays nor alarm is given.

A deterioration in the linearity and/or a rapid fall in the values of O adequate O exhausted.

supply, indicates that the O2 cell is

concentration, despite

Upper pressure limit, airway pressure

The airway pressure exceeds the preset upper pressure limit. When the alarm is activated, inspiration and/or pause in progress is immediately terminated and changed to

expiration. The alarm is given as a single audible signal and a visual flashing signal.

Alarm limit, expired minute volume

Upper or lower alarm limit has been exceeded. There are two alarm limit settings: UPPER ALARM LIMIT 3-43 l/min (adults)

0-4.3 l/min (infants)

LOWER ALARM LIMIT 0-37 l/min (adults)

0-3.7 l/min (infants)

Apnea alarm

Gas supply alarm

This alarm is inoperative if the respiratory rate exceeds 80 breaths/min (with inspiration time 20 or 25%).

In the CPAP and PRESS. SUPPORT modes,

a patient trig is required to activate the alarm.

Alarm schedule

Alarm Visible Audible

SET. MIN. VOL. ALARM SET O2 ALARM GAS SUPPLY ALARM Mains power failure Alarm limit, EXP. MIN. VOL.

2 min

UPPER PRESS. LIMIT APNEA ALARM Alarm limit, O

CONC. %

*The green lamp goes out **The button must be depressed until the alarm stops

Chapter 4

Set-ups

The Servo Ventilator 900 C is designed for several different applications.

It can be positioned in many different ways, e.g. on a cart, on an anesthesia table, on a wall rail, or in an ambulance or a helicopter.

In this chapter:

Intensive care ................ 4:2

Anesthesia ..................... 4:4

Patient transportation ... 4:6

141

Intensive care 1

Two proposals are given regarding the set-up of Servo Ventilator 900 C in intensive care.

This is only an example of a possible set-up.

Some of the equipment shown is available in

different versions, e.g. for adults and children. For details, please see “Products and Accessories” catalogue and, for patient tubing, “Assembling instructions with order form”.

Basic equipment

Servo Ventilator 900 C

! Mobile cart @ Mixer # Clamp $ Support arm % Bacteria filter ^ Nipple connector & Patient tubes * Y-piece ( Servo Humidifier BL Nipple connector BM Flex tube BN Angled connector

Extra equipment

Analyzer 930

Lung Mechanics Calculator 940 Mingograf Recorder Recorder Cable for Servo Ventilator 900 C Manual ventilation accessory

Intensive care 2

This is only an example of a possible set-up. Some of the equipment shown is available in different versions, e.g. for adults and children.

For details, please see “Products and Accessories” catalogue and, for patient tubing, “Assembling instructions with order form.”

Basic equipment

Servo Ventilator 900 C

! Mobile cart @ Mixer # Bacteria filter $ Humidifier % Nipple connector ^ Patient tubes & Muff, angled * Nipple ( Nipple BL Flex tube BM Angled connector BN Cup for water trap

BO Exp. water trap BP Water trap BQ Y-piece

Extra equipment

Analyzer 930

Lung Mechanics Calculator 940 Mingograf Recorder Recorder Cable for Servo Ventilator 900 C Manual ventilation accessory

Anesthesia 1

Two proposals are given regarding the set-up of Servo Ventilator 900 C in anesthesia applications.

This is only an example of a possible set-up.

Some of the equipment shown is available in

different versions, e.g. for adults and children. For details, please see “Products and Accessories” catalogue and, for patient tubing “Assembling instructions with order form”.

Basic equipment

Servo Ventilator 900 C

! Mobile cart @ Mixer # Vaporizer $ Bacteria filter % Nipple connector ^ Manual ventilation accessory & Tube * Tube joint ( Breathing bag BL Patient tubes BM Y-piece BN Servo Humidifier

BO Nipple connector BP Flex tube BQ Angled connector BR Gas evacuation equipment

Extra equipment

Analyzer 930

Lung Mechanics Calculator 940 Mingograf Recorder Recorder Cable for Servo Ventilator 900 C

Anesthesia 2

This is only an example of a possible set-up. Some of the equipment shown is available in different versions, e.g. for adults and children.

For details, please see “Products and Accessories” catalogue and, for patient tubing, “Assembling instructions with order form.”

Basic equipment

Servo Ventilator 900 C Anesthesia table Rotameter box

! Mixer @ Bacteria filter # Nipple connectors $ Manual ventilation accessory % Tube ^ Tube joint & Breathing bag * Patient tubes ( Y-piece

BL Servo Humidifier BM Nipple connector BN Flex tube BO Angled connector BP Gas evacuation equipment

Suction equipment

Extra equipment

Analyzer 930

Lung Mechanics Calculator 940 Mingograf Recorder Recorder Cable for Servo Ventilator 900 C

Patient transportation

A proposal is given regarding the set-up of Servo Ventilator 900 C during patient transportation within the hospital, in an ambulance or a helicopter. This is only an example of a possible set-up.

Some of the equipment shown is available in different versions, e.g. for adults and children. For details, please see “Products and accessories” catalogue and, for patient tubing “Assembling instructions with order form”.

Basic equipment

Servo Ventilator 900 C

! Mobile cart @ Mixer # Vaporizer $ Bacteria filter % Manual ventilation accessory ^ Tube & Tube joint * Breathing bag ( Patient tubes BL Y-piece

BM Servo Humidifer BN Nipple connector BO Flex tube BP Angled connector

Power pack Gas cylinders

Extra equipment

CO2 Analyzer 930 Lung Mechanics Calculator 940

Chapter 5

Preparations

If any malfunction is detected during the preparations, see chapter 8, Troubleshooting, or chapter 13, Calibration.

In this chapter: Prechecks and

presettings..................... 5:2

Connections................... 5:3

151

Prechecks and presettings

VOL. CONTR.ADULTS

Make sure that the ventilator has been cleaned (see the log sheet).

Set the following on the ventilator:

• Mode selector at VOL. CONTR.

• Alarm limits to end positions, according to the

picture.

• Scale range for ADULTS.

• TRIG. SENSITIVITY to –20 cm H

• UPPER PRESS. LIMIT to 80 cm H

• PEEP and INSP. LEVEL to 0 cm H

Make sure that the meters for EXPIRED MINUTE VOLUME and AIRWAY PRESSURE give a zero reading. If not, see Calibration, chapter 13.

Connections

POWER ON GAS SUPPLY ALARM SET MIN. VOL. ALARM SET O

ALARM

Connect patient tubes, holder arm, humidifier, test lung and, if required, manual ventilation accessory and gas evacuation accessory. For details, see previous chapter.

The Manual Ventilation Accessory 963 must not be connected to Servo Ventilator 900 C. Always use the manual ventilation accessory intended for Servo Ventilator 900 C only.

If required, connect CO2 Analyzer 930 and Lung Mechanics Calculator 940.

• Connect the ventilator to mains.

• Set the mains switch on the rear of the ventilator to on. The switch has to be pulled out before switching.

• Make sure that the green lamp lights up when you switch on.

• Make sure that the meters for EXPIRED MINUTE VOLUME and AIRWAY PRESSURE still give a zero reading. If not, see Calibration, chapter 13.

• Make sure that the GAS SUPPLY ALARM activates.

• Make sure that the SET MIN. VOL. ALARM and SET O

ALARM flash.

Connect gases :

Alternative 1, via O O

-air mixer

• Set the desired O2 concentration.

At extremely high flows it may be necessary to increase the working pressure, in order to obtain the desired minute volume.

-air mixer or via O2-N2O/

Connections

Alternative 2, via O2-N2O/O2-air mixer and vaporizer

• Connect a Halothane, Enflurane or Isoflurane vaporizer.

• Set the desired O

Alternative 3, via low-pressure flowmeters

• Connect O flowmeters, necessary pressures at least equal to WORKING PRESSURE.

• Set the desired flow proportions of O N

O on the flowmeters, so that the total gas

flow exceeds PRESET INSP. MIN. VOL. of the ventilator by 10-20%. The working pressure will be constant and the flow pattern unchanged in mode VOL. CONTR. In other ventilation modes, only breaths with limited tidal volumes can be maintained. The limitation is shown by falling WORKING PRESSURE.

Alternative 4, compressed air

• Connect compressed air.

2-N2

concentration.

O (air) via low-pressure

and

Check on functions

• Carry out a check on functions according to chapter 6.

Chapter 6

Check on functions

A check on functions must always be carried out after cleaning and before connecting a patient.

Accessories: Patient tubes, Y-piece, test lung and manual ventilation accessory. If any malfunction is detected during the check, see chapter 8, Troubleshooting, or chapter 13, Calibration.

In this chapter:

1. Checks prior to connection of power

and gas....................... 6:2

2. Start-up.......................6:2

3. Check for leakages....6:3

161

4. Check, manual

ventilation................... 6:3

5. Upper pressure limit

alarm........................... 6:4

6. Minute volume ...........6:4

7. Minute volume alarm.6:4

8. O

alarm...................... 6:5

9. Apnea alarm............... 6:5

10. Digital display ............6:6

11. Check on pressure

levels ..........................6:6

12. Mains supply failure ..6:6

13. Log sheet....................6:6

Prechecks

ADULTS

VOL. CONTR.

If preparation and prechecks, according to chapter 5, have been done, start from para. 3.

1. Checks prior to

connection of power and gas

• Connect patient tubes, Y-piece, holder arm

and humidifier.

• Make sure that the meters for AIRWAY

PRESSURE and EXPIRED MINUTE VOLUME give a zero reading.

• Set the mode selector at VOL. CONTR.

• Set alarm limits to end positions, according

to the picture.

• Set the scale range for ADULTS.

• Set the TRIG SENSITIVITY to -20 cm H

• Set the UPPER PRESS. LIMIT to 80 cm H

• Set PEEP and INSP. PRESS. LEVEL to

0 cm H2O.

2. Start-up

• Connect the ventilator to mains.

• Set the mains switch on the rear of the

ventilator to on.

• Make sure that the green lamp lights up

when you switch on.

• Make sure that the meters for AIRWAY

PRESSURE and EXPIRED MINUTE VOLUME still give a zero reading.

• Make sure that GAS SUPPLY ALARM

activates.

• Make sure that SET MIN. VOL. ALARM and

SET O

ALARM flash.

POWER ON SET O SET MIN. VOL. ALARM GAS SUPPLY ALARM

ALARM

900C003S

7.5

INSP.=

EXP.=

3. Check for leakage

• Connect gases according to chapter 5.

• Set the following: WORKING PRESSURE:

60 cm H min., BREATHS/min.: 10, PAUSE TIME: 30%, constant flow and INSP. TIME: 25%.

• Cover the Y-piece/Servo Humidifier and

make sure that AIRWAY PRESSURE and the manometer WORKING PRESSURE

show the same reading during inspiration and pause.

• Press and hold the INSP. PAUSE HOLD

button and make sure that the AIRWAY PRESSURE reading does not drop more than 3 cm H

• Release INSP. PAUSE HOLD and make

sure that the AIRWAY PRESSURE reading falls to 0 during expiration.

• If AIRWAY PRESSURE drops more than

allowed, block the outlet pipe on the insp. side and repeat as described. If the pressure drop is within the allowed limit, the leakage is to be found in the breathing system or the exp. channel.

O, PRESET INSP. MIN. VOL.: 7.5 l/

O during 5 seconds.

VOL. CONTR. VOL.CONTR + SIGH PRESS. CONTR.

PRESS. SUPPORT

900C004S

O2 FLUSH

CPAP

MAN.

VOL. CONTR. VOL.CONTR + SIGH PRESS. CONTR.

PRESS. SUPPORT

VOL. CONTR. VOL.CONTR + SIGH PRESS. CONTR.

PRESS. SUPPORT

VOL. CONTR. VOL.CONTR + SIGH PRESS. CONTR.

PRESS. SUPPORT

MAN

4. Check of manual

ventilation accessory

Applicable to manual ventilation accessory with motor.

1. Attach a test lung.

CPAP

MAN.

CPAP

MAN.

2. Separate the valve and the motor units and make sure that alarm is activated.

3. Set mode selector to MAN and make sure that alarm is activated.

4. Set the valve arm to MAN and attach the valve unit to the motor unit.

5. Push O

FLUSH and make sure that the

breathing bag fills.

6. Set VOL. CONTR.

7. Compress the breathing bag and make sure that there is no leakage (the gas remains in the breathing bag).

8. Set MAN.

9. Compress the breathing bag with one hand to fill the test lung. With the other hand, immediately compress the test lung and make sure that the expiration valve opens.

10. Let the breathing bag hang loose and be filled. Then make sure that the EXPIRED MINUTE VOLUME meter drops to 0.

Alarms

UPPER PRESS. LIMIT

MIN. VOL. ALARM

VOL. CONTR.

EXP. MIN. VOL. l/min

5. Upper pressure limit alarm

• Set the mode selector at VOL. CONTR.

• Block the Y-piece/Servo Humidifier.

• Turn the knob UPPER PRESS. LIMIT to 55 cm H

• Make sure that inspiration is terminated and the alarm is activated.

• Turn the knob back to 80 cm H

6. Minute volume

• Set the respiratory rate at 20 BREATHS/min.

• Connect a test lung.

• Set the parameter selector at EXP. MIN. VOL. l/min.

• Make sure that the digital display and the meter EXPIRED MINUTE VOLUME read

7.5 ± 0.5 l/min after a few minutes.

7. Minute volume alarm

Lower alarm limit

• Turn the knob LOWER ALARM LIMIT to

7.5 l/min and make sure that the alarm is activated at 7.5 ± 0.5 l/min.

• Turn the knob LOWER ALARM LIMIT to 0 l/min.

If gas evacuation should be used:

• Connect the gas evacuation accessory.

• Set the LOWER ALARM LIMIT to the value which is to be used during the treatment.

• Remove the test lung (“disconnect”).

• Make sure that the LOWER ALARM LIMIT is activated.

• Make sure that the EXPIRED MINUTE VOLUME meter reading is at least 25% below the alarm limit setting.

• If the alarm is not activated: —Set PEEP to 1 cm H —Check the alarm and meter reading as

described above

—Decrease the evacuation flow until the alarm is activated. Also check the meter reading as described above.

Upper alarm limit

• Turn the knob UPPER ALARM LIMIT to

7.5 l/min and make sure that the alarm is activated at 7.5 ± 0.5 l/min.

• Turn the knob UPPER ALARM LIMIT to 40 l/min.

AlarmasAlarms

8. O2 alarm

900C000S

900C001S

KONC. %

CONC. %

O2 LARM

ALARM

20-

22%

When checking the O2 alarm, the working pressure must be 60 cm H

O since the O

cell is calibrated at this pressure.

If there is no O

given when O

cell, no digital display is

CONC. % is set on the

parameter selector.

If the O

cell is expended but still

mounted, it has to be disconnected. If not, the LOWER ALARM LIMIT will be activated.

A deterioration in the linearity and/or a rapid fall in the values of O despite adequate O

cell is exhausted.

the O

• Set the parameter selector at O

• Set the gas mixer at the lowest O

concentration,

supply, indicates that

CONC. %.

concentration value (air) and make sure that the digital display shows 20-22%.

• Set the gas mixer so that 40% is read on the digital display.

Lower alarm limit

• Turn LOWER ALARM LIMIT clockwise and make sure that alarm is activated when the knob setting corresponds to the digital display (±1 scale division).

• Turn LOWER ALARM LIMIT to 18%.

Upper alarm limit

• Turn UPPER ALARM LIMIT counterclockwise and make sure that alarm is activated when the knob setting corresponds to the digital display (±1 scale division).

• Turn UPPER ALARM LIMIT to 100%.

APNEA ALARM

PRESS. SUPPORT

9. Apnea alarm

• Set TRIG. SENSITIVITY at -10.

• Set the mode selector at PRESS. SUPPORT.

• Make sure that the APNEA ALARM is activated approx. 15 s after the mode change.

Pressures

BREATHS/min

PRESS. CONTR.

EXP.

10. Digital display

• Set the parameter selector at BREATHS/min.

• Make sure that the value set with the BREATHS/min knob corresponds to the BREATHS/min value read on the digital display.

11. Check on pressure levels

• Set the mode selector at PRESS. CONTR.

• Set BREATHS/min. to lowest value.

• Set PEEP at +10 cm H

• Set INSP. PRESS. LEVEL at +10 cm H

• Make sure that the reading on the AIRWAY PRESSURE meter remains at +20 ± 2 cm H

• Make sure that a PEEP level of 10 ± 2 cm H2O is maintained on the AIRWAY PRESSURE meter at the end of expiration.

• Set PEEP and INSP. PRESS. LEVEL at 0 cm H

• Set the mode selector at VOL. CONTR.

O during inspiration.

VOL. CONTR.

12. Mains supply failure

alarm

• Switch off the ventilator with the mains switch on the rear.

• Make sure that the green lamp POWER ON goes out and the audible alarm sounds.

13. Log sheet

• Note on the log sheet that a check on functions has been carried out.

If any malfunctions are detected during the check, see chapter 8, Troubleshooting, or chapter 13, Calibration.

Chapter 7

Connection to patient

Be careful when moving the ventilator from the preparation room to the operating theatre. If you bump into something, it may be necessary to check the functions before connection to patient.

For detailed description of the functions, see

chapter 2.

Always start with ventilator checked according to chapter 6.

In this chapter:

171

Compressible volume and

dead space........................7:2

Controlled ventilation

VOL. CONTR. or

VOL. CONTR. + SIGH ..............

PRESS. CONTR. ......................7:5

7:4

Supported ventilation

PRESS. SUPPORT...................7:6

SIMV..........................................7:7

SIMV + PRESS. SUPPORT......7:8

Spontaneous ventilation

CPAP.........................................7:9

Manual ventilation

MAN ....................................... 7:10

Compressible volume and dead space

Compensation for compressible volume

Some of the preset minute volume does not reach the patient because it is needed for compression of gas in tubes and humidifier. The compressible volume of the Servo Ventilator itself is negligible.

When setting the preset insp. minute volume, the compressible volume must be compensated for by adding a corresponding minute volume to the minute volume for the patient.

Compensation procedure

Connect the complete breathing system with patient tubes and Servo Humidifier or heater humidifier to the Servo Ventilator.

VOL. CONTR.

INSP. TIDAL VOL.

Set WORKING PRESSURE at 60 cm H2O.

Set the front panel values as shown. (Values marked in green).

Set PRESET INSP. MIN. VOL. at 10 l/min.

Set UPPER PRESS. LIMIT for AIRWAY PRESSURE at 80 cm H

Set the parameter selector at INSP. TIDAL VOLUME.

Block the opening of the Y-piece/Servo Humidifier.

Note the reading on the INSP. TIDAL VOLUME (ml) display.

Compressible volume and dead space

(

Set the Servo Ventilator as desired for the patient (including the desired minute volume for the patient) and connect the patient. See pages 7:4 to 7:10.

PAUSE PRESS.

PRESET INSP.

MIN. VOL. (l/min)

Set the parameter selector at PAUSE PRESSURE and read actual pause pressure when the patient is connected.

Calculate compensation (l/min) for compressible volume =

read INSP. TIDAL. VOLUME (ml)

according to item 8 above

read PAUSE PRESSURE (cm H2O)

according to item 10 above

1000 (ml/l)

60 (cm H2O)

set BREATHS/ min according

to item 9 above

Set PRESET INSP. MIN. VOL. = desired minute volume for the patient + compensation (l/min)

Example 1 (Servo Humidifer):

Read INSP. TIDAL VOLUME (item 8) = 54 ml (at pause pressure 60 cm H2O). Desired minute volume for the patient = 7.5 l/min. Set BREATHS/min (item 9) = 15. Read PAUSE PRESSURE (item 10) = 22 cm H Compensation for compressible volume (item 11) = 54 ×22

PRESET INSP. MIN. VOL. (item 12) 7.5 + 0.3 = 7.8 l/min.

Example 2 (Heater humidifier):

Read INSP. TIDAL VOLUME (item 8) = 88 ml (at pause pressure 60 cm H2O). Desired minute volume for the patient = 9.0 l/min. Set BREATHS/min (item 9) = 17. Read PAUSE PRESSURE (item 10) = 24 cm H Compensation for compressible volume (item 11) = 88 ×24

PRESET INSP. MIN. VOL. (item 12) 9.0 + 0.6 = 9.6 l/min.

for compressible volume (calculated in item 11 above).

1000 60

× 15 = 0.3 l/min.

× 17 = 0.6 l/min.

– Servo Humidifier 151 : 35 ml – Servo Humidifier 152: 55 ml – Servo Humidifier 153 (incl. flex tube): 70 ml – CO

cuvette adult (for CA 930/CM 130) : 5 ml

cuvette infant (for CA 930/CM 130) : 2.5 ml

– CO

Compensation for dead space

When setting PRESET INSP. MINUTE VOLUME, dead space in the breathing system between the Y-piece and the patient should also be compensated for.

Dead space for some accessories is shown in the table to the left.

Controlled ventilation

VOL. CONTR. or VOL. CONTR. + SIGH

Connect the patient

Set the WORKING PRESSURE.

Set the mode selector at VOL. CONTR. or VOL. CONTR. + SIGH.

Set the desired minute volume (e.g. by means of a Radford nomogram).

Select the curve shape for the inspiration flow.

Set the respiratory rate, BREATHS/min.

Set the INSP. TIME %.

Set the PAUSE TIME %.

Set the mixer.

(

Set the LOWER ALARM LIMIT and UPPER ALARM LIMIT for O

CONC. %.

Set the parameter selector.

Set the PEEP-level.

To protect the patient against high pressures, always start from a low value.

Set the UPPER PRESS. LIMIT for AIRWAY PRESSURE to approximately 10 cm H

O above the patient’s airway pressure.

Set the TRIG. SENSITIVITY.

Set the scale INFANTS/ADULTS.

Connect the ventilator to the patient and check: – that the patient’s chest rises and falls in time with the preset respiratory rate. – the tidal volumes on the digital display and the reading on the EXPIRED MINUTE VOLUME meter. – that the AIRWAY PRESSURE meter gives a reading during inspiration, and that the reading falls to 0 cm H alternatively, to PEEP-level during expiration.

O or,

Set the LOWER ALARM LIMIT and UPPER ALARM LIMIT for EXPIRED MINUTE VOLUME. If the VOL. CONTR. + SIGH mode is selected, it may be necessary to increase the UPPER ALARM LIMIT for EXPIRED MINUTE VOLUME as well as the UPPER PRESS. LIMIT for AIRWAY PRESSURE. This is done in order to avoid activating the alarms when the sigh occurs.

In VOL. CONTR. or VOL. CONTR. + SIGH mode

with respiratory rate above 80 BREATHS/min,

INSP. TIME % should be set at 33 or 50%.

Otherwise the ventilator may give incorrect

minute volumes and incorrect EXPIRED

MINUTE VOLUME meter readings.

Controlled ventilation

PRESS. CONTR.

Connect the patient.

Set the WORKING PRESSURE.

Set the mode selector at PRESS. CONTR.

Set the respiratory rate, BREATHS/min.

Set the INSP. TIME %.

Set the PAUSE TIME %.

Set the mixer.

Set the LOWER ALARM LIMIT and UPPER ALARM LIMIT for O

CONC. %.

Set the parameter selector.

(

Set the INSP. PRESS. LEVEL.

Set the PEEP-level.

To protect the patient against high pressures, always start from a low value.

Set the UPPER PRESS. LIMIT for AIRWAY PRESSURE.

Set the TRIG. SENSITIVITY.

Set the scale INFANTS/ADULTS.

Connect the patient and adjust the INSP. PRESS. LEVEL so that the patient receives decided tidal volumes and check: – the reading on the EXPIRED MINUTE VOLUME meter. – that the AIRWAY PRESSURE meter gives a reading during inspiration, and that the reading falls to 0 cm H level, during expiration.

O, or alternatively, to PEEP-

Set the LOWER ALARM LIMIT and UPPER ALARM LIMIT for EXPIRED MINUTE VOLUME.

Supported ventilation

PRESS. SUPPORT

Connect the patient

Set the WORKING PRESSURE.

Set the mode selector at PRESS. SUPPORT.

Set the respiratory rate, BREATHS/min. (determines the length of inspiration time).

Set the mixer.

Set the LOWER ALARM LIMIT and UPPER ALARM LIMIT for O

CONC. %.

Set the parameter selector.

Set the INSP. PRESS. LEVEL.

Set the PEEP-level.

To protect the patient against high pressures, always start from a low value.

(

Set the UPPER PRESS. LIMIT for AIRWAY PRESSURE.

Set the TRIG. SENSITIVITY.

Set the scale INFANTS/ADULTS.

Connect the patient and check that he can trigger the ventilator. Adjust the INSP. PRESS. LEVEL so that the patient receives decided tidal volumes and check: –the reading on the EXPIRED MINUTE VOLUME meter. – that the AIRWAY PRESSURE meter gives a reading during inspiration, and that the reading falls to 0 cm H level during expiration.

O or, alternatively, to PEEP-

Set the LOWER ALARM LIMIT and UPPER ALARM LIMIT for EXPIRED MINUTE VOLUME.

Supported ventilation

SIMV

Connect the patient.

Set the WORKING PRESSURE.

Set the mode selector at SIMV.

Set the rate, LOW RATE/HIGH RATE.

Set the SIMV BREATHS/min.

Set the PRESET INSP. MIN. VOL. l/min.

Set the respiratory rate, BREATHS/min.

Set the INSP. TIME %.

Set the PAUSE TIME %.

(

Set the mixer.

Set the LOWER ALARM LIMIT and UPPER ALARM LIMIT for O

CONC. %.

To protect the patient against high pressures, always start from a low value.

Set the parameter selector.

Set the PEEP-level.

Set the UPPER PRESS. LIMIT for AIRWAY PRESSURE.

Set the TRIG. SENSITIVITY.

Set the scale INFANTS/ADULTS.

Connect the patient and check: – that the patient can trigger the ventilator. – the tidal volumes on the digital display and the reading on the EXPIRED MINUTE VOLUME meter. – that the AIRWAY PRESSURE meter gives a reading during inspiration, and that the reading falls to 0 cm H level, during expiration.

O or, alternatively, to PEEP-

Set the LOWER ALARM LIMIT and UPPER ALARM LIMIT for EXPIRED MINUTE VOLUME.

Supported ventilation

SIMV + PRESS. SUPPORT

Connect the patient.

Set the WORKING PRESSURE.

Set the mode selector at SIMV + PRESS. SUPPORT.

Set the rate, LOW RATE/HIGH RATE.

Set the SIMV BREATHS/min.

Set the PRESET INSP. MIN. VOL. l/min.

Set the respiratory rate, BREATHS/min.

Set the INSP. TIME %.

Set the PAUSE TIME %.

(

Set the mixer.

Set the LOWER ALARM LIMIT and UPPER ALARM LIMIT for O2 CONC. %.

Set the parameter selector.

To protect the patient against high pressures,

always start from a low value.

Set the INSP. PRESS. LEVEL.

Set the PEEP-level.

Set the UPPER PRESS. LIMIT for AIRWAY PRESSURE.

Set the TRIG. SENSITIVITY.

Set the scale INFANTS/ADULTS.

Connect the patient and check that he can trigger the ventilator. Adjust the INSP. PRESS. LEVEL so that the patient receives the decided tidal volumes and check: – the reading on the EXPIRED MINUTE VOLUME meter. – that the AIRWAY PRESSURE meter gives a reading during inspiration, and that the reading falls to 0 cm H2O or, alternatively, to PEEP-level during expiration.

Set the LOWER ALARM LIMIT and UPPER ALARM LIMIT for EXPIRED MINUTE VOLUME.

Spontaneous ventilation

CPAP

Connect the patient.

Set the WORKING PRESSURE.

Set the mode selector at CPAP.

Set the mixer.

Set the LOWER ALARM LIMIT and UPPER ALARM LIMIT for O

CONC. %.

Set the parameter selector.

Set the PEEP-level.

Set the UPPER PRESS. LIMIT for AIRWAY PRESSURE.

To protect the patient against high pressures, always start from a low value.

Set the TRIG. SENSITIVITY.

(

Set the scale INFANTS/ADULTS.

Connect the patient and check: – that he can trigger the ventilator. – the tidal volumes on the digital display and the reading on the EXPIRED MINUTE VOLUME meter. – that the AIRWAY PRESSURE meter gives a reading during inspiration, and that the reading falls to 0 cm H level during expiration.

O or, alternatively, to PEEP-

Set the LOWER ALARM LIMIT and UPPER ALARM LIMIT for EXPIRED MINUTE VOLUME.

Manual ventilation

Connect the patient.

Set the values to be used after completed manual ventilation.

Set the WORKING PRESSURE.

Set the mode selector at MAN.

Set the mixer.

Set the LOWER ALARM LIMIT and UPPER ALARM LIMIT for O

CONC. %.

Set the parameter selector.

Make sure that the manual ventilation valve is in position MAN.

Set the PRESET INSP. MIN. VOL. l/min. (Set the value so that the breathing bag becomes satisfactorily filled).

Set the UPPER PRESS. LIMIT for AIRWAY PRESSURE.

(

Set the PEEP-level.

Manual ventilation valve in position MAN.

To protect the patient against high pressures, always start from a low value.

Set the scale INFANTS/ADULTS.

Connect the patient and check: – that the patient’s chest rises and falls when manual ventilation is performed. – the tidal volumes on the digital display and the reading on the EXPIRED MINUTE VOLUME meter. – that the AIRWAY PRESSURE meter gives a reading during inspiration, and that the reading falls to 0 cm H2O or, alternatively, to PEEPlevel during expiration.

Set the LOWER ALARM LIMIT and UPPER ALARM LIMIT for EXPIRED MINUTE VOLUME.

Always set UPPER PRESS. LIMIT during

manual ventilation.

In the case of a power failure, manual ventilation is not possible with Servo Ventilator 900 C.

The Manual Ventilation Accessory 963 must not be connected to Servo Ventilator 900 C.

Chapter 8

Clinical judgement and Troubleshooting

Clinical judgement when an alarm indicates that preset ventilation can no longer be maintained. If possible, try to first eliminate technical faults by carrying out a check on functions.

In this chapter:

Clinical judgement ........... 8:2

Technical troubleshooting8:6

181

Clinical judgement — Minute volume

LOWER ALARM LIMIT for EXPIRED MINUTE VOLUME has activated an alarm

Cause Symptoms and diagnostic Suggested treatment

aids

Leakage between the An air leakage may be detected Correct cuff pressure. If the tracheal wall and tracheostomy by palpation or auscultation over leakage cannot be sealed, increase tube or cannula. the trachea. the PRESET INSP. MIN. VOL. so

Temporary increase of lung Variations in measured expired volume. minute voume (spontaneous

breaths or sigh).

Ventilation obstruction, resulting UPPER PRESS. LIMIT for See UPPER PRESS. LIMIT for

that expired minute volume settles at a suitable level. Leakages mainly occur during the inspiration phase and the pause at the end of inspiration when the pressure in the trachea is high. Prolonged inspiration time.

in a pressure activated AIRWAY PRESSURE has also AIRWAY PRESSURE. interruption of inspiration. activated an alarm.

Insufficient patient respiration Variations in the measured during SIMV, CPAP, PRESS. expired minute volume. SUPPORT.

Revert to normal ventilation, or SIMV-position which gives an increased, controlled ventilation.

In SIMV, increase the SIMV BREATHS/min. or the preset tidal volume.

In PRESS. SUPPORT, increase the INSP. PRESS.LEVEL if the tidal volume is too small but the patient has adequate respiratory rate.

Clinical judgement — Minute volume

UPPER ALARM LIMIT for EXPIRED MINUTE VOLUME has activated an alarm

Cause Symptoms and diagnostic Suggested treatment

aids

Temporary decrease in lung Variations in measured expired volume. minute volume (spontaneous

breaths, compression of the lungs during thoracic surgery).

Increase in respiration rate. A signal is also given by the yellow In conjunction with suction of the

lamp below TRIG. SENSITIVITY, trachea and other measures, and indicating that the patient triggers also due to a number of other breaths at a faster rate than the factors (hypoxia, rise in preset basic rate of the ventilator. temperature, pain, restlessness, However, in volume controlled physical activity, physiotherapy, ventilation the patient can also etc.) increased ventilation may be breathing at the same rate as be necessary. The patient can the preset rate on the ventilator. compensate for an increased In assisted ventilation, check the demand on ventilation by BREATHS/min. on the digital using the patient-triggering display. system, if it is set at a suitable

level.

If the necessity of increased ventilation is long-term, this indicates some action (like increasing the ventilation volume, but with increased oxygen supply, reduction of oxygen consumption by sedatives, analgesics and antipyretics).

Clinical judgement — Pressures

UPPER PRESSURE LIMIT for AIRWAY PRESSURE has activated an alarm

(Combined with an interruption of inspiration, in which case LOWER ALARM for EXPIRED MINUTE VOLUME may also have been activated.)

Cause Symptoms and diagnostic Suggested treatment

aids

Airways obstructions In cases of substantial

a) Accumulation of mucus in Auscultatory rales, Rhoncal Suction, Expectorants, airways. fremitus on parts of the chest. Physiotherapy.

b) Bronchospasm. Bronchit. Whistling or wheezing respiratory Bronchodilator drugs, etc.

c) Tracheostomy tube or cannula Often occurs suddenly and with Removal of kinks or correction of has slipped out of the trachea, or variations. Difficult to insert a position. Possibly a reduction of has been kinked or twisted, so suction catheter. Resistance is pressure in the cuff, and possibly that the opening is blocked. The felt when ventilating manually a replacement of tracheostomy cuff protrudes over the opening with a breathing bag. tube or cannula. In case of an of the tube or cannula. Coagulate absolute blockage, it may be or dried mucus block the airway. necessary to withdraw the

obstructions, recordings of flow and airway pressure indicate increased airway resistance. Increased elastic resistance (low compliance) may also occur at the same time. When the UPPER PRESS. LIMIT for AIRWAY PRESSURE is repeatedly exceeded and, at the same time, accompanied by interruptions of inspiration, the expired minute volume falls, and an alarm is activated.

sounds during auscultation.

cannula or tube. The blockage can often be located in the orifice of the tube.

Clinical judgement — Pressures

Cause Symptoms and diagnostic Suggested treatment

aids

Reduced elasticity of the Recordings of flow and pressure respiratory organs. indicate a high elastic resistance

(low compliance).

a) Increased muscular tonus Sometimes caused by mucus, Temporary increase of minute in the patient. Coughing. often after suction. The patient volume and BREATHS/min.

works against the ventilator. Often more convenient for the

patient if the inspiratory flow is increased by reducing INSP. TIME %, until negative airway pressure caused by spontaneous breathing ceases. Consider administering analgesics and sedatives. Blood gas tests. Adjustment of ventilator settings and alarm limits.

b) Atelectasis, pneumonia, Reduced respiratory sounds over Check of blood gases. PEEP, pulmonary edema. affected sections of the lungs. physiotherapeutic treatment,

Possible rales during auscultation. change of patient’s position, Roentgenologic changes. Often postural drainage, sigh function. accompanied by hypoxia.

c) Blockage of main bronchus. The cause is often that the Adjustment of tube position.

tracheal or the tracheostomy tube has slipped too far down.

Reduced respiratory sounds. Roentgenologic changes. Irregular movements of the thorax. Hypoxia, increased resistance and reduced compliance.

d) Pneumothorax. Often occurs suddenly. Out-suction of air in pleura.

Reduced respiratory sounds, and increased percussive tone over the affected side. Sometimes followed by subcutaneous emphysema. Roentgenologic changes.

TRIG. SENSITIVITY lamp flashes

Cause Symptoms and diagnostic Suggested treatment

aids

Patient triggers spontaneous breaths.

The airway pressure (SIMV not used) is usually negative (or under preset PEEP-level) only at the start of inspiration. Negative pressure (or pressure under preset PEEP-level) during the whole inspiration indicates a considerable deviation between preset minute volume and the minute volume the patient needs.

SIMV treatment normally. Patient triggering is more often acceptable and suitable. Usually the patient requires a larger gas volume than that supplied by the controlled breaths. In cases of unexpected patient triggering, an increase of preset minute volume should be considered.

Technical trouble — Power

Ventilator does not start

Malfunction Possible cause Action

Power cable not connected. Connect power cable. Blown fuse in ventilator. Replace fuse. On-Off switch in the Off- Switch to On.

position.

Ventilator stops during operation

Malfunction Possible cause Action

Green lamp goes out, ventilator No mains supply. Ventilate patient manually. stops, audible alarm.

Manual ventilation accessory on Servo Ventilator 900 C cannot be used during a power failure.

Green lamp goes out at intervals Loose connection. Insert the power cable in wall + simultaneous stop of ventilator. socket or ventilator socket

properly.

Technical trouble — Pressures

Fault in working pressure

Malfunction Possible cause Action

Working pressure varies. Pressure/flow from gas source not Low-pressure connection:

enough. increase gas volume/pressure. Fault in gas supply. High-pressure connection:

check gas source/mixer.

Large tidal volumes and short Change respiratory pattern or gas inspiration times set on ventilator. volume. Incorrectly adjusted inlet valve in To be dealt with by service gas supply unit. technician.

WORKING PRESSURE reading Tube connection is loose between Connect tube connections. is 0, but GAS SUPPLY ALARM the safety valve and the not activated. manometer for WORKING

PRESSURE.

WORKING PRESSURE reading Working pressure not set. Set working pressure. is 0. GAS SUPPLY ALARM is Insufficient gas supply. Check gas connections/gas activated. (Alarm is also activated Deformed valve arm on gas mixers/flowmeters. for the LOWER ALARM LIMIT for supply unit. To be dealt with by service EXPIRED MINUTE VOLUME). technician.

No airway pressure

Malfunction Possible cause Action

AIRWAY PRESSURE reading Loose tube between inspiration Attach the tube. is 0. channel and pressure transducer.

UPPER PRESS. LIMIT ALARM for AIRWAY PRESSURE has been activated

Malfunction Possible cause Action

Accumulation of secretion. Suction of trachea

Kink in tracheal tube. Remove the kink or replace the

Patient tries to breathe, increased Clinical judgement. muscle-tonus.

The tracheal tube has slipped Correct the tube position. down into a bronchus.

Spasms in respiratory airways. Medicaments.

Change in patient’s positioning Possible change of respiratory e.g. on operation table. pattern.

Pneumothorax. Suction drainage. Sigh. Set the UPPER PRESS. LIMIT

tube.

alarm somewhat higher.

Technical trouble — Minute volume

LOWER ALARM LIMIT for EXPIRED MINUTE VOLUME has been activated

Malfunction Possible cause Action

Connection between patient and Reconnect the connections, e.g. ventilator has loosened. Y-piece, trach. tube, patient tube,

Leakage in trach. tube/cannula Adjust the cuff, or change trach cuff. tube/cannula cuff.

Changes in upper airway Same action as for UPPER pressure so that the expiration PRESS. LIMIT alarm for airway valve opens at attained upper pressure. pressure limit.

water trap.

Insufficient patient respiration, during SIMV, SIMV + PRESS. SUPPORT, PRESS. SUPPORT or CPAP.

Working pressure too low (lower than the airway pressure needed to provide preset ventilation).

Leakage in ventilator Safety valve out of position. Put the valve in position.

Insufficient gas supply, e.g. from flowmeters.

Leakage due to poor assembling of parts of inspiration channel or expiration channel.

Connection to one of the pressure Reconnect. transducers has loosened.

Rubber valve defect on insp./exp. Replace rubber valve. side.

Change SIMV-rate, INSP. PRESS. LEVEL, or change to controlled ventilation.

Increase working pressure, or change respiratory pattern.

At low pressure: increase gas flow. At high pressure: check gas source/mixer.

Assemble correctly.

Technical trouble — Minute volume

UPPER ALARM LIMIT for EXPIRED MINUTE VOLUME has been activated

Malfunction Possible cause Action

Deeper breaths in VOL. CONTR. + Set the UPPER ALARM LIMIT SIGH, increase in expired minute somewhat higher. volume (every hundredth breath).

Patient breathes more than Clinical judgement. expected during SIMV, SIMV + PRESS. SUPPORT, CPAP, PRESS. SUPPORT.

Condensation in exp. flow Empty water trap if necessary. transducer. Protect exp. inlet by an angled

humidity trap or a bacteria filter. Dry run the ventilator with a test lung if these actions are not enough.

Particles of medicines in exp. flow Replace exp. flow transducer (or transducer. try to clean the transducer

according to chapter 10).

Flow transducer is defective. Replace exp. flow transducer.

Technical trouble—Others

cell

Malfunction Possible cause Action

No digital display when O

Rapidly falling O2 CONC. % a) Insufficient O2 supply. a) Regulate O2 supply. values. LOWER ALARM LIMIT b) O2 cell exhausted. b) Replace O2 cell (see chapter 12) activates an alarm. c) O2 cell not properly inserted. c) Insert properly.

UPPER ALARM LIMIT activates Insufficient air/N2O supply. Regulate gas supply. an alarm.

Leakage detected in ventilator during check on functions

Malfunction Possible cause Action

O2 cell not inserted. Insert an O2 cell (see chapter 12). CONC. % is selected.

Connection between safety valve Reconnect. and manometer has loosened.

Leakage at inlet valve of gas Replace gas supply unit. supply unit.

Leakage in non-return valve of Replace gas supply unit. gas supply unit.

Leakage in bellows. Replace bellows (see chapter 11).

Overfilling of bellows, safety valve Valve arm to be adjusted by opens (caused by deformed valve service technician. arm on gas supply unit).

Leakage in bacteria filter. Replace gas supply unit. Bad connections in the inspiratory Connect properly.

or expiratory channel.

Incorrect values/readings during check on functions

Malfunction Possible cause Action

Ventilator not calibrated. Calibrate ventilator (see chapter

13).

Noises

Malfunction Possible cause Action

Rattle from step motor. Must be dealt with by service

technician as soon as possible.

“Singing” noise from springs Springs hook into one another. Dealt with by service technician, under the bellows. Not dangerous and does not when convenient.

interfere with function of ventilator.

Trig sensitivity flashes without activity from the patient

Malfunction Possible cause Action

Leakage in the expiratory channel which causes spontaneous triggering (when PEEP is used in the presence of leakages).

Chapter 9

Recording

The ventilator can be connected to a recorder, e.g. a Siemens-Elema Mingograf.

In this chapter:

Connection..................... 9:2

Calibration...................... 9:3

Curves ............................ 9:4

191

Connection

Recorder output

• Connect the recorder cable to the 37-pin socket at the rear of the ventilator. The cable has two connections to the Mingograf Recorder, i.e. one for recording of pressure curves and one for recording of flow curves.

• The output signals from the recorder cable are adapted to the inputs of SiemensElema’s Mingograf Recorders.

Use only the recorder cable intended for Servo Ventilator 900 C.

Never connect or disconnect auxiliary equipment while the ventilator is connected to a patient.

Calibration

VOL. CONTR.

a) Flow

Adjust the 0-line on the recorder.

Set WORKING PRESSURE to 60 cm H2O.

Set the UPPER PRESS. LIMIT higher than the WORKING PRESSURE.

Select constant flow.

Set the respiratory rate to 10 BREATHS/min.

Set the mode selector at VOL. CONTR.

Calculate inspiratory flow as follows: Insp. flow (l/s) =

PRESET INSP. MIN. VOL. (l/min)

100

INSP. TIME

(%)

A suitable calibration level for normal conditions is to allow 0.5 l/s correspond to 1 cm deflection on the recorder paper. 0.5 l/s corresponds to a setting of 7.5 l/min for PRESET INSP. MIN. VOL. and 25% INSP. TIME.

(

After this, adjust the recorder to desired reading.

b) Pressure

Adjust the 0-line on the recorder.

Block the inspiration outlet during the inspiration phase, or connect the inspiration outlet to the expiration inlet with a patient tube.

A suitable calibration level for normal conditions is to allow 20 cm H deflection on the recorder paper. The preset WORKING PRESSURE should then, temporarily, be set to 20 cm H

O correspond to 1 cm

Adjust the recorder to desired reading.

Flow Airway pressure

Curves

Constant Accelerating Decelerating

flow flow flow

Insp. Pause Exp.

Pressure and flow curves

If the flow curve is square-shaped and an inspiratory pause is used, it will be possible to calculate, from the pressure curve, airway resistance and the elasticity of the lungs and rib cage, i.e. compliance. It is possible to continuously follow changes in these values in patients with obstructive lung diseases and also when ventilating patients for prolonged periods.

For all measurements, it is assumed that the

patient makes no breathing attempts.

It is possible to read the effects from the

changes in the ventilation, e.g. optimal PEEP or broncho-dilating agents, which give a direct change in resistance.

Assessment of curves

Volume controlled ventilation and constant flow, in order to calculate resistance

Resistance

occurs during the pause.

• Big amplitude of pressure drop indicates high airway resistance.

Resistance is calculated according to the formula:

Resistance (cm H = P

res.

Volume controlled or pressure controlled ventilation, in order to calculate compliance

Compliance

during the expiration phase.

• Big drop in pressure (P compliance, i.e. poor elasticity in lungs and chest, i.e. high elastic resistance.

Compliance is calculated according to the following formula:

Compliance (ml/cm H

Not valid if the flow has not reached zero when the next expiration starts or if the patient makes breathing efforts.

is indicated by a pressure drop that

O/l/s) =

(cm H2O) ×

PRESET INSP. MIN. VOL. (l/min)

PRESET INSP. MIN. VOL.

×Insp. %

is indicated by a pressure drop

O) =

BREATHS/min

1000

(cm H2O)

compl.

(l/min)

100

) indicates low

compl

Chapter 10

Routine cleaning

Servo Ventilator 900 C has been constructed so that the cleaning and sterilizing of contaminated parts can be carried out simply and rapidly.

Routine cleaning should be carried out after

every patient or daily, according to the hospital routines.

In this chapter:

Hygiene .......................... 10:2

Dismantling.................... 10:2

Cleaning ......................... 10:4

Assembling.................... 10:6

1101

Hygiene

The gas, which passes the ventilator’s inspiration system and is supplied to the patient is usually clean and dry. It also passes a bacteria filter.

The dry environment gives unfavorable conditions for bacterial growth, and bacteria spreading against the gas flow is considered virtually impossible.

Bacteria from the patient will, on the other hand, appear in the moist environment of the expiration side. By attaching a disposable bacteria filter to the expiratory inlet of the ventilator, the transmission of bacteria to the expiratory channel and out into the room is reduced. This reduces the risks of infections being spread to the staff as well as cross infections between patients.

Dismantling

Exchange or cleaning of patient tubes and the parts of the expiratory channel and exchange of expiratory bacteria filter is recommended after each patient or according to the hospital routines. The bacteria filter should be replaced according to manufacturer recommendations.

The gas conveying parts of the expiration system can be decontaminated and sterilized.

The parts of the inspiration system should be sterilized or replaced by clean parts after an operating time of 1000 hours or, at the latest, half-yearly, according to chapters 10 and 11 in this manual.

All personnel should be aware of the risk of parts being infected when disassembling and cleaning the ventilator.

• Remove gas connections.

• Disconnect the power cable.

• Remove patient tubes, humidifier and manual

ventilation accessory.

• Remove the O

(if used).

• Wipe the outside of the ventilator with a cloth

moistened in a disinfectant.

FLUSH quick-coupling

• Open the lid on the pneumatic unit.

• Disconnect the connector from the flow

transducer on the expiration side.

• Remove the bacteria filter from the pressure

transducer marked EXP.

Dismantling

• Lift the whole expiration channel upwards.

• Dismantle the different parts.

• Discard the tube and bacteria filter for the pressure transducer.

Cleaning

Ethyl alcohol

1 hour

• Let the flow transducer lie in a 70% ethyl alcohol solution for about one hour.

The flow transducer is a precision instrument and must be handled carefully. The metal disc in the small channel of the transducer is very fragile and may break if it is handled carelessly.

Do not poke at the metal disc in the small

transducer channel.

Do not flush the channel with water.

The flow transducer must not be cleaned in a dish washing machine, by ultrasound or by using agents which contain aldehydes.

Solutions other than ethyl alcohol may give rise to disturbances in the function of the flow transducer.

If agents other than ethyl alcohol are used for disinfection, the cleaning routines should be carried out according to the instructions of the respective manufacturers.

The agents used for cleaning and disinfection must have a pH between 4 and

8.5.

• If solutions other than ethyl alcohol are used, rinse the solution from the flow transducer by carefully moving the transducer to and fro in a bowl containing distilled water.

Water

Let the water run off the flow transducer after rinsing.

• Make sure that the fine mesh net in the transducer is not blocked or damaged, and that the disc in the small channel is in position.

Cleaning

Manual ventilation

valve in position

MAN

• If the manual ventilation valve should be cleaned, do as follows:

• Set the valve in the MAN position, and let it lie in a 70% ethyl alcohol solution for about one hour.

Disinfectant

1 hour

• Let the other parts (NOTE! transducer and manual ventilation valve) lie in a disinfectant for about one hour.

• After this, rinse the parts in water to remove the disinfectant.

not

the flow

• Autoclave all parts, including the flow transducer and manual ventilation valve at a maximum temperature of 150˚C (300˚F).

Assembling

VOL. CONTR.

• Put a new bacteria filter with tube on the pressure transducer marked EXP.

Make sure that the bacteria filter (without caps) is properly connected to the pressure transducer. Otherwise, the expiration could be blocked.

• Assemble the expiration channel.

• Connect the tube from the pressure transducer on the expiration side to the metal pipe. Make sure that the pressure transducer tube is not bent or pinched. The tube should be placed below the silicone rubber muff.

• Push the expiration channel down into position.

• Make sure that the expiration valve is not bent or twisted.

• Connect the connector to the flow transducer.

• Make sure that the serial numbers on the transducer and on the connector agree.

• Fit the manual ventilation accessory, O

FLUSH quick-coupling (if required) and

new patient tubes.

• Note on the log sheet that routine cleaning has been carried out.

• Carry out a check on functions after cleaning (see chapter 6).

After autoclaving in certain autoclaves, the flow transducer may be somewhat damp, and this may give rise to incorrect readings on the EXPIRED MINUTE VOLUME meter.

The moisture is removed in the following way:

• Connect the power cable.

• Connect a test lung to the Y-piece.

• Connect compressed air to the ventilator and let it run for about 15 minutes with a PRESET INSP. MIN. VOLUME of 7.5 l/min.

• Store the ventilator under a cover in normal room temperature and humidity.

Chapter 11

1000 hours overhaul with complete cleaning

After every 1000 hours of operation or after every six months, at the latest, a 1000 hours overhaul should be carried out.

In this chapter:

Dismantling.................... 11:2

Cleaning ......................... 11:4

Assembling.................... 11:6

1111

Dismantling

Disposable parts

•3 bacteria filters (2 with tubes for pressure transducers + 1 without tube for WORKING PRESSURE manometer),

•1 blue main flow bacteria filter (for gas supply unit),

• Bellows,

•2 rubber valves (insp. and exp.),

• Net for exp. flow transducer.

• Remove the gas connections.

• Disconnect the power cable.

• Remove the patient tubes, humidifier and manual ventilation accessory. Also disconnect the O (if used).

• Wipe the outside of the ventilator with a cloth moistened in a disinfectant.

FLUSH quick-coupling

• Open the lid on the pneumatic unit.

• Open the lid over the bellows by releasing the locking pawls on the front edge of the lid.

• Remove the bellows.

• Discard the bellows.

Dismantling

• Disconnect the connectors to the flow transducers.

• Remove the bacteria filters from the pressure transducers marked INSP. and EXP.

• Lift the inspiration channel, excluding the safety valve, straight upwards.

• Remove the safety valve.

• Remove the bacteria filter of the manometer tube from the safety valve (Luer-lock adapter).

• Discard the filter.

• Lift the expiration channel straight upwards.

• Dismantle the parts in the inspiration and expiration channels.

• Discard the rubber valve in the inspiration and expiration channels.

• Discard the tubes and bacteria filters for the pressure transducers.

• Grasp the gas connection nipples and lift the gas supply unit straight upwards.

(

• Unscrew the filter container with a hexagonal spanner 5 mm.

• Discard the blue bacteria filter.

• Remove the connector at the top of the O

cell.

• Remove the O clockwise.

• Discard the O

cell by turning it counter-

cell if it is exhausted.

Cleaning

Ethyl alcohol

1 hour

• Let the flow transducers lie in a 70% ethyl alcohol solution for about one hour.

The flow transducers are precision instruments and must be handled with care. The metal disc in the small channel of the transducer is very fragile and may break if it is handled carelessly.

Do not poke at the metal disc in the small

transducer channel.

Do not flush the channel with water.

The flow transducers must not be cleaned in a dish washing machine, by ultrasound or by using agents which contain aldehydes.

Solutions other than ethyl alcohol may give rise to disturbances in the function of the flow transducers.

If agents other than ethyl alcohol are used for disinfection, the cleaning routines should be carried out according to the instructions of the respective manufacturers.

The agents used for cleaning and disinfection must have a pH between 4 and

8.5.

Water

Manual ventilation

valve in position

MAN

• If solutions other than ethyl alcohol are used, rinse the solution from the flow transducers by carefully moving the transducer to and fro in a bowl containing distilled water.

Let the water run off the flow transducers after rinsing.

• Make sure that the fine mesh nets in the transducers are not blocked or damaged, and that the disc in the small channel is in position.

Clean the manual ventilation valve:

• Set the valve in the MAN position, and let it lie in a 70% ethyl alcohol solution for about one hour.

Cleaning

Disinfectant

1 hour

• Clean the gas supply unit.

The gas supply unit must not be immersed in any liquid.

The gas supply unit must not be

autoclaved.

Only the lid and the gasket can be

cleaned and autoclaved.

• Open the gas supply unit.

• Put the lid, gasket and screws in a disinfectant for about one hour.

• Wipe the outside of the gas supply unit with a soft cloth moistened in a disinfectant.

• Let the other parts lie in a disinfectant solution for about one hour. (NOTE! flow transducers, manual ventilation valve, O2 cell and gas supply unit).

Not

the

MAX 150° C

• After cleaning and rinsing, all parts (

cell and gas supply unit) can be

autoclaved at a maximum temperature of 150˚C (300˚F).

not

the

Assembling

• Insert a new blue filter in the filter container.

• Ensure that the filter is positioned correctly, i.e. with the indicating arrow in the flow direction.

• Tighten the filter container.

• Put, if required, a new O2 cell with O-ring in place by turning it clockwise.

• Connect the connector to the top of the O

cell.

• Place the gas supply unit in the ventilator.

• Put a new bacteria filter on the manometer tube.

• Connect the bacteria filter to the safety valve.

• Mount the safety valve in position in the ventilator.

Assembling

• Put in a new bellows. Make sure it is right side up, i.e. upper side marked UP.

• Push the bellows onto the connection tubes.

• Make sure that the bellows is centered.

• Shut the lid over the bellows and secure the locking pawls on the front edge of the lid.

• Replace the fine mesh net in the expiratory flow transducer as follows:

• Loosen the screw.

• Shake the flow transducer gently until the net loosens.

• Insert and secure the new net.

• Replace the rubber valve in the inspiration channel.

Assembling

• Assemble the parts of the inspiration channel.

• Put a new pressure transducer tube and bacteria filter on the pipe of the inspiration channel (see picture).

(

• Push the inspiration channel down into position and thread the silicone rubber bend onto its supporting pin.

• Make sure that the inspiration valve is correctly positioned and that it is not bent or twisted.

• Connect the filter to the pressure transducer marked INSP.

• Make sure that the pressure transducer tube is not bent or pinched.

• Connect the connector to the flow transducer.

• Make sure that the serial numbers on the transducer and on the connector agree.

Assembling

• Replace the rubber valve in the expiration channel.

• Assemble the parts of the expiration channel.

• Put a new pressure transducer tube and bacteria filter on the pipe of the expiration channel.

• Connect the filter to the pressure transducer marked EXP.

• Push the expiration channel into position. Thread the silicone rubber bend onto its supporting pin.

• Make sure that the expiration valve is not bent or twisted.

• Make sure that the pressure transducer tube is not bent or pinched.

Make sure that the bacteria filter is properly connected to the pressure transducer. Otherwise, the expiration could be blocked.

• Connect the connector to the flow transducer.

• Make sure that the serial numbers on the transducer and on the connector agree.

• Connect manual ventilation accessory, O

FLUSH quick-coupling (if required) and

new patient tubes.

Assembling

VOL. CONTR.

• Note on the log sheet that a complete cleaning has been carried out.

• Calibrate the ventilator (see chapter 13).

• Check/Calibrate the O2 cell (see chapter 12).

• Carry out a check on functions (see chapter 6).

After autoclaving in certain autoclaves, the flow transducers may be somewhat damp, and this may give rise to incorrrect readings on the EXPIRED MINUTE VOLUME meter.

The moisture is removed in the following

way:

• Connect the ventilator to mains.

• Connect a test lung to the Y-piece.

• Connect compressed air to the ventilator and let it run for about 15 minutes with a PRESET INSP. MIN. VOLUME of 7.5 l/min.

• Store the ventilator under a cover in normal room temperature and humidity.

Chapter 12

Replacement of

O2 cell

The O2 cell is an expendable item. An indication of an expended O linearity and/or a rapid drop in the O concentration readings on the digital display. To avoid alarm when the O connector at the top of the O disconnected. If the O plastic cover with an O-ring has to be put in its place.

Sealed unit contains caustic. Leaked liquid may cause severe burns to skin and eyes. In case of contact, immediately flush with plenty of water for at least 15 minutes. For eyes, get medical attention.

cell is a deterioration of the

cell is exhausted, the

cell is removed, a

cell must be

In this chapter:

Replacement.................. 12:2

Calibration...................... 12:2

Log sheet ....................... 12:2

1121

Replacement and calibration

Replacement

Unpack the O2 cell at least 30 minutes before replacement/calibration.

Disconnect mains supply and compressed air.

Disconnect the connector at the top of the O

cell.

Remove the O2 cell by turning it counterclockwise.

Connect the ventilator to mains supply and let it run for about 15 minutes.

Set the parameter selector at O2 CONC. %.

Depress the pushbutton and adjust with trimmer 10 until the display reads 00.0.

Put the new O2 cell in place by turning it clockwise. Do not forget the O-ring at the bottom of the O2 cell.

(

Connect the connector at the top of the O2 cell.

O2 CONC. %

Calibration of O2 cell

Connect compressed air.

Set WORKING PRESSURE to 60 cm H2O.

The digital display should read 20.9%. If not, adjust with trimmer 9.

After about 24 hours, make sure that the O2 cell gives a stable reading (20.9% with compressed air connected). If the reading is not 20.9%, calibrate as described above.

Log sheet

• Note on the log sheet that the O2 cell has

been replaced and calibrated.

Chapter 13

Calibration

The calibration must be carried out after the 1000 hours overhaul and after complete cleaning.

In this chapter:

1. Basic setting for

calibration ..................... 13:2

2. Check on mechanical

zeroing of instruments. 13:3

3. Balancing of flow

transducers ................... 13:3

4. Electric zeroing............. 13:4

5. Gas supply and

working pressure.......... 13:4

6. Check of manometer

and for internal leakage 13:5

7. Pressure transducers... 13:5

8. Upper pressure limit,

airway pressure ............ 13:6

9. Triggering level............. 13:6

10. Flow, inspiration side ... 13:6

11. Check for leakage,

(external) ....................... 13:7

12. Flow, expiration side .... 13:7

13. Volume alarms .............. 13:7

14. O2 cell............................. 13:8

15. Log sheet....................... 13:8

Preparations

Equipment

• Calibration manometer

• Screwdriver

• 2 patient tubes

• Y-piece

• Test lung

1. Basic settings for calibration

Set the following on the ventilator:

Mode .......................................... VOL. CONTR.

Respiratory pattern

PRESET INSP. MIN. VOLUME. 7.5 (l/min)

Flow pattern ............................... – –

BREATHS/min ........................... 10 (breaths/

min)

INSP. TIME %............................ 25 (%)

PAUSE TIME %......................... 30 (%)

Expired minute volume

Measuring range........................ ADULTS

LOWER ALARM LIMIT.............. 0 (l/min)

UPPER ALARM LIMIT............... 40 (l/min)

Airway pressure

TRIG. SENSITIVITY .......... –20 (cm H

PEEP ................................. 0 (cm H

UPPER PRESS. LIMIT...... 80 (cm H2O)

INSP. PRESS. LEVEL....... 0 (cm H2O)

Concentration

LOWER ALARM LIMIT...... 20 (%)

UPPER ALARM LIMIT....... 100 (%)

Calibration

List of trimmers

1.Exp. flow. Gain

2.Exp. flow. Lamp

3.Insp. flow. Gain

4.Insp. flow. Lamp

5.Exp. pressure. Gain

6.Exp. pressure. 0-setting

7.Insp. pressure. Gain

8.Insp. pressure. 0-setting %

9.O

10.O2, 0 volt

2. Check on mechanical zeroing of instruments

• During this check, the ventilator must not be connected to mains or to a gas supply.

• Check that the meters EXPIRED MINUTE VOLUME and AIRWAY PRESSURE read 0.

• If not, adjust the meters.

3. Balancing of flow

transducers

• Open the lid on the pneumatic unit. Open the lid above the trimmers (variable resistors).

NOTE! The adjustment of trimmers is very sensitive. When adjusting, turn the trimmers very slowly while watching the lamp.

• Connect the ventilator to mains.

• Set the mains switch on the rear of the ventilator to on. Make sure that the green lamp POWER ON lights up when you switch on.

• Let the ventilator run at least 15 minutes. Then adjust:

a) Flow transducer on insp. side: Adjust

trimmer 4 until the lamp at trimmer 4 lights up.

b) Flow transducer on exp. side: Adjust trimmer

2 until the lamp at trimmer 2 lights up.

Calibration

4. Electric zeroing

a) Airway pressure (pressure transducer of insp. side)

• Check that the meter AIRWAY PRESSURE reads 0.

• If not, adjust with trimmer 8.

b) Airway pressure (pressure transducer of exp. side)

• Keep the pushbutton depressed and at the same time check that the meter reads 0.

• If not, adjust the reading (with pushbutton depressed) with trimmer 6.

EXP. MIN. VOL. l/min

c) Expired minute volume

• Set the parameter selector at EXP. MIN. VOL l/min.

• Check that the digital display and the meter EXPIRED MINUTE VOLUME read 0. If not, the electronic unit is faulty and must be repaired by a service technician.

5. Gas supply and working

pressure

• Connect compressed air.

• Set the WORKING PRESSURE to 60 cm H2O.

Calibration

6. Check of manometer and for internal leakage

• Connect a calibration manometer to the inspiration outlet pipe.

• Block the calibration manometer.

• Check that the manometer WORKING PRESSURE gives the same reading as the calibration manometer (60 ± 2 cm H If not, replace the WORKING PRESSURE manometer.

• The reading on the meter AIRWAY PRESSURE should not fall more than a few cm H

O during the time the inspiration valve

is closed. If the reading falls more, look for leakage.

• Remove the calibration manometer.

• Connect a patient tube from the inspiration outlet to the expiration inlet.

• Keep the expiration valve closed.

• The reading on the meter AIRWAY PRESSURE should not fall more than a few cm H

O during the time the inspiration valve

is closed. If the reading falls more, look for leakage in the expiration channel.

O).

7. Pressure transducers

a) Inspiration side

• Keep the expiration valve closed.

• Check that the meter AIRWAY PRESSURE gives the same reading as the manometer WORKING PRESSURE (60 ± 1 cm H2O).

• If not, adjust with trimmer 7.

b) Expiration side

• Keep the expiration valve closed and depress the pushbutton.

• Check that the meter AIRWAY PRESSURE gives the same reading as the manometer WORKING PRESSURE (60 ± 1 cm H

• If not, adjust with trimmer 5.

O).

Calibration

UPPER PRESS. LIMIT

TRIG. SENSITIVITY

8. Upper pressure limit, airway pressure

• Block the inspiration outlet.

• Turn the knob UPPER PRESS. LIMIT slowly counter-clockwise from the position 80 cm H where the alarm lamp for UPPER PRESS. LIMIT flashes. At this instant, the readings for WORKING PRESSURE and AIRWAY PRESSURE should agree with the knob setting ±3 cm H is faulty and must be repaired by a service technician.

• Turn the knob back to 80 cm H

O until you reach the exact position

O. If not, the electronic unit

9. Triggering level

• Remove your hand from the inspiration outlet.

• Set the TRIG. SENSITIVITY to -10 cm H

• Turn the PEEP knob and check that the TRIG. lamp lights up when +10 ±2 cm H2O is passed. If not, the electronic unit is faulty and must be repaired by a service technician.

• Reset TRIG. SENSITIVITY to -20 cm H and PEEP to 0 cm H

10. Flow, inspiration side

• Set BREATHS/min to 5.

• Connect a calibration manometer to the inspiration outlet.

• Let compressed air blow through the calibration manometer for a few minutes.

• Check that the reading on the calibration manometer is 45 ±5 cm H inspiration.

• If not, adjust with trimmer 3.

• Check that the lamp at trimmer 4 lights up at pause and expiration. If not, repeat calibration according to 3a.

• After 6-8 breaths, make sure that the calibration manometer reading is stable (45 ±5 cm H

• Remove the calibration manometer.

O).

O during

Calibration

EXP. MIN. VOL. l/min

11. Check for leakage

(external)

• Set BREATHS/min to 10.

• Connect tubes and Y-piece.

• Block the Y-piece.

• Make sure that the AIRWAY PRESSURE does not fall more than a few cm H pause.

O during

12. Flow, expiration side

• Set the respiratory rate at 20 BREATHS/min and PAUSE TIME at 10%.

• Connect a test lung.

• Set the parameter selector at EXP. MIN. VOL. l/min.

• Let the ventilator run for a few minutes.

• Check that the digital display shows

7.5 ±0.1 l/min.

• If not, adjust with trimmer 1.

• The difference between the digital display and the meter EXPIRED MINUTE VOLUME must not be more than ±0.5 l/min.

• Check that the lamp at trimmer 2 lights up at inspiration and pause. If not, repeat calibration according to 3B.

• After 6-8 breaths, make sure that the reading is stable.

MIN. VOL. ALARM LIMITS

13. Volume alarms

Lower alarm limit

• Turn the knob LOWER ALARM LIMIT to

7.5 l/min and make sure that the alarm is activated at 7.5 ±0.5 l/min.

• Turn the knob LOWER ALARM LIMIT to 0 l/min.

Upper alarm limit

• Turn the knob UPPER ALARM LIMIT to

7.5 l/min and make sure that the alarm is activated at 7.5 ±0.5 l/min.

• Turn the knob UPPER ALARM LIMIT to 40 l/min.

Calibration

CONC. %

14. O2 cell

• Set the parameter selector at O2 CONC. %.

• The digital display should read 20.9% (with compressed air connected and WORKING PRESSURE 60 cm H

• If not, adjust with trimmer 9.

• Normally, trimmer 10 needs not to be adjusted. If necessary, see chapter 12.

• Make sure that the UPPER ALARM LIMIT and LOWER ALARM LIMIT are functioning correctly.

O).

15. Log sheet

• Note on the log sheet that the ventilator has been calibrated.

Chapter 14

Technical specifications

In this chapter: Gas and power supply .. 14:2

Ventilation parameters

and controls................... 14:2

Special functions........... 14:2

Monitoring...................... 14:2

Alarm and indicators..... 14:3

General........................... 14:4

Technical specifications

Gas and power supply

Gas .................................................................... Must fulfill specifications for medical gases.

Gas consumption............................................... Approximately equal to preset inspiratory

minute volume or equal to flow meter setting.

Gas supply via high pressure inlet .................... From central gas supply, compressor or gas

cylinder.

Electronic gas supply unit, inlet pressure.......... 2.5-5 bar (250-500 kPa).

Other gas supply unit, inlet pressure ................ 2.5-7 bar (250-700 kPa).

Gas supply via low pressure inlet...................... From flowmeter(s).

Power supply ..................................................... (100), 110 120 220 240 V ±10%, 50 or 60 Hz.

Power consumption ........................................... Approximately 40 W.

Ventilation controls, control ranges

Working pressure .............................................. Up to 120 cm H2O.

Modes ................................................................ VOL. CONTR. (Volume controlled).

VOL. CONTR. + SIGH (Volume controlled with

sigh). PRESS. CONTR. (Pressure controlled).

PRESS. SUPPORT (Pressure support). SIMV

(Synchronized Intermittent Mandatory

Ventilation). SIMV + PRESS. SUPPORT.

CPAP (Continuous Positive Airway Pressure).

MAN. (Manual ventilation—auxiliary equipment

necessary).

Preset inspiratory minute volume...................... 0.5-40 l/min. With sufficient working pressure.

Flow pattern ....................................................... Constant or accelerating.

Respiratory rate ................................................. 5-120 breaths/minute.

Inspiration time .................................................. 20, 25, 33, 50 or 80% of the respiratory cycle.

Pause time......................................................... 0, 5, 10, 20 or 30% of the respiratory cycle.

Inspiratory pressure (above PEEP)................... 0-100 cm H

PEEP ................................................................. 0-50 cm H

Upper pressure limit .......................................... 15-120 cm H

Trig sensitivity (below PEEP) ............................ -20-0 cm H

SIMV-rate........................................................... HIGH RATE (4-40 SIMV breaths/min). LOW

Sigh.................................................................... Double tidal volume every hundredth breath.

Compressible volume (internal) ........................ 0.075 l.

Accuracy (for momentary insp. flow up to

1.6 l/s): ±10% or 0.2 l/min.

RATE (0.4-4 SIMV breaths/min.).

Special functions

Inspiratory pause hold Expiratory pause hold Gas change

Monitoring

Analog presentation

Airway pressure ................................................. Range -20-120 cm H

Accuracy: ±5% or ±2 cm H

Maquet Servo 900c User manual

Specifications and Main Features

Frequently Asked Questions

User Manual