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Adequacy of Preoperative Resuscitation in Laparoscopic Pyloromyotomy and Anesthetic Emergence
Laura E Gilbertson1, Christopher S Fiedorek, Michael C Fiedorek
1From the Department of Pediatric Anesthesiology, Children's Healthcare of Atlanta, Emory University, Atlanta, Georgia.
Insights
Higher preoperative serum bicarbonate levels in infants undergoing pyloromyotomy correlate with longer anesthetic emergence times. This finding is significant for managing metabolic alkalosis and potential respiratory complications during recovery.
Area of Science:
- Pediatric Surgery
- Anesthesiology
- Metabolic Disorders
Background:
- Pyloromyotomy is a common infant surgery for pyloric stenosis.
- Pyloric stenosis causes metabolic alkalosis, linked to increased apnea risk.
- Apnea often occurs during anesthetic emergence, prompting this study.
Purpose of the Study:
- To investigate the association between preoperative serum bicarbonate and anesthetic emergence time.
- To understand the impact of metabolic alkalosis on recovery after laparoscopic pyloromyotomy.
Main Methods:
- Analysis of 529 laparoscopic pyloromyotomies (April 2014-October 2018).
- Weighted quantile mixed regression used to model correlations.
- Serum bicarbonate levels analyzed as continuous intervals (<24 and ≥24 mEq/L) due to nonlinear association.
Main Results:
- Preoperative serum bicarbonate ≥24 mEq/L showed a linear association with increased median emergence time (0.81 min/mEq/L increase).
- A significant difference in median emergence time was observed between bicarbonate levels ≥30 mEq/L and <30 mEq/L (5.4 minutes).
- Apneic episodes were rare (0.6%) despite elevated bicarbonate levels in some patients.
Conclusions:
- Preoperative serum bicarbonate is positively associated with anesthetic emergence time in infants undergoing pyloromyotomy.
- While the per-unit increase may seem small, dichotomizing at a clinical threshold reveals a substantial difference in emergence time.
- Findings suggest careful consideration of preoperative metabolic alkalosis for optimizing anesthetic recovery.
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).
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