DAN Medical Frequently Asked Questions

Oxygen to divers without symptoms

I am curious if DAN has a position on how to handle a diver that has surfaced with a decompression obligation i.e., has inadvertently omitted a decompression stop, but is asymptomatic for DCS? There seems to be no consistent recommendation on the correct procedure. US Navy recommend in-water recompression, The CMAS publication Scientific Diving: A General Code of Practice recommends observation unless symptomatic, NOAA recommends placing the diver on oxygen for 1/2 hour and then observing and evacuating if DCS symptoms develop. But if placing a potential DCS patient on oxygen may mask symptoms and delay treatment, would it not be better to observe and treat if they become symptomatic? It seems to me that once oxygen has been used the diver must be evacuated to an emergency facility for evaluation as a precaution.

The issue of oxygen administration in the situation you have described has prompted very spirited discussion among experts. There are very appropriate and valid arguments that can be made regarding any particular approach. In our experience at DAN there is no true “one-size-fits-all” solution. There are innumerable scenarios and events that do not provide a clear universal solution. Obviously in water recompression is not recommended as a viable plan outside of the military/commercial operations theater. The data available clearly supports the use of surface oxygen for symptomatic individuals. There is little to no data relevant to asymptomatic divers.

DAN encourages each dive operator, scientific group or organization to work with local medical authorities to develop their own specific policy. There are problems and advantages to either approach. Again based on our experience at DAN, neither the “wait and see” approach nor the “prophylactic oxygen” approach has been verified to alter any outcome. DAN is available for consultation to any group or organization that develops a policy. We can provide the contact information for local dive medicine experts to also assist in policy conception. If we can be any further assistance do not hesitate to contact DAN.