Preventable anesthesia mishaps: a study of human factors

Abstract

A modified critical-incident analysis technique was used in a retrospective examination of the characteristics of human error and equipment failure in anesthetic practice. The objective was to uncover patterns of frequently occurring incidents that are in need of careful prospective investigation. Forty seven interviews were conducted with staff and resident anesthesiologists at one urban teaching institution, and descriptions of 359 preventable incidents were obtained. Twenty three categories of details from these descriptions were subjected to computer-aided analysis for trends and patterns. Most of the preventable incidents involved human error (82%), with breathing-circuit disconnections, inadvertent changes in gas flow, and drug syringe errors being frequent problems. Overt equipment failures constituted only 14% of the total number of preventable incidents, but equipment design was indictable in many categories of human error, as were inadequate experience and insufficient familiarity with equipment or with the specific surgical procedure. Other factors frequently associated with incidents were inadequate communication among personnel, haste or lack of precaution, and distraction. Results from multi-hospital studies based on the methodology developed could be used for more objective determination of priorities and planning of specific investments for decreasing the risk associated with anesthesia.

Drug related critical incidents

“…Critical incident analysis was introduced to anaesthesia practice by Cooper et al [1] in 1978 and is now firmly established. This analysis can be used for auditing work practice, for correction of factors contributing to the incident and for identification of recurrent problems [2].…”

Toxicology in the Service of Patient and Medication Safety: a Selected Glance at Past and Present Innovations

“…While anesthesiologists comprised 3 % of the physician workforce and a similar percentage of overall malpractice claims, they accounted for 12 % of the medical liability insurance payouts [3]. Employing methodologies typically applied in aviation accident investigations [4], investigators determined that anesthesia mishaps were frequently a result of preventable human and technical factors [5]. Their results were striking.…”

“…BHard-wired^propor-tioning systems (also known as hypoxic guard systems) were engineered-for example, linking oxygen and nitrous oxide to preclude delivering anything less than 25 % oxygen during nitrous oxide administration. This was a significant improvement over previously inadequately designed solutions to this known problem such as a square, protruding oxygen control knob intended to provide tactile distinction from the nitrous knob; that solution had engendered its own low flow oxygen failures when adjacent objects disrupted the protuberant oxygen knob [5]. Vaporizer interlock devices (vaporizer exclusion systems) precluded more than one vaporizer from functioning at a time and inadvertent delivery of unintended mixtures.…”

Fatal errors in nitrous oxide delivery

“…Human errors account for the vast majority (82%) of adverse events during anaesthesia, with technical failure accounting for only 14% [18]. The human error of misconnecting oxygen pipelines with a nitrous oxidetank, which may not even be located in the anaesthesia machine or in the operating room itself, results in technical failure which may subsequently not be recognised due to a further human error.…”