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).

Background Infants undergoing pyloromyotomy are at a high risk of aspiration, making rapid sequence induction the preferred method of induction. Since succinylcholine use in infants can be associated with complications, rocuronium is frequently substituted despite its prolonged duration of action. Aims To examine the likelihood of non‐reversibility to neostigmine at the end of surgery in laparoscopic pyloromyotomies and its correlation to both rocuronium dose and out of operating room time. Methods Patients who underwent laparoscopic pyloromyotomy for infantile hypertrophic pyloric stenosis, received rocuronium, and were reversed with neostigmine were included. Bayesian multivariable logistic regression was utilized to determine the probability of non‐reversibility, and Bayesian multivariable median regression was performed to ascertain the correlation between out of operating room time and non‐reversibility. Results 306 patients were analyzed with a median surgical duration of 19 min (interquartile range 16 to 23). 74% received succinylcholine for intubation followed by rocuronium, and the remaining received rocuronium alone. The median rocuronium dose was 0.41 mg/kg (interquartile range 0.27 – 0.56 mg/kg). Prolonged block occurred in 68 (22.2%) patients. There was a non‐trivial probability of prolonged block with low rocuronium doses, and each 0.1 mg/kg increase in total rocuronium dose was associated with an odds ratio of 1.36 (95% credible interval: 1.17–1.58) of neostigmine non‐reversibility at the end of surgery. Non‐reversibility was correlated with a substantial increase in median out of operating room time (13.4 min, 95% credible interval: 5.5–20.8 min), which was compounded by high rocuronium dosing (2.2 min increase per 0.1 mg/kg for doses greater than 0.5 mg/kg, 95% credible interval: 0.7–3.6 min). Conclusion Prolonged blockade can occur from rocuronium administration in infants undergoing pyloromyotomy even at low doses. Therefore, consideration of appropriate rocuronium dosing or the use of sugammadex should be considered.