RESUMEN
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: 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. RESULTS: 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: 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.
RESUMEN
BACKGROUND: The heart rate variability-derived Newborn Infant Parasympathetic Evaluation (NIPE) monitor has been designed to be an objective, non-invasive tool for the assessment of pain and discomfort in children under 2 years of age. The aim of this systematic review was to evaluate the ability of NIPE to assess pain in neonates and infants during surgical and/or painful procedures. METHODS: A systematic review (2010-2023) was conducted using PRISMA guidelines. Studies containing children above 2-years-old were excluded. The ROBINS-I (Risk of Bias in Non-randomised Studies of Interventions) tool was used to assess the quality of included studies. RESULTS: 9 databases were searched identifying 470 articles, 460 did not meet the inclusion criteria and were excluded; therefore, 10 studies with 548 participants were included. NIPE was used to assess intraoperative and postoperative pain for surgery under general anaesthesia (5 studies), as well as acute and prolonged pain from other interventional procedures (5 studies). For surgery under general anaesthesia: NIPE has shown to detect nociceptive events (e.g., skin incision, intubation), insufficient analgesia intraoperatively and to predict early postoperative pain. For painful interventional procedures: NIPE has shown to detect acute pain with a high sensitivity and negative predictive value. CONCLUSION: NIPE has been used to assess pain in surgery and for various painful procedures. NIPE can detect intraoperative pain and reflect early postoperative pain. NIPE may be useful in evaluating procedural pain, however with heterogenous outcomes, more studies are required to confirm its efficacy. TYPE OF STUDY: Systematic Review. LEVEL OF EVIDENCE: Level II.