Background
Emergence agitation (EA) is a common complication of general anaesthesia in children. Estimating the risk of EA in children is essential for developing a strategy for its prevention. However, reliable predictive methods have not been established. The aim of this study was to develop an EA risk score by performing a two-phase (development and validation phases) study.
Methods
The data from 120 children aged 1.5–8 years who were enrolled in our previous randomized controlled trial and who were anesthetized with sevoflurane was used for the development phase. By using logistic regression analysis with Akaike information criterion stepwise selection, we determined the best predictive model for EA. The scores of the selected predictors were determined using their odds ratio, and the EA risk score was calculated by summing them. In the validation phase, we prospectively enrolled 81 children aged 1.5–8 years scheduled to undergo general anaesthesia with sevoflurane. We assessed the incidence of EA using a PAED scale. We examined the predictive ability of the EA risk score by generating a receiver operating characteristic (ROC) curve for both development and validation phases. We calculated the area under the curve (AUC) of the ROC as well as the sensitivity and specificity at the best cut-off point.
Results
The EA risk score ranged 0–23 points and included factors such as age, preoperative behaviour score, surgical procedures, and anaesthesia time (Fig. 1A). In the development phase, the AUC was 0.84 (95% confidence interval (CI): 0.74-0.94) and the best cut-off point was 10 (sensitivity: 88%, specificity: 66%). In the validation phase, the AUC was 0.83 (95%CI: 0.73–0.94) and the best cut-off point was 10 (sensitivity: 93%, specificity: 69%) (Fig. 1B). The similar results between the different set of patients indicated the validity of the EA risk score.
Conclusion
We established and validated the EA risk score for children, with relatively high accuracy. We consider that the EA risk score is useful not only for predicting EA in clinical settings but also for stratifying the EA risk in future studies focused on patients with high (or low) risk of EA.

Establishment of a scoring system for predicting emergence agitation after general anaesthesia in children