Along with DAN Asia-Pacific — which has trained more than 38,000 oxygen providers — diver certification agencies, first aid associations and lifesaving organisations offer oxygen first aid training.
After more than 30 years of teaching oxygen first aid and 22 years of fielding diving emergency calls, I’ve seen and heard about a broad range of errors made by oxygen providers; here I will highlight three of the most common.
ERROR 1: INADEQUATE EQUIPMENT
Every diver’s oxygen unit should include:
• a suitable and well-functioning demand valve that can provide a high concentration of oxygen to a breathing diver;
• a non-rebreather mask fitted with three oneway valves for use with a breathing diver;
• a resuscitation mask for rescue breathing during CPR;
• a supply of oxygen sufficient to last until a doctor trained in dive medicine advises that oxygen first aid should stop or until an alternative oxygen supply is available.
Unfortunately, inadequate and poorly maintained equipment is common, especially in remote locations. I’ve seen many units in the field that are in poor condition or are missing components.
ERROR 2: POOR CHOICE OR USE OF DELIVERY DEVICE
When faced with an emergency, the oxygen provider must choose the most appropriate delivery device for the circumstances.
It is generally taught that a demand valve is the device of first choice for use with a breathing diver, usually conscious but not necessarily so. The bottom line is that they need to be breathing strongly and slowly enough to open the demand valve effectively. These are very easy to use, familiar to divers and often relatively economical on oxygen gas. The best demand valves available are the medical valves and an oronasal mask needs to be attached to these to provide an interface and seal between the valve and the diver’s face.
While demand valves have the potential to deliver close to 100-percent oxygen to divers, the reality is that this efficiency relies on the mask seal, the demand valve’s service status and, to some extent, the diver’s position (which should be lying on the back rather than sitting, especially with the head down).
ERROR 3: STARTING OXYGEN FIRST AID TOO LATE AND/OR FINISHING TOO EARLY
Although we are seeing progress in how quickly providers administer oxygen, we still see many situations in which extended delays endanger divers who may have DCI. Generally, these delays have to do with the diver and/or the dive operator failing to recognise that the diver requires oxygen.
The next step is to call a diving accident hotline to get proper advice. Let a dive doctor or medic decide whether continued oxygen is necessary. Hotline operators have considerable experience with DCI treatment and will know more than the dive operator or diver.
A common mistake made at this point, especially if a dive doctor is not in the loop, is that oxygen first aid is stopped too soon. Too often, divers are given oxygen for periods of say 15 minutes to two hours. Sometimes the symptoms improve or completely disappear during this time and this gives an often false impression of safety.