First Aid
As in any occasion, basic life support comes first. Unconscious diver must be safely brought to land as soon as possible and then check for signs of life. Cardiopulmonary resuscitation should be initiated in the unfortunate occasion of a comatose unresponsive diver. This a very rare occasion though.
Pure Oxygen provision is very important and should be initiated when oxygen becomes available in any case with possible DCS. High flow through a face mask is used, covering the holes with adhesive tape. Oxygen is able to slow-down DCS progression, reduce or even eliminate symptoms. Its beneficial properties include increased oxygenation of injured tissues and edema reduction.
CAUTION: Even in the case of symptoms relief with the use of oxygen at surface, treatment in a decompression chamber may be necessary. Recurrence with persisting symptoms will require prolonged treatment. It is safe practice for any incident related with diving to communicate with respective staff of the decompression chamber, in order to establish contact and receive appropriate instructions regardless of the need of transfer or not.
Fluid replacement is another necessary regimen, and this may begin onsite. A conscious diver that doesn’t vomit is able to drink water. Drinking approximately 2 liters within 2 hours is an easy rule to follow. Fluid replacement is necessary because of dehydration caused both by DCS (if present) and diving itself. If the diver is transferred to a health center or nearby hospital, fluid replacement will be accomplished intravenously (placement of iv catheter). There, if needed, other supportive measures will include urinary catheterization, medications etc in coordination with respective Diving & Hyperbaric department.
Treatment in the decompression (hyperbaric) chamber – Recompression & Hyperbaric Oxygen Therap
Recompression & hyperbaric oxygen therapy is the treatment of choice for both DCS & AGE. Recompression reduces bubbles’ size and hyperbaric oxygen leads to elimination of inert gas, normalization of tissue oxygenation and reduction of tissue edema. Evacuation of the patient-diver to the nearest hyperbaric facility should be prompt, with no delay unless required for patient’s safety (in Greece, geographical characteristics implies that necessity-other cases should be carefully monitored and treated locally awaiting for air-transfer, while others should better be immediately evacuated by road). Emergency Services (EKAB) take all the above into account when arranging a sick diver’s transport (air transport with a pressurized cabin aircraft, or if a helo is available it will fly below 300 meters or 1000 feet, transport with continuous oxygen provision). If however, there is no advice available when facing a sick diver, transport to the nearest health center is a safe and good choice. On the other hand, placing a semi-conscious diver in a car to have a 3-hour trip to the nearest decompression chamber could be very risky and should be avoided. In any case, calling the department of hyperbaric & diving medicine is beneficial in order to resolve all such issues and get appropriate instructions. The diving buddy should also be prepared to provide some info concerning the diving profile, breathing mixture, repetitive dives, time of symptoms onset, change of symptoms, medical history, diving location and telephone number.
Treatment in the decompression (hyperbaric) chamber includes recompression and depending on the case and response, gradual pressure reduction until the “depth” where 100% oxygen breathing through a specifically designed mask begins (= hyperbaric oxygen). In some cases, hyperbaric oxygen is provided promptly after compression to the desired pressure, and duration and “depth” of treatment are largely individualized. Symptoms may not resolve after the initial treatment and it’s very common for the patient to undergo further hyperbaric oxygen sessions the following days. However, the usual result is resolution of disease and associated symptoms. Emergency DCS commonly necessitates admission for medications and monitoring, not forgetting that initially, other treatment modalities may be required (urinary catheter).