From Andrew Ferguson
The use of hyperbaric chambers as a humane method to render chickens unconscious before slaughter (9 November, p 14) brought to mind my flying training. A group of us were put into a decompression chamber to learn how to recognise the signs of hypoxia before we passed out.
We wore oxygen masks, and the operator cut off the oxygen to each person in turn, without saying who would be next. What we found was that the others in the group would notice the effect on the person whose oxygen was cut off – blue fingertips and loss of performance while writing – but the person deprived of oxygen was oblivious that this was happening and invariably lost consciousness.
Is there any better example of how humane the process is? Why is it not discussed as the method of choice for places where voluntary euthanasia is legal?
Henley-on-Thames, Oxfordshire, UK
