Postoperative Pain and Analgesic Requirements in the First Year after Intraoperative Methadone for Complex Spine and Cardiac Surgery

Methadone and Buprenorphine in the Perioperative Setting: A Review of the Literature

PURPOSE OF REVIEW

The purpose of this review is to highlight the most recent literature and guidelines regarding perioperative methadone and buprenorphine use.

RECENT FINDINGS

Surgical patients taking methadone and buprenorphine are being encountered more frequently in the perioperative period, and providers are becoming more familiar with their pharmacologic properties, benefits as well as precautions. Recommendations pertaining to buprenorphine therapy in the perioperative settings have changed in recent years, owing to more clinical and basic science research. In addition to their use in chronic pain and opioid use disorders, they can also be initiated for acute postoperative pain indications, in select patients and situations. Methadone and buprenorphine are being more commonly prescribed for pain management and opioid use disorder, and their continuation during the perioperative period is generally recommended, to reduce the risk of opioid withdrawal, relapse, or inadequately controlled pain. Additionally, both may be initiated safely and effectively for acute pain management during and after the operating room period.

Perioperative methadone for posterior spinal fusion in adolescents: Results from a double-blind randomized-controlled trial

BACKGROUND

Posterior spinal fusion is the most common surgical procedure performed for correction of adolescent idiopathic scoliosis in the United States. Intraoperative methadone has been shown to improve pain control in adult patients undergoing complex spine surgery, and current pediatric studies show encouraging results; however, prospective randomized-controlled trials are lacking in the pediatric literature.

AIMS

We conducted a single-center double-blind randomized-controlled trial to compare intraoperative use of methadone to morphine in pediatric patients undergoing posterior spinal fusion.

METHODS

A total of 47 adolescents undergoing posterior spinal fusion were randomized (stratified by sex) to either a methadone (n = 25) or morphine (n = 22) group. The primary outcome was postoperative opioid consumption. Secondary outcomes included postoperative pain severity, opioid-related side effects, and ratio of patient-controlled analgesia injections: attempts as a behavioral index of uncontrolled pain.

RESULTS

Patients in the methadone group consumed less total opioid postoperatively (median [interquartile range], 0.3 mg/kg [0.1, 0.5]) than patients in the morphine group (0.3 mg/kg [0.2, 0.6]), median difference [95% confidence interval] -0.07 [-0.2 to 0.02]; (p = .026). Despite the lower amount of opioid used postoperatively, pain scores for the methadone group (3.5 [3.0, 4.3]) were not significantly different from those in the morphine group (4.0 [3.2, 5.0]; p = .250). Groups did not differ on opioid-related side effects.

CONCLUSIONS

A two-dose intraoperative methadone regimen resulted in decreased opioid consumption compared to morphine. Although the clinical significance of these results may be limited, the analgesic equipoise without increased opioid-related side effects and potential for a lower incidence of chronic pain may tip the balance in favor of routine methadone use for adolescents undergoing posterior spinal fusion.

Intraoperative methadone for day-case gynaecological laparoscopy: A double-blind, randomised controlled trial

Optimal pain relief in day-case surgery is imperative to patient comfort and timely discharge from hospital. Short-acting opioids are commonly used for analgesia in modern anaesthesia, allowing rapid recovery after surgery. Plasma concentration fluctuations from repeated dosing of short-acting opioids can cause patients to oscillate between analgesia with potential adverse effects, and inadequate analgesia requiring rescue dosing. Methadone's unique pharmacology may offer effective and sustained analgesia with less opioid consumption, potentially reducing adverse effects. Using a double-blind, randomised controlled trial, we compared post-anaesthesia care unit opioid consumption between day-case gynaecological laparoscopy patients who received either intravenous methadone (10 mg), or short-acting opioids intraoperatively. The primary outcome was post-anaesthesia care unit opioid consumption in oral morphine equivalents. Secondary outcomes included total opioid consumption, discharge opioid consumption, pain scores (0-10) until discharge, adverse effects (respiratory depression, postoperative nausea and vomiting, excess sedation), and rate of admission. Seventy patients were randomly assigned. Patients who received methadone consumed on average 9.44 mg fewer oral morphine equivalents in the post-anaesthesia care unit than the short-acting group (18.02 mg vs 27.46 mg, respectively, 95% confidence interval 0.003 to 18.88, P = 0.050) and experienced lower postoperative pain scores at every time point, although absolute differences were small. There was no evidence of lower hospital or discharge opioid consumption. No significant differences between the methadone and short-acting groups in other outcomes were identified: respiratory depression 41.2% versus 31.4%, Padjusted >0.99; postoperative nausea and vomiting 29.4% versus 42.9%, Padjusted >0.99; overnight admission 17.7% versus 11.4%, Padjusted >0.99; excess sedation 8.82% versus 8.57%, Padjusted >0.99. This study provides evidence that, although modestly, methadone can reduce post-anaesthesia care unit opioid consumption and postoperative pain scores after day-case gynaecological laparoscopy. There were no significant differences in any secondary outcomes.

Opioid use disorder in pediatric populations: considerations for perioperative pain management and precision opioid analgesia

INTRODUCTION

Opioids are commonly used for perioperative analgesia, yet children still suffer high rates of severe post-surgical pain and opioid-related adverse effects. Persistent and severe acute surgical pain greatly increases the child's chances of chronic surgical pain, long-term opioid use, and opioid use disorder.

AREAS COVERED

Enhanced recovery after surgery (ERAS) protocols are often inadequate in treating a child's severe surgical pain. Research suggests that 'older' and longer-acting opioids such as methadone are providing better methods to treat acute post-surgical pain. Studies indicate that lower repetitive methadone doses can decrease the incidence of chronic persistent surgical pain (CPSP). Ongoing research explores genetic components influencing severe surgical pain, inadequate opioid analgesia, and opioid use disorder. This new genetic research coupled with better utilization of opioids in the perioperative setting provides hope in personalizing surgical pain management, reducing pain, opioid use, adverse effects, and helping the fight against the opioid pandemic.

EXPERT OPINION

The opioid and analgesic pharmacogenomics approach can proactively 'tailor' a perioperative analgesic plan to each patient based on underlying polygenic risks. This transition from population-based knowledge of pain medicine to individual patient knowledge can transform acute pain medicine and greatly reduce the opioid epidemic's socioeconomic, personal, and psychological strains globally.

Perioperative Methadone for Spine Surgery: A Scoping Review

Complex spine surgery is associated with significant acute postoperative pain. Methadone possesses pharmacological properties that make it an attractive analgesic modality for major surgeries. This scoping review aimed to summarize the evidence for the perioperative use of methadone in adults undergoing complex spine surgery. The review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR). A search was performed using MEDLINE, CINAHL, Cochrane Library, Scopus, Embase, and Joanna Briggs between January 1946 and April 2023. The initial search identified 317 citations, of which 12 met the criteria for inclusion in the review. There was significant heterogeneity in the doses, routes of administration, and timing of perioperative methadone administration in the included studies. On the basis of the available literature, methadone has been associated with reduced postoperative pain scores and reduced postoperative opioid consumption. Though safety concerns have been raised by observational studies, these have not been confirmed by prospective randomized studies. Further research is required to explore optimal methadone dosing regimens, the potential synergistic relationships between methadone and other pharmacological adjuncts, as well as the potential long-term antinociceptive benefits of perioperative methadone administration.

Perioperative Pain Management for Thoracic Surgery: A Multi-Layered Approach

Cardiothoracic surgeries frequently pose unique challenges in the management of perioperative acute pain that require a multifaceted and personalized approach in order to optimize patient outcomes. This article discusses various analgesic strategies including regional anesthesia techniques such as thoracic epidurals, erector spinae plane blocks, and serratus anterior plane blocks and underscores the significance of perioperative multimodal medications, while providing nuanced recommendations for their use. This article further attempts to provide evidence for the efficacy of the different modalities and compares the effectiveness of the choice of analgesia. The roles of Acute Pain Services (APS) and Transitional Pain Services (TPS) in mitigating opioid dependence and chronic postsurgical pain are also discussed. Precision medicine is also presented as a potential way to offer a patient tailored analgesic strategy. Supported by various randomized controlled trials and meta-analyses, the article concludes that an integrated, patient-specific approach encompassing regional anesthesia and multimodal medications, while also utilizing the services of the Acute Pain Service can help to enhance pain management outcomes in cardiothoracic surgery.

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.

The nuts and bolts of multimodal anaesthesia in the 21st century: a primer for clinicians

PURPOSE OF REVIEW

This review article explores the application of multimodal anaesthesia in general anaesthesia, particularly in conjunction with locoregional anaesthesia, specifically focusing on the importance of EEG monitoring. We provide an evidence-based guide for implementing multimodal anaesthesia, encompassing drug combinations, dosages, and EEG monitoring techniques, to ensure reliable intraoperative anaesthesia while minimizing adverse effects and improving patient outcomes.

RECENT FINDINGS

Opioid-free and multimodal general anaesthesia have significantly reduced opioid addiction and chronic postoperative pain. However, the evidence supporting the effectiveness of these approaches is limited. This review attempts to integrate research from broader neuroscientific fields to generate new clinical hypotheses. It discusses the correlation between high-dose intraoperative opioids and increased postoperative opioid consumption and their impact on pain indices and readmission rates. Additionally, it explores the relationship between multimodal anaesthesia and pain processing models and investigates the potential effects of nonpharmacological interventions on preoperative anxiety and postoperative pain.

SUMMARY

The integration of EEG monitoring is crucial for guiding adequate multimodal anaesthesia and preventing excessive anaesthesia dosing. Furthermore, the review investigates the impact of combining regional and opioid-sparing general anaesthesia on perioperative EEG readings and anaesthetic depth. The findings have significant implications for clinical practice in optimizing multimodal anaesthesia techniques (Supplementary Digital Content 1: Video Abstract, http://links.lww.com/COAN/A96 ).

Development and prospective validation of postoperative pain prediction from preoperative EHR data using attention-based set embeddings

Preoperative knowledge of expected postoperative pain can help guide perioperative pain management and focus interventions on patients with the greatest risk of acute pain. However, current methods for predicting postoperative pain require patient and clinician input or laborious manual chart review and often do not achieve sufficient performance. We use routinely collected electronic health record data from a multicenter dataset of 234,274 adult non-cardiac surgical patients to develop a machine learning method which predicts maximum pain scores on the day of surgery and four subsequent days and validate this method in a prospective cohort. Our method, POPS, is fully automated and relies only on data available prior to surgery, allowing application in all patients scheduled for or considering surgery. Here we report that POPS achieves state-of-the-art performance and outperforms clinician predictions on all postoperative days when predicting maximum pain on the 0-10 NRS in prospective validation, though with degraded calibration. POPS is interpretable, identifying comorbidities that significantly contribute to postoperative pain based on patient-specific context, which can assist clinicians in mitigating cases of acute pain.

Error traps and preventative strategies for adolescent idiopathic scoliosis spinal surgery

Anesthesia for posterior spinal fusion for adolescent idiopathic scoliosis remains one of the most common surgeries performed in adolescents. These procedures have the potential for significant intraprocedural and postoperative complications. The potential for pressure injuries related to prone positioning must be understood and addressed. Additionally, neuromonitoring remains a mainstay for patient care in order to adequately assess patient neurologic integrity and alert the providers to a reversible action. As such, causes of neuromonitoring signal loss must be well understood, and the provider should have a systematic approach to signal loss. Further, anesthetic design must facilitate intraoperative wake-up to allow for a definitive assessment of neurologic function. Perioperative bleeding risk is high in posterior spinal fusion due to the extensive surgical exposure and potentially lengthy operative time, so the provider should undertake strategies to reduce blood loss and avoid coagulopathy. Pain management for adolescents undergoing spinal fusion is also challenging, and inadequate analgesia can delay recovery, impede patient/family satisfaction, increase the risk of chronic postsurgical pain/disability, and lead to prolonged opioid use. Many of the significant complications associated with this procedure, however, can be avoided with intentional and evidence-based approaches covered in this review.

Intraoperative Methadone in Next-day Discharge Outpatient Surgery: A Randomized, Double-blinded, Dose-finding Pilot Study

BACKGROUND

Contemporary perioperative practice seeks to use less intraoperative opioid, diminish postoperative pain and opioid use, and enable less postdischarge opioid prescribing. For inpatient surgery, anesthesia with intraoperative methadone, compared with short-duration opioids, results in less pain, less postoperative opioid use, and greater patient satisfaction. This pilot investigation aimed to determine single-dose intraoperative methadone feasibility for next-day discharge outpatient surgery, determine an optimally analgesic and well-tolerated dose, and explore whether methadone would result in less postoperative opioid use compared with conventional short-duration opioids.

METHODS

This double-blind, randomized, dose-escalation feasibility and pilot study in next-day discharge surgery compared intraoperative single-dose IV methadone (0.1 then 0.2, 0.25 and 0.3 mg/kg ideal body weight) versus as-needed short-duration opioid (fentanyl, hydromorphone) controls. Perioperative opioid use, pain, and side effects were assessed before discharge. Patients recorded pain, opioid use, and side effects for 30 days postoperatively using take-home diaries. Primary clinical outcome was in-hospital (intraoperative and postoperative) opioid use. Secondary outcomes were 30-day opioid consumption, pain, opioid side effects, and leftover opioid counts.

RESULTS

Median (interquartile range) intraoperative methadone doses were 6 (5 to 7), 11 (10 to 12), 14 (13 to 16), and 18 (15 to 19) mg in 0.1, 0.2, 0.25, and 0.3 mg/kg ideal body weight groups, respectively. Anesthesia with single-dose methadone and propofol or volatile anesthetic was effective. Total in-hospital opioid use (IV milligram morphine equivalents [MME]) was 25 (20 to 37), 20 (13 to 30), 27 (18 to 32), and 25 (20 to 36) mg, respectively, in patients receiving 0.1, 0.2, 0.25 and 0.3 mg/kg methadone, compared to 46 (33 to 59) mg in short-duration opioid controls. Opioid-related side effects were not numerically different. Home pain and opioid use were numerically lower in patients receiving methadone.

CONCLUSIONS

The most effective and well-tolerated single intraoperative induction dose of methadone for next-day discharge surgery was 0.25 mg/kg ideal body weight (median, 14 mg). Single-dose intraoperative methadone was analgesic and opioid-sparing in next-day discharge outpatient surgery.

EDITOR’S PERSPECTIVE

Perioperative Analgesia in Spine Surgery: A Review of Current Data Supporting Future Direction

This Clinical Research discusses the diverse nature of spine surgery procedures and the use of multimodal analgesia within enhanced recovery after surgery (ERAS) protocols to improve patient outcomes. Spine surgeries range from minor decompressions to extensive tumor resections, performed by neurosurgeons or orthopedic spine surgeons on adults and children. To manage perioperative pain effectively, various methods have been employed, including multimodal analgesia within ERAS protocols. Incorporating ERAS protocols into spine surgery has shown benefits such as reduced pain scores, decreased opioid use, shorter hospital stays, and improved functionality. ERAS protocols help to enhance patient outcomes, focusing on deconstructing these protocols for surgeons and anesthesiologists.

Association of Intraoperative Opioid Administration With Postoperative Pain and Opioid Use

IMPORTANCE

Opioids administered to treat postsurgical pain are a major contributor to the opioid crisis, leading to chronic use in a considerable proportion of patients. Initiatives promoting opioid-free or opioid-sparing modalities of perioperative pain management have led to reduced opioid administration in the operating room, but this reduction could have unforeseen detrimental effects in terms of postoperative pain outcomes, as the relationship between intraoperative opioid usage and later opioid requirements is not well understood.

OBJECTIVE

To characterize the association between intraoperative opioid usage and postoperative pain and opioid requirements.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study evaluated electronic health record data from a quaternary care academic medical center (Massachusetts General Hospital) for adult patients who underwent noncardiac surgery with general anesthesia from April 2016 to March 2020. Patients who underwent cesarean surgery, received regional anesthesia, received opioids other than fentanyl or hydromorphone, were admitted to the intensive care unit, or who died intraoperatively were excluded. Statistical models were fitted on the propensity weighted data set to characterize the effect of intraoperative opioid exposures on primary and secondary outcomes. Data were analyzed from December 2021 to October 2022.

EXPOSURES

Intraoperative fentanyl and intraoperative hydromorphone average effect site concentration estimated using pharmacokinetic/pharmacodynamic models.

MAIN OUTCOMES AND MEASURES

The primary study outcomes were the maximal pain score during the postanesthesia care unit (PACU) stay and the cumulative opioid dose, quantified in morphine milligram equivalents (MME), administered during the PACU stay. Medium- and long-term outcomes associated with pain and opioid dependence were also evaluated.

RESULTS

The study cohort included a total of 61 249 individuals undergoing surgery (mean [SD] age, 55.44 [17.08] years; 32 778 [53.5%] female). Increased intraoperative fentanyl and intraoperative hydromorphone were both associated with reduced maximum pain scores in the PACU. Both exposures were also associated with a reduced probability and reduced total dosage of opioid administration in the PACU. In particular, increased fentanyl administration was associated with lower frequency of uncontrolled pain; a decrease in new chronic pain diagnoses reported at 3 months; fewer opioid prescriptions at 30, 90, and 180 days; and decreased new persistent opioid use, without significant increases in adverse effects.

CONCLUSIONS AND RELEVANCE

Contrary to prevailing trends, reduced opioid administration during surgery may have the unintended outcome of increasing postoperative pain and opioid consumption. Conversely, improvements in long-term outcomes might be achieved by optimizing opioid administration during surgery.

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.

Comparison of oral versus intravenous methadone on postoperative pain and opioid use after adult spinal deformity surgery: A retrospective, non-inferiority analysis

OBJECTIVE

To compare efficacy of oral versus intravenous (IV) methadone on postoperative pain and opioid requirements after spine surgery.

METHODS

This was a retrospective, single-academic center cohort study evaluating 1010 patients who underwent >3 level spine surgery from January 2017 to May 2020 and received a one-time dose of oral or intravenous methadone prior to surgery. The primary outcome measured was postoperative opioid use in oral morphine equivalents (ME) and verbal response scale (VRS) pain scores up to postoperative day (POD) three. Secondary outcomes were time to first bowel movement and adverse effects (reintubation, myocardial infarction, and QTc prolongation) up to POD 3.

RESULTS

A total of 687 patients received oral and 317 received IV methadone, six patients were excluded. The IV group received a significantly greater methadone morphine equivalent (ME) dose preoperatively (112.4 ± 83.0 mg ME versus 59.3 ± 60.9 mg ME, p < 0.001) and greater total (methadone and non-methadone) opioid dose (119.1 ± 81.4 mg ME versus 63.9 ± 62.5 mg ME, p < 0.001), intraoperatively. Although pain scores for the oral group were non-inferior to the IV group for all postoperative days (POD), non-inferiority for postoperative opioid requirements was demonstrated only on POD 3. Based on the joint hypothesis for the co-primary outcomes, oral methadone was non-inferior to IV methadone on POD 3 only. No differences in secondary outcomes, including QTc prolongation and arrhythmias, were noted between the groups.

CONCLUSIONS

Oral methadone is a feasible alternative to IV methadone for patients undergoing spine surgery regarding both pain scores and postoperative opioid consumption.

Pro-Con Debate: Role of Methadone in Enhanced Recovery After Surgery Protocols-Superior Analgesic or Harmful Drug?

Enhanced recovery after surgery (ERAS) protocols are standardized and designed to provide superior analgesia, reduce opioid consumption, improve patient recovery, and reduce hospital length of stay. Yet, moderate-to-severe postsurgical pain continues to afflict over 40% of patients and remains a major priority for anesthesia research. Methadone administration in the perioperative setting may reduce postoperative pain scores and have opioid-sparing effects, which may be beneficial for enhanced recovery. Methadone possesses a multimodal profile consisting of µ-opioid agonism, N-methyl-d-aspartate (NMDA) receptor antagonism, and reuptake inhibition of serotonin and norepinephrine. Furthermore, it may attenuate the development of chronic postsurgical pain. However, caution is advised with perioperative use of methadone in specific high-risk patient populations and surgical settings. Methadone's wide pharmacokinetic variability, opioid-related adverse effects, and potential negative impact on cost-effectiveness may also limit its use in the perioperative setting. In this PRO-CON commentary article, the authors debate whether methadone should be incorporated in ERAS protocols to provide superior analgesia with no increased risks.

Practice Advisory for Preoperative and Intraoperative Pain Management of Cardiac Surgical Patients: Part 2

Pain after cardiac surgery is of moderate to severe intensity, which increases postoperative distress and health care costs, and affects functional recovery. Opioids have been central agents in treating pain after cardiac surgery for decades. The use of multimodal analgesic strategies can promote effective postoperative pain control and help mitigate opioid exposure. This Practice Advisory is part of a series developed by the Society of Cardiovascular Anesthesiologists (SCA) Quality, Safety, and Leadership (QSL) Committee's Opioid Working Group. It is a systematic review of existing literature for various interventions related to the preoperative and intraoperative pain management of cardiac surgical patients. This Practice Advisory provides recommendations for providers caring for patients undergoing cardiac surgery. This entails developing customized pain management strategies for patients, including preoperative patient evaluation, pain management, and opioid use-focused education as well as perioperative use of multimodal analgesics and regional techniques for various cardiac surgical procedures. The literature related to this field is emerging, and future studies will provide additional guidance on ways to improve clinically meaningful patient outcomes.

Intravenous Methadone for Perioperative and Chronic Cancer Pain: A Review of the Literature

Intravenous methadone may be useful in acute and chronic pain management compared with other opioids because of its pharmacokinetic and pharmacodynamic characteristics, including the long duration of effect and ability to modulate both pain stimuli propagation and analgesic descending pathways. However, methadone is underused in pain medicine because of several misperceptions. A review of studies was performed to assess data regarding the use of methadone in perioperative pain and chronic cancer pain. The majority of studies have shown that intravenous methadone produces an effective postoperative analgesia and lowers opioid consumption in the postoperative period, without more adverse effects in comparison with other opioid analgesics, and has an interesting potential to prevent persistent postoperative pain. A minority of studies investigated the use of intravenous methadone for cancer pain management. These studies were mostly case series that showed promising activities of intravenous methadone for difficult pain conditions. There is sufficient evidence suggesting that intravenous methadone is effective in perioperative pain, while more studies are needed in patients with cancer pain.

A Single-Center Retrospective Comparison of Opioid Based and Multimodal Analgesic Regimens in Adult Cardiac Surgery

OBJECTIVES

To compare the outcomes of 2 multimodal analgesic regimens with an opioid-based one.

DESIGN

A 2-stage, retrospective study.

SETTING

A large tertiary-care facility.

PARTICIPANTS

Adult cardiac surgical patients.

INTERVENTIONS

Patients received one of three regimens: opioid-only or 2 multimodal regimens. The opioid regimen included intraoperative fentanyl and patient-controlled analgesia pumps. Multimodal regimen 1 included preoperative extended-release oxycodone, intraoperative ketamine infusion, and postoperative morphine suppository. Multimodal regimen 2 included intraoperative methadone and dexmedetomidine infusion.

MEASUREMENTS AND MAIN RESULTS

Outcomes measured included opioid use, pain scores, time to tracheal extubation, postoperative antiemetic use as a surrogate marker for postoperative nausea and vomiting (PONV), age, sex, surgical procedure(s), body mass index, time to first bowel movement, intensive care unit length of stay (LOS), and hospital LOS. Intraoperative median oral morphine equivalents (OMEs) declined from 425 mg (314, 518) to 150 mg (75, 150) and 230 mg (160, 240), p < 0.001, in multimodal regimens 1 and 2, respectively, compared with the opioid-only regimen. Predischarge opioid use was reduced from a median OME of 7.5 mg (0, 22.5) to 5 mg (0, 22.5) and 0 mg (0, 15.0), p < 0.001, in multimodal regimens 1 and 2, respectively. Pain scores were reduced in the multimodal regimen 2 for hours 0 to 6 (estimated difference = -1.5, 95% CI -1.8 to -1.2, p < 0.001) compared with the opioid-only regimen. The PONV treatment was reduced in multimodal regimen 1 versus the opioid-based or multimodal regimen 2 (53% v 64% and 62%), and time to tracheal extubation was clinically equivalent across all regimens: 4.2 (2.8, 6.0), 3.6 (2.3, 5.7), and (3.0, 6.2) hours for the opioid and multimodal regimens 1 and 2, respectively.

CONCLUSIONS

Multimodal analgesic regimens, particularly when incorporating methadone and dexmedetomidine, significantly reduced total and predischarge opioid use in cardiac surgical patients.

Postoperative analgesia for complex spinal surgery

PURPOSE OF REVIEW

Complex spinal surgery is associated with significant postoperative pain. The purpose of this paper is to review recent literature on postoperative pain management in adult and adolescent patients having complex spinal surgery.

RECENT FINDINGS

We conducted a literature search using the Medline database for relevant publications from 2020 to 2022 on postoperative pain after complex spinal surgery. Although opioids remain the mainstay to manage pain after complex spinal surgery, they are associated with adverse effects. Multimodal analgesia may be used to reduce these adverse effects by combining different drugs targeting different parts of the pain pathway. Recent publications suggest continuous low dose fentanyl or morphine infusion, methadone, intravenous paracetamol and ibuprofen, ketorolac, ketamine, magnesium infusion, lidocaine infusion and dexmedetomidine appear to be effective and safe to manage pain after complex spinal surgery. Regional techniques including bilateral erector spinae block, interfascial plane block and intrathecal morphine also appear to be effective and safe.

SUMMARY

Pain management after complex spinal surgery remains challenging. Therefore, further studies are still required to determine the optimal multimodal analgesic regimen for these patients.

Cardiac surgery's long opioid dependency: time to recalibrate pain therapy?

Opioid analgesia is the cornerstone of anaesthetic management during cardiac surgery. However, a subset of patients use opioids persistently after 3 months of surgery. We discuss a recent meta-analysis and systematic review by Liu and colleagues describing both patient and peri-procedural risk factors that contribute to this phenomenon in the context of chronic pain after cardiac surgery. Anaesthetists for cardiac surgery should consider opioid alternatives and individual patient risk factors to optimise recovery and pain control.

Intraoperative Methadone and Short Stay Spine Surgery: Possible Barriers to Implementation and Future Opportunities

The frequency of shorter stay spine surgery is increasing. Acute pain is a common barrier to discharge following spine surgery. Long-acting opioid medications like methadone have the potential to provide sustained analgesia when given intraoperatively. Methadone has been effectively used in complex spine surgery, cardiac surgery, and more recently applied to ambulatory procedures. In this article, we summarize the pertinent available literature on the use of intraoperative methadone for spine surgery as well as the recent data on intraoperative methadone for ambulatory surgery. The aim of this perspectives article is to describe the potential opportunities for applying intraoperative methadone to shorter stay spine surgery as well as barriers to more widespread use. While there are currently no trials that have specifically studied methadone for shorter stay spine surgery specifically to date, it is a promising area for future research.

Management of Postoperative Pain in Patients Following Spine Surgery: A Narrative Review

Perioperative pain management is a unique challenge in patients undergoing spine surgery due to the increased incidence of both pre-existing chronic pain conditions and chronic postsurgical pain. Peri-operative planning and counseling in spine surgery should involve an interdisciplinary approach that includes consideration of patient-level risk factors, as well as pharmacologic and non-pharmacologic pain management techniques. Consideration of psychological factors and patient focused education as an adjunct to these measures is paramount in developing a personalized perioperative pain management plan. Understanding the currently available body of knowledge surrounding perioperative opioid management, management of opioid use disorder, regional/neuraxial anesthetic techniques, ketamine/lidocaine infusions, non-opioid oral analgesics, and behavioral interventions can be useful in developing a comprehensive, multi-modal treatment plan among patients undergoing spine surgery. Although many of these techniques have proved efficacious in the immediate postoperative period, long-term follow-up is needed to define the impact of such approaches on persistent pain and opioid use. Future techniques involving the use of precision medicine may help identify phenotypic and physiologic characteristics that can identify patients that are most at risk of developing persistent postoperative pain after spine surgery.

Controversies in enhanced recovery after cardiac surgery

Advances in cardiac surgical operative techniques and myocardial protection have dramatically improved outcomes in the past two decades. An unfortunate and unintended consequence is that 80% of the preventable morbidity and mortality following cardiac surgery now originates outside of the operating room. Our hope is that a renewed emphasis on evidence-based best practice and standardized perioperative care will reduce overall morbidity and mortality and improve patient-centric care. The Perioperative Quality Initiative (POQI) and Enhanced Recovery After Surgery–Cardiac Society (ERAS® Cardiac) have identified significant evidence gaps in perioperative medicine related to cardiac surgery, defined as areas in which there is significant controversy about how best to manage patients. These five areas of focus include patient blood management, goal-directed therapy, acute kidney injury, opioid analgesic reduction, and delirium.

Opioid-Sparing Perioperative Analgesia Within Enhanced Recovery Programs

Opioid-based analgesia in the perioperative period can provide excellent pain control, but this approach exposes the patient to avoidable side effects and possible harm. Optimal analgesia, an approach that targets the fastest functional recovery with adequate pain control while minimizing side effects, can be achieved with opioid minimization. Many different options for nonopioid multimodal analgesia exist and have been shown to be efficacious, with certain modalities being more beneficial for specific surgeries. This review will present the evidence and practical tips for these management strategies.

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.

Intrathecal Morphine for Analgesia in Minimally Invasive Cardiac Surgery: A Randomized, Placebo-controlled, Double-blinded Clinical Trial

BACKGROUND

Intrathecal morphine decreases postoperative pain in standard cardiac surgery. Its safety and effectiveness have not been adequately evaluated in minimally invasive cardiac surgery. The authors hypothesized that intrathecal morphine would decrease postoperative morphine consumption after minimally invasive cardiac surgery.

METHODS

In this randomized, placebo-controlled, double-blinded clinical trial, patients undergoing robotic totally endoscopic coronary artery bypass received either intrathecal morphine (5 mcg/kg) or intrathecal saline before surgery. The primary outcome was postoperative morphine equivalent consumption in the first 24 h after surgery; secondary outcomes included pain scores, side effects, and patient satisfaction. Pain was assessed via visual analog scale at 1, 2, 6, 12, 24, and 48 h after intensive care unit arrival. Opioid-related side effects (nausea/vomiting, pruritus, urinary retention, respiratory depression) were assessed daily. Patient satisfaction was evaluated with the Revised American Pain Society Outcome Questionnaire.

RESULTS

Seventy-nine patients were randomized to receive intrathecal morphine (n = 37) or intrathecal placebo (n = 42), with 70 analyzed (morphine 33, placebo 37). Intrathecal morphine patients required significantly less median (25th to 75th percentile) morphine equivalents compared to placebo during first postoperative 24 h (28 [16 to 46] mg vs. 59 [41 to 79] mg; difference, -28 [95% CI, -40 to -18]; P < 0.001) and second postoperative 24 h (0 [0 to 2] mg vs. 5 [0 to 6] mg; difference, -3.3 [95% CI, -5 to 0]; P < 0.001), exhibited significantly lower visual analog scale pain scores at rest and cough at all postoperative timepoints (overall treatment effect, -4.1 [95% CI, -4.9 to -3.3] and -4.7 [95% CI, -5.5 to -3.9], respectively; P < 0.001), and percent time in severe pain (10 [0 to 40] vs. 40 [20 to 70]; P = 0.003) during the postoperative period. Mild nausea was more common in the intrathecal morphine group (36% vs. 8%; P = 0.004).

CONCLUSIONS

When given before induction of anesthesia for totally endoscopic coronary artery bypass, intrathecal morphine decreases use of postoperative opioids and produces significant postoperative analgesia for 48 h.

EDITOR’S PERSPECTIVE

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.

In-hospital opioid usage following posterior spinal fusion for adolescent idiopathic scoliosis: Does methadone offer an advantage when used with an ERAS pathway?

PURPOSE

Intraoperative methadone has been shown to decrease opioid medication requirement following posterior spinal fusion (PSF) for adolescent idiopathic scoliosis (AIS). No study to date has investigated the effect of methadone on opioid medication requirement when used in conjunction with an enhanced recovery after surgery (ERAS) protocol following PSF.

METHODS

A retrospective cohort study was performed at a single, tertiary care pediatric hospital. Patients with AIS undergoing PSF were consecutively given a single intra-operative methadone dose and matched 1:2 to a AIS control group without methadone. Patients were matched for age, curve magnitude, levels fused, blood loss, and operating time. All children followed a standard ERAS protocol with methadone being the only change in the post-operative regimen. In-hospital data for opioid and non-opioid medication use, surgical, and patient variables were recorded and compared between cohorts.

RESULTS

Twenty-six patients received methadone (average 15.1 ± 1.9 years) and were matched with 52 control patients without methadone (average 14.7 ± 2.2 years). There were no significant differences in total opioid usage at any time-interval prior to hospital discharge or in cumulative opioid usage. Additionally, patients had a similar VAS pain level at discharge (methadone: 4.0 ± 2.3 vs control: 3.8 ± 1.9; P = 0.572). Total opioid usage was correlated with LOS. There were no opioid-related medication complications in either cohort.

CONCLUSION

There was no decrease of in-hospital opioid usage when methadone was used with an ERAS protocol. Total opioid usage is correlated with hospital LOS following PSF.

Year in Review 2020: Noteworthy Literature in Cardiothoracic Anesthesiology

The year 2020 was marred by the emergence of a deadly pandemic that disrupted every aspect of life. Despite the disruption, notable research accomplishments in the practice of cardiothoracic anesthesiology occurred in 2020 with an emphasis on optimizing care, improving outcomes, and expanding what is possible for patients undergoing cardiac surgery. This year's edition of Noteworthy Literature Review will focus on specific themes in cardiac anesthesiology that include preoperative anemia, predictors of acute kidney injury following cardiac surgery, pain management modalities, anticoagulation strategies after transcatheter aortic valve replacement, mechanical circulatory support, and future directions in research.

Perioperative Opioid Administration

Opioids form an important component of general anesthesia and perioperative analgesia. Discharge opioid prescriptions are identified as a contributor for persistent opioid use and diversion. In parallel, there is increased enthusiasm to advocate opioid-free strategies, which include a combination of known analgesics and adjuvants, many of which are in the form of continuous infusions. This article critically reviews perioperative opioid use, especially in view of opioid-sparing versus opioid-free strategies. The data indicate that opioid-free strategies, however noble in their cause, do not fully acknowledge the limitations and gaps within the existing evidence and clinical practice considerations. Moreover, they do not allow analgesic titration based on patient needs; are unclear about optimal components and their role in different surgical settings and perioperative phases; and do not serve to decrease the risk of persistent opioid use, thereby distracting us from optimizing pain and minimizing realistic long-term harms.

A Novel Perioperative Multidose Methadone-Based Multimodal Analgesic Strategy in Children Achieved Safe and Low Analgesic Blood Methadone Levels Enabling Opioid-Sparing Sustained Analgesia With Minimal Adverse Effects

BACKGROUND

Intraoperative methadone, a long-acting opioid, is increasingly used for postoperative analgesia, although the optimal methadone dosing strategy in children is still unknown. The use of a single large dose of intraoperative methadone is controversial due to inconsistent reductions in total opioid use in children and adverse effects. We recently demonstrated that small, repeated doses of methadone intraoperatively and postoperatively provided sustained analgesia and reduced opioid use without respiratory depression. The aim of this study was to characterize pharmacokinetics, efficacy, and safety of a multiple small-dose methadone strategy.

METHODS

Adolescents undergoing posterior spinal fusion (PSF) for idiopathic scoliosis or pectus excavatum (PE) repair received methadone intraoperatively (0.1 mg/kg, maximum 5 mg) and postoperatively every 12 hours for 3-5 doses in a multimodal analgesic protocol. Blood samples were collected up to 72 hours postoperatively and analyzed for R-methadone and S-methadone, 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidene (EDDP) metabolites, and alpha-1 acid glycoprotein (AAG), the primary methadone-binding protein. Peak and trough concentrations of enantiomers, total methadone, and AAG levels were correlated with clinical outcomes including pain scores, postoperative nausea and vomiting (PONV), respiratory depression, and QT interval prolongation.

RESULTS

The study population included 38 children (10.8-17.9 years): 25 PSF and 13 PE patients. Median total methadone peak plasma concentration was 24.7 (interquartile range [IQR], 19.2-40.8) ng/mL and the median trough was 4.09 (IQR, 2.74-6.4) ng/mL. AAG concentration almost doubled at 48 hours after surgery (median = 193.9, IQR = 86.3-279.5 µg/mL) from intraoperative levels (median = 87.4, IQR = 70.6-115.8 µg/mL; P < .001), and change of AAG from intraoperative period to 48 hours postoperatively correlated with R-EDDP (P < .001) levels, S-EDDP (P < .001) levels, and pain scores (P = .008). Median opioid usage was minimal, 0.66 (IQR, 0.59-0.75) mg/kg morphine equivalents/d. No respiratory depression (95% Wilson binomial confidence, 0-0.09) or clinically significant QT prolongation (median = 9, IQR = -10 to 28 milliseconds) occurred. PONV occurred in 12 patients and was correlated with morphine equivalent dose (P = .005).

CONCLUSIONS

Novel multiple small perioperative methadone doses resulted in safe and lower blood methadone levels, <100 ng/mL, a threshold previously associated with respiratory depression. This methadone dosing in a multimodal regimen resulted in lower blood methadone analgesia concentrations than the historically described minimum analgesic concentrations of methadone from an era before multimodal postoperative analgesia without postoperative respiratory depression and prolonged corrected QT (QTc). Larger studies are needed to further study the safety and efficacy of this methadone dosing strategy.

Neuroanesthesiology Update

This review summarizes the literature published in 2020 that is relevant to the perioperative care of neurosurgical patients and patients with neurological diseases as well as critically ill patients with neurological diseases. Broad topics include general perioperative neuroscientific considerations, stroke, traumatic brain injury, monitoring, anesthetic neurotoxicity, and perioperative disorders of cognitive function.

Hemodynamically significant cardiac arrhythmias during general anesthesia for spine surgery: A case series and literature review

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Although multiple factors have been implicated, our case series highlights SSEP stimulation as a common etiology of arrhythmia.

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Significant bradycardia and CA during spine surgery does not always require termination of the surgical procedure.

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Decision making should be undertaken in each case individually based on patient condition and circumstances of each event.

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Surgeons and anesthesiologists should be aware of and prepared to treat significant cardiac arrhythmias during spine surgery even in otherwise healthy patients without known risk factors.

Background context

Hemodynamically significant bradycardia and cardiac arrest (CA) are rare under general anesthesia (GA) for spine surgery. Although patient risks are well defined, emerging data implicate surgical, anesthetic and neurologic factors which should be considered in the immediate management and decision to continue or terminate surgery.

Purpose

To characterize causes and contributors to significant arrhythmias during spine surgery. We also provide an updated literature review to inform spine care teams and aid in the management of intraoperative bradycardia and CA.

Study design

Case series and literature review

Patient sample

Six patients who underwent spine surgery from 03/2016 to 01/2020 at a single institution and developed unexpected hemodynamically significant arrhythmia

Outcome measures

Our primary outcome was to identify potential risk factors of interest for significant arrhythmia during spine surgery.

Methods

Medical records of patients who underwent spine surgery from 03/2016 to 01/2020 at a single institution and developed unexpected hemodynamically significant arrhythmia during spine surgery were identified from a departmental Quality Assurance Database. We evaluated the presence/absence of patient, surgical, anesthetic and neurologic risk factors and estimated the most likely etiology of the event, immediate and subsequent management, whether surgery was postponed or continued and outcomes.

Results

We found a temporal relationship of bradyarrhythmia and CA after somatosensory evoked potential (SSEP) stimulation in 4/6 cases and pharmacy/polypharmacy in 2/6. Surgery was completed in 4/6 patients, and terminated in 2/6 (subsequently completed in both). We found no adverse outcomes in any patients. Our literature review predominately identified case reports for guidance to support decision making. New literaure suggests peripheral nerve blocks and opioid-sparing anesthetic agents should also be considered.

Conclusions

Significant bradycardia and CA during spine surgery does not always require termination of the surgical procedure. Decision making should be undertaken in each case individually, with an updated awareness of potential causes. The study also suggests the need for large prospective studies to adequately assess incidence, risk factors and outcomes.

Intra-operative methadone effect on quality of recovery compared with morphine following laparoscopic gastroplasty: a randomised controlled trial

The effect of intra-operative intravenous methadone on quality of postoperative recovery was compared with morphine after laparoscopic gastroplasty. We included 137 adult patients with a body mass index > 35 kg.m^-2 who underwent bariatric surgery. Patients were allocated at random to receive either intra-operative methadone (n = 69) or morphine (n = 68). All patients received the same postoperative care and analgesia. The primary outcome of postoperative quality of recovery was assessed using the Quality of Recovery-40 questionnaire total score 24 h after surgery. Secondary outcomes were assessed in the post-anaesthesia care unit the night of the day of surgery (T1), in the morning after surgery (T2); and at night on the day following surgery (T3). The median (IQR [range]) total Quality of Recovery-40 questionnaire score of 194 (190-197 [165-200]) was higher (p < 0.0001) in the methadone group compared with the score of 181 (174-185.5 [121-200]) in the morphine group. In the post-anaesthesia care unit, the pain burden; incidence of nausea and vomiting; rescue morphine dose; and time to discharge, were significantly lower in the methadone group. On the ward, the methadone group had a lower: incidence of rescue morphine requests at T1 (5.8 vs. 54.4%, p < 0.0001) and T2 (0 vs. 20.1%, p < 0.0001); and incidence of nausea (21.7 vs. 41.2%, p = 0.014), compared with the morphine group. We conclude that intra-operative intravenous methadone improved quality of recovery in patients who underwent laparoscopic gastroplasty, compared with intra-operative morphine. Methadone also reduced postoperative pain, postoperative opioid consumption and the incidence of opioid-related adverse events.

Pharmacogenomics of methadone: a narrative review of the literature

Background: Methadone, a synthetic opioid with longer duration of action and lower abuse potential compared with morphine, is used to prevent opioid withdrawal, as well as to manage chronic and acute surgical pain. The variability in response to methadone has been widely recognized. The purpose of this article is to review the literature on the pharmacogenetic factors underlying this variability. Materials & methods: This is a narrative overview of the literature on the genetic variants affecting pharmacodynamics and pharmacokinetics of methadone, retrieved from searches of databases such as PubMed and google scholar. Discussion: Clinical responses to methadone may be affected by genetic variants in the opioidergic, dopaminergic and neurotrophic pathways. Polymorphisms in genes related to disposition and elimination of methadone alter the pharmacokinetics, and possibly pharmacodynamics of methadone. Cytochrome P450 enzymes and P-glycoprotein variants contribute to the interindividual variability in methadone pharmacokinetics. Evidence for single gene variants affecting methadone response remains weak. Multiple genetic variants must be considered in conjunction to improve predictive ability. Conclusion: Evidence remains scarce at this time, to recommend pharmacogenetic testing before methadone administration. Well-powered clinical studies are needed with population pharmacokinetic-pharmacodynamic modeling and multigenetic signature-based predictions to enable tailored use of methadone in clinical practice.