title: Immersion pulmonary edema and comorbidities: case series and updated review.
abstract: OBJECTIVE
  Immersion pulmonary edema (IPE) occurs in swimmers (especially triathletes) and scuba divers. Its pathophysiology and risk factors are incompletely understood. This study was designed to establish the prevalence of preexisting comorbidities in individuals who experience IPE.
  
  
  METHODS
  From 2008 to May 2010, individuals who had experienced IPE were identified via recruitment for a physiological study. Past medical history and subject characteristics were compared with those available in the current body of literature.
  
  
  RESULTS
  At Duke University Medical Center, Durham, NC, 36 subjects were identified (mean age = 50.11 ± 10.8 yr), of whom 72.2% had one or more significant medical conditions at the time of IPE incident (e.g., hypertension, cardiac dysrhythmias or structural abnormality or dysfunction, asthma, diabetes mellitus, overweight or obesity, obstructive sleep apnea, hypothyroidism). Forty-five articles were included, containing 292 cases of IPE, of which 24.0% had identifiable cardiopulmonary risk factors. Within the recreational population, cases with identifiable risk factors comprised 44.9%. Mean age was 47.8 ± 11.3 yr in recreational divers/swimmers and 23.3 ± 6.4 yr in military divers/swimmers.
  
  
  CONCLUSIONS
  Cardiopulmonary disease may be a common predisposing factor in IPE in the recreational swimming/diving population, whereas pulmonary hypertension due to extreme exertion may be more important in military cases. Individuals with past history of IPE in our case series had a greater proportion of comorbidities compared to published cases. The role of underlying cardiopulmonary dysfunction may be underestimated, especially in older swimmers and divers. We conclude that an episode of IPE should prompt the evaluation of cardiac and pulmonary function.
authors.affiliation: 1Department of Anesthesiology, Center for Hyperbaric Medicine and Environmental Physiology, Duke University Medical Center, Durham, NC; 2Department of Medicine, Center for Hyperbaric Medicine and Environmental Physiology, Duke University Medical Center, Durham, NC.
authors.forename: Dionne F
authors.initials: DF
authors.lastname: Peacher
authors.forename: Stefanie D
authors.initials: SD
authors.lastname: Martina
authors.forename: Claire E
authors.initials: CE
authors.lastname: Otteni
authors.forename: Tracy E
authors.initials: TE
authors.lastname: Wester
authors.forename: Jennifer F
authors.initials: JF
authors.lastname: Potter
authors.forename: Richard Edward
authors.initials: RE
authors.lastname: Moon
mesh_terms: D000328:Adult; D000368:Aged; D015897:Comorbidity; D004242:Diving / Q000009:adverse effects*; D005260:Female; D006801:Humans; D007101:Immersion / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D011654:Pulmonary Edema / Q000209:etiology*; D012307:Risk Factors; D013550:Swimming