Immersion pulmonary edema: case reports from Oceania.

INTRODUCTION: We aimed to document identified cases of immersion pulmonary edema (IPE) in divers from Oceania (the Indo-Pacific region) from January 2002 to May 2018, inclusive. METHOD: Cases were identified using various sources, including searches of the Divers Alert Network Asia-Pacific (DAN AP) Fatality Database, published case reports, and interviews with survivors who had reported their incident to DAN AP. Where available, investigations, pathology and autopsy results were obtained. Only incidents diagnosed as IPE by diving physicians or pathologists with experience in the investigation of diving accidents were included. Individual case histories and outcomes, together with brief individual summaries of the associations and possible contributing factors were recorded. RESULTS: Thirty-one IPE incidents in divers from Oceania were documented. There were two surface snorkelers, 22 scuba air divers and seven nitrox divers which included three closed-circuit rebreathers (CCR). The mean (SD) age was 53 (12) years, 58% of victims were females, and the average dive profile was to a maximum depth of 19 meters of seawater for 25 minutes. Six victims (19%) had previous episodes of IPE. There were nine recorded fatalities. Cardiac anomalies dominated the associated or possible contributing factors. These included valvular disease in 29%, transient cardiomyopathies in 26% and dysrhythmias in 16%. CONCLUSIONS: Previously reported associations of IPE such as exertion, stress, cold exposure, negative inspiratory pressure, hypertension, overhydration, ascent or surfacing, tight wetsuit, aspiration and certain medications were identified. Cardiac conditions were frequent and included chronic disorders (valvular pathology, coronary artery disease) and transient disorders (dysrhythmias, transient myocardial dysfunction, takotsubo or stress cardiomyopathy). It is likely that the chronic cardiac disorders may have contributed to the IPE, whereas the transient cases could be either sequelae, contributors or coincidental to the IPE.

Immersion pulmonary edema: an analysis of 31 cases from Oceania.

AIM: To review incidents of immersion pulmonary edema (IPE) from Oceania, to determine the demographics, diving parameters, and comorbidities that may be related to this disorder. METHOD: Incidents of IPE, most of which were documented by Divers Alert Network Asia-Pacific (DAN AP) or reported in our medical literature, were analyzed. They included interviews with the survivors and a review of available medical records. Only incidents diagnosed as IPE by specialist diving physicians or pathologists with experience in the investigation of diving accidents were included. RESULTS: Thirty-one IPE incidents in divers from Oceania were documented. There were two surface snorkelers, 22 scuba air divers and seven nitrox divers, which included three closed-circuit rebreathers (CCR). The mean (SD) age was 53 (12) years, 58% of victims were females, and the average dive profile was to a maximum depth of 19 msw for 25 minutes. Six victims (19%) had previous episodes of IPE. There were nine recorded fatalities in this cohort. Medical comorbidities were recorded in 68%, with 42% being cardiac. The latter included valvular disease in 29%, transient cardiomyopathies in 26% and dysrhythmias in 16%. CONCLUSION: IPE was more likely in middle-aged females, in experienced divers, and during ascent or after surfacing. Commonly reported associations such as exertion, stress, cold exposure, negative inspiratory pressure, hypertension, overhydration, tight wetsuit, aspiration and certain medications were identified. This series supports the hypothesis that the elderly IPE subjects are likely to have comorbidities and be susceptible to IPE recurrences and fatalities unless the contributing factors can be identified and addressed.

The evolution of scuba divers pulmonary edema.

The evolution of scuba divers pulmonary edema is described. When discovered in 1981, it was believed to be a cold-induced response in a submerged, otherwise healthy, scuba diver. The clinical features are described and discussed, as are the demographics. An alleged prevalence of 1.1% was complicated by problematic statistics and an apparent increase in reported cases. Recurrences both while diving and swimming or snorkeling were common. More recent case reports and surveys are described, identifying predisposing factors and associations, including cardiac pathology. Stress cardiomyopathies, reversible myocardial disorder or Takotsubo cardiomyopathy, may complicate the presentation, especially in older females. Relevant cardiac investigations and autopsy findings are reviewed. Disease severity and potential lethality of scuba divers pulmonary edema became more apparent early this century, and these influence our current recommendations to survivors. First aid and treatment are also discussed.

Immersion pulmonary oedema and Takotsubo cardiomyopathy.

A 67-year-old female scuba diver developed a typical immersion pulmonary oedema (IPE), but investigations strongly indicated Takotsubo cardiomyopathy (TC). The cardiac abnormalities included increased cardiac enzymes, electrocardiographic anomalies and echocardiographic changes, all reverting to normal within days. This case demonstrates a similarity and association between IPE and TC, and the importance of prompt cardiac investigations both in the investigation of IPE and in making the diagnosis of TC.

Diving fatality investigations: recent changes.

Modifications to the investigation procedures in diving fatalities have been incorporated into the data acquisition by diving accident investigators. The most germane proposal for investigators assessing diving fatalities is to delay the drawing of conclusions until all relevant diving information is known. This includes: the accumulation and integration of the pathological data; the access to dive computer information; re-enactments of diving incidents; post-mortem CT scans and the interpretation of intravascular and tissue gas detected. These are all discussed, with reference to the established literature and recent publications.

Recent modifications to the investigation of diving related deaths.

The investigation of deaths that involve diving using a compressed breathing gas (SCUBA diving) is a specialized area of forensic pathology. Diving related deaths occur more frequently in certain jurisdictions, but any medical examiner or coroner's office may be faced with performing this type of investigation. In order to arrive at the correct conclusion regarding the cause and manner of death, forensic pathologists and investigators need to have a basic understanding of diving physiology, and should also utilize more recently developed technology and ancillary techniques. In the majority of diving related deaths, the cause of death is drowning, but this more often represents a final common pathway due to a water environment. The chain of events leading to the death is just as important to elucidate if similar deaths are to be minimized in the future. Re-enactment of accident scenarios, interrogation of dive computers, postmortem radiographic imaging, and slight alterations in autopsy technique may allow some of these diving related deaths to the better characterized. The amount and location of gas present in the body at the time of autopsy may be very meaningful or may simply represent a postmortem artifact. Medical examiners, coroners, and forensic investigators should consider employing select ancillary techniques to more thoroughly investigate the factors contributing a death associated with SCUBA diving.

A forensic diving medicine examination of a highly publicised scuba diving fatality.

A high-profile diving death occurred in 2003 at the site of the wreck of the SS Yongala off the Queensland coast. The victim's buddy, her husband, was accused of her murder and found guilty of manslaughter in an Australian court. A detailed analysis of all the evidence concerning this fatality suggests alternative medical reasons for her death. The value of decompression computers in determining the diving details and of CT scans in clarifying autopsy findings is demonstrated. The victim was medically, physically and psychologically unfit to undertake the fatal dive. She was inexperienced and inadequately supervised. She was over-weighted and exposed for the first time to difficult currents. The analysis of the dive demonstrates how important it is to consider the interaction of all factors and to not make deductions from individual items of information. It also highlights the importance of early liaison between expert divers, technicians, diving clinicians and pathologists, if inappropriate conclusions are to be avoided.

Scuba divers' pulmonary oedema: recurrences and fatalities.

Scuba divers' pulmonary oedema (SDPE) is an increasingly recognised disorder in divers. We report three fatal cases of SDPE, demonstrating its potential serious nature even in the absence of underlying cardiac disease demonstrable clinically or at autopsy. This, together with the frequency of recurrences, has implications on assessing fitness for subsequent diving, snorkelling and swimming. The differential diagnosis of this disorder is also considered, as is its possible inducement by salt water aspiration and its relationship to drowning.

Scuba divers' pulmonary oedema. A review.

The literature on scuba divers' pulmonary oedema (SDPE) is reviewed, especially in its relationship to other immersioninduced pulmonary oedemas. It is concluded that although the three forms induced by swimming, freediving and scuba diving have some features in common, there are significant differences in their demographics, causation and clinical management. The swimming-induced cases tend to be young and fit, but exposed to excessive exertion. The freedivers experience extreme breath-holding and barotraumatic influences. The scuba divers are an older group and may have preexisting or occult cardiovascular disease. Although the first-aid treatments may be similar, subsequent investigations and preventative measures will differ considerably.

Scuba divers' pulmonary oedema. A case report.

A case of presumed scuba divers' pulmonary oedema (SDPE) is presented. The symptomatology and clinical progress is typical and it illustrates some of the aetiological factors incriminated in this disease, as well as measures taken to avoid the disorder. Such factors include the effects of immersion, negative-pressure inspiration induced by vertical positioning in the water, resistance to breathing by the scuba regulator and advanced age. Dyspnoea may have been exacerbated by the respiratory restriction imposed by the diving equipment. Other aetiological factors not relevant to this case are mentioned, as is the possible differential diagnosis. An accompanying review article discusses SDPE in greater detail.