Abstract and Introduction
Background: Some studies have found surgery and anesthesia in children to be associated with neurodevelopmental deficits, but specific reasons for this association have not been fully explored. This study evaluates intraoperative mean arterial pressure (MAP) during a single ambulatory procedure in children and subsequent mental disorder diagnoses.
Methods: A retrospective observational study was performed including children ≥28 days and <18 years of age with intraoperative electronic anesthetic records between January 1, 2009, and April 30, 2017, at our institution. Eligible children were categorized based on their mean intraoperative MAP relative to other children of the same sex and similar age: category 1 (very low): children with mean intraoperative MAP values below the 10th percentile, category 2 (low): mean MAP value ≥10th and <25th percentiles, category 3 (reference): mean MAP value ≥25th and <75th percentiles, category 4 (high): mean MAP value ≥75th and <90th percentile, and category 5 (very high): mean MAP value ≥90th percentile. International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9) and ICD, Tenth Revision, Clinical Modification (ICD-10)-coded mental disorders were identified in hospital and outpatient claims, with a median duration of follow-up after surgery of 120 days (interquartile range [IQR], 8–774.5 days). Cox proportional hazards models evaluated the hazard ratio (HR) of time to first mental disorder diagnosis associated with intraoperative blood pressure category between the end of surgery and censoring, with the primary analysis adjusting for demographic, anesthetic, comorbidity, and procedure-type variables as potential confounders.
Results: A total of 14,724 eligible children who received general anesthesia for a single ambulatory surgical procedure were identified. After adjusting for all available potential confounders, when compared to the reference, there were no statistically significant differences in mental disorder diagnosis risk based on intraoperative mean MAP category. Compared to reference, children in the very low and low blood pressure categories reported HRs of 1.00 (95% confidence interval [CI], 0.74–1.35) and 1.10 (95% CI, 0.87–1.41) for a mental disorder diagnosis, respectively, and children in the high and very high categories reported HRs of 0.87 (95% CI, 0.68–1.12) and 0.76 (95% CI, 0.57–1.03), respectively.
Conclusions: Presence in a predefined mean intraoperative MAP category was not associated with subsequent mental disorder diagnoses within our follow-up period. However, the limitations of this study, including uncertainty regarding what constitutes an adequate blood pressure in children, may limit the ability to form definitive conclusions.
Millions of children undergo surgery and anesthesia each year.[1,2] In some clinical studies, surgery and anesthesia in children are associated with long-term problems in behavior and executive function, as well as mental disorders such as attention deficit hyperactivity disorder (ADHD).[3–8] However, there is controversy regarding whether these reported effects are due to the anesthesia, the underlying medical condition necessitating surgical treatment, or intraoperative physiological factors such as hypotension.[9,10] Varying degrees of hypotension are common during surgery and anesthesia, and it has been hypothesized that this intraoperative hypotension results in a mismatch of oxygen supply and demand causing end-organ ischemia. This concept has been evaluated in adults with the findings that hypotension has been associated with myocardial and kidney injuries[11–13] and even postoperative delirium. In children, extreme hypotension has also been found to be associated with neurological injuries in preterm infants. However, evaluating the effects of intraoperative hypotension on children is complex, as blood pressure in children varies based on age and sex, and what constitutes an adequate blood pressure, particularly under anesthesia, is not well defined. Reference ranges for intraoperative blood pressure have only recently been released, which show that blood pressures in anesthetized children undergoing surgery are significantly lower than normal awake measurements.
The goal of this study was to assess the association between intraoperative blood pressure and subsequent mental disorder diagnoses in children. The hypothesis was that in children with a single ambulatory procedure and no major underlying comorbidities, increased rates of mental disorder diagnoses would be found in children with the lowest intraoperative blood pressures.
Anesth Analg. 2022;135(4):787-797. © 2022 International Anesthesia Research Society