Scuba diving deaths: a review and approach for the pathologist.

A series of 34 cases of SCUBA-related fatalities in military personnel from the files of the Armed Forces Institute of Pathology has been presented. It may be concluded that the potential problems that can occur in the hyperbaric aquatic milieu while using scuba are not completely appreciated by pathologists. The resulting investigations of such fatalities give little hard data relevant to such entities as true incidence of barotraumatic injuries, aseptic bone necrosis, and contaminated air supply, the interrelationship of human, environmental, and life support system factors in such fatalities, and the pathophysiologic sequences leading to drowning or death due to causes other than drowning. Hyperbaric pathophysiology is reviewed with the hope that more reasonable interpretations of cause and mechanisms of death will be possible, and the entities air embolism and decompression sickness are differentiated in a similar light. The importance of the type of SCUBA is discussed, through analysis of ten operational diving fatalities, and the possibility of anoxia, hyperoxic convulsions, and hypercapnia existing with the use of rebreather SCUBA is emphasized. A general approach to the medical investigation of a SCUBA fatality is given, under broad headings including on-the-scene investigation, clothing and equipment examination, external and internal examinations, and toxicologic examination.