Opioid-free Anesthesia: Time to Regain Our Balance

Can intraoperative opioid use in hip and knee arthroplasty be reduced further without negatively affecting pain control: A case controlled study

Background

Whilst forming the backbone of perioperative analgesic regimes in joint replacement surgery, the negative side effect profile of opioids is well known. Common impediments to a smooth running Enhanced Rapid Recovery model of care are often altered cognitive function and postoperative nausea and vomiting (PONV), both related to opioid use.This study focuses on evaluating whether further reductions in intraoperative opioid use during joint arthroplasty can be safely achieved with minimal impact of such reductions on pain control and postoperative outcomes including opioid requirements and the incidence of PONV and ability to mobilise.

Method

Case controlled review of prospectively collected data assessing intraoperative opioid use, postoperative analgesic requirement, incidence of PONV and cognitive status as well as day 0 mobility postoperatively. 50 patients were randomized in the study and control groups.

Results

The study group received statistically significant lower dose of intraoperative opioids equivalent to 24.18 mg of Morphine compared to control group with equivalent to 69.58 mg of Morphine (p < 0.001). There was no statistically significant increase in analgesia requirement postoperatively and no negative influence on PONV or ability to follow immediate postoperative rehabilitative protocols.

Conclusion

Opioid use intraoperatively can be reduced even further without any compromise of postoperative pain control and PONV and may further reduce impediments to efficiency in rapid recovery models of care.

Opioid-Free versus Opioid-Sparing Anesthesia for Postoperative Pain and Early Recovery After Laparoscopic Cholecystectomy: A Randomized Controlled Trial

Purpose

Enhanced recovery after surgery emphasizes effective analgesia while minimal opioid use. Opioid-free anesthesia (OFA) and opioid-sparing anesthesia (OSA) have been shown to enhance recovery by reducing opioid-induced side effects. This study compared the efficacy of OFA and OSA in managing postoperative pain and recovery after laparoscopic cholecystectomy (LC).

Patients and Methods

A single-center, randomized controlled trial was conducted with 86 adults undergoing LC. Patients received either OSA (sufentanil/remifentanil) or OFA (no opioids). Both groups received propofol, esketamine, dexmedetomidine, and erector spinae plane block. The primary outcome was pain area under the curve (AUCVAS) within 36 hours postsurgery. Secondary outcomes included hemodynamics, recovery times and bowel function.

Results

Eighty-one patients (41 and 40 in the OFA and OSA groups, respectively) completed the study. The AUCVAS scores were similar between the OFA (7.3 ± 1.4) and OSA (6.9 ± 1.3) groups (P = 0.201), the difference in AUCVAS between the two groups was 0.384 (95% CI: -0.296, 1.064), which was significantly below the preset noninferiority threshold of 1.0, demonstrating the noninferiority of OFA. While early pain scores within the first 12 hours postanesthesia care unit (PACU) discharge were slightly higher in the OFA group, but overall pain control was sufficient in both groups. The VAS scores from PACU discharge to 36 hours postoperatively, intraoperative hemodynamic variables, and the need for rescue analgesia were comparable. OFA patients experienced a faster bowel recovery (13.8 ± 2.4 vs 15.5 ± 2.3 hours, P = 0.002). Recovery times, postoperative QoR-40 scores, and patient satisfaction were similar between the groups.

Conclusion

OFA is noninferior to OSA in pain management and hemodynamic stability, with faster bowel recovery after LC.

Sex-Related Analgesic Effects of Opioid-Based Anesthesia and Low-Opioid Anesthesia with Non-Opioid Postoperative Analgesia-A Clinical Observational Study

Background/Objectives: Sex is a crucial factor in modulating the perioperative aspects of anesthesia. A growing number of studies demonstrate that women and men experience pain differently and respond differentially to analgesics. Methods: This study evaluated the analgesic trajectory of low-opioid anesthesia (LOA) and opioid-based anesthesia (OBA) in women and men after laparoscopic cholecystectomy. The primary objective was to assess pain intensity at various time intervals after surgery (0-2, 2-6, 6-12, and 12-24 h) using the Numerical Rating Scale (NRS). The secondary objective was to assess the difference in mean pain intensity on the first postoperative day between the women and men. Results: The mean pain intensity did not differ significantly for men using LOA and OBA, but the value was significantly lower in the LOA group for women (p = 0.0002). The analgesic trajectory in women and men undergoing LOA presented a negative trend, but the pain intensity at 0-2, 2-6, 6-12, and 12-24 h in women was statistically lower than that of the OBA group (p = 0.01, p = 0.008, p = 0.002, and p = 0.001). Total fentanyl doses of 0.3 mg (sensitivity 44%, specificity 76%, AUC 0.55) and 0.35 mg achieved a mean NRS of <2 for pain intensity in the female and male OBA groups (sensitivity 33%, specificity 100%, AUC 0.53). Conclusions: A model combining low-opioid anesthesia and non-opioid postoperative analgesia presents a favorable therapeutic effect for women. OBA does not provide proper analgesic effects after laparoscopic cholecystectomy.

Biased Opioid Receptor Agonists: Balancing Analgesic Efficacy and Side-Effect Profiles

Opioids are the most effective option for severe pain. However, it is well documented that the side effects associated with prolonged opioid use significantly constrain dosage in the clinical setting. Recently, researchers have concentrated on the development of biased opioid receptor agonists that preferentially activate the G protein signaling pathway over β-arrestin signaling. This approach is based on the hypothesis that G protein signaling mediates analgesic effects, whereas β-arrestin signaling is implicated in adverse side effects. Although certain studies have demonstrated that the absence or inhibition of β-arrestin signaling can mitigate the incidence of side effects, recent research appears to challenge these earlier findings. In-depth investigations into biased signal transduction of opioid receptor agonists have been conducted, potentially offering novel insights for the development of biased opioid receptors. Consequently, this review elucidates the contradictory roles of β-arrestin signaling in the adverse reactions associated with opioid receptor activation. Furthermore, a comparative analysis was conducted to evaluate the efficacy of the classic G protein-biased agonists, TRV130 and PZM21, relative to the traditional non-biased agonist morphine. This review aims to inform the development of novel analgesic drugs that can optimize therapeutic efficacy and safety, while minimizing adverse reactions to the greatest extent possible.

Opioid-Free Anesthesia for Upper Limb Surgery in Obese Patients as a Day Case Surgery: A Prospective Observational Study

Background

Opioid-free anesthesia (OFA) is a relatively new approach, and many studies are still needed to assess its effectiveness and compare it to opioid-based anesthesia (OBA).

Objectives

This study investigated the use of OFA in obese patients undergoing upper limb surgery and compares its outcomes with those of OBA.Methods:This prospective randomized clinical study included 76 obese patients with a Body Mass Index (BMI) ≥ 30 kg/m² who were scheduled for upper limb surgery. Patients were randomly assigned to receive either OFA (group A, n = 38) or OBA (group B, n = 38). The OBA group was administered propofol, fentanyl, and atracurium, while the OFA group received lidocaine, propofol, atracurium, and dexmedetomidine. All patients were mechanically ventilated, and anesthesia was maintained with isoflurane and atracurium. Primary outcomes monitored included postoperative pain [Visual Analog Scale (VAS) ≥ 4] and the number of rescue doses of tramadol. Secondary outcomes included extubation time, any cardiac events, hypoxia, postoperative nausea and vomiting (PONV), intensive care unit (ICU) admission rates, and duration of hospital stay.

Results

The OFA group had significantly lower extubation time, mean arterial pressure (MAP), and heart rate (HR) compared to the OBA group. Additionally, VAS scores were significantly lower at the 30-minute and 2-hour marks after extubation (P < 0.001 and P < 0.001, respectively) in patients receiving OFA. The OFA group also experienced fewer adverse effects, required fewer rescue doses of tramadol, and had shorter hospital stays.

Conclusions

Opioid-free anesthesia may result in better and safer outcomes for obese patients undergoing upper limb surgeries, with fewer postoperative complications and shorter hospital stays. However, further research is needed to fully understand the potential benefits of OFA compared to OBA.

Effects of opioid-sparing general anesthesia on postoperative nausea and vomiting in laparoscopic gynecological surgery

BACKGROUND

In this study, we aimed to investigate whether opioid-sparing anesthesia (OSA) reduces postoperative nausea and vomiting (PONV) in patients undergoing laparoscopic gynecological surgery.

METHODS

Adult patients undergoing elective laparoscopic gynecological surgery were randomly assigned to either the opioid-using anesthesia (OUA) or the OSA groups. In the OUA group, remifentanil was administered as an opioid during general anesthesia. In the OSA group, apart from a single dose of 5 μg/kg of alfentanil for tracheal intubation, no other opioids were used. In both groups, a multimodal intravenous non-opioid analgesic regimen was used preferentially in the post-anesthesia care unit (PACU). The primary outcome was the incidence of PONV, assessed by symptoms until the postoperative day 1.

RESULTS

A total of 120 patients were included in this study. The incidence of nausea in the PACU was significantly lower in the OSA group compared to in the OUA group (31.7% in the OSA group vs. 51.7% in the OUA group, P = 0.026). Pain scores and the incidence of opioid analgesic administration were lower in the OSA group during PACU stay, resulting in a significantly lower number of patients requiring rescue opioid analgesics (3.3% vs. 18.3%, P = 0.008). There were no significant differences in intraoperative vital signs, hemodynamic interventions, or duration of PACU and hospital stay between the two groups.

CONCLUSIONS

OSA significantly reduced postoperative nausea, pain scores, and the need for rescue analgesics in the PACU without increasing hemodynamic instability in patients undergoing laparoscopic gynecological surgery.

Opioid alternatives in spine surgeries

PURPOSE OF REVIEW

The escalating opioid crisis has intensified the need to explore alternative pain management strategies for patients undergoing spine surgery. This review is timely and relevant as it synthesizes recent research on opioid alternatives for perioperative management, assessing their efficacy, side effects, and postoperative outcomes.

RECENT FINDINGS

A systematic search was conducted to capture articles from the past 18 months that examined opioid-sparing strategies. Findings indicate that multimodal analgesia, incorporating nonsteroidal anti-inflammatory drugs (NSAIDs), acetaminophen, lidocaine, gabapentinoids, N-methyl-D-aspartate (NMDA) antagonists, dexmedetomidine, and emerging regional block techniques like the erector spinae block and TLIF (thoraco lumbar interfascial block), can significantly reduce opioid consumption without compromising pain relief. Additionally, these approaches reduce opioid-related side effects such as postoperative nausea, vomiting, and prolonged hospital stays.

SUMMARY

The use of multimodal analgesia aligns with current pain management guidelines and addresses public health concerns related to opioid misuse. While effective, these alternatives are not without side effects, and the ultimate outcome depends on balancing benefits and risks. Future research should focus on the long-term outcomes of opioid alternatives, their effectiveness across diverse populations, and further validation and optimization of these strategies.

Effect of nociception level-directed analgesic management on opioid usage in robot-assisted laparoscopic radical prostatectomy: a single-center, single-blinded, randomized controlled trial

PURPOSE

To assess the importance of appropriate opioid administration methods according to nociceptive monitoring.

METHODS

We conducted a randomized controlled trial involving 54 patients who underwent robot-assisted laparoscopic radical prostatectomy at our hospital. Patients were randomly allocated to either receive nociception level (NOL)-directed intraoperative opioid management with a minimum flow of remifentanil (NOL group) or conventional intraoperative analgesic management (control group). The primary outcome was the mean intraoperative remifentanil infusion flow rate (intraoperative remifentanil usage [μg]/ideal body weight [kg]/operation time [min]). The main secondary outcomes were plasma concentrations of three perioperative inflammatory biomarkers (interleukin-6, C-reactive protein [CRP], and cortisol levels) and postoperative pain (Numeric Rating Scale [NRS]) scores 2 h postoperatively and on postoperative days 1, 2, 3, and 7.

RESULTS

Compared with standard analgesia management, NOL-directed analgesic management reduced remifentanil consumption by 20% ( - 0.038; 95% confidence interval, - 0.059 to - 0.017; p = 0.0007). NOL-directed management did not lead to an increase in IL-6, CRP, or cortisol levels compared with conventional analgesic management. Furthermore, this protocol led to improvements in the NRS scores at rest 2 h postoperatively and upon movement up to postoperative day 3.

CONCLUSION

NOL-directed analgesic management reduced remifentanil consumption by 20% and the NRS scores at rest 2 h postoperatively and upon movement up to postoperative day 3 without an increase in inflammatory marker levels.

REGISTRY NUMBER

Japan Registry of Clinical Trials, JRCTs052220034.

Effect of modified opioid sparing anaesthesia on postoperative quality of recovery in patients undergoing laparoscopic bariatric surgery: protocol for a monocentre, double-blind randomised controlled trial - the MOSA study

INTRODUCTION

Obesity patients undergoing laparoscopic bariatric surgery (LBS) are frequently encountered perioperative adverse events related to opioids-based anaesthesia (OBA) or opioids-free anaesthesia (OFA). While modified opioid-sparing anaesthesia (MOSA) has been shown to lower the occurrence of adverse events related to OBA and OFA. This study is to assess the efficacy of MOSA in enhancing the recovery quality among individuals undergoing LBS.

METHODS AND ANALYSIS

A single-centre, prospective, double-blind, randomised controlled trial is conducted at a tertiary hospital. A total of 74 eligible participants undergoing elective LBS will be recruited and randomly allocated. Patients in the MOSA group will receive a combination of low-dose opioids, minimal dexmedetomidine, esketamine and lidocaine, while in the OBA group will receive standard general anaesthesia with opioids. Patients in both groups will receive standard perioperative care. The primary outcome is the quality of recovery-15 score assessed at 24 hours after surgery. Secondary outcomes include pain levels, anxiety and depression assessments, gastrointestinal function recovery, perioperative complication rates, opioid consumption and length of hospital stay.

ETHICS AND DISSEMINATION

Ethical approval has been provided by the Ethical Committee of Yan'an Hospital of Kunming City (approval No. 2023-240-01). Eligible patients will provide written informed consent to the investigator. The outcomes of this trial will be disseminated in a peer-reviewed scholarly journal.

TRIAL REGISTRATION NUMBER

The study protocol is registered at https://www.chictr.org.cn/ on 19 December 2023. (identifier: ChiCTR2300078806). The trial was conducted using V.1.0.

Postoperative opioid-free analgesia in dogs undergoing tibial plateau leveling osteotomy: a feasibility study

Objectives

This study was designed to prospectively evaluate the feasibility of an opioid-free anesthesia protocol and describe the quality of recovery and management of postoperative analgesia in dogs after a tibial plateau leveling osteotomy (TPLO).

Methods

In total, 20 dogs presented for TPLO were included. After premedication with intravenous (IV) medetomidine (0.005-0.007 mg/kg) and midazolam (0.2 mg/kg), the dogs were anesthetized using ketamine (2 mg/kg) and propofol and maintained with isoflurane and ketamine CRI (0.6 mg/kg/h). Sciatic and femoral nerve blocks were performed with bupivacaine 0.5% (0.087 +/- 0.01 and 0.09 +/- 0.02 mL/kg, respectively). Meloxicam (0.2 mg/kg IV) was administered intraoperatively, after osteotomy. Fentanyl (0.002 mg/kg IV) was administered intraoperatively, as rescue analgesia in the case of sustained increase in cardiorespiratory variables. Two pain scores (French 4A-VET and Glasgow short form) were performed at conscious sternal recumbency and 2, 4, 6, 8, 12, and 20 h after extubation and compared to baseline using a Friedman test followed by a Nemenyi post-hoc test. The time taken for the first food intake and urination was reported.

Results

Intraoperative opioid-free anesthesia was feasible in 11 dogs, whereas 9 dogs received fentanyl once during arthrotomy. No opioid postoperative rescue analgesia was required. Food intake occurred within 6 h, and all dogs were discharged after 24 h without any complication.

Conclusion

Total opioid-free postoperative analgesia was achieved in all dogs, with adequate recoveries. Although opioid-free anesthesia was feasible in 55% of the population, a single dose of fentanyl was necessary in 45% of the dogs during arthrotomy.

Opioid-Obviating Analgesia for Adolescent Multilevel Spinal Fusion Surgery: A Problem-Based Learning Discussion

A female teenager with a history of polysubstance use, including a recent overdose, is scheduled for multilevel posterior spinal fusion surgery due to idiopathic scoliosis and has asked to avoid the use of opioids in the context of her upcoming surgery. This problem-based learning discussion (PBLD) focuses on the examination of the care of a spinal fusion patient that allowed for the successful provision of opioid-obviating care.

Opioid-free Anesthesia Protocol on the Early Quality of Recovery after Major Surgery (SOFA Trial): A Randomized Clinical Trial

BACKGROUND

Opioid-free anesthesia is increasingly being adopted to reduce opioid consumption, but its impact on early postoperative recovery after major surgery has not been evaluated in comparative trials. The hypothesis was that an opioid-free anesthesia protocol would enhance the early quality of recovery for patients undergoing scheduled major surgery under general anesthesia.

METHODS

The SOFA study was a monocentric, randomized, controlled, assessor- and patient-blinded clinical trial conducted from July 10, 2021, to February 12, 2022. The eligible population included male and female patients undergoing scheduled major surgery, excluding bone procedures, that typically require opioids for postoperative pain management. Patients in the intervention group received a combination of at least two drugs among ketamine, lidocaine, clonidine, and magnesium sulfate, without opioids for anesthesia. The standard group received opioids. The primary outcome was early postoperative quality of recovery, assessed by Quality of Recovery-15 score at 24 h after surgery. Secondary outcomes were Quality of Recovery-15 at 48 and 72 h after surgery, incidence of chronic pain, and quality of life at 3 months.

RESULTS

Of the 136 randomized patients, 135 were included in the primary analysis (mean age, 45.9 ± 15.7 yr; 116 females [87.2%]; 85 underwent major plastic surgery [63.9%]), with 67 patients in the opioid-free anesthesia group and 68 in the standard group. The mean Quality of Recovery-15 at 24 h was 114.9 ± 15.2 in the opioid-free anesthesia group versus 108.7 ± 18.1 in the standard group (difference, 6.2; 95% CI, 0.4 to 12.0; P = 0.026). Quality of Recovery-15 scores also differed significantly at 48 h (difference, 8.7; 95% CI, 2.9 to 14.5; P = 0.004) and at 72 h (difference, 7.3; 95% CI, 1.6 to 13.0; P = 0.013). There were no differences in other secondary outcomes. No major adverse events were noticed.

CONCLUSIONS

The opioid-free anesthesia protocol improved quality of recovery after major elective surgery in a statistically but not clinically significant manner when compared to standard anesthesia.

EDITOR’S PERSPECTIVE

[Opioid-free anesthesia : Wrong track or meaningful exit from the era of opioid-based analgesia?]

The limitations and disadvantages of opioids in anesthesia are very well known but the advantages combined with a lack of effective alternatives even now still prevents refraining from using opioids as part of an adequate pain therapy. For decades, pain research has had the declared goal of replacing opioids with new substances which have no serious side effects; however, currently this goal seems to be a long way off. Due to the media coverage of the "opioid crisis" in North America, the use of opioids for pain management is also increasingly being questioned by the patients. Measures to contain this crisis are only slowly taking effect in view of the increasing number of deaths, which is why the triggers are still being sought. The perioperative administration of opioids is not only a possible gateway to addiction and abuse but it can also cause outcome-relevant complications, such as respiratory depression, postoperative nausea and vomiting and an increase in postoperative pain. Therefore, these considerations gave rise to the idea of an opioid-free anesthesia (OFA), i.e., opioids are not administered as part of anesthesia to carry out surgical procedures. Although this idea may make sense at first glance, a rapid introduction of this concept appears to be risky as it entails significant changes for the entire anesthesiological management. Based on relatively robust data from clinical studies, this concept can now be evaluated and discussed not only emotionally but also objectively. This review article presents arguments for or against the complete avoidance of intraoperative or even perioperative opioids. The current conditions in Germany are primarily taken into account, so that the perioperative pain therapy is transferable to the established standards. The results from current clinical studies on the implementation of an opioid-free anesthesia are summarized and discussed.

Exploring the need for reconsideration of trial design in perioperative outcomes research: a narrative review

"Enhanced recovery after surgery" is a multimodal effort to control perioperative pathophysiology and improve outcome. However, despite advances in perioperative care, postoperative complications and the need for hospitalisation and prolonged recovery continue to be challenging. This is further complicated by procedure-specific and patient-associated risk factors, given the increase in the number of elderly and frail patients with multiple comorbidities undergoing surgery. This paper is a critical assessment of current methodology for trials in perioperative medicine. We make a plea to reconsider the design of future interventional trials to improve surgical outcome, based upon studies of potentially effective interventions, but often without improvements in recovery. The complexity of perioperative pathophysiology necessitates a procedure- and patient-specific approach whenever outcome is assessed or interventions are planned. With improved understanding of perioperative pathophysiology, the way to improve outcomes looks promising, provided that knowledge and established enhanced recovery programmes are integrated in trial design.

Funding

None.

Influence of Intravenous S-Ketamine on the Pharmacokinetics of Oral Morphine in Healthy Volunteers

BACKGROUND

Subanesthetic ketamine may reduce perioperative consumption of opioids. We studied whether intravenous S-ketamine alters the pharmacokinetics of oral morphine in healthy volunteers.

METHODS

In this paired, randomized, double-blind, crossover trial, 12 participants under a 2-hour intravenous S-ketamine (0.57 mg/kg/h) or placebo infusion received oral morphine (0.2 mg/kg) at 30 minutes. Plasma concentrations of ketamine, morphine, and their major metabolites were quantified for 24 hours. The primary end point was area under the curve (AUC) 0-24 of morphine. Other pharmacokinetic variables for morphine and its metabolites were studied as secondary end points. The data were analyzed as between-phase comparisons for each participant using Wilcoxon matched-pairs signed-rank tests ( tmax ) or paired t -tests on log-transformed variables (other variables).

RESULTS

While the AUC 0-24 was similar between the 2 phases, S-ketamine reduced the AUC 0-1.5 of oral morphine by 69% (ratio to control, 0.31; 90% confidence interval [CI], 0.15-0.65; P = .0171) and increased its tmax from 0.5 (range, 0.50-1.5) to 1.0 hour (range, 0.50-4.0; P = .010). The AUC 0-1.5 of morphine-6-glucuronide (M6G) was reduced by 84% (0.16; 90% CI, 0.07-0.37; P = .0025) and maximum plasma concentration ( Cmax ) by 43% (0.57; 90% CI, 0.40-0.81; P = .0155), while its tmax was increased from 1.5 (range, 1.0-2.0) to 4.0 (range, 1.0-8.0; P = .0094) hours by S-ketamine. Similarly, the AUC 0-1.5 of morphine-3-glucuronide (M3G) was reduced by 85% (0.15; 90% CI, 0.05-0.43; P = .0083), and tmax increased from 1.0 (range, 0.5-1.5) to 4.0 hours (range, 1.0-8.0; P = .0063). In addition, the M6G-to-morphine and M3G-to-morphine metabolic AUC ratios were decreased by 47% (0.53; 90% CI, 0.39-0.71; P = .0033) and 52% (0.48; 90% CI, 0.27-0.85; P = .0043) during 0 to 1.5 hours and by 15% (0.85; 90% CI, 0.78-0.92; P = .0057) and 10% (0.90; 90% CI, 0.83-0.98; P = .0468) during 0 to 24 hours, respectively. One participant was excluded from the analyses due to vomiting in the S-ketamine phase.

CONCLUSIONS

Intravenous S-ketamine inhibited the metabolism of oral morphine and delayed its absorption, resulting in a net reduction in the exposure to morphine during the first 1.5 hours. Intravenous S-ketamine may delay the absorption and impair the efficacy of orally administered analgesics and other drugs.

Variation in Intraoperative Opioid Administration by Patient, Clinician, and Hospital Contribution

Importance

The opioid crisis has led to scrutiny of opioid exposures before and after surgical procedures. However, the extent of intraoperative opioid variation and the sources and contributing factors associated with it are unclear.

Objective

To analyze attributable variance of intraoperative opioid administration for patient-, clinician-, and hospital-level factors across surgical and analgesic categories.

Design, Setting, and Participants

This cohort study was conducted using electronic health record data collected from a national quality collaborative database. The cohort consisted of 1 011 268 surgical procedures at 46 hospitals across the US involving 2911 anesthesiologists, 2291 surgeons, and 8 surgical and 4 analgesic categories. Patients without ambulatory opioid prescriptions or use history undergoing an elective surgical procedure between January 1, 2014, and September 11, 2020, were included. Data were analyzed from January 2022 to July 2023.

Main Outcomes and Measures

The rate of intraoperative opioid administration as a continuous measure of oral morphine equivalents (OMEs) normalized to patient weight and case duration was assessed. Attributable variance was estimated in a hierarchical structure using patient, clinician, and hospital levels and adjusted intraclass correlations (ICCs).

Results

Among 1 011 268 surgical procedures (mean [SD] age of patients, 55.9 [16.2] years; 604 057 surgical procedures among females [59.7%]), the mean (SD) rate of intraoperative opioid administration was 0.3 [0.2] OME/kg/h. Together, clinician and hospital levels contributed to 20% or more of variability in intraoperative opioid administration across all analgesic and surgical categories (adjusting for surgical or analgesic category, ICCs ranged from 0.57-0.79 for the patient, 0.04-0.22 for the anesthesiologist, and 0.09-0.26 for the hospital, with the lowest ICC combination 0.21 for anesthesiologist and hosptial [0.12 for the anesthesiologist and 0.09 for the hospital for opioid only]). Comparing the 95th and fifth percentiles of opioid administration, variation was 3.3-fold among anesthesiologists (surgical category range, 2.7-fold to 7.7-fold), 4.3-fold among surgeons (surgical category range, 3.4-fold to 8.0-fold), and 2.2-fold among hospitals (surgical category range, 2.2-fold to 4.3-fold). When adjusted for patient and surgical characteristics, mean (square error mean) administration was highest for cardiac surgical procedures (0.54 [0.56-0.52 OME/kg/h]) and lowest for orthopedic knee surgical procedures (0.19 [0.17-0.21 OME/kg/h]). Peripheral and neuraxial analgesic techniques were associated with reduced administration in orthopedic hip (51.6% [95% CI, 51.4%-51.8%] and 60.7% [95% CI, 60.5%-60.9%] reductions, respectively) and knee (48.3% [95% CI, 48.0%-48.5%] and 60.9% [95% CI, 60.7%-61.1%] reductions, respectively) surgical procedures, but reduction was less substantial in other surgical categories (mean [SD] reduction, 13.3% [8.8%] for peripheral and 17.6% [9.9%] for neuraxial techniques).

Conclusions and Relevance

In this cohort study, clinician-, hospital-, and patient-level factors had important contributions to substantial variation of opioid administrations during surgical procedures. These findings suggest the need for a broadened focus across multiple factors when developing and implementing opioid-reducing strategies in collaborative quality-improvement programs.

Pain management and opioid stewardship in adult cardiac surgery: Joint consensus report of the PeriOperative Quality Initiative and the Enhanced Recovery After Surgery Cardiac Society

BACKGROUND

Opioid-based anesthesia and analgesia is a traditional component of perioperative care for the cardiac surgery patient. Growing enthusiasm for Enhanced Recovery Programs (ERPs) coupled with evidence of potential harm associated with high-dose opioids suggests that we reconsider the role of opioids in cardiac surgery.

METHODS

An interdisciplinary North American panel of experts, using a structured appraisal of the literature and a modified Delphi method, derived consensus recommendations for optimal pain management and opioid stewardship for cardiac surgery patients. Individual recommendations are graded based on the strength and level of evidence.

RESULTS

The panel addressed 4 main topics: the harms associated with historical opioid use, the benefits of more targeted opioid administration, the use of nonopioid medications and techniques, and patient and provider education. A key principle that emerged is that opioid stewardship should apply to all cardiac surgery patients, entailing judicious and targeted use of opioids to achieve optimal analgesia with the fewest potential side effects. The process resulted in the promulgation of 6 recommendations regarding pain management and opioid stewardship in cardiac surgery, focused on avoiding the use of high-dose opioids, as well as encouraging more widespread application of foundational aspects of ERPs, such as the use of multimodal nonopioid medications and regional anesthesia techniques, formal patient and provider education, and structured system-level opioid prescription practices.

CONCLUSIONS

Based on the available literature and expert consensus, there is an opportunity to optimize anesthesia and analgesia for cardiac surgery patients. Although additional research is needed to establish specific strategies, core principles of pain management and opioid stewardship apply to the cardiac surgery population.

Perioperative opioid-minimization approach as a useful protocol in the management of patients with Ehlers-Danlos syndrome-hypermobility type, craniocervical instability and severe chronic pain who are to undergo occipito-cervical fixation

Patients suffering from connective tissue disorders like Ehlers-Danlos syndrome hypermobility type/joint hypermobility syndrome (EDS-HT/JHS) may be affected by craniocervical instability (CCI). These patients experience myalgic encephalomyelitis, chronic fatigue, depression, extreme occipital-cervical pain, and severe widespread pain that is difficult to relieve with opioids. This complex and painful condition can be explained by the development of chronic neuroinflammation, opioid-induced hyperalgesia, and central sensitization. Given the challenges in treating such severe physical pain, we evaluated all the analgesic methods previously used in the perioperative setting, and updated information was presented. It covers important physiopathological aspects for the perioperative care of patients with EDS-HT/JHS and CCI undergoing occipital-cervical/thoracic fixation/fusion. Moreover, a change of paradigm from the current opioid-based management of anesthesia/analgesia in these patients to the perioperative opioid minimization strategies used by the authors was analyzed and proposed as follow-up considerations from our previous case series. These strategies are based on total-intravenous opioid-free anesthesia, multimodal analgesia, and a postoperative combination of anti-hyperalgesic coadjuvants (lidocaine, ketamine, and dexmedetomidine) with an opioid-sparing effect.

Postoperative delirium: identifying the patient at risk and altering the course: A narrative review

Postoperative delirium (POD) is a common neurocognitive syndrome seen in older patients after major surgery. POD is linked to longer stays in hospital and intensive care, a greater incidence of postoperative complications, worse functional outcome, and higher mortality. Researchers have not yet fully elucidated the exact pathophysiology of POD. Several risk factors that contribute to the development of POD have been identified, such as advanced age, cardiac or hip surgery, preoperative cognitive decline or delirium, disturbances in brain levels of neurotransmitters and information processing, oxidative stress and neuro-inflammation. Identifying patients at risk for POD enables a more precise and efficient allocation of medical resources and facilitates POD prevention and management. The present review addresses how to identify patients at risk of POD and summarizes the currently available evidence and best-practice recommendations for peri-operative management and prevention of POD.

Intraoperative hydromorphone decreases postoperative pain: an instrumental variable analysis

BACKGROUND

Intraoperative administration of short-acting opioids might lead to increased postoperative pain and opioid requirements. There are few data describing the effects of intermediate-duration opioids such as hydromorphone on these outcomes. We have previously shown that a switch from a 2 mg to a 1 mg vial of hydromorphone was associated with decreased intraoperative dose administration. As presentation dose affected intraoperative hydromorphone administration and was unrelated to other policy changes, it could serve as an instrumental variable, assuming significant secular trends were not present during the study period.

METHODS

In this observational cohort study of patients who received intraoperative hydromorphone (n=6750), an instrumental variable analysis was used to evaluate whether intraoperative hydromorphone administration affected postoperative pain scores and opioid administration. Before July 2017, hydromorphone was available as a 2-mg unit dose. From July 1, 2017 to November 20, 2017, hydromorphone was only available in a 1-mg unit dose. A two-stage least squares regression analysis was used to estimate causal effects.

RESULTS

A 0.2-mg increase in intraoperative hydromorphone administration caused a decrease in admission PACU pain scores (mean difference, -0.8; 95% confidence interval, -1.2 to -0.4; P<0.001) and decreased maximum and time-weighted mean pain scores over 2 days postoperatively, without increased opioid administration.

CONCLUSIONS

This study suggests that intraoperative administration of intermediate-duration opioids does not cause the same effects as short-acting opioids with respect to postoperative pain. Instrumental variables can be used to estimate causal effects using observation data when unmeasured confounding is present.

No association of postoperative opioid usage with long-term surgery outcomes in patients with liver cancer: a population-based retrospective cohort study

ABSTRACT

Hepatocellular carcinoma (HCC) is a fatal cancer worldwide, and surgical resection remains the standard treatment. Postoperative opioid prescription has been believed to affect cancer recurrence through complex biological pathways. We conducted a retrospective cohort study using the Longitudinal Health Insurance Database of Taiwan to evaluate the relationship between postoperative opioid use and long-term surgical outcomes of patients with HCC. This study had a retrospective cohort design. In total, 812 patients older than 20 years who underwent hepatectomy because of HCC were included. The exposure group comprised patients who used opioids during hospitalization postoperatively. The comparison group included those who never used opioids during hospitalization postoperatively. A Cox proportional hazards model was used to evaluate the overall survival or recurrence-free survival rate between the opioid group and the nonopioid group. A total of 530 patients received opioids postoperatively and 282 patients did not. The hazard ratios of overall survival and recurrence-free survival were 1.10 (95% confidence interval [CI], 0.85-1.41) and 1.15 (95% CI, 0.91-1.46), respectively. Total postoperative opioids were converted into oral morphine milligram equivalents and then divided into 3 equal subgroups: low dose, <40 mg; medium dose, 40 to 144 mg; and high dose, ≥145 mg. The hazard ratios of overall survival were 0.88 (95% CI, 0.63-1.24) for the low-dose group, 1.27 (95% CI, 0.92-1.74) for the medium-dose group, and 1.14 (95% CI, 0.83-1.58) for the high-dose group. Postoperative opioids do not affect overall and recurrence-free survival in patients undergoing hepatectomy or liver transplantation because of HCC. Cancer recurrence should not be a clinical concern regarding postoperative opioid prescription.

Opioid-sparing anesthesia and patient-reported outcomes after open gynecologic surgery: a historical cohort study

PURPOSE

Dexmedetomidine and ketamine may be administered intraoperatively as continuous infusions to provide opioid-sparing anesthesia. Recent evidence has yielded controversial results regarding the impact of opioid-free anesthesia on postoperative complications, and there is a gap in knowledge regarding patient-reported outcomes (PROs). This study aimed to determine the impact of opioid-sparing anesthesia and opioid-based anesthesia on PROs among gynecologic patients within an enhanced recovery after surgery (ERAS) program.

METHODS

We formed a single-center historical cohort from patients enrolled in another study who underwent open gynecologic surgery on an ERAS program from November 2014 to December 2020 (n = 2,095). We identified two cohorts based on the type of balanced anesthesia administered: 1) opioid-sparing anesthesia defined as the continuous infusion of dexmedetomidine and ketamine (adjuvants) during surgery or 2) opioid-based anesthesia (no adjuvants). We measured the quality of postoperative recovery using the MD Anderson Symptom Inventory (MDASI), a 29-item validated tool that was administered preoperatively, daily while admitted, and weekly after discharge until week 6. The primary outcome was interference with walking. We matched both cohorts and used a multilevel linear mixed-effect model to evaluate the effect of opioid-sparing anesthesia on the primary outcome.

RESULTS

In total, 498 patients were eligible (159 in the opioid-sparing anesthesia cohort and 339 in the opioid-based anesthesia cohort), of whom 149 matched pairs were included in the final analysis. Longitudinal assessment showed no significant or clinically important difference in interference with walking (P = 0.99), general activity (P = 0.99), or other PROs between cohorts. Median [interquartile range (IQR)] intraoperative opioid administration (expressed as morphine milligram equivalents [MME]) among matched patients in the opioid-sparing anesthesia cohort was 30 [25-55] mg vs 58 [8-70] mg in the opioid-based anesthesia cohort (P < 0.01). Patients in the opioid-sparing anesthesia cohort had a lower opioid consumption in the postanesthesia care unit than those in the opioid-based anesthesia cohort (MME, 3 [0-10] mg vs 5 [0-15] mg; P < 0.01), but there was no significant difference between cohorts in total postoperative opioid consumption (MME, 23 [0-94] mg vs 35 [13-95] mg P = 0.053).

CONCLUSIONS

In this single-center historical cohort study, opioid-sparing anesthesia had no significant or clinically important effects on interference with walking or other PROs in patients undergoing gynecologic surgery compared with opioid-based anesthesia. Opioid-sparing anesthesia was associated with less short-term opioid consumption than opioid-based anesthesia.

Opioid-Free Anesthesia: The Pros and Cons

Appropriate perioperative pain control is essential to aid in patients' recovery after surgery; however, acute postsurgical pain remains poorly treated and there continues to be an overreliance on opiates. Perioperative pain control starts in the operating room, and opiate-free anesthesia (OFA), where no opiates are used intraoperatively, has been proposed as a feasible strategy to further minimize opiates in the perioperative period. In this article, we address the potential benefits and shortcomings of OFA, while exploring tools available to accomplish multimodal anesthesia and ideally OFA, and the evidence behind the techniques proposed.

Effects of Intraoperative Opioid Administration on Postoperative Pain and Pain Threshold: A Randomized Controlled Study

Fentanyl and short-acting remifentanil are often used in combination. We evaluated the effect of intraoperative opioid administration on postoperative pain and pain thresholds when the two drugs were used. Patients who underwent gynecological laparoscopic surgery were randomly assigned into two groups (15 patients each) to receive either sufficient (group A) or minimum (group B) fentanyl (maximum estimated effect site concentration: A: 7.86 ng/mL, B: 1.5 ng/mL). The estimated effect site concentration at the end of surgery was adjusted to the same level (1 ng/mL). Patients in both groups also received continuous intravenous remifentanil during surgery. The primary outcome was the pressure pain threshold, as evaluated by a pressure algometer 3 h postoperatively. The pressure pain threshold at 3 h postoperatively was 51.1% (95% CI: [44.4–57.8]) in group A and 56.6% [49.5–63.6] in group B, assuming a preoperative value of 100% (p = 0.298). There were no significant differences in pressure pain threshold and numeric rating scale scores between the groups after surgery. The pain threshold decreased significantly in both groups at 3 h postoperatively compared to preoperative values, and recovered at 24 h. Co-administration of both opioids caused hyperalgesia regardless of fentanyl dose.

Opioid-Sparing Techniques in Orthopedic Anesthesia-One Step to Opioid-Free Anesthesia?

Opioid-free anesthesia is a multimodal anesthesia aimed at avoiding the negative impact of intraoperative opioid on patient's postoperative outcomes. It is based on the physiology of pathways involved in intraoperative nociception. It has been shown to be feasible but the literature is still scarce on the clinically meaningful benefits as well as on the side effects and/or complications that might be associated with it. Moreover, most studies involved abdominal and/or bariatric surgery. Procedure-specific studies are lacking, especially in orthopedics.

Status quo of pain-related patient reported outcomes and perioperative pain management in 10 415 patients from 10 countries: analysis of registry data

BACKGROUND

Postoperative pain is common at the global level, despite considerable attempts for improvement, reflecting the complexity of offering effective pain relief. In this study, clinicians from Mexico, China, and eight European countries evaluated perioperative pain practices and patient-reported outcomes (PROs) in their hospitals as a basis for carrying out quality improvement (QI) projects in each country.

METHODS

PAIN OUT, an international perioperative pain registry, provided standardized methodology for assessing management and multi-dimensional PROs on the first postoperative day, in patients undergoing orthopedic, general surgery, obstetric & gynecology or urological procedures.

RESULTS

Between 2017-2019, data obtained from 10,415 adult patients in 105 wards, qualified for analysis. At the ward level: 50% (median) of patients reported worst pain intensities ≥7/10 NRS, 25% spent ≥50% of the time in severe pain and 20-34% reported severe ratings for pain-related functional and emotional interference. Demographic variables, country and surgical discipline explained a small proportion of the variation in the PROs, leaving about 88% unexplained. Most treatment processes varied considerably between wards. Ward effects accounted for about 7% and 32% of variation in PROs and treatment processes, respectively.

CONCLUSIONS

This comprehensive evaluation demonstrates that many patients in this international cohort reported poor pain-related PROs on the first postoperative day. PROs and treatments varied greatly. Most of the variance of the PROs could not be explained. The findings served as a basis for devising and implementing QI programs in participating hospitals.

Successful Management of a Patient With a History of Postoperative Delirium Undergoing Cardiac Surgery With an Erector Spinae Plane Block and Multimodal Analgesia: A Case Report

Perioperative delirium is an acute confusional state with fluctuating levels of consciousness, which can be precipitated by opioid-based anesthetics and inadequate pain control, especially in patients undergoing cardiac surgery. We seek to minimize opioid usage to avoid postoperative delirium in a patient with multiple risk factors undergoing aortic valve replacement. We used cardiac enhanced recovery after surgery protocols (ERAS-C), which include multimodal analgesia and regional anesthesia via bilateral erector spinae plane (ESP) blocks. Our observations suggest that bilateral ESP blocks and cardiac ERAS protocols offer a potential option to manage pain and control risk factors in patients at high risk of postoperative delirium undergoing cardiac surgery.

A critical review of oliceridine injection as an IV opioid analgesic for the management of severe acute pain

INTRODUCTION

Oliceridine is a G protein-selective (biased) agonist at the μ-opioid receptor, with less recruitment of β-arrestin-2, a signaling pathway associated with opioid-related adverse events. Nonclinical evidence showed that oliceridine elicits a rapid systemic analgesic effect while attenuating opioid-related adverse events.

AREAS COVERED

Three pivotal studies in patients with moderate to severe acute pain, including two randomized, double-blind, placebo- and morphine-controlled efficacy studies following either orthopedic surgery-bunionectomy or plastic surgery-abdominoplasty; and an open-label safety study following a surgical procedure or due to a medical condition.

EXPERT OPINION

Poorly controlled acute postoperative pain is associated with poorer recovery, longer hospitalization, increased complications, and worse healthcare outcomes. Recently, oliceridine intravenous injection was approved for use in adults for the management of acute pain severe enough to require an intravenous opioid analgesic and for whom alternative treatments are inadequate. Introduction of this new IV opioid provides a valuable option to manage postoperative pain.

End-tidal Anesthetic Concentration: Monitoring, Interpretation, and Clinical Application

Age-adjusted fraction of minimum alveolar concentration derived from end-tidal anesthetic partial pressure measurement remains a useful drug advisory display to help prevent awareness if interpreted with proper understanding of the quantal and probabilistic nature of minimum alveolar concentration, semantics, drug interactions, and hysteresis.

Perioperative Opioids, the Opioid Crisis, and the Anesthesiologist

This review summarizes current evidence related to perioperative opioid prescription fulfillment and use and discusses the role of personalized anesthesia care in mitigating opioid-related harms without compromising analgesia.

Budget impact and pharmacy costs with targeted use of oliceridine for postsurgical pain in patients at high risk of opioid-related adverse events

BACKGROUND

Oliceridine, a new class of μ-opioid receptor agonist, may be associated with fewer opioid-related adverse events (ORAEs) due to its unique mechanism of action. Thus, it may provide a cost-effective alternative to conventional opioids such as morphine.

PATIENTS AND METHODS

Using a decision tree with a 24-hour time horizon, we calculated costs for medication and management of the three most common AEs (oxygen saturation <90%, vomiting, somnolence) following postoperative oliceridine or morphine in high-risk patients. Costs were enumerated as differences in cost of analgesics and resource utilization in the first 24 hours post-surgery. An economic model compared expected AEs and costs in a blended cohort where elderly/obese patients at higher risk for ORAEs received oliceridine while those presumed to be at lower risk received morphine with a cohort that received morphine alone.

RESULTS

In high-risk patients, use of oliceridine resulted in overall savings of $363,944 (in 1,000 patients). Implementing a targeted approach of oliceridine utilization in patients with high risk for ORAEs can save a typical hospital system $122,296 in total cost of care.

CONCLUSION

Use of oliceridine in postoperative care among patients at high risk provides a favorable health economic benefit compared to the use of morphine.

Current Issues in the Use of Opioids for the Management of Postoperative Pain: A Review

Importance

Uncontrolled and indiscriminate prescribing of opioids has led to an opioid crisis that started in North America and spread throughout high-income countries. The aim of this narrative review was to explore some of the current issues surrounding the use of opioids in the perioperative period, focusing on drivers that led to escalation of use, patient harms, the move away from using self-reported pain scores alone to assess adequacy of analgesia, concerns about the routine use of controlled-release opioids for the management of acute pain, opioid-free anesthesia and analgesia, and prescription of opioids on discharge from hospital.

Observations

The origins of the opioid crisis are multifactorial and may include good intentions to keep patients pain free in the postoperative period. Assessment of patient function may be better than unidimensional numerical pain scores to help guide postoperative analgesia. Immediate-release opioids can be titrated more easily to match analgesic requirements. There is currently no good evidence to show that opioid-free anesthesia and analgesia affects opioid prescribing practices or the risk of persistent postoperative opioid use. Attention should be paid to discharge opioid prescribing as repeat and refill prescriptions are risk-factors for persistent postoperative opioid use. Opioid stewardship is paramount, and many governments are passing legislation, while statutory bodies and professional societies are providing advice and guidance to help mitigate the harm caused by opioids.

Conclusions and Relevance

Opioids remain a crucial part of many patients' journey from surgery to full recovery. The last few decades have shown that unfettered opioid use puts patients and societies at risk, so caution is needed to mitigate those dangers. Opioid stewardship provides a multilayered structure to allow continued safe use of opioids as part of broad pain management strategies for those patients who benefit from them most.

Opioids and Public Health: The Prescription Opioid Ecosystem and Need for Improved Management

While U.S. opioid prescribing has decreased 38% in the past decade, opioid deaths have increased 300%. This opioid paradox is poorly recognized. Current approaches to opioid management are not working, and new approaches are needed. This article reviews the outcomes and shortcomings of recent U.S. opioid policies and strategies that focus primarily or exclusively on reducing or eliminating opioid prescribing. It introduces concepts of a prescription opioid ecosystem and opioid pool, and it discusses how the pool can be influenced by supply-side, demand-side, and opioid returns factors. It illuminates pressing policy needs for an opioid ecosystem that enables proper opioid stewardship, identifies associated responsibilities, and emphasizes the necessity of making opioid returns as easy and common as opioid prescribing, in order to minimize the size of the opioid pool available for potential diversion, misuse, overdose, and death. Approaches are applicable to opioid prescribing in general, and to opioid prescribing after surgery.

Oliceridine Exhibits Improved Tolerability Compared to Morphine at Equianalgesic Conditions: Exploratory Analysis from Two Phase 3 Randomized Placebo and Active Controlled Trials

INTRODUCTION

In the management of postoperative acute moderate-to-severe pain, opioids remain an important component. However, conventional opioids have a narrow therapeutic index and are associated with dose-limiting opioid-related adverse events (ORAEs) that can result in worse patient outcomes. Oliceridine, a new intravenous µ-opioid receptor agonist, is shown in nonclinical studies to be biased for G protein signaling (achieving analgesia) with limited recruitment of β-arrestin (associated with ORAEs). In two phase 3 randomized controlled studies of patients with moderate-to-severe acute pain following hard or soft tissue surgery, in which analgesia was measured using Sum of Pain Intensity Differences (SPID) from baseline over 48 and 24 h (SPID-48 and -24 respectively, oliceridine at demand doses of 0.1, 0.35, or 0.5 mg was highly effective compared to placebo, with a favorable safety profile compared to morphine. This exploratory analysis was conducted to determine whether the safety benefits seen with oliceridine persisted when adjusted for equal levels of analgesia compared to morphine.

METHODS

Presence of at least one treatment-emergent ORAE (based on Medical Dictionary for Regulatory Activities [MedDRA]-coded events: hypoxemia, nausea, vomiting, sedation, pruritus, or dizziness) was used as the composite safety endpoint. A logistic regression model was utilized to compare oliceridine (pooled regimens) versus morphine, after controlling for analgesia (using SPID-48 or SPID-24 with pre-rescue scores carried forward 6 h). This analysis excluded patients receiving placebo and was repeated for each study and for pooled data.

RESULTS

At a given level of SPID-48 or SPID-24, patients receiving oliceridine were less likely to experience the composite safety endpoint. Although not statistically significant at the 0.05 level in the soft tissue model, the odds ratio (OR) showed a consistent numerical trend for oliceridine, being approximately half that observed with morphine in both the hard (OR 0.499; 95% confidence interval [CI] 0.255, 0.976; p = 0.042) and soft (OR 0.542; 95% CI 0.250, 1.175; p = 0.121) tissue studies. Results from the pooled data were consistent with those observed in the individual studies (OR 0.507; 95% CI 0.304, 0.844; p = 0.009).

CONCLUSION

Findings from this exploratory analysis suggest that at comparable levels of analgesia, patients receiving oliceridine were less likely to experience the composite safety endpoint consisting of ORAEs compared to patients treated with morphine. Oliceridine Exhibits Improved Tolerability Compared to Morphine at Equianalgesic Conditions: Exploratory Analysis from Two Phase 3 Randomized Placebo and Active Controlled Trials- A Video (MP4 99188 kb).

Persistent Pain After Cardiac Surgery: Prevention and Management

Persistent postoperative pain (PPP) after cardiac surgery is a significant complication that negatively affects patient quality of life and increases health care system burden. However, there are no standards or guidelines to inform how to mitigate these effects. Therefore, in this review, we will discuss strategies to prevent and manage PPP after cardiac surgery. Adequate perioperative analgesia may prove instrumental in the prevention of PPP. Although opioids have historically been the primary analgesic approach to cardiac surgery, an opioid-sparing strategy may prove advantageous in reducing side effects, avoiding secondary hyperalgesia, and decreasing risk of PPP. Implementing a multimodal analgesic plan using alternative medications and regional anesthetic techniques may offer superior efficacy while reducing adverse effects.

Opioid-Free Anesthesia Benefit-Risk Balance: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Opioid-free anesthesia (OFA) is used in surgery to avoid opioid-related side effects. However, uncertainty exists in the balance between OFA benefits and risks. We searched for randomized controlled trials (RCTs) comparing OFA to opioid-based anesthesia (OBA) in five international databases. The co-primary outcomes were postoperative acute pain and morphine consumption at 2, 24, and 48 h. The secondary outcomes were the incidence of postoperative chronic pain, hemodynamic tolerance, severe adverse effects, opioid-related adverse effects, and specific adverse effects related to substitution drugs. Overall, 33 RCTs including 2209 participants were assessed. At 2 h, the OFA groups had lower pain scores at rest MD (0.75 (−1.18; −0.32)), which did not definitively reach MCID. Less morphine was required in the OFA groups at 2 and 24 h, but with very small reductions: 1.61 mg (−2.69; −0.53) and −1.73 mg (p < 0.05), respectively, both not reaching MCID. The reduction in PONV in the OFA group in the PACU presented an RR of 0.46 (0.38, 0.56) and an RR of 0.34 (0.21; 0.56), respectively. Less sedation and shivering were observed in the OFA groups with an SMD of −0.81 (−1.05; −0.58) and an RR of 0.48 (0.33; 0.70), respectively. Quantitative analysis did not reveal differences between the hemodynamic outcomes, although severe side effects have been identified in the literature. No clinically significant benefits were observed with OFA in terms of pain and opioid use after surgery. A clear benefit of OFA use was observed with respect to a reduction in PONV. However, more data on the safe use of OFAs should be collected and caution should be taken in the development of OFA.