Emergence delirium or pain after anaesthesia--how to distinguish between the two in young children: a retrospective analysis of observational studies.

BACKGROUND Early postoperative negative behaviour in preschool children after general anaesthesia is a common problem. The distinction between emergence delirium (ED) and pain is difficult, but management differs between the two. The aim of the current analysis was to identify individual observational variables that can be used to diagnose ED and allow distinction from postoperative pain. METHODS This retrospective analysis of data from three previous prospective observational studies included children undergoing general anaesthesia for elective adeno-tonsillectomy, sub-umbilical surgery, and MRI scanning. Two trained observers simultaneously applied the Face, Legs, Activity, Cry, Consolability Scale; the Children's Hospital Eastern Ontario Pain Scale; the Children's and Infants' Postoperative Pain Scale or the Paediatric Anaesthesia Emergence Delirium (PAED) scale. Data from each domain of the scales were available at awakening and at five, 10, and 15 min after anaesthesia. Each patient was analysed over time, and subsequently, each evaluation was considered as a single event. The descriptive behaviour items overlapping in the assessed scales were identified as dichotomous variable ('true/false') and then were applied for each evaluation. RESULTS Children (n=512) were assessed for a total of 2048 evaluations. Most children (69%) displayed at least one episode of ED and/or pain. Almost 15% of children demonstrated both ED and pain. Children with ED showed 'no eye contact' and 'no awareness of surroundings'. Children with pain displayed 'abnormal facial expression', 'crying', and 'inconsolability'. CONCLUSIONS 'No eye contact' and 'no awareness of surroundings' identifies ED. 'Abnormal facial expression', 'crying', and 'inconsolability' indicate acute pain in children in the early postoperative period.