Root-cause analysis of an airway filter occlusion: A way to imrove the reliability of the repiratory circuit

BACKGROUND: To show how root-cause analysis can identify system-level factors causing critical incidents and accidents, we present an investigation of the occlusion of an airway filter during anaesthesia. METHOD: The investigation was based on a framework specifically developed for the analysis of medical accidents. This framework helped to identify the chronology and outcome of the case, the care management problems and the factors that led to the event. Information was obtained by interviewing the anaesthesiologist in charge of the patient. RESULTS: Occlusion was not recognized because the filter was hidden under the drapes and below the patient's head. To reduce the frequency of this event, we recommend that filters should be visible, placed above the level of the patient's body, or mounted on the expiratory circuit, at a distance from patient's airway. CONCLUSIONS: To allow appropriate corrective actions, critical incidents and accidents should be systematically investigated using root-cause analysis.