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Archive for the ‘Resuscitation valves’ Category

Resuscitation valves.
There is little to say about these, there are a number of different types, but in general they have internal silicone rubber flap valves of one design or another.
If you think that it is not working correctly, attach a 0.5 litre bag or similar and operate it with the self inflating resuscitation bag, watch the flaps open and close to see if you can spot the problem, otherwise strip it down and check that the flap valves are clean and not damaged.
Check the body for cracks. Clean the parts in warm soapy water and rinse and dry well.
One of the common reasons for valves not working well is that they have been washed and not dried properly and the flaps have stuck down.
Most can be sterilised if they are known to be contaminated.

NON-REBREATHING VALVES.
Advantages are;

1. No possibility of rebreathing provided the dead space of the valve is small.

2. Can be used for spontaneous or controlled respiration.

3. Can be used to measure minute volume if the flow-meters are accurate.

Disadvantages are;
1. Wasteful.

2. Variations of minute volume during spontaneous breathing require frequent adjustment of
the flow-meters to prevent collapse or distension of the reservoir bag.

3. Valves may stick.
Some valves are noisy.

Some examples of non-rebreathing valves;

a. Rubens valve.
A bobbin moves against a spring to act as a uni-directional valve and an outlet valve prevents the taking in of atmospheric air. The dead space is 9 ml, resistance. The resuscitation version has no outlet valve so that the patient who is breathing spontaneously will take in atmospheric air.

Photo of  Rubens valve.

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b. The Ambu Valves.
The bobbin of the Rubens valve is replaced by one or two silicone rubber flap valves.
The valve can be dismantled quite easily for cleaning and sterilisation.
Take great care when re-assembling the valve it is possible to do it incorrectly. It can be used with a self inflating bag. The valve with one flap is only suitable for I.P.P.V. (Intermittent positive pressure ventilation.)
The valve with two rubber flaps is suitable for both I.P.P.V and spontaneous respiration.
It has a very low dead space.
There are a few versions of this valve, both for adult and paediatric use.
The ideal valve should have no forward leak, no back leak, low resistance, minimal dead space, minimal opening pressure without sticking, lightweight, transparent, easy cleaning and sterilising, reliability and durability, a single exit port so that the expired air can be collected and measured, and be cheap. When cleaning these valves that have silicone flaps do take care to wash them well, if you leave any soap behind it will dry and stick the flaps down.
Afterwards, connect them to a 1-litre bag and test that they do work properly.

The Ambu valve, I forget which model this is but there are a couple.

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This photo shows the Ambu valve taken apart. the yellow thing is a silicone rubber one-way valve, it sits on top of the blue bit and they screw into the body.

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Another Ambu valve.

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and showing it taken apart.

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