BACKGROUND: Preoperative anxiety is a significant stressor for children and is associated with negative postoperative outcomes. Although the incidence of difficult inductions during a single anesthetic encounter is well documented, the longitudinal trajectory of anxiety behaviors in children undergoing repeated anesthesia remains poorly characterized. It is unclear whether repeated inductions lead to habituation (reduced difficult inductions) or sensitization (increased difficult inductions). METHODS: We conducted a secondary analysis of a large multicenter retrospective observational study involving data from six pediatric hospitals between 2019 and 2022. The cohort consisted of children under 18 years of age. The primary outcome was the trajectory of difficult induction, defined as a Child Induction Behavioral Assessment (CIBA) score of 3. Secondary outcomes included mask acceptance and trends in anxiolytic interventions. We employed mixed effects logistic regression models to analyze anxiety trajectories, adjusting for age, parental presence, and behavioral diagnoses. Lorenz curves were used to assess the concentration of anesthetic burden within the population. RESULTS: The study included 102 017 unique patients, of whom 24 564 (24%) underwent multiple encounters. The prevalence of difficult induction remained stable during the initial visits but decreased significantly after the fifth encounter, with the odds of difficult induction decreasing by at least 30% compared to the index visit. This "learning effect" was setting-dependent: children aged 1-12 years undergoing Nonoperating room anesthesia (NORA) demonstrated significant habituation, whereas difficult induction rates in the operating room (OR) remained static regardless of visit frequency. Additionally, high-frequency utilizers in NORA settings exhibited a pragmatic shift in anxiolytic strategy, transitioning from pharmacological premedication to increased incidence of parental presence at induction of anesthesia. CONCLUSIONS: In this secondary analysis, we found that repeated anesthetic exposure did not inherently lead to sensitization. Instead, children-particularly in NORA settings-exhibited habituation, characterized by decreasing anxiety behaviors over time. This divergence suggests that the less hostile physical environment and absence of surgical pain in NORA facilitate desensitization, whereas the OR environment maintains a higher baseline threat level. Clinicians should consider these distinct trajectories and prioritize environmental adaptations or parental involvement for high-frequency patients.
Xin et al. (Wed,) studied this question.