Hersill KAV-1 User Manual

USER MANUAL FOR CO2 ABSORBER

CIRCUIT

KAV-1

Puerto de Navacerrada 3, P.I. Las Nieves
28935 Móstoles - España
Tlfo.: 91 616 4642 - Fax: [phone]

Manual Ref.: 9130001
Edition: 2002
Revision: 3

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KAV-1

INSTRUCTION MANUAL

CO2 absorber

INTRODUCTION

The circular circuit is a respiration system that contains one-way inspiration and expiration
circuits, together with a CO2 absorbing device.

COMPONENTS OF A CIRCULAR SYSTEM

The basic components of a circular system are:

- A common fresh gas intake.

- One inspiratory branch and one expiratory branch, each one equipped with a one-way
valve.

- A spontaneous / manual ventilation circuit, including a reservoir bag.

- A mechanical ventilation circuit, including a concertina or bellows.

-A CO2 absorption system (canister).

- An APL or overpressure valve for manual ventilation, a pressure-limiting valve for
mechanical ventilation and a residual gas exhaust conduit.

HERSILL KAV-I ABSORBER DEVICE

The new KAV-1 CO2 absorber is made of stainless steel, brass, polysulfone and silicon,
making it the ideal choice for:

- Surgery in the operating theatres of hospitals and public health clinics.

- Veterinary and dental surgery.

- Emergencies, ambulances and military uses.

All the device’s components have been designed and manufactured to optimise its use. For
example, the apparatus has a smaller-than-usual canister because experience has shown that
large tanks of soda lime are harder to handle.

The CO2 absorption capacity can easily be doubled or trebled by placing one canister on top
of another.

The circuit can be used both for high and low flow techniques:

1. High flows: Using fresh gas flows near the patient’s normal ventilation. In this case the
circular system behaves as a partial reinhalation/non-reinhalation system, increasing the
effective life of the soda lime with higher fresh gas flows.

2. Low flows (1 - 1.5 l/min) or minimum flows (0.5 - 1 l/min) of fresh gases for the patient’s
ventilation. Using this circular circuit with low flows permits the following:

a) High use of fresh gases;
b) Minimum possibilities of leaks;
c) Efficient use of the soda lime;
d) Minimum risk of disconnection;
e) Only the inhaled gas passes through the soda lime;
f) It improves heat and humidity retention;
g) Economic benefit, reducing the annual costs of volatile anaesthetic agents;
h) Reduction in amount of nitrous oxide (N2O) released to the atmosphere, where it

causes a greenhouse effect, and of other inhalatory agents.

To change the nature of the circuit from reinhalation to non-reinhalation, or vice-versa, you
only have to change the flow of fresh gases, and there are no switches.

When the circuit is adapted to our REX and REGINA anaesthesia machines, and to our ORBI
portable anaesthesia device, with all the monitoring devices, it can be used for the following
purposes:

a.- For monitoring of essential ventilation parameters.
b.- For extensive monitoring of respiratory gases.

It can be also used with the following devices:

c.- A respirator with an ascending concertina.
d.- A vaporiser suitable for operating with low flows.
e.- High-precision variable area flowmeters equipped with an antihipoxia system.

The appropriate position of the expiratory valve in the system, and the

carefully studied position of the fresh gas supply, make the KAV-1 the

IDEAL CIRCUIT FOR USE WITH LOW FLOWS

INSTRUCTIONS FOR USE

1. Respiratory Circuit.

Visually inspect all the components.
Check that the inspiratory and expiratory valves work properly.
Replace any faulty parts.

For instructions on how to assemble the circuit, please turn to the annexes:

- Assembly of the absorber circuit - Basic option

- Assembly of the absorber circuit - Basic option + expirometer + manometer

2. Canister

Check the state of use of the soda lime. Please note the absorbent change date, because
an absorbent that has remained in a canister too long and become unusable may not have
changed colour, without having reversed.

Calculate the duration of the operation in relation to the state of the absorbent and its
location (inspiratory or expiratory branch) so that it does not have to be changed while
the patient is being anaesthetised.

Before each operation, pass flows of 100% O2 through the lime deposit to remove any
residual gases that may have accumulated during previous operations.

Disconnect the canister from the circuit before filling it with soda lime. Pour the soda
lime granules into the canister, turning it to ensure it fills smoothly (without pressing it).
Put the canister back in the circuit.

PRECAUTIONS

- The canister must only be used in the upright position.

- It must not be used near inflammable anaesthesia.

- The accumulated condensation at the bottom of the canister is caustic, so be very careful
and make sure that it does touch your skin when draining you are draining the canister.

- If the ventilator is not connected, keep the manual/automatic switch in the manual position
to avoid gas leaks.

- A lack of absorbent may cause inefficient CO2 absorption, whereas an excess may cause
inefficient sealing.

- Make sure to check to respirator (see equipment manual) before you use the circular
circuit and the canister.