An objective evaluation of intraoperative and postoperative pain in infants undergoing open inguinal herniotomy and laparoscopic inguinal hernia repair using the newborn infant parasympathetic evaluation (NIPETM) monitor.

Abstract

Purpose: The heart rate variability-derived Newborn Infant Parasympathetic Evaluation (NIPE) monitor is an objective, non-invasive tool for the assessment of pain in children under 2 years of age. The aim of this study was to objectively compare pain in infants undergoing open and laparoscopic inguinal hernia surgery using the NIPE monitor. Method(s): This prospective observational study included neonates and infants (<2 years of age) undergoing elective open inguinal herniotomy and laparoscopic inguinal hernia repair under general anaesthesia with a caudal block. The NIPE monitor was connected to the electrocardiogram monitor with continuous monitoring performed intraoperatively, and postoperatively in the Post Anaesthesia Care Unit. The NIPE index was recorded at different intraoperative steps. The median NIPE index (NIPEm) was calculated for the entire procedure and postoperative period. The NIPE index ranges from 0 to 100; lower values indicate greater levels of pain, values < 50 indicate severe pain. P values < 0.05 were considered significant. Result(s): There were 40 infants recruited: 27 underwent open herniotomy and 13 underwent laparoscopic repair. Intraoperatively, NIPEm was found to be significantly lower in the laparoscopic group (59.00 vs. 77.00, p = 0.0018). Postoperatively, NIPEm was also found to be significantly lower in the laparoscopic group (49.00 vs. 57.50, p = 0.0001). Conclusion(s): This is the first study to objectively demonstrate that laparoscopic inguinal hernia repair is more painful intraoperatively and leads to greater levels of pain in the early postoperative period compared to open inguinal herniotomy. This difference might explained by painful stimuli in anatomical areas not covered by the caudal block. Type of Study: Treatment Study/Prospective Study. Level of Evidence: Level II.Copyright © 2024 The Author(s)