Analgesia Nociception Index-Guided Remifentanil versus Standard Care during Propofol Anesthesia: A Randomized Controlled Trial

Abstract

The clinical benefits to be expected from intraoperative nociception monitors are currently under investigation. Among these devices, the Analgesia Nociception-Index (ANI) has shown promising results under sevoflurane anesthesia. Our study investigated ANI-guided remifentanil administration under propofol anesthesia. We hypothesized that ANI guidance would result in reduced remifentanil consumption compared with standard management. This prospective, randomized, controlled, single-blinded, bi-centric study included women undergoing elective gynecologic surgery under target-controlled infusion of propofol and remifentanil. Patients were randomly assigned to an ANI or Standard group. In the ANI group, remifentanil target concentration was adjusted by 0.5 ng mL−1 steps every 5 min according to the ANI value. In the Standard group, remifentanil was managed according to standard practice. Our primary objective was to compare remifentanil consumption between the groups. Our secondary objectives were to compare the quality of anesthesia, postoperative analgesia and the incidence of chronic pain. Eighty patients were included. Remifentanil consumption was lower in the ANI group: 4.4 (3.3; 5.7) vs. 5.8 (4.9; 7.1) µg kg−1 h−1 (difference = −1.4 (95% CI, −2.6 to −0.2), p = 0.0026). Propofol consumption was not different between the groups. Postoperative pain scores were low in both groups. There was no difference in morphine consumption 24 h after surgery. The proportion of patients reporting pain 3 months after surgery was 18.8% in the ANI group and 30.8% in the Standard group (difference = −12.0 (95% CI, −32.2 to 9.2)). ANI guidance resulted in lower remifentanil consumption compared with standard practice under propofol anesthesia. There was no difference in short- or long-term postoperative analgesia.

Monitoring of analgesia level during general anesthesia in children

“…The ANI interval recommended by the manufacturer for 'adequate analgesia' is 50-70. In adults, ANI guidance of intraoperative opioids has resulted in an intraoperative opioid-sparing effect [31,32], lower pain scores and reduced fentanyl consumption in the postanesthesia care unit [33].…”

Analgesia nociception index and high frequency variability index: promising indicators of relative parasympathetic tone

“…Several studies have adjusted the dose of remifentanil or fentanyl to maintain the ANI around 50–70 during general anesthesia, and they revealed that ANI-guided management can reduce intraoperative opioid consumption without deteriorating postoperative outcomes [ 36 – 40 ]. Sabourdin et al investigated ANI-guidance versus standard care in elective gynecologic surgery ( n = 80) under target-controlled infusion of propofol and remifentanil [ 37 ]. They showed that intraoperative remifentanil consumption was lower in the ANI-guided group [4.4 vs 5.8 µg/kg/h, difference of −1.4; 95% confidence interval (95% CI) −2.6 to −0.2, p = 0.0026] with no difference in postoperative morphine consumption.…”

“…Regarding the potential of ANI, Anderson et al described that ANI-based analgesia has the potential to be good for individualized titration of anesthesia management [ 63 ], and trials of ANI-based goal-directed analgesia are currently underway [ 64 ]. If ANI/HFVI studies are accumulated and their validity is confirmed, ANI-based administration may be realized [ 37 ]. A machine learning-based method combining ANI and hemodynamic monitoring has already been investigated with continuous administration of remifentanil [ 65 ].…”

Comparison of Single Target-Controlled Infusion Pump-Delivered Mixed Propofol and Remifentanil with Two Target-Controlled Infusion Pumps-Delivered Propofol and Remifentanil in Patients Undergoing Breast Cancer Surgery—A Prospective Study

“…The analgesia nociception index (ANI) is an index that measures the high-frequency component of heart-rate variability (parasympathetic component of the autonomic response) using the electrocardiogram signal as an input on a scale from 0 (maximum of nociception) to 100 (complete analgesia) [23][24][25][26]. Based on the published studies [23][24][25][26], an ANI of between 50 and 70 may correspond to adequate antinociception. Gruenewald et al reported that ANI enabled consistent reflection of stimulation during propofol-remifentanil anesthesia [23].…”

“…In breast cancer patients under GA, use of ANI monitoring can help optimize opioid consumption and provide data about nociception/antinociception intraoperatively [25]. Recently, in a randomized controlled trial, Sabourdin et al demonstrated that ANI guidance resulted in lower remifentanil consumption compared with standard practice under propofol and remifentanil anesthesia [26]. In previous clinical studies of RP mixtures, their monitors only included the hemodynamic monitors and sometimes a bispectral index (BIS) monitor, and there was no ANI monitor.…”