///2009 Abstract Details
2009 Abstract Details2019-08-03T15:55:31-06:00

Airway Misadventure Remains the Leading Cause of Anesthesia-related Maternal Death Reported by the Confidential Enquiry into Maternal and Child Health in the United Kingdom

Abstract Number: 158
Abstract Type: Original Research

Mhyre M Jill MD1 ; Mary Lou VH Greenfield MPH, MS2; Monica N Servin MD3


Anesthesia-related maternal death (ARMD) has been attributed to a variety of causes, including airway misadventure, neuraxial block complications, medication reactions, and problems with hemodynamic resuscitation. Increasing rates of population obesity may increase the risk of airway misadventure. We undertook a review of all deaths described by the Confidential Enquiry into Maternal Death and the Confidential Enquiry into Maternal and Child Health (CEMACH) in the United Kingdom (UK) for the years 1979-2005 to determine the proportion of deaths attributed to airway disasters, the timing of death relative to the anesthetic, and the proportion of deceased described as obese.


We compared all ARMDs, including late deaths, described in CEMACH reports for the years 1979-1990 with those for the years 1991-2005. One investigator developed a diagnostic coding sheet based on the CEMACH reports and other reviews of ARMDs. A second investigator applied the codes independently, and the Kappa statistic was used to measure initial agreement. Disagreements were resolved by discussion. Those with a complicated causal chain received both a primary cause and at least one secondary cause. Proportions between cohorts were compared using the Chi-square test or Fischers exact test as appropriate.


There were 79 total deaths. Across all 45 potential cause-of-death codes (including 23 specific airway disasters), two reviewers agreed on 61/79 primary causes (77%) before discussion, with a Kappa of 76% (95% CI 66, 85%). After discussion, agreement achieved 100%, and six cases received at least one secondary cause of death. See Table for results. There was 100% initial agreement with respect to obesity. The rate of obesity did not change (1979-1990 = 11/54, 20.4% versus 1991-2005 = 9/25, 36.0%, P=0.14).


Airway misadventure remains the leading cause of ARMD in the UK as reported by CEMACH, although other causes have become more common since 1991. With respect to the timing of airway disaster, there is a non-significant trend away from events on induction and towards events in the post-anesthesia care unit. Of all women who died, the proportion who were obese increased by an amount that was not statistically significant, but could be clinically important.

SOAP 2009