The Newborn Infant Parasympathetic Evaluation (NIPE™) monitor predicts post-operative pain in children undergoing day-procedures: A prospective observational study

Does heart rate variability using the Newborn Infant Parasympathetic Evaluation index identify postsurgical pain levels and emergence delirium in toddlers? A prospective observational study

PURPOSE

Children recovering from anesthesia commonly experience early postoperative negative behaviour, caused by pain and emergence delirium. Differentiating the two is challenging in young children. Perioperative pain influences the heart rate variability-derived Newborn Infant Parasympathetic Evaluation (NIPE) index and may also affect emergence delirium. We sought to investigate whether the perioperative NIPE index can discriminate between mild, moderate, or severe pain levels and can detect emergence delirium.

METHODS

This prospective observational study enrolled children aged three years or younger undergoing elective adenotonsillectomy, tonsillectomy, or adenoidectomy. The NIPE index, the Faces, Legs, Activity, Cry, Consolability (FLACC) score, and the Pediatric Anesthesia Emergence Delirium (PAED) score were recorded in the postanesthesia care unit (PACU). The primary aim was to investigate the relationship between the postoperative NIPE index and postoperative pain severity. The secondary aims were to evaluate the association between the NIPE index and emergence delirium (PAED ≥ 10) and its delirium-specific (ED-I) and pain-specific (ED-II) components.

RESULTS

Sixty-nine children were recruited. In the PACU, the mean (standard deviation [SD]) NIPE values in children experiencing moderate and severe pain were 50 (12) and 49 (14), respectively. These values were significantly lower than the mean (SD) value of 64 (13) observed in children with mild pain (mean difference moderate vs no/mild pain, -14; 95% confidence interval [CI], -17 to -11; P < 0.001, and mean difference severe vs no/mild pain, -17; 95% CI, -20 to -14; P < 0.001, respectively). The NIPE index was significantly lower in children experiencing pain-specific ED-II (mean [SD] NIPE instantaneous [NIPEi] for ED-II 49 [10] vs no ED-II 55 [13]; mean difference, -6; 95% CI, -11 to -2; P = 0.009). The NIPE index was unable to detect emergence delirium (mean [SD] NIPEi for ED, 54 [15] vs no ED, 51 [10]; mean difference, 3; 95% CI, -2 to 8; P = 0.23) or the delirium-specific component ED-I (mean [SD] NIPEi for ED-I, 55 [15] vs no ED-I, 51 [11]; mean difference, 4; 95% CI, 0 to 8; P = 0.06).

CONCLUSION

The NIPE index can identify moderate and severe postoperative pain after adenotonsillectomy but not emergence delirium in children aged three years and younger. This discrimination can be valuable in the early postoperative phase when the differentiation between pain and emergence delirium is difficult.

STUDY REGISTRATION

ClinicalTrials.gov ( NCT04909060 ); first submitted 26 May 2021.

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 (NIPE™) Monitor

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.

Newborn and Infant Parasympathetic Evaluation (NIPE™) Monitor for Assessing Pain During Surgery and Interventional Procedures: A Systematic Review

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.

Dexmedetomidine: An Alternative to Pain Treatment in Neonatology

Infants might be exposed to pain during their admissions in the neonatal intensive care unit [NICU], both from their underlying conditions and several invasive procedures required during their stay. Considering the particularities of this population, recognition and adequate management of pain continues to be a challenge for neonatologists and investigators. Diverse therapies are available for treatment, including non-pharmacological pain management measures and pharmacological agents (sucrose, opioids, midazolam, acetaminophen, topical agents…) and research continues. In recent years one of the most promising drugs for analgesia has been dexmedetomidine, an alpha-2 adrenergic receptor agonist. It has shown a promising efficacy and safety profile as it produces anxiolysis, sedation and analgesia without respiratory depression. Moreover, studies have shown a neuroprotective role in animal models which could be beneficial to neonatal population, especially in preterm newborns. Side effects of this therapy are mainly cardiovascular, but in most studies published, those were not severe and did not require specific therapeutic measures for their resolution. The main objective of this article is to summarize the existing literature on neonatal pain management strategies available and review the efficacy of dexmedetomidine as a new therapy with increasing use in the NICU.