Emergence delirium in adults in the post-anaesthesia care unit

Background. Emergence delirium in the post-anaesthesia careunit (PACU) is poorly understood. The goal of this prospectivestudy was to determine frequency and risk factors of emergencedelirium in adults after general anaesthesia. Methods. In this prospective study, 1359 consecutive patientswere included. Contextual risk factors and occurrence of deliriumaccording to the Riker sedation scale were documented. Groupswere defined for the analysis according to the occurrence ornot of agitation, then after exclusion of patients with preoperativeanxiety and neuroleptics, or both, and antidepressants or benzodiazepinestreatments. Results. Sixty-four (4.7%) patients developed delirium in thePACU, which can go from thrashing to violent behaviour and removalof tubes and catheters. Preoperative anxiety was not found tobe a risk factor. Preoperative medication by benzodiazepines(OR=1.910, 95% CI=1.101–3.315, P=0.021), breast surgery(OR=5.190, 95% CI=1.422–18.947, P=0.013), abdominal surgery(OR=3.206, 95% CI=1.262–8.143, P=0.014), and long durationof surgery increased the risk of delirium (OR=1.005, 95% CI=1.002–1.008,P=0.001), while a previous history of illness and long-termtreatment by antidepressants decreased the risk (respectively,OR=0.544, 95% CI=0.315–0.939, P=0.029 and OR=0.245, 95%CI=0.084–0.710, P=0.010). Conclusions. Preoperative benzodiazepines, breast and abdominalsurgery and surgery of long duration are risk factors for emergencedelirium.