In a report on diving fatalities in Australia during 2009, Lippmann and colleagues identified 12 cases among breath-hold (BH) and nine cases among scuba divers (SD). Cardiovascular disease was the apparent disabling condition in 3 BH and 3 SD fatalities, and possibly in 4 more BH and 3 SD fatality cases.
In comparison to the period 1977 – 2005 when 18% of deaths were caused by apparent cardiovascular diseases, the proportion in 2009 is much higher and more in-line with what DAN America reported for the period 1992-2003. Authors assume that this is probably due to the increased participation of older divers, which makes the current population of divers in Australia closer in age to the population of recreational divers in the United States. In this series, the age range of the victims who likely died of cardiac cause was 50 to 63 years. Seven out of 12 BH fatalities and four out of nine SC were older than 50 years.
Other causes of disabling conditions in BH were apneic hypoxia (3) and aspiration (2), while in SC fatalities there were two cases of seizures and two of probable cerebral arterial gas embolism (CAGE). Being over-weighted and failure to establish positive buoyancy needed to surface contributed to three deaths.
Besides the cardiac disease that may not be diagnosed previously, many victims may not have been physically fit for diving. Many were overweight and in one case the victim was extremely obese. A medical statement is not mandatory for snorkeling; however, this snorkel operator required a medical statement, but the extremely obese victim failed to declare various medical conditions (asthma, hypertension, arrhythmia and depression) and the medications she was taking. She died quietly, at the surface, a few meters from the boat. The autopsy did not document any apparent cause. While the authors justifiably suggest that in the case of an unfit customer who insists on snorkeling she could be assigned a personal guide, in this particular case even that may not have prevented the fatal outcome.
In some cases victims knew that they had conditions which may turn fatal in diving (seizures, poor physical fitness) but failed to report them. However, most victims who died of cardiac causes in this series were apparently healthy. Age itself is not a disease, but it is associated with increasing incidence of coronary artery disease, which may remain asymptomatic for a long time. The discussion of who should undergo additional medical testing and how often is ongoing with no satisfactory answer in sight.
This paper provides detailed accounts of each accident with an extensive expert comment and thus it makes a worthy read for all divers.
Resource
Lippmann J, Lawrence C, Fock Andrew, Wodal T, Jamieson S. Provisional report on diving-related fatalities in Australian waters 2009. Diving and Hyperbaric Medicine. 2013. December; 43(4):194-217.