Unplanned incidents during comprehensive anesthesia simulation.

In analyzing recordings of first- and second-year residents performing anesthesia in a comprehensive anesthesia simulation environment (CASE 1.2), we noted the occurrence of unplanned incidents. Utilizing a modified critical incident technique, we documented 132 unplanned incidents during 19 simulations (range 3-14, mean 6-947). Ninety-six (73%) of the incidents were considered simple incidents, and 36 (27%) were considered critical incidents. The incidents were classified as either human errors (65.9%), equipment failures (3%), fixation errors (20.5%), or unknown causes (10.6%). Human errors accounted for 87 of the incidents (range 1-12, mean 4.579), fixation errors accounted for 27 of the incidents (range 0-3, mean 1.421), and equipment failures accounted for only four of the incidents (range 0-2, mean 0.211). There was a significant (P less than 0.025) difference overall between resident groups, although no one class differed significantly from the others. The data confirm that most incidents are due to human error rather than equipment failure, and document fixation errors as a frequent cause of incidents in anesthesia. The data indicate that although most incidents are simple and do not progress into more serious incidents, human error remains ubiquitous, and that formal training and education should include recognition of events and the responses to them, in addition to prevention.