Assessing behaviour in children emerging from anaesthesia:: can we apply psychiatric diagnostic techniques?

Background: No standardized instrument exists for the systematic analysis of emergence behaviour in children after anaesthesia. Our purpose was to evaluate children's behaviour prior to anaesthetic induction and immediately upon emergence to develop an assessment tool using psychiatric terminology and techniques. Methods: This prospective study evaluated 25 children from 2 to 9 years of age for preanaesthetic psychosocial factors that might affect behaviour. Children's behaviour was observed from admission to the surgical unit through the induction of anaesthesia. All children received a standardized premedication and induction of anaesthesia. The maintenance anaesthetic was randomized to intravenous remifentanil or inhaled isoflurane. All children underwent repair of strabismus. We assessed the behaviour of children for 30 min upon emergence from anaesthesia for symptoms of pain, distress and delirium using an assessment tool we developed guided by the principles of psychiatry as described in Diagnostic and Statistical Manual of Mental Disorders (DSM-IV). Results: Using our assessment tool, 44% of children demonstrated altered behaviour on emergence; 20% demonstrated complex symptoms with characteristics of delirium. Children anaesthetized with isoflurane had significantly higher postanaesthesia behaviour assessment scores than those anaesthetized with remifentanil ( P = 0.04). Age was a significant variable; children < 62 months were more prone to altered behaviour than those > 62 months ( P = 0.02). Scores did not correlate with preanaesthetic risk factors including preexisting psychological or social variables or observed preanaesthetic distress. There was no delay in hospital discharge in children assessed as having altered behaviour. Conclusions: This exploratory study suggests that postanaesthetic behaviour abnormalities with characteristics of distress or delirium can be categorized using known DSM-IV terminology; in our cohort this behaviour was dependent on age and anaesthetic technique.