title: Patient injuries from anesthesia gas delivery equipment: a closed claims update.
abstract: BACKGROUND
  Improvements in anesthesia gas delivery equipment and provider training may increase patient safety. The authors analyzed patient injuries related to gas delivery equipment claims from the American Society of Anesthesiologists Closed Claims Project database over the decades from 1970s to the 2000s.
  
  
  METHODS
  After the Institutional Review Board approval, the authors reviewed the Closed Claims Project database of 9,806 total claims. Inclusion criteria were general anesthesia for surgical or obstetric anesthesia care (n = 6,022). Anesthesia gas delivery equipment was defined as any device used to convey gas to or from (but not involving) the airway management device. Claims related to anesthesia gas delivery equipment were compared between time periods by chi-square test, Fisher exact test, and Mann-Whitney U test.
  
  
  RESULTS
  Anesthesia gas delivery claims decreased over the decades (P < 0.001) to 1% of claims in the 2000s. Outcomes in claims from 1990 to 2011 (n = 40) were less severe, with a greater proportion of awareness (n = 9, 23%; P = 0.003) and pneumothorax (n = 7, 18%; P = 0.047). Severe injuries (death/permanent brain damage) occurred in supplemental oxygen supply events outside the operating room, breathing circuit events, or ventilator mishaps. The majority (85%) of claims involved provider error with (n = 7) or without (n = 27) equipment failure. Thirty-five percent of claims were judged as preventable by preanesthesia machine check.
  
  
  CONCLUSIONS
  Gas delivery equipment claims in the Closed Claims Project database decreased in 1990-2011 compared with earlier decades. Provider error contributed to severe injury, especially with inadequate alarms, improvised oxygen delivery systems, and misdiagnosis or treatment of breathing circuit events.
authors.affiliation: * Fellow, ‡ Research Professor, Department of Anesthesiology and Pain Medicine, University of Washington, Seattle, Washington. † Professor, Department of Anesthesiology, Icahn School of Medicine at Mount Sinai, New York, New York. § Professor, Departments of Anesthesiology and Pain Medicine, and Neurological Surgery (Adjunct), University of Washington.
authors.forename: Sonya P
authors.initials: SP
authors.lastname: Mehta
authors.forename: James B
authors.initials: JB
authors.lastname: Eisenkraft
authors.forename: Karen L
authors.initials: KL
authors.lastname: Posner
authors.forename: Karen B
authors.initials: KB
authors.lastname: Domino
mesh_terms: D000293:Adolescent; D000328:Adult; D000768:Anesthesia, General / Q000009:adverse effects / Q000295:instrumentation; D000769:Anesthesia, Inhalation / Q000009:adverse effects / Q000295:instrumentation*; D000773:Anesthesia, Obstetrical / Q000009:adverse effects / Q000295:instrumentation; D002648:Child; D016208:Databases, Factual / Q000331:legislation & jurisprudence / Q000706:statistics & numerical data; D004868:Equipment Failure / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D002534:Hypoxia, Brain / Q000209:etiology; D007345:Insurance Claim Review / Q000331:legislation & jurisprudence / Q000706:statistics & numerical data*; D016365:Liability, Legal; D008297:Male; D019300:Medical Errors / Q000009:adverse effects / Q000331:legislation & jurisprudence / Q000706:statistics & numerical data*; D008875:Middle Aged; D009873:Operating Rooms / Q000331:legislation & jurisprudence / Q000706:statistics & numerical data; D061214:Patient Safety / Q000331:legislation & jurisprudence* / Q000706:statistics & numerical data*; D011030:Pneumothorax / Q000209:etiology; D012720:Severity of Illness Index; D014481:United States