title: Risk factors for pulmonary barotrauma in divers.
abstract: OBJECTIVE
  Pulmonary barotrauma (PBT) of ascent is a feared complication in compressed air diving. Although certain respiratory conditions are thought to increase the risk of suffering PBT and thus should preclude diving, in most cases of PBT, risk factors are described as not being present. The purpose of our study was to evaluate factors that possibly cause PBT.
  
  
  METHODS
  We analyzed 15 consecutive cases of PBT with respect to dive factors, clinical and radiologic features, and lung function. They were compared with 15 cases of decompression sickness without PBT, which appeared in the same period.
  
  
  RESULTS
  Clinical features of PBT were arterial gas embolism (n=13), mediastinal emphysema (n=1), and pneumothorax (n=1). CT of the chest (performed in 12 cases) revealed subpleural emphysematous blebs in 5 cases that were not detected in preinjury and postinjury chest radiographs. A comparison of predive lung function between groups showed significantly lower midexpiratory flow rates at 50% and 25% of vital capacity in PBT patients (p<0.05 and p<0.02, respectively).
  
  
  CONCLUSIONS
  These results indicate that divers with preexisting small lung cysts and/or end-expiratory flow limitation may be at risk of PBT.
authors.affiliation: Department of Diving and Hyperbaric Medicine, Naval Medical Institute, Kiel, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Tetzlaff
authors.forename: M
authors.initials: M
authors.lastname: Reuter
authors.forename: B
authors.initials: B
authors.lastname: Leplow
authors.forename: M
authors.initials: M
authors.lastname: Heller
authors.forename: E
authors.initials: E
authors.lastname: Bettinghausen
mesh_terms: D000328:Adult; D001469:Barotrauma / Q000000981:diagnostic imaging / Q000209:etiology* / Q000503:physiopathology; D003560:Cysts / Q000150:complications; D003665:Decompression Sickness / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology; D004242:Diving / Q000293:injuries*; D004618:Embolism, Air / Q000209:etiology; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology; D005544:Forecasting; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging / Q000503:physiopathology; D008171:Lung Diseases / Q000150:complications; D055370:Lung Injury; D008297:Male; D008448:Maximal Expiratory Flow Rate / Q000502:physiology; D008450:Maximal Midexpiratory Flow Rate / Q000502:physiology; D008478:Mediastinal Emphysema / Q000209:etiology; D010994:Pleura / Q000000981:diagnostic imaging; D011030:Pneumothorax / Q000209:etiology; D011655:Pulmonary Embolism / Q000209:etiology; D012189:Retrospective Studies; D012307:Risk Factors; D014057:Tomography, X-Ray Computed; D014797:Vital Capacity / Q000502:physiology