Intraoperative Methadone Is Associated with Decreased Perioperative Opioid Use Without Adverse Events: A Case-Matched Cohort Study

The role of methadone in cardiac surgery for management of postoperative pain

Background

This retrospective study evaluated the efficacy and safety of intraoperative methadone compared with short-acting opioids.

Methods

Patients undergoing cardiac surgery with cardiopulmonary bypass (n=11 967) from 2018 to 2023 from a single health system were categorised into groups based on intraoperative opioid administration: no methadone (Group O), methadone plus other opioids (Group M+O), and methadone only (Group M).

Results

Patients in Groups M and M+O had lower mean pain scores until postoperative day (POD) 7 compared with Group O after adjusting for covariates (P<0.01). Both Groups M and M+O had lower total opioid administered compared with Group O for all days POD0-POD6 (all P<0.001). The median number of hours until initial postoperative opioid after surgery was 2.55 (inter-quartile range [IQR]=1.07-5.12), 6.82 (IQR=3.52-12.98), and 7.0 (IQR=3.82-12.95) for Group O, Group M+O, and Group M, respectively. The incidence of postoperative complications did not differ between groups.

Conclusions

Intraoperative administration of methadone was associated with better pain control without significant side-effects after cardiac surgery.

Short-acting versus long-acting opioids for pediatric postoperative pain management

INTRODUCTION

Opioids are potent analgesics commonly used to manage children's moderate to severe perioperative pain in children. A wide range of short and long-acting opioids are used to treat surgical pain and will be reviewed in this article.

AREAS COVERED

Both short- and long-acting opioids contain unique therapeutic benefits and adverse effects; however, due to the side effect profile and safety concerns, lack of familiarity, and evidence with long-acting opioids to treat surgical pain, shorter-acting opioids have traditionally been used in children. Almost all opioids work by binding to the mu receptor. Methadone, a long-acting opioid, is an exception because it also has beneficial N-methyl-D-aspartate antagonist properties. Clinically methadone's properties could translate to improved analgesic outcomes, reduced risk of adverse events, less risk for acute hyperalgesia, tolerance and abuse potential, faster recovery, and reduced risk for chronic persistent surgical pain. This review article summarizes and compares the evidence of commonly used short and long-acting opioids for perioperative pain control in the pediatric population.

EXPERT OPINION

Individualized methadone therapy using pharmacogenomics has the potential to transform opioid use in pain management by improving patient safety and analgesic outcomes, thereby addressing the gaps in current standardized ERAS protocols.

Quantifying the impact of reduced opioid use in patients after emergency laparotomy

BACKGROUND

Emergency laparotomies have high rates of morbidity and mortality. The evaluation and management of pain are crucial, as poorly managed pain may contribute to postoperative complications and increase the risk of mortality. This study aims to describe the relationship between opioid use and opioid-related adverse effects and identify what constitutes appropriate dose reductions to elicit clinically relevant benefits.

METHODS

This was a retrospective, observational study of patients presenting for emergency laparotomy due to trauma from 2014 to 2018. The primary objective was to define clinical outcomes that may be significantly affected by changes in milligrams of morphine equivalent during the first 72 hours postoperatively; additionally, we sought to quantify the approximate differences in morphine equivalent that correlate with clinically meaningful outcomes such as hospital length of stay, pain scores, and time to first bowel movement. For descriptive summaries, patients were categorized into low, moderate, and high groups based on morphine equivalent requirements of 0 to 25, 25 to 50, and >50, respectively.

RESULTS

A total of 102 (35%), 84 (29%), and 105 (36%) patients were stratified into the low, moderate, and high groups, respectively. Mean pain scores for postoperative days 0 to 3 (P = .034), time to first bowel movement (P = .002), and nasogastric tube duration (P = .003) were the clinical outcomes found to be significantly associated with morphine equivalent. Estimated clinically significant reductions in morphine equivalent for these outcomes ranged from 194 to 464.

CONCLUSION

Clinical outcomes, such as pain scores, and opioid-related adverse effects, such as time to first bowel movement and nasogastric tube duration, may be linked with the amount of opioids used.

What we know and what we don't know about the perioperative use of methadone in children and adolescents

Postoperative pain control is essential to optimizing patient outcomes, improving satisfaction, and allowing patients to resume their baseline functional activities. Methadone, a synthetic mu-opioid agonist, has multiple pharmacologic properties that may be optimal for perioperative use. Compared to other opioids, methadone has a longer duration of action, rapid onset, extended dosing intervals, high oral bioavailability, low cost, lack of active metabolites, and action on multiple receptors. The current literature examining the use of methadone in the perioperative care of children and adolescents is limited and most often reported within the context of spine or cardiothoracic surgery. Overall, these studies support the hypothesis that perioperative methadone in pediatric patients may decrease postoperative pain, opioid consumption, length-of-stay, and the incidence of some opioid-related side effects, like constipation and urinary retention. A variety of protocols for the perioperative use of methadone have been described, including a single intraoperative dose as well as multiple small doses within multimodal pain protocols. The superiority of these protocols has not been established. Like all opioids, methadone has a side effect profile which includes nausea, vomiting, reduced GI motility, sedation, and respiratory depression at high doses. There is also a concern that it can cause QTc prolongation in patients. The primary aim of this educational review is to examine the pharmacologic data, published perioperative protocols, dosing considerations, and risks and benefits associated with inclusion of methadone in analgesic regimens for surgical patients. A secondary aim is to introduce opportunities for research around the perioperative use of methadone in children and adolescents. Based on our review, we would prioritize establishing optimal procedure-specific methadone protocols, determining generalizability for use in routine pediatric surgeries, and investigating methadone safety and efficacy prospectively as the primary opioid for pain management in the postanesthesia care unit or postsurgical floors.

Management of routine postoperative pain for children undergoing cardiac surgery: a Paediatric Acute Care Cardiology Collaborative Clinical Practice Guideline

BACKGROUND

Pain following surgery for cardiac disease is ubiquitous, and optimal management is important. Despite this, there is large practice variation. To address this, the Paediatric Acute Care Cardiology Collaborative undertook the effort to create this clinical practice guideline.

METHODS

A panel of experts consisting of paediatric cardiologists, advanced practice practitioners, pharmacists, a paediatric cardiothoracic surgeon, and a paediatric cardiac anaesthesiologist was convened. The literature was searched for relevant articles and Collaborative sites submitted centre-specific protocols for postoperative pain management. Using the modified Delphi technique, recommendations were generated and put through iterative Delphi rounds to achieve consensus.

RESULTS

60 recommendations achieved consensus and are included in this guideline. They address guideline use, pain assessment, general considerations, preoperative considerations, intraoperative considerations, regional anaesthesia, opioids, opioid-sparing, non-opioid medications, non-pharmaceutical pain management, and discharge considerations.

CONCLUSIONS

Postoperative pain among children following cardiac surgery is currently an area of significant practice variability despite a large body of literature and the presence of centre-specific protocols. Central to the recommendations included in this guideline is the concept that ideal pain management begins with preoperative counselling and continues through to patient discharge. Overall, the quality of evidence supporting recommendations is low. There is ongoing need for research in this area, particularly in paediatric populations.

Novel use of methadone intraoperatively in pediatric burn patients

Burn injury in children can cause severe and chronic physical and mental sequelae. Opioids are a mainstay in burn pain management but increasing utilization in this country has led to concern for their continued use and potential for dependence. Methadone is a long-acting analgesic that targets the N-methyl-D-aspartate (NMDA) receptor in addition to the mu opioid receptor and has benefit in adult burn patients. However, its use in the pediatric burn population has been less robustly studied. This is a retrospective cohort study at a single Level 1 Burn Center whose primary aim is to compare opioid utilization 36 hours postoperatively between pediatric burn patients who received intraoperative, intravenous methadone and those who did not. Secondary aim was to describe differences in methadone-related complications between the cohorts. There was decreased opioid utilization measured by median morphine equivalents per kilogram (ME/kg) postoperatively in the methadone cohort compared to the control cohort (0.54mg/kg v. 0.77mg/kg, p = 0.18). No adverse events were noted upon chart review. The data suggests methadone use is beneficial in pediatric burn patients, but further prospective studies are warranted on a larger population.

Impact of intraoperative methadone use on postoperative opioid requirements after cardiac surgery

DISCLAIMER

In an effort to expedite the publication of articles, AJHP is posting manuscripts online as soon as possible after acceptance. Accepted manuscripts have been peer-reviewed and copyedited, but are posted online before technical formatting and author proofing. These manuscripts are not the final version of record and will be replaced with the final article (formatted per AJHP style and proofed by the authors) at a later time.

PURPOSE

Inadequate pain control after cardiac surgery increases postoperative morbidity. Increasing evidence suggests that perioperative intravenous (IV) methadone results in improved analgesia. This study evaluated the effect of intraoperative IV methadone on postoperative opioid requirements and surgical recovery.

METHODS

A retrospective review of patients undergoing coronary artery bypass graft (CABG), valvular surgery or both between April 2017 and August 2018 was conducted. Patients were separated into a usual care cohort of those who received short-acting opioids (ie, IV fentanyl, hydromorphone, or morphine) alone or a methadone cohort of those who received IV methadone plus short-acting opioids. Opioid requirements were assessed within the first 24 hours of surgery (postoperative day [POD] 0) and 25 to 48 hours after surgery (POD 1) as oral morphine milligram equivalents (MME). Postoperative pain scores, adjunctive analgesia, time to extubation, use of noninvasive respiratory support (continuous positive airway pressure [CPAP] or bilevel positive airway pressure [BiPAP]), and intensive care unit (ICU) and hospital length of stay (LOS) were also evaluated.

RESULTS

A total of 117 patients were evaluated (methadone cohort, n = 52; usual care cohort, n = 65). Median cumulative intraoperative opioid consumption was less in the methadone cohort (150 MME vs 314.1 MME; P < 0.0001). The methadone cohort required 44% fewer MME than the usual care cohort on POD 0 (median MME, 15.8 vs 36; P = 0.025), with low and not significantly different opioid use in both cohorts on POD 1 (15.5 MME vs 7.5 MME; P = 0.47). Weight-based methadone dosing ranged from 0.1 to 0.4 mg/kg (mean, 0.22 mg/kg). There were no significant differences in pain scores, time to extubation, use of CPAP or BiPAP, or ICU and hospital LOS.

CONCLUSION

Intraoperative IV methadone in cardiac surgery patients was safe and significantly reduced intraoperative and postoperative opioid requirements on POD 0.

Intraoperative Methadone Reduces Postoperative Opioid Requirements in Nuss Procedure for Pectus Excavatum

INTRODUCTION

Surgical correction of pectus excavatum by Nuss procedure, commonly referred to as minimally invasive repair of pectus excavatum (MIRPE), often results in significant postoperative pain. This study investigated whether adding intraoperative methadone would reduce the postoperative opioid requirement during admission for patients undergoing MIRPE.

METHODS

A retrospective cohort chart review was conducted for 40 MIRPE patients between 2018 and 2020. Patients were stratified into 2 groups: those who received multimodal anesthesia (MM, n = 20) and those who received multimodal anesthesia with the addition of intraoperative methadone (MM + M, n = 20). Data collected included total opioid consumption during hospital stay (morphine milligram equivalents [MMEs]), hospital length of stay (LOS), pain scores, time to ambulation, and time to tolerating solid food.

RESULTS

Addition of intraoperative methadone for patients undergoing MIRPE significantly reduced postoperative opioid requirements (MME/kg) during admission (P = .007). On average, patients in the MM group received 1.61 ± .55 MME/kg while patients in the MM + M group received 1.16 ± .44 MME/kg. Hospital opioid (non-methadone) total was also significantly reduced between the MM (1.87 ± .54) and MM + M group (1.37 ± .46), P = .003. There was no significant difference in hospital opioid total MME/kg administered between the groups. There were no significant differences observed in hospital LOS, pain scores, time to ambulation, or time to toleration of solid food.

DISCUSSION

Incorporating intraoperative methadone for patients undergoing MIRPE reduced postoperative opioid requirements and hospital opioid (non-methadone) totals without a significant change in pain scores. Patients undergoing the Nuss procedure may benefit from the administration of intraoperative methadone.

Intraoperative Methadone Use in Cardiac Surgery: A Systematic Review

OBJECTIVE

To investigate the effects of intraoperative methadone to standard of care opioids such as fentanyl and morphine on pain scores, opioid consumption, and adverse effects in adults undergoing cardiothoracic surgery.

METHODS

The literature was reviewed on PubMed, Embase, Cochrane Library, and Google Scholar, followed by a manual search using reference lists of the identified articles. Search terms included a combination of intraoperative methadone, methadone, and cardiac surgery. Our review includes four studies published between 2011 and 2020. Quality assessment of the studies was performed.

RESULTS

The initial search identified 715 articles with 461 duplicates removed, and 236 eliminated based on inclusion and exclusion criteria. Eighteen articles underwent full-text review. Four studies evaluating a total of 435 patients with various cardiothoracic procedures were included in this review. We found that intraoperative methadone decreases acute postoperative pain and reduces postoperative opioid consumption in the first 24 postoperative hours in patients who received 0.1-0.3 mg/kg intraoperative methadone in comparison to morphine and fentanyl. No difference was found in adverse effects between the groups. Quality assessment of the studies showed a low risk of bias in three of the randomized controlled trials and a high risk of bias in the retrospective review because of the baseline confounding bias in the study design.

CONCLUSIONS

Intraoperative methadone use reduces acute postoperative pain and lowers opioid consumption in comparison to morphine and fentanyl. Initial results suggest that methadone may be an equivalent opioid to be administered during cardiothoracic procedures to reduce acute post-surgical pain, though further research is warranted.

Methadone: applications in pediatric anesthesiology and critical care medicine

Like morphine, methadone is a pure agonist at the µ opioid receptor. However, in distinction to morphine which has an elimination half-life of 2-3 h, methadone has an elimination half-life of 24-36 h. In addition to its effects at the µ opioid receptor, methadone is an antagonist at the N-methyl-D-aspartate (NMDA) receptor and also inhibits the reuptake of the neurotransmitters, serotonin and norepinephrine, in the central nervous system. Given its long half-life and high oral bioavailability, methadone has had a primary role in the outpatient treatment of patients with a history of opioid abuse or addiction. However, its unique pharmacology and cellular effects make it a valuable agent in the treatment of both acute and chronic pain of various etiologies. The following manuscript reviews the pharmacologic properties of methadone and discusses its clinical applications in the practice of pediatric anesthesiology and pediatric critical care medicine.

Postoperative Nausea and Vomiting and Pain After Robotic-Assisted Mitral Valve Repair

OBJECTIVE

To determine the rate and clinical factors associated with postoperative nausea and vomiting (PONV) and severe pain after robotic-assisted mitral valve repair.

DESIGN

Retrospective chart review.

SETTING

Major quaternary academic medical center.

PARTICIPANTS

Adult patients undergoing robotic-assisted mitral valve repair from May 5, 2018 through September 13, 2019.

INTERVENTIONS

Participant electronic medical records were abstracted for clinical characteristics, PONV within the first 72 postoperative hours, episodes of severe pain (defined as pain score ≥7 using an 11-point numerical pain rating scale), and opioid use within the first 24 postoperative hours. Multivariate analyses were performed.

MEASUREMENTS AND MAIN RESULTS

Of 124 participants, PONV was noted in 83 (67%; 95% confidence interval [CI] 58%-75%) patients and severe pain in 96 (77%, 95% CI 69%-84%) patients. The median (interquartile range) time to PONV was 6.1 (3.7-14.7) hours. After adjusting for age, sex, and duration of surgery, pre-incisional use of methadone was associated with reduced risk for severe pain (odds ratio 0.40 [95% CI 0.16-0.99]; p = 0.048) and a lower 24-postoperative hour opioid requirement (estimate -29.0 mg intravenous morphine equivalents [95% CI -46.7 to -11.3]; p = 0.006). However, methadone was not associated with a reduction of the cumulative opioid dose (intraoperative and 24-hour postoperative opioid dose; p = 0.248). Both severe pain and PONV were associated with longer hospital stay.

CONCLUSION

PONV and severe pain are common after robotic-assisted mitral valve repair. Peri-incisional methadone is associated with a modest decrease in the severe pain rate but without a reduction in opioid dose or hospital stay.