By Stella Domoney
The club has recently acquired a defibrillator thanks to the generosity of the parents of a club member.
A short piece about the theory and its use could be of interest to those unfamiliar and also to include an important caveat at the end.
Ventricular Fibrillation (VF) is a state of unsynchronised contraction of the individual muscle fibres of the pumping chambers of the heart (ventricles) resulting in failure of the pump to maintain output of oxygenated blood to the body and most importantly, to the brain. Unconsciousness follows in a few seconds and irreversible changes in minutes. (Any club members who have Atrial Fibrillation, can be reassured that this is different in effects and seriousness…Phew!).
Heart muscle has the unique property that its fibres contract intrinsically and spontaneously without any external stimulation. In normal function, all the ventricular fibres contract synchronously, regulated in rate and force by nerves and hormones. Each fibre needs a resting period of milliseconds (refractory period) to recharge, before it can contract again.
When subject to the passage of electricity through heart muscle as happens on a cellular level during a heart attack or externally as in electrocution for example, the system is disturbed and the fibres lose their synchrony and the pump output fails.
The principal of defibrillation is to pass a suitably powerful shock through the heart to “fire” all the fibres simultaneously, synchronise their refractory periods so that when they resume contracting, they are all in phase.
Modern portable defibrillators are “intelligent”. When applied to the subject they will diagnose VF, avoiding inappropriate (and dangerous) use and direct the untrained operator with a flow diagram and verbal commands. They are self checking as regards battery state and serviceability.
Ours will be located in the clubhouse hallway and I understand that the emergency services will hold the locations of all defibrillators in the community.
It would seem sensible that despite the above, we might each familiarise ourselves with the equipment before being presented with a real event.
With accidents on and around the field, (not all accidents occur conveniently on the airfield), associated with flying activities and also the operation of motor vehicles, heavy machinery such as the winch, inflammable liquids, remember VF is not the problem.
Most serious trauma will involve internal or external bleeding, chest or head injury, fractures and lacerations with or without loss of consciousness, breathing problems and possibly burns.
Basic First Aid management is paramount.
Attention to airway, breathing, unconsciousness, blood loss and wounds are the most important tasks. (“BBC”..breathing, bleeding, consciousness)
It goes without saying that time and available manpower should not be wasted on obtaining the defibrillator in precedence to essential First Aid measures and calling the Emergency Services.