Development and psychometric evaluation of the pediatric anesthesia emergence delirium scale

Background: Emergence delirium has been investigated in several clinical trials. However, no reliable and valid rating scale exists to measure this phenomenon in children. Therefore, the authors developed and evaluated the Pediatric Anesthesia Emergence Delirium (PAED) scale to measure emergence delirium in children. Methods: A list of scale items that were statements describing the emergence behavior of children was compiled, and the items were evaluated for content validity and statistical significance. Items that satisfied these evaluations comprised the PAED scale. Each item was scored front 1 to 4 (with reverse scoring where applicable), and the scores were summed to obtain a total scale score. The degree of emergence delirium varied directly with the total score. Fifty children were enrolled to determine the reliability and validity of the PAED scale. Scale validity was evaluated using five hypotheses: The PAED scale scores correlate negatively with age and time to awakening and positively with clinical judgment scores and Post Hospital Behavior Questionnaire scores, and were greater after sevoflurane than after halothane. The sensitivity of the scale was also determined. Results: Five of 27 items that satisfied the content validity and statistical analysis became the PAED scale: (1) The child makes eye contact with the caregiver, (2) the child's actions are purposeful, (3) the child is aware of his/her surroundings, (4) the child is restless, and (5) the child is inconsolable. The internal consistency of the PAED scale was 0.89, and the reliability was 0.84 (95% confidence interval, 0.76-0.90). Three hypotheses supported the validity of the scale: The scores correlated negatively with age (r = - 0.31, P < 0.04) and time to awakening (r = -0.5, P < 0.001) and were greater after sevoflurane anesthesia than halothane (P < 0.008). The sensitivity was 0.64. Conclusions: These results support the reliability and validity of the PAED scale.