Nociception Level Index-Guided Intraoperative Analgesia for Improved Postoperative Recovery: A Randomized Trial

Just another tool in their repertoire: uncovering insights into public and patient perspectives on clinicians' use of machine learning in perioperative care

OBJECTIVES

Successful implementation of machine learning-augmented clinical decision support systems (ML-CDSS) in perioperative care requires the prioritization of patient-centric approaches to ensure alignment with societal expectations. We assessed general public and surgical patient attitudes and perspectives on ML-CDSS use in perioperative care.

MATERIALS AND METHODS

A sequential explanatory study was conducted. Stage 1 collected public opinions through a survey. Stage 2 ascertained surgical patients' experiences and attitudes via focus groups and interviews.

RESULTS

For Stage 1, a total of 281 respondents' (140 males [49.8%]) data were considered. Among participants without ML awareness, males were almost three times more likely than females to report more acceptance (OR = 2.97; 95% CI, 1.36-6.49) and embrace (OR = 2.74; 95% CI, 1.23-6.09) of ML-CDSS use by perioperative teams. Males were almost twice as likely as females to report more acceptance across all perioperative phases with ORs ranging from 1.71 to 2.07. In Stage 2, insights from 10 surgical patients revealed unanimous agreement that ML-CDSS should primarily serve a supportive function. The pre- and post-operative phases were identified explicitly as forums where ML-CDSS can enhance care delivery. Patients requested for education on ML-CDSS's role in their care to be disseminated by surgeons across multiple platforms.

DISCUSSION AND CONCLUSION

The general public and surgical patients are receptive to ML-CDSS use throughout their perioperative care provided its role is auxiliary to perioperative teams. However, the integration of ML-CDSS into perioperative workflows presents unique challenges for healthcare settings. Insights from this study can inform strategies to support large-scale implementation and adoption of ML-CDSS by patients in all perioperative phases. Key strategies to promote the feasibility and acceptability of ML-CDSS include clinician-led discussions about ML-CDSS's role in perioperative care, established metrics to evaluate the clinical utility of ML-CDSS, and patient education.

Initial Validation of the NOL Nociception Level Index® Monitoring System in Black and Multiracial People

The NOL-Nociception Level Index® is a multiparameter index, based on artificial intelligence for the monitoring of nociception (physiological pain response) during anesthesia that has recently been authorized by the FDA. The monitor utilizes continuous streams of information from a finger probe comprising four sensors, including photoplethysmography, to provide a personalized nociception score on a scale of 0-100. Recent studies have suggested racial bias in pulse oximeter measurements due to the effect of melanin levels on photoplethysmography measurements. Therefore, there is a need to clinically validate new monitoring technologies in patients of all skin tones. The performance of the NOL scale in 8 patients that self-identified as Black or multiracial was compared to a database of 447 consented patients, assessing the response to surgical events at different levels of intensity. The descriptive, pilot data suggest that NOL performance in Black and multiracial patients is not different from the performance shown for the large database. Larger studies utilizing recognized skin tone scales to ensure accurate assessment of skin pigmentation are planned for the future.

Progress in the validation of nociception monitoring in guiding intraoperative analgesic therapy

PURPOSE OF REVIEW

This article summarizes the current level of validation for several nociception monitors using a categorized validation process to facilitate the comparison of performance.

RECENT FINDINGS

Nociception monitors improve the detection of a shift in the nociception and antinociception balance during anesthesia, guiding perioperative analgesic therapy. A clear overview and comparison of the validation process for these monitors is missing.

RESULTS

Within a 2-year time-frame, we identified validation studies for four monitors [analgesia nociception index (ANI), nociception level monitor (NOL), surgical pleth index (SPI), and pupillometry]. We categorized these studies in one out of six mandatory validation steps: developmental studies, clinical validation studies, pharmacological validation studies, clinical utility studies, outcome improvement studies and economical evaluation studies. The current level of validation for most monitors is mainly focused on the first three categories, whereas ANI, NOL, and SPI advanced most in the availability of clinical utility studies and provide confirmation of a clinical outcome improvement. Analysis of economical value for public health effects is not yet publicly available for the studied monitors.

SUMMARY

This review proposes a stepwise structure for validation of new monitoring technology, which facilitates comparison between the level of validation of different devices and identifies the need for future research questions.

Neuraxial Anesthesia for Combined Left Nephrectomy and Left Hemicolectomy in a One-Lung Patient

Monopulmonary patients undergoing major abdominal surgery represent a high-risk population. While general anesthesia is typically the standard approach, mechanical ventilation can cause significant complications, particularly in patients with pre-existing lung conditions. Tailored anesthesia strategies are essential to mitigate these risks and preserve respiratory function. We present the case of a 71-year-old female with a history of prior right pneumonectomy for lung cancer. She was scheduled for combined left nephrectomy and left hemicolectomy laparotomic surgery because of extended colon cancer. The patient was prepared according to the local Enhanced Recovery After Surgery (ERAS) protocol and underwent thoracic neuraxial anesthesia with sedation maintaining spontaneous breathing, so avoiding general anesthesia and mechanical ventilation. Anesthesia in the surgical field was effective, and no respiratory problems occurred intraoperatively. The patient's rapid recovery and early discharge underscore the success of our "tailored anesthesia strategy." Our experience highlights the feasibility and benefits of tailored anesthesia in monopulmonary patients undergoing major abdominal surgery. By avoiding general anesthesia and mechanical ventilation, we mitigated risks and optimized patient outcomes, emphasizing the importance of individualized approaches in high-risk surgical populations.

Effect of nociception level index-guided intra-operative analgesia on early postoperative pain and opioid consumption: a systematic review and meta-analysis

Acute postoperative pain remains a critical treatment priority and has prompted a search for technologies and techniques to assist with intra-operative analgesic monitoring and management. Anaesthetists traditionally rely on clinical judgement to guide intra-operative analgesia, but several emerging technologies such as the nociception level index herald the possibility of routine intra-operative analgesia monitoring. However, the impact of devices like nociception level index on postoperative outcomes has not been proven. We undertook a systematic review and meta-analysis of articles which compared nociception level index-guided analgesia to standard care. The primary outcomes were pain intensity and opioid consumption during the first 60-120 min after surgery. Secondary outcomes were the incidence of postoperative nausea and vomiting and duration of stay in the post-anaesthesia care unit. Ten studies, collectively including 662 patients and published between 2019 and 2023, met inclusion criteria for both the qualitative systematic review and quantitative meta-analysis. Risk of methodological bias was generally low or unclear, and six studies reported a significant conflict of interest relevant to their findings. Our meta-analysis was performed using a random-effects model. It found statistically significant benefits of nociception level index-guided analgesia for early postoperative pain (mean (95%CI) difference -0.46 (-0.88 to -0.03) on an 11-point scale, p = 0.03), and opioid requirement (mean (95%CI) difference -1.04 (-1.94 to -0.15) mg intravenous morphine equivalent, p = 0.02). Our meta-analysis of the current literature finds that nociception level index-guided analgesia statistically significantly reduces reported postoperative pain intensity and opioid consumption but fails to show clinically relevant outcomes. We found no evidence that nociception level index-guided analgesia affected postoperative nausea and vomiting nor duration of stay in the post-anaesthesia care unit.

[New Approaches in Perioperative Algesimetry]

The measurement of anaesthetic depth and muscle relaxation have been routine procedures during general anaesthesia for years. Quantification of intraoperative nociception, on the other hand, is still largely impossible. Various methods have been tested and commercialised for more than 10 years. However, a real breakthrough has not yet been achieved and the routine application of all methods available so far is not without problems. This article explains methodological similarities, but also points to specific aspects of various commercial solutions for perioperative algesimetry.

Generalizability of nociception level as a measure of intraoperative nociceptive stimulation: A retrospective analysis

BACKGROUND

Nociception-guided intraoperative opioid administration might help reduce postoperative pain. A commonly used and validated nociception monitor system is nociception level (NOL), which provides the nociception index, ranging from 0 to 100, with 0 representing no nociception and 100 representing extreme nociception. We tested the hypothesis that NOL responses are similar in men and women given remifentanil and fentanyl, across various types of anesthesia, as a function of American Society of Anesthesiologists physical status designations, and over a range of ages and body morphologies.

METHODS

We conducted a retrospective cohort analysis of trial data from eight prospective NOL validation studies. Among 522 noncardiac surgical patients enrolled in these studies, 447 were included in our analysis. We assessed NOL responses to various noxious and non-noxious stimuli.

RESULTS

The average NOL in response to 315 noxious stimuli was 47 ± 15 (95% CI = 45-49). The average NOL in response to 361 non-noxious stimuli was 10 ± 12 (95% CI = 9-11). NOL responses were similar in men and women, in patients given remifentanil and fentanyl, across various types of anesthesia, as a function of American Society of Anesthesiologists physical status designations, and over a range of ages and body morphologies.

CONCLUSION

Nociception level appears to provide accurate estimates of intraoperative nociception over a broad range of patients and anesthetic conditions.