Background: Anesthesia services are a major contributor to healthcare sector greenhouse gas emissions. Interventions aimed to reduce waste are necessary. Reusable anesthesia circuits offer a sustainable alternative to single-use circuits. Their adoption in the United States remains limited. The objective of this project was to evaluate the feasibility, cost-effectiveness, and environmental impact of using FDA-approved reusable anesthesia circuits. Methods: Supported by the SMART QI framework, we evaluated the impact of switching to reusable circuits on elective electroconvulsive therapy (ECT) procedures. We measured waste generation, room preparation times, material costs, and projected system wide financial and greenhouse gas emissions impact. Greenhouse gas emissions were estimated using the Practice Greenhealth Scope 3 Emissions Accounting Tool. Descriptive statistics compared pre-and post-intervention outcomes, with statistical significance atp < 0.05. Results: We compared 185 ECT procedures: 98 single-use from pre-intervention and 87 reusable circuits from post-intervention. Preparation times did not change. Daily waste from reusable circuits was significantly lower than single-use circuits (99.2 g vs. 357.2 g, p < 0.001). Cost analysis revealed 40 % reduction in median per-case expenditures with reusable circuits ($4.30 vs. $8.50 per patient, p < 0.001).Scope 3 greenhouse gas emissions per procedure decreased nearly 50 % (1.09 kgCO2vs. 2.57 kgCO2, p < 0.001). Modeling of institutional-level data projected an annual cost savings of $108,860 and a reduction of 45,062.4 kgCO2if reusable circuits were implemented across all hospitals in the network. Discussion: Reusable anesthesia circuits can significantly reduce hospital waste, lower costs, and decrease carbon emissions without compromising procedural efficiency.

Objective:To identify and categorize the pain instruments used to evaluate phantom limb pain (PLP), phantom limb sensations (PLSs), and residual limb pain (RLP) stratified by frequency of use, instrument completion time, and inclusion of descriptive terms to distinguish between the 3 phenomena. Data Sources:MEDLINE/PubMed and Google Scholar from 1986 to 2024. Study Selection:Cross-sectional, cohort, and case-control studies investigating the prevalence of PLP in adults (18y or older) with surgical and traumatic upper or lower limb amputation. Data Extraction:Studies were identified and their methods were evaluated for mention of instruments used to assess for PLP. Tools were then evaluated for frequency of usage, completion time, differentiation of pain and sensations after limb amputation, and qualitative assessment using descriptor words associated with PLP and PLSs. Data Synthesis:The review included 44 studies and identified 25 tools (5 unidimensional and 20 multidimensional). Unidimensional pain scales, particularly the Numeric Rating Scale, were the most frequently used. Of the multidimensional instruments identified, 9 of them were specific to PLP, and 6 distinguished between PLP, PLS, and RLP. Only one multidimensional instrument that was specific to PLP used descriptor words to differentiate between PLP and PLS. No tool was assessed for all 3 conditions and used descriptor words to distinguish between PLP and PLSs. Conclusions:Based on this systematic review, no PLP-specific instrument is suitable for standardizing the diagnosis of PLP in its current form. Further research is needed to establish a standardized tool that can reliably distinguish between PLP, PLS, and RLP while incorporating qualitative assessments to ensure accurate diagnosis.

BACKGROUND:Physiological stress and reserve negatively impact surgical patients. STUDY DESIGN:Patients undergoing elective surgery were included. Operative stress was defined by operative stress score (OSS) and frailty by Risk Analysis Index. RESULTS:A total of 6,182 patients were included. With an OSS score of 5, patients were older (67 vs 65.4 years), more likely men (70.2 vs 53.9), had longer length of stay (9.7 vs 3.3 days), and higher mortality (30 days: 3.9 vs 0.7; 90 days: 6.27 vs 1.37; and 120 days: 8.24 vs1.8). Frail patients were older (76 vs 65.4 years), more likely men (68.9 vs 53.9), had higher mortality (30 days: 1.6 vs 0.7; 90 days: 4.4 vs 1.73; and 120 days: 4.7 vs 1.8,), and longer length of stay (4.8 vs 3.3 days). Cost increased with OSS. Net income differed between OSS categories; the highest was OSS of 4 ($9,350 vs mean $5,213, p < 0.001). Total charges and cost increased with increasing frailty (p < 0.0001). There is a decrease in net income with frailty. Overall, for frail patients, there was a net negative income ($-3,658 vs $5,231, p < 0.0001). Trends were similar with each OSS category (1/2, 3, 4, and 5). Net income was negative for almost all OSS categories in frail (1/2: $-3,658; 3: $-4,440; 4: $971; and 5: $-9,932). Net income was positive for commercially insured but negative for most with Medicare. CONCLUSIONS:Increasing OSS was associated with increased cost and profit, and frailty was associated with increased cost and decreased profit. Most with Medicare are cared for at a loss.

OBJECTIVE:To identify predictors of persistent opioid use in opioid-naïve individuals undergoing total joint arthroplasty. DESIGN:Retrospective cohort study. SETTING:Maine Health System. SUBJECTS:Opioid-naïve patients who underwent at least one total joint arthroplasty (knee, hip, or shoulder) between 2015 and 2020. METHODS:Least Absolute Shrinkage and Selection Operator (LASSO) logistic regression was used to create a predictive model for persistent opioid use after surgery from a US Electronic Health Record dataset in the Observational Medical Outcomes Partnership Common Data Model format. 75% of the data was used to build the LASSO model using 10-fold cross-validation and 25% of the data was used to determine the optimal probability threshold for predicting the binary outcome. RESULTS:Out of 6432 patients, 12.3% (792) were identified as having persistent opioid use across combined total joint arthroplasties defined as at least one opioid prescription between 90 days and 1 year after surgery. Patients with persistent opioid use were more likely to be current smokers (OR 1.65), use antidepressants (OR 1.76), or have a diagnosis of post-traumatic stress disorder (OR 2.07) or a substance-related disorder (OR 1.69). Other factors associated with persistent opioid use included back pain (OR 1.43), dementia (OR 1.65), and body mass index over 40 (OR 2.50). The probability of persistent opioid use was not associated with age, sex, or ethnicity. CONCLUSIONS:This predictive model for persistent opioid use after total joint arthroplasty shows promise as an evidence-based, validated, and standardized tool for identifying high-risk patients before surgery in order to target strategies and interventions to reduce the reliance on opioids for postoperative pain control.

The removal of the X-waiver in the Mainstreaming Addiction Treatment (MAT) Act of 2023 has substantial implications for buprenorphine prescribing as one of the options to treat opioid use disorder. The purpose of this commentary is to discuss the unanswered questions regarding buprenorphine in the intensive care unit (ICU) including how the passage of the MAT Act will affect ICU providers, which patients should receive buprenorphine, what is the most appropriate route of administration and dose of buprenorphine, what medications interact with buprenorphine, and how can transitions of care be optimized for these patients.

Background: Transversus abdominis plane blocks are an established method of postoperative analgesia for abdominopelvic surgeries. Liposomal bupivacaine is an extended-release formulation of bupivacaine providing up to 72 h of analgesia. This study aims to determine if transversus abdominis plane blocks performed with liposomal bupivacaine are associated with reduced opioid consumption and level of pain intensity compared to conventional bupivacaine in patients undergoing lower abdominal surgery. Methods: This retrospective cohort study was conducted at a single institution between December 2020 and December 2021. After institutional review board approval, we identified patients who underwent lower abdominopelvic surgery with transversus abdominis plane blocks done with liposomal or conventional bupivacaine and collected demographic, clinical, and procedural information for analysis. We compared total opioid consumption over 72-h postoperatively in milligram morphine equivalents (MME), frequency of opioid utilization, and average level of pain intensity between groups. These outcomes were also evaluated after adjusting for covariates. Data were presented as mean +/- SD, median [IQR] or frequency (%), as appropriate; p < 0.05 was accepted as significant. Results: A total of 178 patients met inclusion criteria, with 79 patients receiving an admixture of liposomal bupivacaine and conventional bupivacaine and 99 patients receiving conventional bupivacaine. The liposomal bupivacaine group had a median opioid consumption 72-h postoperatively of 47.5 [18-91.8] MME compared to 88 [43.8-160] MME in the conventional bupivacaine group, p = 0.045. Differences in opioid consumption between the groups did not reach statistical significance after adjustment for demographic and clinical characteristics, p = 0.11. There was no significant difference in frequency of opioid use or average pain intensity. Conclusion: Transversus abdominis plane blocks using an admixture of liposomal bupivacaine conventional bupivacaine are not associated with decreased opioid consumption or reduced pain up to 72 h following elective abdominopelvic surgery.

Background Colorectal cancer is a leading cause of cancer-related death. Adenomas and serrated polyps are precursors of colorectal cancer, with serrated polyps being more difficult to detect during colonoscopy. The relationship between propofol use and polyp detection remains unclear. The authors investigated the association of propofol-based versus mild–moderate sedation on adenoma and serrated polyp detection during colonoscopy. Methods This retrospective cohort study used observational data from the New Hampshire Colonoscopy Registry. Patients aged greater than 50 yr with screening or surveillance colonoscopies between January 1, 2015, and February 28, 2020, were included. Exclusions were diagnostic examinations, no sedation, missing pathology data, and poor bowel preparation. Multivariate logistic regression was used to evaluate differences in polyp detection between propofol and moderate sedation in the full sample while adjusting for covariates. Propensity score adjustment and clustering at the endoscopist level were used in a restricted sample analysis that included endoscopists and facilities with between 5% and 95% propofol sedation use. Results A total of 54,063 colonoscopies were analyzed in the full sample and 18,998 in the restricted sample. Serrated polyp prevalence was significantly higher using propofol (9,957 of 29,312; 34.0% [95% CI, 33.4 to 34.5%]) versus moderate sedation (6,066 of 24,751; 24.5% [95% CI, 24.0 to 25.1%]) in the full sample and restricted samples (1,410 of 4,661; 30.3% [95% CI, 28.9 to 31.6%] vs. 3,690 of 14,337; 25.7% [95% CI, 25.0 to 26.5%]). In the full sample multivariate logistic regression, propofol was associated with higher neoplasm (adjusted odds ratio, 1.25 [95% CI, 1.21 to 1.29]), adenoma (odds ratio, 1.07 [95% CI, 1.03 to 1.11]), and serrated polyp detection (odds ratio, 1.51 [95% CI, 1.46 to 1.57]). In the restricted sample using inverse probability of treatment weighted propensity score adjustment and clustering at the endoscopist level, an attenuated but statistically significant effect size was observed for serrated polyps (odds ratio, 1.13 [95% CI, 1.07 to 1.19]), but not for adenomas (odds ratio, 1.00 [95% CI, 0.95 to 1.05]) or any neoplastic lesion (odds ratio, 1.03 [95% CI, 0.98 to 1.08]). Conclusions Propofol sedation during colonoscopy may be associated with improved detection of serrated polyps, but not adenomas. Editor’s Perspective What We Already Know about This Topic What This Article Tells Us That Is New

Objective: This study aimed to determine whether there is a difference in pain scores and opioid consumption after elective surgery in patients maintained on methadone or buprenorphine for opioid use disorder (OUD). Additionally, we investigated the impact of continuing or discontinuing methadone or buprenorphine on post-operative pain outcomes. Design: A single-center retrospective cohort study. Setting: Tertiary care medical center. Patients and participants: Adults aged 18 years or older with OUD maintained on buprenorphine or methadone who underwent elective surgery between January 1, 2017, and January 1, 2021. Interventions: Patients were identified through electronic medical records, and demographic and clinical data were collected. Main outcome measures: The primary outcome was opioid consumption at 24 hours post-operatively, measured in milligram morphine equivalents. The secondary outcome was opioid consumption and pain scores up to 72 hours postoperatively, assessed using a numeric rating scale. Results: This study included 366 patients (64 percent on buprenorphine and 36 percent on methadone). Opioid utilization significantly increased when buprenorphine was not administered post-operatively. Both groups exhibited comparable total opioid consumption during the post-operative period. In the buprenorphine cohort, pain scores differed significantly based on the receipt of medications for OUD post-operatively. Conclusions: This study reinforces existing evidence supporting the continuation of medications for opioid use disorder, specifically buprenorphine and methadone, during the perioperative period. Dissemination of guideline recommendations is essential to ensure optimal post-operative pain management for this patient population.

Total knee arthroplasty (TKA) is a commonly performed procedure to alleviate pain and improve functional limitations caused by end-stage joint damage. Effective management of postoperative pain following TKA is crucial to the prevention of complications and enhancement of recovery. Adductor canal blocks (ACB) with conventional bupivacaine (CB) provide adequate analgesia after TKA, but carry a risk of rebound pain following block resolution. Liposomal bupivacaine (LB) is an extended-release local anesthetic that can provide up to 72 h of pain relief. The objective of this study was to compare postoperative outcomes between ACBs using LB and CB after TKA. This single institution, prospective, randomized, clinical trial enrolled patients scheduled for TKA. Participants were randomized to receive ACB with either LB or CB. Pain scores up to 72 h postoperatively were assessed as the primary outcome. Opioid consumption and length of stay were evaluated as secondary outcomes. A total of 80 patients were enrolled. Demographic and clinical characteristics were similar between the two groups. LB group showed significantly lower cumulative opioid use during the 72 h evaluated (P = 0.016). There were no differences in pain scores or length of stay between the groups. The study demonstrated that LB ACBs led to significantly lower opioid consumption in the days following TKA without affecting pain scores or length of stay. This finding has important implications for improving postoperative outcomes and reducing opioid use in TKA patients. Previous studies have reported inconsistent results regarding the benefits of LB, highlighting the need for further research. This project was retrospectively registered with clinicaltrials.gov ( NCT05635916 ) on 2 December 2022.

Purpose There are hospitalized patients with chronic opioid use who will experience signs and symptoms of opioid withdrawal who were not on medications for opioid use disorder (OUD) prior to admission, do not want to start or are unable to start medications for OUD during admission, and want to limit or avoid the use of opioids. The purpose of this scoping review was to assess the potential effectiveness and safety of using non-opioid agents for managing acute opioid withdrawal in acute care settings.Methods PubMed (inception to 2024), Embase (inception to 2024), and Cochrane Library (inception to 2024) were the databases evaluated for the literature search. Bibliographies of full-text articles were reviewed for additional relevant papers.Results Twenty-eight studies evaluating nonopioid agents for managing acute opioid withdrawal were identified in the literature search. The agents could be divided into 4 broad mechanistic categories: alpha-adrenergic receptor agonists, N-methyl-d-aspartate (NMDA) antagonists, gamma-aminobutyric acid (GABA) modulators, and serotonergic agents. Of these drug classes, the available literature suggests the alpha-adrenergic receptor agonists clonidine and lofexidine have the best evidence of efficacy as alternative agents for acute opioid withdrawal, although the majority of studies comparing such agents to opioids for opioid withdrawal were conducted well before the rise in synthetic opioid overdose deaths and have other methodologic issues that limit firm conclusions concerning efficacy and, particularly, safety.Conclusion For the nonopioid alternative agents that have been studied for acute opioid withdrawal, there is more evidence supporting the efficacy of alpha-adrenergic receptor agonists as opposed to NMDA antagonists, GABA modulators, or sertonergic agents; however, more research is needed regarding the efficacy and safety of nonopioid alternatives for acute opioid withdrawal in order to better guide clinical decision-making.

Introduction: Buprenorphine is highly effective for the treatment of opioid use disorder (OUD), and, in recent years, the rates of patients maintained on buprenorphine requiring critical care have been steadily increasing. Currently, no unified guidance exists for buprenorphine management during critical illness. Likewise, we do not know if patients maintained on buprenorphine for OUD are prescribed medications for OUD (MOUD) following hospital discharge or if buprenorphine management influences mu opioid agonist dispensing. Methods: In our cohort of adults over the age of 18 with OUD, receiving buprenorphine formulations in the 3 months preceding their ICU admission, we sought to investigate the relationship between receipt of MOUD and non-MOUD opioid prescribing up to 12 months following hospital discharge. This was a single-center, retro-spective cohort study approved by the MaineHealth institutional review board. The study analyzed differences in prescription rates between discharge and subsequent time points using chi square or Fisher's exact test, as appropriate. We performed analyses using SPSS Statistical Software version 28 (IBM SPSS Inc., Armonk, NY) with significance set at p < 0.05. Results: We identified a statistically significant increase in MOUD prescribing 3 months posthospital discharge in patients who received MOUD at time of discharge (87.9 % vs 40 % p = 0.002.) The study found a significant increase in nonbuprenorphine opioid prescribing in patients who did not receive an MOUD prescription at time of discharge (24.2 % vs 70 % p = 0.007). This trend persisted at the 6-month and 12-month time points; however, it did not reach statistical significance. Additionally, the study identified a significant reduction in the incidence of non-MOUD opioid dispensing in patients prescribed MOUD at each time point measured (p = 0.007, p < 0.001. p < 0.001 and p = 0.008 at discharge, 3, 6, and 12 months, respectively). Conclusions: These findings support continuing buprenorphine dispensing following hospital discharge.

OBJECTIVES:Buprenorphine maintenance for opioid use disorder (OUD) can present potential challenges for acute postoperative pain management. Provider practice and consistency of buprenorphine management strategies within institutions are unknown. This study aims to identify how providers nationwide manage patients on buprenorphine when they present for elective surgery.METHODS:A prospective survey of anesthesiologists was performed nationwide between November 2021 and March 2022. Survey respondents were selected from academic institutions identified using public databases and were also distributed to online social media platforms where members are required to verify medical licensure and hospital affiliation. Survey results were calculated and interpreted as the percentage rate of response.RESULTS:Survey invitations were sent to 190 institutions and returned 54 responses (28% response rate). An additional 12 completed surveys were obtained from online social media distribution resulting in 66 responses. Only 36% of respondents reported an established protocol for perioperative management of buprenorphine at their institution. Regarding consistency of buprenorphine management within institutions, the majority of respondents endorsed buprenorphine continuation without dose reduction in procedures where minimal pain was anticipated. However, there was a large discrepancy in buprenorphine management for surgeries with moderate-severe pain. Perioperative dosing frequency of buprenorphine was also inconsistent.CONCLUSIONS:The majority of institutions surveyed do not have an established protocol for perioperative buprenorphine management. In addition, there is provider variability in buprenorphine dosing for procedures with moderate-severe pain. This study highlights the need for dissemination of consensus guidelines for buprenorphine management.

For over two decades, the United States has grappled with our current opioid use disorder (OUD) epidemic [1]. In response, there has been a significant increase in the utilization of buprenorphine for OUD treatment, in part because of its distinctive pharmacologic properties [2, 3]. Compared to other opioids, buprenorphine has a long half-life, high binding affinity and slow dissociation from opioid receptors. Therefore, it resists displacement from these receptors when other opioids are used in conjunction [4]. The therapeutic doses of buprenorphine used for chronic pain treatment are significantly lower than those required for OUD treatment; therefore, opioid receptors are available when additional opioids are used concomitantly to enhance analgesia [5]. Conversely, when buprenorphine is used for OUD treatment, the diminished availability of opioid receptors resulting from the higher buprenorphine doses required can pose challenges for analgesic management [6]. Although routine practice involves continuing chronic pain buprenorphine formulations when acute pain is anticipated, the prevailing practice until recently has been withholding OUD dosed buprenorphine [4, 7]. Emerging evidence challenges these notions and supports opioid based analgesia can be achieved in parallel with OUD buprenorphine continuation [5, 8, 9]. In our previous retrospective study of surgical patients with OUD comparing patients where buprenorphine was continued or discontinued, we identified significantly higher outpatient opioid dispensing with buprenorphine discontinuation [5]. Similar findings were reported by Li et al., [8] where patients who continued buprenorphine perioperatively at various tapered doses received significantly fewer opioid prescriptions compared to those where buprenorphine was discontinued. Despite these studies, our recent national survey revealed significant variation in perioperative buprenorphine management practices [10]. Among surveyed anesthesiologists, only 36% of institutions had a protocol for buprenorphine management, and over a third endorsed either discontinuing buprenorphine in situations where moderate to severe pain was anticipated or adopting inconsistent management practices because of the lack of an institutional protocol. Premature discontinuation of buprenorphine is associated with an increased risk of opioid-induced relapse, making such practices concerning [11, 12]. The lack of clear guidance for buprenorphine management also extends to the critical care community. The 2018 Clinical Practice Guidelines for the Prevention and Management of Pain, Agitation/Sedation, Delirium, Immobility and Sleep Disruption in Adult Patients in the Intensive Care Unit did not provide recommendations for managing buprenorphine in patients maintained on this medication [13]. In our retrospective study evaluating the relationship between opioid exposure and buprenorphine administration in the intensive care unit, we identified the odds of receiving additional opioids were more than six times higher on days when buprenorphine was not administered compared to when it was given [14]. These findings support continuation of buprenorphine during critical illness, as it is associated with significantly decreased use of supplemental opioids, similar to current best practice established for perioperative populations. The above information reveals that high-level evidence on the analgesic outcomes based on buprenorphine management need to be conducted to establish a consensus for managing patients maintained on this medication [15]. In the face of the opioid crisis, evidence-based practices are crucial to guide clinicians and policymakers in providing the best possible care for patients maintained on buprenorphine. Aurora Quaye: Conceptualization (lead); investigation (equal); writing—original draft (lead); writing—review and editing (equal). Charlotte Crist: Conceptualization (supporting); investigation (supporting); writing—original draft (supporting); writing—review and editing (supporting). Simba Matoi: Conceptualization (supporting); investigation (supporting); writing—original draft (supporting); writing—review and editing (supporting). Yi Zhang: Conceptualization (equal); investigation (equal); writing—original draft (equal); writing—review and editing (equal). The authors would like to thank Janelle Richard for her assistance with formatting this manuscript for publication. None. Data sharing not applicable to this article as no datasets were generated or analysed for this Letter to the Editor.

The number of patients maintained on buprenorphine is steadily increasing. To date, no study has reported buprenorphine management practices for these patients during critical illness, nor its relationship with supplemental full‐agonist opioid administration during their hospital stay. In this single‐center retrospective study, we have explored the incidence of buprenorphine continuation during critical illness among patients receiving buprenorphine for the treatment of opioid use disorder. Additionally, we investigated the relationship between nonbuprenorphine opioid exposure and buprenorphine administration during the intensive care unit (ICU) and post‐ICU phases of care. Our study included adults maintained on buprenorphine for opioid use disorder admitted to the ICU between December 1, 2014, and May 31, 2019. Nonbuprenorphine, full agonist opioid doses were converted to fentanyl equivalents (FEs). Fifty‐one (44%) patients received buprenorphine during the ICU phase of care, with an average dose of 8 (8–12) mg/day. During the post‐ICU phase of care, 68 (62%) received buprenorphine, with an average dose of 10 (7–14) mg/day. Lack of mechanical ventilation and acetaminophen use were also associated with buprenorphine use. Full agonist opioid use was more frequent on days when buprenorphine was not given (odds ratio [OR], 6.2 [95% CI, 2.3–16.4]; P < .001). Additionally, the average cumulative dose of opioids given on nonbuprenorphine administration days was significantly higher both in the ICU (OR, 1803 [95% CI, 1271–2553] vs OR, 327 [95% CI, 152–708] FEs/day; P < 0.001) and after ICU discharge (OR, 1476 [95% CI, 962–2265] vs OR, 238 [95% CI, 150‐377] FEs/day; P < .001). Given these findings, buprenorphine continuation during critical illness should be considered, as it is associated with significantly decreased full agonist opioid use.

Introduction: An increasing number of individuals are taking buprenorphine for management of opioid use disorder (OUD). Pain control can be challenging when these patients develop acute pain requiring supplemental analgesia. Buprenorphine’s pharmacokinetic profile can render supplemental opioid-based analgesia ineffective. There is limited guidance on the optimal management of buprenorphine when acute pain is anticipated. Although there is growing acceptance that the risk of OUD relapse with buprenorphine discontinuation overshadows the risks of increased opioid utilization and difficult pain control with buprenorphine continuation, perioperative courses comparing buprenorphine dose reduction and full dose buprenorphine continuation have yet to be investigated. Here, we describe the protocol for our randomized controlled, prospective trial investigating the effect of buprenorphine continuation compared to buprenorphine dose reduction on pain control, post-operative opioid use, and OUD symptom management in patients on buprenorphine scheduled for elective surgery. Methods and analysis: This is a single institution, randomized trial that aims to enroll 80 adults using 12 mg buprenorphine or greater for treatment of OUD, scheduled for elective surgery. Participants will be randomly assigned to receive 8mg of buprenorphine on the day of surgery onwards until postsurgical pain subsides or to have their buprenorphine formulation continued at full dose perioperatively. Primary outcome will be a clinically significant difference in pain scores 24 hours following surgery. Secondary outcomes will be opioid consumption at 24, 48, and 72 hours postoperatively, opioid dispensing up to 30 days following surgery, changes in mood and withdrawal symptoms, opioid cravings, relapse of opioid misuse, and continued use of buprenorphine treatment postoperatively.

Objective We aimed to quantify the effect of opioid agonist pharmacotherapy on pain management after cesarean delivery, compared with patients not on these medications. Methods Patients undergoing cesarean delivery at our institution between January 2016 and December 2018 were stratified by peripartum use of opioid agonist pharmacotherapy versus no agonist therapy. We compared 24-hour postoperative opioid consumption not including buprenorphine and methadone, in milligram morphine equivalents (MME) (primary outcome), highest pain score on a 0 to 10 numerical rating scale in the first 24 postoperative hours, and postoperative length of stay in hours (secondary outcomes) between groups. These outcomes were also compared after covariate adjustment using logistic regression. Results We identified 123 patients on opioid agonist pharmacotherapy – in the form of buprenorphine or methadone and 2856 patients not on these medications. The groups differed in demographic characteristics, including age, smoking, and marital status. Opioid consumption during the first 24 postoperative hours (median [interquartile range]) was 99 [75,120] MME for patients on agonist therapy and 30 [0, 64] MME among parturients not taking these medications ( P < 0.001). Highest pain scores during this time were also higher for patients on opioid agonist pharmacotherapy (mean [standard deviation]: 8.2 [1.6] vs 5.5 [2.2], P < 0.001 for the no agonist group). Postoperative length of stay was 73 [68, 77] hours for patients on agonist pharmacotherapy, and 71 [62, 76] hours for parturients taking no agonist ( P < 0.001). All differences remained significant after covariate adjustment. Conclusions Parturients on opioid agonist pharmacotherapy have markedly increased opioid utilization and pain severity after cesarean delivery.