Background: Neonatal patients are at higher risk in the perioperative period than older infants and children. Extubation as an early goal for noenatal intensive care unit patients presenting for surgery is undergoing a renaissance period, and an exploration of adverse events following selection for extubation immediately after general anesthesia has not specifically been undertaken in this population. Aims:The objective of this study is to determine the adverse events most commonly encountered in neonatal intensive care unit patients recovering from anesthesia in the post anesthesia care unit, quantify the risk of event occurrence, and identify risk factors that may increase the risk of postoperative adverse events. Methods: All neonatal intensive care unit patients presenting to the operating room 6/1/2014-5/31/2018 who recovered in the post anesthesia care unit were included for analysis. Univariate analyses were conducted utilizing the Wilcoxon ranksum test or Fisher exact test. Due to the low event rate, a small-sample generalized estimating equation model was created with a major event composite as the outcome and explanatory variables with P values < .1 on univariate analysis. Statistically significant continuous variables were then dichotomized based on Youden index.Results: There were 707 operative cases in 607 patients. There were 81 total events recorded, and 64/81 were considered to be major events; all of which were respiratory. The risk of any postoperative event was 11.5%, major respiratory event requiring intervention by a nurse or provider was 9.1%, and reintubation was 0.8%. Birth weight < 1.58 kg (OR 3.71; 95% CI 2.11-6.53; P < .001) and postmenstrual age at surgery <41 weeks (OR 3.20; 95% CI 1.54-6.63; P < .001) were strongly associated with an increased risk of a major postoperative respiratory event. Conclusion:The most important factors associated with major events in the post anesthesia care unit following extubation of neonatal intensive care unit patients were birth weight < 1.58 kg and postmenstrual age at surgery < 41 weeks. A patient with both features has a 7-fold increase in the odds of a major respiratory event in the post anesthesia care unit. Careful consideration of the postoperative ventilation and monitoring strategy must be given to patients with low birth weight (<1.58 kg) or who are <41 weeks postmenstrual age at the time of surgery. | 1187LONG et aL.

BACKGROUND: Pyloromyotomy is one of the most common surgical procedures performed on otherwise healthy infants. Pyloric stenosis results in a hypochloremic, hypokalemic metabolic alkalosis that is considered a medical emergency. This alkalotic state is believed to be associated with an increased incidence of apneic episodes. Because apnea tends to occur during anesthetic emergence, we sought to examine the association between the preoperative serum bicarbonate level and anesthetic emergence time after laparoscopic pyloromyotomy. METHODS: Data were collected from patients who underwent laparoscopic pyloromyotomies from April 2014 to October 2018. To estimate the correlation between preoperative bicarbonate level and emergence time while accounting for the positive skew of emergence time and potential confounding variables, a weighted quantile mixed regression was used. Due to a nonlinear association with emergence time, preoperative serum bicarbonate was split into 2 continuous intervals (<24 and ≥24 mEq/L) and the slope versus outcome was fit for each interval. RESULTS: A total of 529 patients who underwent laparoscopic pyloromyotomy were analyzed in this study. After controlling for confounders, the preoperative serum bicarbonate interval of ≥24 mEq/L was linearly associated with median emergence time (median increase of 0.81 minutes per 1 mEq/L increase of bicarbonate; 95% confidence interval [CI], 0.42–1.20; P < .001). Only 3 patients (0.6%) had apneic episodes after pyloromyotomy despite all having preoperative serum bicarbonate levels <29 mEq/L. CONCLUSIONS: Preoperative serum bicarbonate was positively associated with median anesthetic emergence time in a linear manner for values ≥24 mEq/L, although this correlation may not appear to be clinically substantial per 1 mEq/L unit. However, when preoperative serum bicarbonate levels were dichotomized at a commonly used presurgical threshold, the difference in median emergence time between ≥30 and <30 mEq/L was an estimated 5.4 minutes (95% CI, 3.1–7.8 minutes; P < .001).