title: Iatrogenic cerebral gas embolism: analysis of the presentation, management and outcomes of patients referred to The Alfred Hospital Hyperbaric Unit.
abstract: BACKGROUND
  The aim of this study was to review patients with iatrogenic cerebral gas embolism (CGE) referred to The Alfred Hospital hyperbaric unit to determine whether hyperbaric oxygen treatment (HBOT) reduced morbidity and mortality.
  
  
  METHODS
  This is a retrospective cohort study with a contemporaneous comparison group of patients referred between January 1998 and December 2014. The primary end point was good neurological outcome at the time of discharge from hospital or rehabilitation facility as assessed by the Glasgow Outcome Scale (GOS-E).
  
  
  RESULTS
  Thirty-six patients were treated with HBOT for CGE and nine patients were diagnosed with CGE but did not receive HBOT. Thirty-two patients developed CGE from an arterial source and 13 from a venous source. The mean time from recognition of the event to institution of HBOT was 15 hours. Four of 45 patients (8.9%) died. Good neurological outcomes (defined as GOS-E 7 or 8) occurred in 27 patients and moderate disability in 13. The only independent factor that was associated with good neurological outcome was time to first HBOT (OR 0.94, 0.89-0.99; P = 0.05). Hemiplegia as the first presenting sign, however, was associated with poor outcome (OR 0.27, 0.06-1.08; P = 0.05). The source of embolus (arterial versus venous), hyperbaric treatment table used and patient age did not affect outcome.
  
  
  CONCLUSIONS
  Appropriate treatment of CGE with hyperbaric oxygen was found to be impeded by delays in diagnosis and subsequent transfer of patients. Better neurological outcome was associated with HBOT within eight hours of CGE.
authors.affiliation: Department of Intensive Care and Hyperbaric Medicine, The Alfred Hospital, Melbourne, Victoria, Australia.
authors.forename: Harriet
authors.initials: H
authors.lastname: Beevor
authors.affiliation: Department of Intensive Care and Hyperbaric Medicine, The Alfred Hospital, 55 Commercial Rd, Prahran, Victoria 3181 Australia, Phone: +61-(0)3-9076-2269, E-mail: G.Frawley@alfred.org.au.
authors.forename: Geoff
authors.initials: G
authors.lastname: Frawley
mesh_terms: D000328:Adult; D055592:Biophysical Phenomena / Q000502:physiology; D016009:Chi-Square Distribution; D004618:Embolism, Air / Q000209:etiology / Q000401:mortality / Q000628:therapy*; D005260:Female; D015600:Glasgow Coma Scale; D006801:Humans; D006931:Hyperbaric Oxygenation; D007049:Iatrogenic Disease; D020766:Intracranial Embolism / Q000209:etiology / Q000401:mortality / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D012044:Regression Analysis; D012189:Retrospective Studies; D013997:Time Factors
keywords: Cerebral arterial gas embolism (CAGE); clinical audit; hyperbaric oxygen therapy; outcome; venous gas embolism