Background: Emesis after pyloromyotomy for pyloric stenosis is a common clinical phenomenon and the limiting factor in time to goal feeds. The amount of emesis that can be expected after myotomy is unknown. No data have been published that equip caregivers with the ability to understand which patients are more likely to have emesis and take longer to advance to goal feeds after pyloromyotomy. Therefore, we performed analysis of prospective data obtained from a randomized trial to determine if outcome can be predicted from preoperative or intraoperative variables.
Methods: The dataset was prospectively collected from a randomized trial comparing open to laparoscopic pyloromyotomy in 200 patients. All patients had serum electrolytes and sonographic pyloric measurement recorded upon presentation. The postoperative feeding schedule and criteria for stopping feeds was controlled by a standard computer entry order set. In this study, we used Pearson's correlation to evaluate the influence of patient variables, presenting electrolytes, and intraoperative variables against 2 outcome variables (postoperative emesis and time to goal feeds). Significance is defined as a P <or= .01.
Results: In patient demographics, only weight on admission held a significant correlation to the number of episodes of postoperative emesis, which was an inverse correlation. Of the electrolytes on admission, chloride, potassium, and anion gap correlated significantly with number of emesis and time to goal feeds. There was an inverse correlation for potassium and chloride, whereas it was direct with anion gap. Significance was not detected in the correlation to outcomes for operative or sonographic variables.
Conclusions: The degree of hypochloremic, hypokalemic, metabolic alkalosis on presentation strongly correlates to the number of episodes of postoperative emesis and time to goal feeds in patients undergoing pyloromyotomy for pyloric stenosis. Furthermore, the corresponding duration of dehydration and failure to thrive appears to correlate with outcomes as there was a significant inverse correlation with weight on admission to the number of episodes of postoperative emesis and time to goal feeds.