Benefits of intraoperative analgesia guided by the Analgesia Nociception Index (ANI) in bariatric surgery: An unmatched case-control study

Effects of goal-directed analgesia using the analgesia nociception index in children undergoing surgery for moyamoya disease: A randomised controlled trial

BACKGROUND

The potential benefits of Analgesia Nociception Index guided intra-operative analgesia on intra-operative opioid consumption remains to be demonstrated in paediatric anaesthesia.

OBJECTIVES

This study aimed to explore the effects of Analgesia Nociception Index guided analgesia on sufentanil consumption during anaesthesia and postoperative pain scores in paediatric patients with moyamoya disease.

DESIGN

A prospective randomised controlled study.

SETTING

Seoul National University Children's Hospital, Seoul, Republic of Korea.

PATIENTS

A total of 40 children scheduled for encephaloduroarteriosynangiosis.

MAIN OUTCOME MEASURES

The primary outcome was total intra-operative sufentanil consumption, and the secondary outcomes included postoperative pain scores and incidence of opioid-related adverse events.

RESULTS

The Analgesia Nociception Index group showed lower intra-operative sufentanil consumption (in μg kg-1 h-1) compared with the Standard group (0.30 ± 0.12 and 0.39 ± 0.17, respectively; mean difference, -0.09; 95% confidence interval, -0.19 to 0.00; P = 0.049). Postoperatively, compared with the Standard group, the Analgesia Nociception Index group reported lower median pain scores at 18 and 24 h and maximum pain within 24 h (1 [0 to 2] vs. 3 [2 to 5]; P = 0.004, 1 [0 to 2] vs. 3 [1 to 4]; P = 0.041, and 4 [3 to 5] vs. 5 [4 to 7]; P = 0.045, respectively), with fewer patients experiencing nausea (3 [15%] vs. 10 [50%], P = 0.043).

CONCLUSION

The Analgesia Nociception Index guided analgesic protocol can reduce intra-operative sufentanil consumption and postoperative pain within 24 h with fewer nausea symptoms in paediatric patients with moyamoya disease who undergo encephaloduroarteriosynangiosis.

TRIAL REGISTRATION NUMBER

NCT05672212 (registered at clinicaltrials, principal investigator: K.E.H., registration date: 2 January 2023).

Current perioperative nociception monitoring and potential directions

Perioperative nociception-antinociception balance is essential for the prevention of adverse postoperative events. Estimating the nociception level helps optimize intraoperative management. In the past two decades, various nociception monitoring devices have been developed for the identification of intraoperative nociception. However, each type of nociception monitoring device has advantages and disadvantages, limiting their clinical application in particular patients and settings. Therefore, this review aimed to summarize the information on nociceptor monitoring in current clinical settings, explore each technique's particularities, and possible future directions to provide a reference for clinicians and researchers.

Pain Assessment Using the Analgesia Nociception Index (ANI) in Patients Undergoing General Anesthesia: A Systematic Review and Meta-Analysis

The analgesia nociception index (ANI) has emerged as a potential measurement for objective pain assessment during general anesthesia. This systematic review and meta-analysis aimed to evaluate the accuracy and effectiveness of ANI in assessing intra- and post-operative pain in patients undergoing general anesthesia. We conducted a comprehensive search of Ovid-MEDLINE, Ovid-EMBASE, Cochrane Central Register of Controlled Trials, Google Scholar, public clinical trial databases (ClinicalTrials and Clinical Research Information Service), and OpenSIGLE to identify relevant studies published prior to May 2023 and included studies that evaluated the accuracy and effectiveness of ANI for intra- or post-operative pain assessment during general anesthesia. Among the 962 studies identified, 30 met the eligibility criteria and were included in the systematic review, and 17 were included in the meta-analysis. For predicting intra-operative pain, pooled sensitivity, specificity, diagnostic odds ratio (DOR), and area under curve of ANI were 0.81 (95% confidence interval [CI] = 0.79-0.83; I2 = 68.2%), 0.93 (95% CI = 0.92-0.93; I2 = 99.8%), 2.32 (95% CI = 1.33-3.30; I2 = 61.7%), and 0.77 (95% CI = 0.76-0.78; I2 = 87.4%), respectively. ANI values and changes in intra-operative hemodynamic variables showed statistically significant correlations. For predicting post-operative pain, pooled sensitivity, specificity, and DOR of ANI were 0.90 (95% CI = 0.87-0.93; I2 = 58.7%), 0.51 (95% CI = 0.49-0.52; I2 = 99.9%), and 3.38 (95% CI = 2.87-3.88; I2 = 81.2%), respectively. ANI monitoring in patients undergoing surgery under general anesthesia is a valuable measurement for predicting intra- and post-operative pain. It reduces the use of intra-operative opioids and aids in pain management throughout the perioperative period.

The validity and applications of the analgesia nociception index: a narrative review

Pain refers to the subjective, unpleasant experience that is related to illness or injury. In contrast to pain, nociception refers to the physiological neural processing of noxious stimuli, such as intra-operative surgical stimuli. One novel device, the Analgesia Nociception Index (ANI), aims to objectively measure intra-operative nociception by analyzing the heart rate variability in patients undergoing surgery. Through this method of nociceptive monitoring, the ANI device aims to provide an objective, continuous evaluation of patient comfort levels and allow anesthesiologists to better manage surgical stress and patient analgesia, perhaps with even better efficacy than current practices used to assess nociception. Additionally, ANI may have clinical application in settings outside of the operating room, such as in the intensive care unit. In this narrative review, we compiled and summarized the findings of many studies that have investigated ANI's validity and applications in different clinical settings. Currently, the literature appears mostly supportive of ANI's ability to detect nociception in both surgical and non-surgical settings. However, the ability for ANI to provide clinical benefits, such as decreased intra-operative opioid use, post-operative opioid use, and post-operative pain compared to standard practices appear controversial. Because of the wide variety of methodology, clinical settings, patient populations, and limitations in these studies, more investigation of ANI is needed before any firm conclusions can be drawn on its clinical benefits.

Effect of analgesia nociception index monitor-based nociception control on perioperative stress responses during laparoscopic surgery in Trendelenburg position: a randomized controlled trial

Introduction

The analgesia nociception index (ANI) monitor is a nociception monitoring device based on heart rate variability. We aimed to determine the effect of ANI monitor-based intraoperative nociception control on the perioperative stress response during laparoscopic surgery in the Trendelenburg position.

Methods

Altogether, 72 female patients who underwent total laparoscopic hysterectomy were randomized to either the control or ANI group. Intraoperative nociception was controlled by remifentanil administration in a conventional manner (based on blood pressure and heart rate) in the control group and by ANI monitoring in the ANI group. Perioperative stress responses were estimated by measuring the levels of serum catecholamines and catabolic stress hormones at three timepoints: after loss of consciousness, at the end of surgery, and 1 h after the end of surgery.

Results

The serum cortisol level at the end of surgery was significantly higher in the ANI group than in the control group (p < 0.001), although more remifentanil was administered in the ANI group than in the control group (p < 0.001). Changes in the other estimators' levels were comparable between groups during the perioperative period. The hemodynamic profiles during surgery were also significantly different between the two groups. Phenylephrine use to treat hypotension was more common in the ANI group than in the control group (p = 0.005). However, postoperative clinical outcomes such as pain and nausea/vomiting did not differ between groups.

Conclusion

ANI monitor-based nociception control in laparoscopic surgery in the Trendelenburg position did not improve perioperative stress responses, intraoperative opioid consumption, or postoperative clinical outcomes.Clinical trial registration: ClinicalTrials.gov (NCT04343638).

A randomised controlled trial of the analgesia nociception index for intra-operative remifentanil dose and pain after gynaecological laparotomy

We aimed to investigate the effect of the analgesia nociception index on postoperative pain. We randomly allocated 170 women scheduled for gynaecological laparotomy and analysed results from 159: in 80 women, remifentanil was infused to maintain analgesia nociception indices 50-70; and in 79 women, remifentanil was infused to maintain systolic blood pressure < 120% of baseline values. The primary outcome was the proportion of women with pain scores ≥ 5 (scale 0-10) within 40 min of admission to recovery. The proportion of women with pain scores ≥ 5 was 62/80 (78%) vs. 64/79 (81%), p = 0.73. Mean (SD) doses of fentanyl in recovery were 53.6 (26.9) μg vs. 54.8 (20.8) μg, p = 0.74. Intra-operative remifentanil doses were 0.124 (0.050) μg.kg-1 .min-1 vs. 0.129 (0.044) μg.kg-1 .min-1 , p = 0.55.

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

At present, there is no objective and absolute measure of nociception, although various monitoring techniques have been developed. One such technique is the Analgesia Nociception Index (ANI), which is calculated from heart rate variability that reflects the relative parasympathetic tone. ANI is expressed on a non-unit scale of 0-100 (100 indicates maximal relative parasympathetic tone). Several studies indicated that ANI-guided anesthesia may help reduce intraoperative opioid use. The usefulness of ANI in the intensive care unit (ICU) and during surgery has also been reported. However, some limitations of ANI have also been reported; for example, ANI is affected by emotions and some drugs. In 2022, a high frequency variability index (HFVI), which was renamed from ANI and uses the same algorithm as ANI, was commercialized; therefore, ANI/HFVI are currently in the spotlight. Unlike ANI, HFVI can be displayed along with other biometric information on the Root® monitor. ANI/HFVI monitoring may affect the prognosis of not only patients in the perioperative period but those in ICU, those who receive home medical care, or outpatients. In this article, we present an updated review on ANI that has been published in the last decade, introduce HFVI, and discuss the outlooks of ANI/HFVI.

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

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.

Current trends in anesthetic depth and antinociception monitoring: an international survey

Current trends in anesthetic depth (i.e., hypnosis) and antinociception monitoring are unclear. We thus aimed to determine contemporary perspectives on monitoring these components of anesthesia during general anesthesia. Participants received and responded anonymously to an internet-based international survey supported by the European Society of Anaesthesiology and Intensive Care. Comparisons, when applicable, were carried out using Chi² analysis or Fischer's exact test. A total of 564 respondents, predominantly from Europe (80.1%), participated. There was a strong participation from Belgium (11.5%). A majority (70.9%) of anesthetists considered hypnotic monitoring important on most occasions to always. In contrast, a majority (62.6%) never or only occasionally considered antinociception monitoring important. This difference in the perceived importance of anesthetic depth versus antinociception monitoring was significant (p < 0.0001). A majority of respondents (70.1%) believed that guiding hypnosis and antinociception using these monitors would improve patient care on most occasions to always. Nonetheless, a substantial number of participants were unsure if hypnotic (23%) or antinociception (32%) monitoring were recommended and there was a lack of knowledge (58%) of any published algorithms to titrate hypnotic and/or antinociceptive drugs based on the information provided by the monitors. In conclusion, current trends in European academic centers prioritize anesthesia depth over antinociception monitoring. Despite an agreement among respondents that applying strategies that optimize anesthetic depth and antinociception could improve outcome, there remains a lack of knowledge of appropriate algorithms. Future studies and recommendations should focus on clarifying goal-directed anesthetic strategies and determine their impact on perioperative patient outcome.

Available Instruments to Assess Pain in Infants

Pain assessment in newborns and infants is challenging for clinicians. Although behavioral and behavioral-physiological scales are validated pain assessment instruments, their use in this age group has significant limitations. In this review, we summarize the methods currently available for assessing pain in neonates and infants. It is possible that these pain detection methods are also useful for assessing the quality of anesthesia and analgosedation in these populations. Further research should be aimed at confirming the usefulness of these tools in infants and identifying additional pain assessment options for clinical practice.

[Nociception monitoring : Method for intraoperative opioid control?]

The intraoperative dosing of opioids is a challenge in routine anesthesia as the potential effects of intraoperative overdosing and underdosing are not completely understood. In recent years an increasing number of monitors were approved, which were developed for the detection of intraoperative nociception and therefore should enable a better control of opioid titration. The nociception monitoring devices use either continuous hemodynamic, galvanic or thermal biosignals reflecting the balance between parasympathetic and sympathetic activity, measure the pupil dilatation reflex or the nociceptive flexor reflex as a reflexive response to application of standardized nociceptive stimulation. This review article presents the currently available nociception monitors. Most of these monitoring devices detect nociceptive stimulations with higher sensitivity and specificity than changes in heart rate, blood pressure or sedation depth monitoring devices. There are only few studies on the effect of opioid titration guided by nociception monitoring and the possible postoperative benefits of these devices. All nociception monitoring techniques are subject to specific limitations either due to perioperative confounders (e.g. hypovolemia) or special accompanying medical conditions (e.g. muscle relaxation). There is an ongoing discussion about the clinical relevance of nociceptive stimulation in general anesthesia and the effect on patient outcome. Initial results for individual monitor systems show a reduction in opioid consumption and in postoperative pain level. Nevertheless, current evidence does not enable the routine use of nociception monitoring devices to be recommended as a clear beneficial effect on long-term outcome has not yet been proven.

Intraoperative Monitoring of the Obese Patient Undergoing Surgery: A Narrative Review

With the increasing prevalence of obesity in the population, anaesthetists must confidently manage both the pathophysiological and technical challenges presented in bariatric and non-bariatric surgery. The intraoperative period represents an important opportunity to optimise and mitigate risk. However, there is little formal guidance on what intraoperative monitoring techniques should be used in this population. This narrative review collates the existing evidence for intraoperative monitoring devices in the obese patients. Although a number of non-invasive blood pressure monitors have been tested, an invasive arterial line remains the most reliable monitor if accurate, continuous monitoring is required. Goal-directed fluid therapy is recommended by clinical practice guidelines, but the methods tested to assess this had guarded applicability to the obese population. Transcutaneous carbon dioxide (CO₂) monitoring may offer additional benefit to standard capnography in this population. Individually titrated positive end expiratory pressure (PEEP) and recruitment manoeuvres improved intraoperative mechanics but yielded no benefit in the immediate postoperative period. Depth of anaesthesia monitoring appears to be beneficial in the perioperative period regarding recovery times and complications. Objective confirmation of reversal of neuromuscular blockade continues to be a central tenet of anaesthesia practice, particularly relevant to this group who have been characterised as an "at risk" extubation group. Where deep neuromuscular blockade is used, continuous neuromuscular blockade is suggested. Both obesity and the intraoperative context represent somewhat unstable search terms, as the clinical implications of the obesity phenotype are not uniform, and the type and urgency of surgery have significant impact on the intraoperative setting. This renders the generation of summary conclusions around what intraoperative monitoring techniques are suitable in this population highly challenging.

Analgesia nociception index for early detection of vagal stimulation during carotid body tumor resection: A case report

ANI can be used for early detection of parasympathetic signals before the occurrence of bradycardia or to locate unidentified carotid structures in the head and neck region.

Effect of Laryngeal Mask Airway Insertion on Parameters Derived From Catacrotic Phase of Photoplethysmography Under Different Concentrations of Remifentanil

BACKGROUND

Some parameters have been extracted from photoplethysmography (PPG) with a good relativity with nociception, but without encouraging results in qualifying the balance of nociception-anti-nociception (NAN). The features of PPG have not been thoroughly depicted and more prospective univariate parameters deserve to be explored. The aim of this study was to investigate the ability of parameters derived from catacrotic phase of PPG to grade the level of analgesia.

METHODS

45 patients with ASA I or II were randomized to receive a remifentanil effect-compartment target controlled infusion (Ceremi) of 0, 1, or 3 ng/ml, and a propofol effect-compartment target controlled infusion to maintain an acceptable level of hypnosis with state entropy (SE) at 40~60. Laryngeal mask airway (LMA) insertion was applied as a noxious stimulus. Five diastole-related parameters, namely diastolic interval (DI), diastolic slope (DS), the minimum slope during catacrotic phase (DSmin), the interval between DSmin and its nearest trough (DTI), and area difference ratio (ADR), were extracted. Pulse beat interval (PBI) was calculated as a reference parameter.

RESULTS

LMA insertion elicited a significant variation in all parameters except ADR during Ceremi of 0 and 1 ng/ml. Compared to PBI (prediction probability ([Formula: see text]) = 0.796), the parameters of DI, DS, and DTI presented a better consistence with the level of anti-nociceptive medication, with [Formula: see text] of 0.825, 0.822, and 0.822 respectively.

CONCLUSION

The features extracted from catacrotic phase of PPG, including DI, DS, and DTI, could provide a promising potential to qualify the balance of NAN.

Does nociception monitor-guided anesthesia affect opioid consumption? A systematic review of randomized controlled trials

Monitors that estimate nociception during anesthesia may be used to guide opioid and other analgesics administration to optimize anesthesia care and possibly outcome. We reviewed the literature to evaluate current evidence of the effect of nociception-guided management over standard anesthesia practice during surgery. A systematic review of the literature on the effect of nociception monitoring on anesthesia practice was conducted. Reports were eligible if they compared nociception-guided anesthesia to standard practice during surgery. Primary endpoint of this review is intraoperative opioid consumption. Secondary endpoints included hemodynamic control, postoperative pain and pain treatment. We identified 12 randomized controlled trials that compared one of five different nociception monitoring techniques to standard anesthesia care. Most studies were single center studies of small sample size. Six studies reported intraoperative opioid consumption as primary outcome. There was considerable variability with respect to surgical procedure and anesthesia technique. For nociception monitors that were investigated by more than one study, analysis of the pooled data was performed. The surgical plethysmographic index was the only monitor for which an intra operative opioid sparing effect was found. For the other monitors, either no effect was detected, or pooled analysis could not be performed due to paucity of study data. On secondary outcomes, no consistent effect of nociception-guided anesthesia could be established. Although some nociception monitors show promising results, no definitive conclusions regarding the effect of nociception monitoring on intraoperative opioid consumption or other anesthesia related outcome can be drawn.Clinical trial number PROSPERO ID 102913.

High-Frequency Heart Rate Variability Index: A Prospective, Observational Trial Assessing Utility as a Marker for the Balance Between Analgesia and Nociception Under General Anesthesia

BACKGROUND

Maintaining a balance between nociception and analgesia perioperatively reduces morbidity and improves outcomes. Current intraoperative analgesic strategies are based on subjective and nonspecific parameters. The high-frequency heart rate (HR) variability index is purported to assess the balance between nociception and analgesia in patients under general anesthesia. This prospective observational study investigated whether intraoperative changes in the high-frequency HR variability index correlate with clinically relevant nociceptive stimulation and the addition of analgesics.

METHODS

Instantaneous and mean high-frequency HR variability indexes were measured continuously in 79 adult subjects undergoing general anesthesia for laparoscopic cholecystectomy. The indexes were compared just before and 2 minutes after direct laryngoscopy, orogastric tube placement, first skin incision, and abdominal insufflation and just before and 6 minutes after the administration of IV hydromorphone.

RESULTS

Data from 65 subjects were included in the final analysis. The instantaneous index decreased after skin incision ([SEM], 58.7 [2.0] vs 47.5 [2.0]; P < .001) and abdominal insufflation (54.0 [2.0] vs 46.3 [2.0]; P = .002). There was no change in the instantaneous index after laryngoscopy (47.2 [2.2] vs 40.3 [2.3]; P = .026) and orogastric tube placement (49.8 [2.3] vs 45.4 [2.0]; P = .109). The instantaneous index increased after hydromorphone administration (58.2 [1.9] vs 64.8 [1.8]; P = .003).

CONCLUSIONS

In adult subjects under general anesthesia for laparoscopic cholecystectomy, changes in the high-frequency HR variability index reflect alterations in the balance between nociception and analgesia. This index might be used intraoperatively to titrate analgesia for individual patients. Further testing is necessary to determine whether the intraoperative use of the index affects patient outcomes.

Clinical Practice Guidelines for the Perioperative Nutrition, Metabolic, and Nonsurgical Support of Patients Undergoing Bariatric Procedures - 2019 Update: Cosponsored by American Association of Clinical Endocrinologists/American College of Endocrinology, The Obesity Society, American Society for Metabolic and Bariatric Surgery, Obesity Medicine Association, and American Society of Anesthesiologists

OBJECTIVE

The development of these updated clinical practice guidelines (CPGs) was commissioned by the American Association of Clinical Endocrinologists (AACE), The Obesity Society (TOS), American Society for Metabolic and Bariatric Surgery (ASMBS), Obesity Medicine Association (OMA), and American Society of Anesthesiologists (ASA) Boards of Directors in adherence with the AACE 2017 protocol for standardized production of CPGs, algorithms, and checklists.

METHODS

Each recommendation was evaluated and updated based on new evidence from 2013 to the present and subjective factors provided by experts.

RESULTS

New or updated topics in this CPG include: contextualization in an adiposity-based chronic disease complications-centric model, nuance-based and algorithm/checklist-assisted clinical decision-making about procedure selection, novel bariatric procedures, enhanced recovery after bariatric surgery protocols, and logistical concerns (including cost factors) in the current health care arena. There are 85 numbered recommendations that have updated supporting evidence, of which 61 are revised and 12 are new. Noting that there can be multiple recommendation statements within a single numbered recommendation, there are 31 (13%) Grade A, 42 (17%) Grade B, 72 (29%) Grade C, and 101 (41%) Grade D recommendations. There are 858 citations, of which 81 (9.4%) are evidence level (EL) 1 (highest), 562 (65.5%) are EL 2, 72 (8.4%) are EL 3, and 143 (16.7%) are EL 4 (lowest).

CONCLUSIONS

Bariatric procedures remain a safe and effective intervention for higher-risk patients with obesity. Clinical decision-making should be evidence based within the context of a chronic disease. A team approach to perioperative care is mandatory, with special attention to nutritional and metabolic issues.

Machine learning based method for the evaluation of the Analgesia Nociception Index in the assessment of general anesthesia

Measuring the level of analgesia to adapt the opioids infusion during anesthesia to the real needs of the patient is still a challenge. This is a consequence of the absence of a specific measure capable of quantifying the nociception level of the patients. Unlike existing proposals, this paper aims to evaluate the suitability of the Analgesia Nociception Index (ANI) as a guidance variable to replicate the decisions made by the experts when a modification of the opioid infusion rate is required. To this end, different machine learning classifiers were trained with several sets of clinical features. Data for training were captured from 17 patients undergoing cholecystectomy surgery. Satisfactory results were obtained when including information about minimum values of ANI for predicting a change of dose. Specifically, a higher efficiency of the Support Vector Machine (SVM) classifier was observed compared with the situation in which the ANI index was not included: accuracy: 86.21% (83.62%-87.93%), precision: 86.11% (83.78%-88.57%), recall: 91.18% (88.24%-91.18%), specificity: 79.17% (75%-83.33%), AUC: 0.89 (0.87-0.90) and kappa index: 0.71 (0.66-0.75). The results of this research evidenced that including information about the minimum values of ANI together with the hemodynamic information outperformed the decisions made regarding only non-specific traditional signs such as heart rate and blood pressure. In addition, the analysis of the results showed that including the ANI monitor in the decision making process may anticipate a dose change to prevent hemodynamic events. Finally, the SVM was able to perform accurate predictions when making different decisions commonly observed in the clinical practice.

Clinical practice guidelines for the perioperative nutrition, metabolic, and nonsurgical support of patients undergoing bariatric procedures - 2019 update: cosponsored by American Association of Clinical Endocrinologists/American College of Endocrinology, The Obesity Society, American Society for Metabolic & Bariatric Surgery, Obesity Medicine Association, and American Society of Anesthesiologists

OBJECTIVE

The development of these updated clinical practice guidelines (CPG) was commissioned by the American Association of Clinical Endocrinologists, The Obesity Society, the American Society of Metabolic and Bariatric Surgery, the Obesity Medicine Association, and the American Society of Anesthesiologists boards of directors in adherence to the American Association of Clinical Endocrinologists 2017 protocol for standardized production of CPG, algorithms, and checklists.

METHODS

Each recommendation was evaluated and updated based on new evidence from 2013 to the present and subjective factors provided by experts.

RESULTS

New or updated topics in this CPG include contextualization in an adiposity-based, chronic disease complications-centric model, nuance-based, and algorithm/checklist-assisted clinical decision-making about procedure selection, novel bariatric procedures, enhanced recovery after bariatric surgery protocols, and logistical concerns (including cost factors) in the current healthcare arena. There are 85 numbered recommendations that have updated supporting evidence, of which 61 are revised and 12 are new. Noting that there can be multiple recommendation statements within a single numbered recommendation, there are 31 (13%) Grade A, 42 (17%) Grade B, 72 (29%) Grade C, and 101 (41%) Grade D recommendations. There are 858 citations, of which 81 (9.4%) are evidence level (EL) 1 (highest), 562 (65.5%) are EL 2, 72 (8.4%) are EL 3, and 143 (16.7%) are EL 4 (lowest).

CONCLUSIONS

Bariatric procedures remain a safe and effective intervention for higher-risk patients with obesity. Clinical decision-making should be evidence-based within the context of a chronic disease. A team approach to perioperative care is mandatory with special attention to nutritional and metabolic issues.

Pain monitor: reality or fantasy in ambulatory patients

PURPOSE OF REVIEW

In an unconscious patient, there can be significant challenges to monitoring nociception and proper dosing of analgesic medications. The traditional measures of intraoperative nociception have poor sensitivity and specificity with little predictive value in postoperative outcomes such as postoperative pain, opioid-induced side effects, length of stay or incidence of opioid use disorder. To date, several monitoring modalities are in development to establish objective measures of the balance between nociception and analgesia with the goal of guiding anesthesiologists and improve patient outcomes. In this review, some of the most promising monitoring modalities are discussed with the most recent findings.

RECENT FINDINGS

Multiple modalities are beginning to demonstrate utility compared with traditional care. Most, but not all, of these studies show decreased intraoperative opioid use and some show lower pain scores and opioid requirements in the postanesthesia care unit.

SUMMARY

Recent evidence points to promising efficacy for these monitoring modalities; however, this field is in its infancy. More investigation is required to demonstrate differences in outcome compared with traditional care, and these differences need to be of sufficient import to achieve widespread adoption.

Objective monitoring of nociception: a review of current commercial solutions

Nociception, in contrast to pain, is not a subjective feeling, but the physiological encoding and processing of nociceptive stimuli. However, monitoring nociception remains a challenge in attempts to lower the incidence of acute postoperative pain and the move towards a more automated approach to analgesia and anaesthesia. To date, several commercialised devices promise a more accurate reflection of nociception than the traditionally used vital signs, blood pressure and heart rate. This narrative review presents an overview of existing technologies and commercially available devices, and offers a perspective for future research. Although firm conclusions about individual methods may be premature, none currently appears to offer a sufficiently broad applicability. Furthermore, there is currently no firm evidence for any clinically relevant influence of such devices on patient outcome. However, the available monitors have significantly aided the understanding of underlying mechanisms and identification of potential pitfalls.

Impact of CYP3A4*1G Polymorphism on Fentanyl Analgesia Assessed by Analgesia Nociception Index in Chinese Patients Undergoing Hysteroscopy

Background:

The clinical efficacy of fentanyl for pain control differs greatly across individuals. The purpose of this study was to investigate the impact of CYP3A4*1G polymorphism including wild-type homozygote (CYP3A4*1/*1, GG), mutant heterozygote (CYP3A4*1/*1G, GA), and mutant homozygote (CYP3A4*1G/*1G, AA) on fentanyl analgesia in Chinese patients undergoing hysteroscopy by the assessment of analgesia nociception index (ANI).

Methods:

A total of 200 gynecologic patients scheduled for elective hysteroscopy under general anesthesia at Peking University People's Hospital from May to December in 2017 were enrolled in this study. Venous blood was withdrawn for genotyping of CYP3A4*1G before operation. Fentanyl 1 μg/kg was administered preoperatively followed by target-controlled infusion of propofol for induction and maintenance. Intraoperative analgesic efficacy of fentanyl was assessed by ANI monitoring at T0 (entering room), T1 (cervical dilation), T2 (start of cervical aspiration), and T3 (end of cervical aspiration) time points. The duration of propofol infusion and total dosage of propofol were recorded as well.

Results:

The patients were divided into three groups according to CYP3A4*1G polymorphism, including 143 in GG group, 47 in GA group, and 10 in AA group. There was no significant difference in clinical demographics among three groups. The frequency of CYP3A4*1G variant alleles accounted for 16.8% and the distribution of variant alleles was consistent with Hardy–Weinberg equilibrium. Using a multilevel model, ANI values at T1 (63.81 ± 19.61), T2 (63.63 ± 17.82), and T3 (65.68 ± 17.79) were significantly lower than that at T0 (77.16 ± 12.93) in the study population (F = 23.50, P < 0.001), suggesting that higher levels of pain at T1, T2, and T3 than T0. Patients with GG genotype showed significantly lower ANI than those with GA or AA genotypes during hysteroscopy under the same dose of fentanyl.

Conclusion:

CYP3A4*1G polymorphism associated with the analgesic efficacy of intraoperative fentanyl in the patients undergoing hysteroscopy under general anesthesia.