We all know, or should know, that if we suspect a diver is suffering from decompression sickness, that the immediate first aid response is to provide the diver with pure oxygen.
It is a globally recognised first aid in-the-field treatment, and it’s beneficial. Breathing oxygen may alleviate or even resolve DCS symptoms in a sick diver.
Unfortunately, it is quite possible that you may have a long wait for the rescue services, and the emergency oxygen cylinder can be emptied. Undoubtedly these days there will probably be divers in the vicinity with cylinders containing EANx rich (enriched air nitrox) mixes or oxygen. Whilst it is perfectly possible to ask a conscious diver in distress to breathe from a standard diving regulator, it is not an optimal solution. Their jaw can get tired, they may end up dribbling, and they could end up gagging on the mouthpiece. It is a more comfortable solution if the diver is able to breathe the oxygen via a non-rebreather mask c/w a reservoir bag, or an oronasal resuscitation mask (also known as a pocket mask).
So how do you access the gas in an alternative scuba cylinder, so that it can be delivered through a specialist oxygen regulator at a set flow rate, via one of these specialist masks? You use an adaptor and there are a number of the market.
The most recent one to hit our shelves is from AP Diving. The Cornish manufacturer has designed an adaptor with a standard 5/8” ‘male’ DIN at one end, and a medical oxygen pin index at the other end. This can be screwed into a scuba tank. The first aider can then attach a medical oxygen regulator into the PIN index pillar valve.
It should be noted that this adaptor should only be used in an emergency when the medical oxygen cylinder is not available or exhausted. AP Diving have confirmed that they have also made a M26 version of this adaptor.