Does the Risk Scale Predict Emergence Agitation in Children?
The authors included several other factors in their risk development for ED. They identified “operative procedures” as a risk factor for ED.1 However, the only mechanism by which surgery could contribute to ED is if it causes pain (eg, adenotonsillectomy). Surgery in the absence of sevoflurane does not cause ED; otherwise surgery during propofol anesthesia would cause ED, which it does not. Although the authors cite studies in which certain surgeries were associated with ED, those studies also conflated pain and delirium. They also asserted that the duration of anesthesia was associated with the incidence of ED in children. A predominantly sevoflurane-based anesthetic introduces a 10%–30% risk of ED in children in the vulnerable age range, independent of the duration of anesthesia. There is no evidence that duration of anesthesia is associated with ED. Preoperative behavior has been correlated with ED in a previous study.4 However, those authors treated the PAED score as a continuous variable and identified a correlation between preoperative behavior and the PAED score, although scores <10 (or other cutoff values) hold no clinical significance or meaning. Indeed, preoperative behavior has never been confirmed as a predictor of ED. I submit that creating a risk scale for ED based to a large extent on factors that are not known to be associated with ED (eg, type of surgery, duration of anesthesia, preoperative behavior score and pain) may yield internally consistent results but holds no external validity or predictive value for the true risk of ED in children anesthetized with sevoflurane.