When decompression sickness happens, the gas bubbles in blood and body tissue must be reduced as quickly as possible. This should not be achieved by in-water recompression - a further descent. Instead, the injured person must be put under pressure and treated -- ideally under medical supervision -- in a pressure chamber.
For treatment in a pressure chamber, the dive profiles of the last sequence of dives and a description of the decompression sickness symptoms are vital. If the casualty has to be transported via helicopter or plane, the maximum flying altitude must not exceed 300 metres, as otherwise an additional decompression would occur. The normal ascension times of the decompression table are not used for treatment in a pressure chamber. The pressure in the chamber and the type of gas used during treatment is determined by the symptoms of decompression sickness. Here, special treatment tables are used.
If we as divers detect symptoms of a decompression or lung pressure accident, we can help until the doctor arrives by administering pure oxygen. To repeat: the symptoms of decompression sickness include itching skin, aching joints, dizziness, and vomiting. Respiratory depression can be a symptom of a lung pressure accident. In both cases, the physician or the person responsible for the pressure chamber must be notified. Until help arrives, give 100% O2 with an oxygen mask if possible.
