Acute pain Factors predictive of post-operative pain and opioid requirement in multimodal analgesia following knee replacement

Operative treatment of clavicle fractures results in more opioids prescribed as compared to non-operative management

PURPOSE

The operative treatment of mid-shaft clavicle fractures shows benefit in union rates, return to work, and lower pain scores relative to non-operative treatment. We sought to determine if the surgical treatment of isolated mid-shaft clavicle fractures would result in fewer opioids prescribed as compared to those managed non-operatively.

METHODS

All mid-shaft clavicle fractures treated at a Level 1 trauma center were identified from 2012 to 2016. Demographics, fracture characteristics, surgical complications/outcomes, non-operative outcomes, and all narcotics prescribed for 6 months post-injury were collected. Narcotic prescriptions, in morphine equivalents (ME), were obtained through the state prescription drug monitoring program (PDMP).

RESULTS

One hundred and ten operative and 48 non-operative patients were included. Age, gender, previous alcohol, tobacco or drug use, and final range of motion were similar between groups. Pre-treatment fracture shortening (1.8 cm vs. 0.7 cm, p < 0.001) and displacement (150% vs. 70%, p < 0.001) were greater in the operative group. Total ME's (604 vs. 187, p < 0.001) and post-operative ME's (420 vs. 187, p < 0.001) were greater for the operative group. In either group, no other variable influenced ME's prescribed.

CONCLUSION

Clavicles treated operatively receive substantially more opiates than those treated non-operatively, despite data suggesting that operative treatment makes clavicle fractures less painful. The total amount of narcotic analgesics obtained by operatively treated patients was over three times that obtained by non-operatively managed patients, which equates to 55 5 mg oxycodone pills or 85 5 mg hydrocodone pills per patient. While there may certainly be advantages to the operative treatment of clavicle fractures, they must be weighed against the risks of a significant increase in opiate prescribing and potential consumption.

Influence of COMT (rs4680) and OPRM1 (rs1799971) on Cancer Pain, Opioid Dose, and Adverse Effects

Background: The influence of pharmacogenomics on opioid response, particularly with COMT (rs4680) and OPRM1 (rs1799971) variants, has been studied individually and in combination. However, most studies are in a noncancer context and not all their possible variant combinations have been examined. Objectives: This study examined COMT (rs4680) and OPRM1 (rs1799971), and their allele combinations, in advanced cancer to examine associations with pain scores, opioid dose, and adverse effects. Setting/Subjects: This multicenter prospective cohort study recruited patients receiving opioids for advanced cancer pain in Melbourne, Australia. Clinical data (demographics, opioids), validated instruments (pain and adverse effects), and blood (DNA) were collected. Descriptive analyses were used. Univariate and multivariate logistic regression analyses were used to evaluate associations between clinical outcomes (opioid dose, pain, adverse effects) and genotypes of interest. Results: Fifty-four participants were recruited to the study. Those with COMT A allele required lower opioid doses [130 mg (interquartile range [IQR] 67.5,230) versus 180 mg (IQR 55,322.5), p = 0.047] and experienced greater adverse effects [sickness response aOR (adjusted odds ratio) 7.1 (95% CI 1.51,33.41), p = 0.01]. Those with the COMT GG/OPRM1 G allele combination required higher opioid doses [322.5 mg (IQR 264,360) versus 125 mg (65,225), (p = 0.04)]. Those with COMT AG/OPRM1 AA experienced higher average pain [aOR 1.55 (95% CI 1.03, 2.33), p = 0.04] and moderate-severe nausea [aOR 5.47 (95% CI 1.35, 22.21), p = 0.02] but reduced drowsiness [aOR 0.25 (95% CI 0.06, 1.02), p = 0.05]. Conclusions: Patients with cancer with the COMT alternate (A) allele have greater sickness response adverse effects, which may be responsible for the lower opioid doses observed. Significant results of two new COMT/OPRM1 genotype combinations are presented that have not previously been studied, with plausible phenotype descriptions suggested.

Preoperative pain sensitivity and its correlation with postoperative acute and chronic pain: a systematic review and meta-analysis

BACKGROUND

Preoperative pain sensitivity (PPS) can be associated with postsurgical pain. However, estimates of this association are scarce. Confirming this correlation is essential to identifying patients at high risk for severe postoperative pain and for developing analgesic strategy. This systematic review and meta-analysis summarises PPS and assessed its correlation with postoperative pain.

METHODS

PubMed, Scopus, Cochrane Library, and PsycINFO were searched up to October 1, 2023, for studies reporting the association between PPS and postsurgical pain. Two authors abstracted estimates of the effect of each method independently. A random-effects model was used to combine data. Subgroup analyses were performed to investigate the effect of pain types and surgical procedures on outcomes.

RESULTS

A total of 70 prospective observational studies were included. A meta-analysis of 50 studies was performed. Postoperative pain was negatively associated with pressure pain threshold (PPT; r=-0.15, 95% confidence interval [CI] -0.23 to -0.07]) and electrical pain threshold (EPT; r=-0.28, 95% CI -0.42 to -0.14), but positively correlated with temporal summation of pain (TSP; r=0.21, 95% CI 0.12-0.30) and Pain Sensitivity Questionnaire (PSQ; r=0.25, 95% CI 0.13-0.37). Subgroup analysis showed that only TSP was associated with acute and chronic postoperative pain, whereas PPT, EPT, and PSQ were only associated with acute pain. A multilevel (three-level) meta-analysis showed that PSQ was not associated with postoperative pain.

CONCLUSIONS

Lower PPT and EPT, and higher TSP are associated with acute postoperative pain while only TSP is associated with chronic postoperative pain. Patients with abnormal preoperative pain sensitivity should be identified by clinicians to adopt early interventions for effective analgesia.

SYSTEMATIC REVIEW PROTOCOL

PROSPERO (CRD42023465727).

A "just in time" educational intervention for opioid overprescribing in dialysis access surgery

BACKGROUND

Despite widespread efforts to combat the opioid epidemic, an ongoing contributor to opioid misuse remains post-operative opioid overprescribing by residents. The goal of this study was to evaluate the impact of a low-cost, reproducible "just in time" intervention on opioid prescribing in dialysis access operations.

METHODS

Standardized opioid prescribing guidelines were emailed to residents on the vascular service on the first day of the rotation. Opioid prescriptions were reviewed for four years before and one year after this intervention. Wilcoxon rank-sum test and tests of proportions were used to compare groups.

RESULTS

Overall, 299 patients underwent dialysis access procedures. There was a decrease in patients discharged with opioids following the intervention from 58% to 36% (p ​= ​0.003). For patients prescribed opioids, the median quantity decreased from 90 to 45 oral morphine equivalents (p ​= ​0.03).

CONCLUSIONS

This low-cost and timely learning intervention may be a useful adjunct to reduce post-operative opioid prescriptions.

Differences in the relationship between pain and anxiety in total knee and hip arthroplasty: a longitudinal cross-lagged analysis mediated by depression and pain catastrophizing

Acute postsurgical pain (APSP) is an important risk factor for pain chronification, with reports of being more intense after total knee arthroplasty (TKA) than after total hip arthroplasty (THA). Psychological variables have been associated with differences in postsurgical pain experience. This study aimed to analyse the longitudinal reciprocal association between pain and anxiety levels in patients undergoing TKA or THA, to investigate the moderator role of the type of surgery and to explore psychological mediators in the anxiety - pain association. Patients undergoing TKA (n = 120) or THA (n = 109) were evaluated before surgery and in the acute postsurgical period (48 h postsurgery). Presurgical assessment comprised sociodemographic, pain-related and psychological variables (anxiety, depression, pain catastrophizing, self-efficacy, optimism and satisfaction with life). Postsurgical assessment focused on pain frequency, pain intensity and anxiety. Longitudinal associations were explored using cross-lagged panel models that included the indirect effect paths through possible mediators (pain catastrophizing and depression). Multigroup analyses compared TKA and THA. In the global sample, higher APSP was predicted by higher presurgical pain and worse presurgical anxiety. Multigroup analyses revealed that worse APSP was predicted by higher presurgical anxiety in patients undergoing TKA and by higher presurgical pain in patients undergoing THA. Furthermore, there was a positive significant indirect effect of pain catastrophizing, but not depressive symptoms, in the relationship between presurgical anxiety and APSP in THA. Anxiety and APSP are differently interrelated in TKA and THA. Psychological characteristics could be managed before surgery to favour better APSP control and potentially prevent pain chronification after total joint arthroplasty.

Risk Factors for Acute Postsurgical Pain: A Narrative Review

Acute postsurgical pain (APSP) has received growing attention as a surgical outcome. When poorly controlled, APSP can affect short- and long-term outcomes in patients. Despite the steady increase in awareness about postoperative pain and standardization of pain prevention and treatment strategies, moderate-to-severe APSP is frequently reported in clinical practice. This is possibly because pain varies widely among individuals and is influenced by distinct factors, such as demographic, perioperative, psychological, and genetic factors. This review investigates the risk factors for APSP, including gender, age, obesity, smoking history, preoperative pain history, pain sensitivity, preoperative anxiety, depression, pain catastrophizing, expected postoperative pain, surgical fear, and genetic polymorphisms. By identifying patients having an increased risk of moderate-to-severe APSP at an early stage, clinicians can more effectively manage individualized analgesic treatment protocols with a combination of pharmacological and non-pharmacological interventions. This would alleviate the transition from APSP to chronic pain and reduce the severity of APSP-induced chronic physical disability and social psychological distress.

Pain and Opioid use Following Total Knee Arthroplasty: Psycho-Social Factors are More Predictive Than Pharmacogenomics

BACKGROUND

This prospective, observational study was designed to assess the phenotype variation of the genes associated with pain and opioid use following total knee arthroplasty (TKA) in comparison to psycho-social elements.

METHODS

Preoperative demographic data and Patient-Reported Outcomes Measurement Information System-43 scores were obtained on 305 elective TKA patients. Patient visual analog scale pain scores and opioid use were extracted from the hospital record. Following discharge, participants completed a daily log of visual analog scale pain score, and medications used over 30 days. Pharmacogenomic testing was performed for three genes, CYP2D6, COMT, and OPRM1, which are involved in the opioid pathway and pain modulation.

RESULTS

Other than increased pain seen in the COMT high activity group while in the hospital, none of the phenotype variations of the three genes were significantly associated with the participants' pain or opioid use. The Patient-Reported Outcomes Measurement Information System-43 domains of pain interference and anxiety were significantly associated with pain and opioid use using multiple logistic regression.

CONCLUSIONS

Pharmacogenomic testing in this study was not predictive of pain and opioid use following TKA compared with psycho-social variables.

Opioid-free versus opioid-sparing anaesthesia in ambulatory total hip arthroplasty: a randomised controlled trial

BACKGROUND

Enhanced recovery after surgery pathways are essential for ambulatory surgery. They usually recommend lower intraoperative opioid use to avoid opioid-related adverse effects. This has led to opioid-sparing anaesthesia (OSA) techniques, with the extreme approach of opioid-free anaesthesia (OFA) mostly with dexmedetomidine. As evidence is lacking in day-case primary total hip arthroplasty, this study was performed to assess the potential benefits in postoperative analgesia of OFA over OSA.

METHODS

In this single-centre, prospective, triple blind study, we randomly allocated 80 patients undergoing day-case primary THA under general anaesthesia. Patients received a total intravenous anaesthesia with a laryngeal mask and multimodal analgesic regimen with non-opioid analgesics. The OSA group received low dose of sufentanil, and the OFA group received dexmedetomidine The primary outcome was the opioid consumption in the first 24 h in oral morphine equivalents (OME).

RESULTS

There was no difference in median cumulative OME consumption at 24 h between the OSA and OFA groups (12 [0-25] mg vs 16 [0-30] mg, respectively; P=0.7). Pain scores were similar and low in both groups with comparable walking recovery time. Adverse events were sparse and equivalent in both groups except for dizziness, which was more frequent in the OSA group (P<0.05).

CONCLUSIONS

In day-case total hip arthoplasty under general anaesthesia, opioid-free anaesthesia and opioid-sparing anaesthesia both provide early recovery and effective postoperative pain relief. When compared with opioid-sparing anaesthesia, opioid-free anaesthesia does not decrease opioid consumption in the first 24 h. These findings do not suggest any significant benefit from complete intraoperative avoidance of opioids.

CLINICAL TRIAL REGISTRATION

NCT0507270.

Secondary analysis: heat and self-report pain sensitivity associate with biological sex and racialized sociocultural group but may not be mediated by anxiety or pain catastrophizing

Introduction

Previous studies have demonstrated associations between sex and racialized group on pain sensitivity and tolerance. We analyzed the association of sex and racialized group on heat pain sensitivity, sensibility to painful suprathreshold mechanical pain (STMP), and pain sensitivity questionnaire (PSQ). We hypothesized that anxiety and pain catastrophizing reported by racialized minority groups and women would mediate enhanced pain sensitivity. Our secondary aim was to evaluate validity of the PSQ in a diverse population.

Methods

Using quantitative sensory testing for painful heat, STMP (forces: 64, 128, 256, and 512 mN), and PSQ, we evaluated pain sensitivity in 134 healthy participants [34 (18 women) Asian, 25 (13 women) Black, and 75 (41 women) White]. We used general linear and linear mixed models to analyze outcomes. We assessed mediation of state and trait anxiety and pain catastrophizing on pain sensitivity.

Results

Racialized minority status was associated with greater heat pain sensitivity (F = 7.63; P = 0.00074) and PSQ scores (F = 15.45; P = 9.84 × 10-7) but not associated with STMP (F = 1.50; P = 0.23). Female sex was associated with greater heat pain sensitivity (F = 4.9; P = 0.029) and lower PSQ (F = 9.50; P = 0.0025) but not associated with STMP (F = 0.0018; P = 0.97). Neither anxiety nor pain catastrophizing mediated associations between sex or racialized group with heat pain threshold or PSQ. Differential experience of individual items (F = 19.87; P = 3.28 × 10-8) limited PSQ face validity in racialized minorities.

Conclusion

Consistent with previous research, sensitivity to painful heat was associated with racialized minority status and female sex. By contrast, there was no significant effect of racialized minority status or female sex on STMP. Some PSQ items are inapplicable to participants from racialized minority groups.

Patient genetic heterogeneities acting as indicators of post-operative pain and opioid requirement in orthopedic surgery: A systematic review

INTRODUCTION

Orthopedic surgical procedures are expected to increase annually, making it imperative to understand the correlations between patient genetic makeup and post-operative pain levels.

METHODS

We performed a systematic literature review using PubMed and Cochrane databases in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A total of 299 articles were initially selected, 20 articles remained after title and abstract review, and nine articles were selected for inclusion upon full text review.

RESULTS

Genetic risk factors identified included the A allele of the 5HT2A gene single nucleotide polymorphism, the AA genotype of the ADRB2 gene, the CG genotype of the IL6 gene, the genotypes CT and TT of the NTRK1 gene, genotypes AA and GA of the OPRM gene, and the AA and GA genotypes of the COMT gene. Additional studies in the review discuss statistical significance of other variants of the COMT gene.

CONCLUSION

There have been genetic association studies performed on the patient heterogeneity and its relationship on patient pain levels, but more data need to be collected to understand the clinical utility of stratifying patients based on genomic sequence.

Psychological predictors of acute postoperative pain after total knee and hip arthroplasty: A systematic review

BACKGROUND

Identifying patients at high risk of acute postoperative pain after total knee or hip arthroplasty (TKA/THA) will facilitate individualized pain management and research on the efficacy of treatment options. Numerous studies have reported that psychological patient factors may influence acute postoperative pain, but most reviews have focused on chronic pain and functional outcomes. This systematic review aims to evaluate which psychological metrics are associated with acute postoperative pain after TKA and THA.

METHODS

A systematic search was conducted using the databases PubMed, EMBASE, Web of Science, and Cochrane Library until June 2022. Full-text articles reporting associations of preoperative psychological factors with acute pain within 48 h of TKA or THA surgery were identified. Quality was assessed using the Quality in Prognostic Studies tool.

RESULTS

Eighteen studies containing 16 unique study populations were included. TKA was the most common procedure, and anxiety and depression were the most evaluated psychological metrics. Several different anesthetic techniques and analgesic regimens were used. The studies were generally rated as having a low to moderate risk of bias. Catastrophizing was associated with acute pain in six studies (of nine), mainly after TKA. In contrast, three studies (of 13) and two studies (of 13) found anxiety and depression, respectively, to be associated with acute postoperative pain.

CONCLUSION

Pain catastrophizing seemed to be the most consistent psychological predictor of acute postoperative pain after TKA. The results for other psychological factors and THA were inconsistent. However, the interpretation of results was limited by considerable methodological heterogeneity.

Predicting chronic postsurgical pain: current evidence and a novel program to develop predictive biomarker signatures

ABSTRACT

Chronic pain affects more than 50 million Americans. Treatments remain inadequate, in large part, because the pathophysiological mechanisms underlying the development of chronic pain remain poorly understood. Pain biomarkers could potentially identify and measure biological pathways and phenotypical expressions that are altered by pain, provide insight into biological treatment targets, and help identify at-risk patients who might benefit from early intervention. Biomarkers are used to diagnose, track, and treat other diseases, but no validated clinical biomarkers exist yet for chronic pain. To address this problem, the National Institutes of Health Common Fund launched the Acute to Chronic Pain Signatures (A2CPS) program to evaluate candidate biomarkers, develop them into biosignatures, and discover novel biomarkers for chronification of pain after surgery. This article discusses candidate biomarkers identified by A2CPS for evaluation, including genomic, proteomic, metabolomic, lipidomic, neuroimaging, psychophysical, psychological, and behavioral measures. Acute to Chronic Pain Signatures will provide the most comprehensive investigation of biomarkers for the transition to chronic postsurgical pain undertaken to date. Data and analytic resources generatedby A2CPS will be shared with the scientific community in hopes that other investigators will extract valuable insights beyond A2CPS's initial findings. This article will review the identified biomarkers and rationale for including them, the current state of the science on biomarkers of the transition from acute to chronic pain, gaps in the literature, and how A2CPS will address these gaps.

Antepartum depressive symptoms are associated with significant postpartum opioid use

BACKGROUND

Antepartum depression is common, and outside of childbirth preoperative anxiety and depression have been associated with heightened postoperative pain. In light of the national opioid epidemic, the relationship between antepartum depressive symptoms and postpartum opioid use is particularly relevant.

OBJECTIVE

This study evaluated the association between antepartum depressive symptoms and significant postpartum opioid use during birth hospitalization.

STUDY DESIGN

This retrospective cohort study at an urban academic medical center from 2017 to 2019 included patients who received prenatal care at the medical center and linked pharmacy and billing data with electronic medical records. The exposure was antepartum depressive symptoms, defined as Edinburgh Postnatal Depression Scale ≥10 during the antepartum period. The outcome was significant opioid use, defined as: (1) any opioid use following vaginal birth and (2) the top quartile of total opioid use following cesarean delivery. Postpartum opioid use was quantified using standard conversions for opioids dispensed on postpartum days 1 to 4 to calculate morphine milligram equivalents. Poisson regression was used to calculate risk ratios and 95% confidence intervals, stratified by mode of delivery and adjusted for suspected confounders. Mean postpartum pain score was a secondary outcome.

RESULTS

The cohort included 6094 births; 2351 births (38.6%) had an antepartum Edinburgh Postnatal Depression Scale score. Of these, 11.5% had a maximum score ≥10. Significant opioid use was observed in 10.6% of births. We found that individuals with antepartum depressive symptoms were more likely to have significant postpartum opioid use, with an adjusted risk ratio of 1.5 (95% confidence interval, 1.1-2.0). When stratified by mode of delivery, this association was more pronounced for cesarean births, with an adjusted risk ratio of 1.8 (95% confidence interval, 1.1-2.7), and was no longer significant for vaginal births. Mean pain scores after cesarean delivery were significantly higher in parturients with antepartum depressive symptoms.

CONCLUSION

Antepartum depressive symptoms were associated with significant postpartum inpatient opioid use, especially following cesarean delivery. Whether identifying and treating depressive symptoms in pregnancy may impact the pain experience and opioid use postpartum warrants further investigation.

Genetic risk factors for chronic postsurgical pain in children: A narrative review

Genetic risk factors for chronic postsurgical pain in adults have been established, but little is known whether the same associations exist in children. It is even less clear how much influence single nucleotide polymorphisms can exert on the phenotypic expression of chronic postsurgical pain in children in general. To this effect, a search was made for original articles which met the following criteria: evaluation of postsurgical pain in children with known genetic mutations or, conversely, evaluation of atypical pain trajectories of postsurgical children assessing for possible genetic mutations that may explain the phenotype. All titles and abstracts retrieved were reviewed for suitability for inclusion. The references of the selected articles were also checked for additional relevant papers. To assess the transparency and quality of the genetic studies both STrengthening the REporting of Genetic Association studies scores and Q-Genie scores were applied. Overall, there is a paucity of information regarding the link between genetic mutations and eventual chronic postsurgical pain development although there is some information on acute postoperative pain. Evidence has shown that the contribution of genetic risk factors to chronic postsurgical pain development appears to be minor, with its clinical relevance yet to be described. More advanced techniques in systems biology (proteomics, transcriptomics) suggest promising avenues for investigating the disease.

Cigarette smoking, opioid consumption, and pain intensity after major surgery: An observational study

BACKGROUND

Chronic exposure to nicotine may change pain perception and promote opioid intake. This study aimed to evaluate the putative effect of cigarette smoking on opioid requirements and pain intensity after surgery.

METHODS

Patients who underwent major surgery and received intravenous patient-controlled analgesia (IV-PCA) at a medical center between January 2020 and March 2022 were enrolled. Patients' preoperative smoking status was assessed using a questionnaire by certified nurse anesthetists. The primary outcome was postoperative opioid consumption within 3 days after surgery. The secondary outcome was the mean daily maximum pain score, assessed using a self-report 11-point numeric rating scale, and the number of IV-PCA infusion requests within three postoperative days. Multivariable linear regression models were used to calculate the regression coefficient (beta) and 95% confidence interval (CI) for the association between smoking status and outcomes of interest.

RESULTS

A total of 1162 consecutive patients were categorized into never smokers (n = 968), former smokers (n = 45), and current smokers (n = 149). Current smoking was significantly associated with greater postoperative opioid consumption (beta: 0.296; 95% CI, 0.068-0.523), higher pain scores (beta: 0.087; 95% CI, 0.009-0.166), and more infusion requests (beta: 0.391; 95% CI, 0.073-0.710) compared with never smokers. In a dose-dependent manner, smoking quantity (cigarette per day) was positively correlated with both intraoperative (Spearman's rho: 0.2207, p = 0.007) and postoperative opioid consumption (Spearman's rho: 0.1745, p = 0.033) among current smokers.

CONCLUSION

Current cigarette smokers experienced higher acute pain, had more IV-PCA infusion requests, and consumed more opioids after surgery. Multimodal analgesia with nonopioid analgesics and opioid-sparing techniques, along with smoking cessation should be considered for this population.

Post-surgical contributors to persistent knee pain following knee replacement: The Multicenter Osteoarthritis Study (MOST)

Objective

Pain persistence following knee replacement (KR) occurs in ∼20-30% of patients. Although several studies have identified preoperative risk factors for persistent post-KR pain, few have focused on post-KR contributing factors. We sought to determine whether altered nociceptive signaling and other peripheral nociceptive drivers present post-operatively contribute to post-KR pain.

Design

We included participants from the Multicenter Osteoarthritis Study who were evaluated ∼12 months after KR. We evaluated the relation of measures of pain sensitivity [pressure pain threshold (PPT), temporal summation (TS), and conditioned pain modulation (CPM)] and the number of painful body sites to post-KR WOMAC knee pain, and of the number of painful sites to altered nociceptive signaling using linear or logistic regression models, as appropriate.

Results

171 participants (mean age 69 years, 62% female) were included. TS was associated with worse WOMAC pain post-KR (β ​= ​0.77 95% CI:0.19-1.35) and reduced odds of achieving patient acceptable symptom state (aOR ​= ​0.54 95%CI:0.34-0.88). Inefficient CPM was also associated with worse WOMAC pain post-KR (β ​= ​1.43 95% CI:0.15-2.71). In contrast, PPT was not associated with these outcomes. The number of painful body sites present post-KR was associated with TS (β ​= ​0.05, 95% CI:0.01, 0.05).

Conclusions

Post-KR presence of central sensitization and inefficient descending pain modulation was associated with post-KR pain. We also noted that presence of other painful body sites contributes to altered nociceptive signaling, and this may thus also contribute to the experience of knee pain post-KR. Our findings provide novel insights into central pain mechanisms and other peripheral pain sources contributing to post-KR persistent knee pain.

Evaluation of preoperative duloxetine use for postoperative analgesia following laparoscopic cholecystectomy: A randomized controlled trial

Background: The pain pattern after laparoscopic cholecystectomy (LC) is complex and distinct from postoperative pain after other laparoscopic procedures, suggesting that procedure-specific optimal analgesic management plans should be proposed. Duloxetine, a non-opioid neuromodulator, has been widely used to manage pain with dual central and peripheral analgesic properties.

Aims: To assess the effect of preoperative administration of duloxetine compared to placebo on postoperative pain control in patients undergoing LC.

Patients and Methods: This study was a randomized, parallel-group, placebo-controlled, double-blinded study performed on patients undergoing LC. Patients were randomly divided into two groups of 30 each on the day of surgery in the preoperative holding area, using a computer-generated random number to receive 60 mg duloxetine as a single oral dose 2 h before the procedure or placebo. The primary outcome was the difference in the mean of visual analogue scale (VAS) scores between the two studied groups, as measured by the area under the curve (AUC) of the VAS scores.

Results: The derived AUC of VAS scores in the duloxetine group (757.89 ± 326.01 mm × h) was significantly lower than that calculated for the control group (1005.1 ± 432.5 mm × h). The mean postoperative VAS scores recorded at 4 and 24 h were statistically different between the study groups (p = 0.041 and 0.003, respectively). As observed in the survival curve analysis, there was no significant difference (p = 0.665) for the time until the patient’s first request for rescue medications in the two groups. The frequency of postoperative nausea and vomiting (PONV) was lower in patients of the duloxetine group than that recorded in those allocated to the control group at 8 and 24-h time intervals (p = 0.734 and 0.572, respectively).

Conclusion: Preoperative use of duloxetine reduces postoperative pain significantly compared with placebo. In addition, its use is associated with a reduction in PONV. These preliminary findings suggest that duloxetine could play a role in the acute preoperative period for patients undergoing LC.

Clinical Trial Registration: [https://clinicaltrials.gov/ct2/show/NCT05115123, identifier NCT05115123],

Identifying Patients Vulnerable to Inadequate Pain Resolution After Cardiac Surgery

Acute postoperative pain (APOP) is often evaluated through granular parameters, though monitoring postoperative pain using trends may better describe pain state. We investigated acute postoperative pain trajectories in cardiac surgical patients to identify subpopulations of pain resolution and elucidate predictors of problematic pain courses. We examined retrospective data from 2810 cardiac surgical patients at a single center. The k-means algorithm for longitudinal data was used to generate clusters of pain trajectories over the first 5 postoperative days. Patient characteristics were examined for association with cluster membership using ordinal and multinomial logistic regression. We identified 3 subgroups of pain resolution after cardiac surgery: 37.7% with good resolution, 44.2% with moderate resolution, and 18.2% exhibiting poor resolution. Type I diabetes (2.04 [1.00-4.16], p = 0.05), preoperative opioid use (1.65 [1.23-2.22], p = 0.001), and illicit drug use (1.89 [1.26-2.83], p = 0.002) elevated risk of membership into worse pain trajectory clusters. Female gender (1.72 [1.30-2.27], p < 0.001), depression (1.60 [1.03-2.50], p = 0.04) and chronic pain (3.28 [1.79-5.99], p < 0.001) increased risk of membership in the worst pain resolution cluster. This study defined 3 APOP resolution subgroups based on pain score trend after cardiac surgery and identified factors that predisposed patients to worse resolution. Patients with moderate or poor pain trajectory consumed more opioids and received them for longer before discharge. Future studies are warranted to determine if altering postoperative pain monitoring and management improve postoperative course of patients at risk of moderate or poor pain resolution.

Perioperative medicine role in painful knee prosthesis prevention

Total knee arthroplasty is one of the most frequently performed orthopaedic surgeries. However, up to 20% of patients develop persistent postoperative pain. Persistent postoperative pain may be an extension of acute postoperative pain, but can also occur after more than 3 months without symptoms. Risk factors associated with persistent postoperative pain after arthroplasty have now been characterised within the patient's perioperative context (preoperative, intraoperative and postoperative), and can be grouped under genetic, demographic, clinical, surgical, analgesic, inflammatory and psychological factors. Identification and prevention of persistent postoperative pain through a multimodal and biopsychosocial approach is essential in the context of perioperative medicine, and has been shown to prevent or ameliorate postoperative pain.

Less stress, better success: a scoping review on the effects of anxiety on anesthetic and analgesic consumption

Preoperative anxiety has an incidence of 11-80% in patients undergoing surgical or interventional procedures. Understanding the role of preoperative anxiety on intraoperative anesthetic requirements and postoperative analgesic consumption would allow personalized anesthesia care. Over- or under-anesthetizing patients can lead to complications such as postoperative cognitive dysfunction in elderly patients, or procedural discomfort, respectively. Our scoping review focuses on the current evidence regarding the association between preoperative anxiety and intraoperative anesthetic and/or postoperative analgesic consumption in patients undergoing elective surgical or interventional procedures. Based on 44 studies that met the inclusion criteria, we found that preoperative anxiety has a significant positive correlation effect on intraoperative propofol and postoperative opioid consumption. The analysis of the literature is limited by the heterogeneity of preoperative anxiety tools used, study designs, data analyses, and outcomes. The use of shorter, validated preoperative anxiety assessment tools may help optimize the intraoperative anesthetic and postoperative analgesic regimen. Further research to determine the most feasible and clinically relevant preoperative anxiety tool and subsequent implementation has the potential to optimize perioperative care and improve patient outcomes.

Multi-Site Observational Study to Assess Biomarkers for Susceptibility or Resilience to Chronic Pain: The Acute to Chronic Pain Signatures (A2CPS) Study Protocol

Chronic pain has become a global health problem contributing to years lived with disability and reduced quality of life. Advances in the clinical management of chronic pain have been limited due to incomplete understanding of the multiple risk factors and molecular mechanisms that contribute to the development of chronic pain. The Acute to Chronic Pain Signatures (A2CPS) Program aims to characterize the predictive nature of biomarkers (brain imaging, high-throughput molecular screening techniques, or "omics," quantitative sensory testing, patient-reported outcome assessments and functional assessments) to identify individuals who will develop chronic pain following surgical intervention. The A2CPS is a multisite observational study investigating biomarkers and collective biosignatures (a combination of several individual biomarkers) that predict susceptibility or resilience to the development of chronic pain following knee arthroplasty and thoracic surgery. This manuscript provides an overview of data collection methods and procedures designed to standardize data collection across multiple clinical sites and institutions. Pain-related biomarkers are evaluated before surgery and up to 3 months after surgery for use as predictors of patient reported outcomes 6 months after surgery. The dataset from this prospective observational study will be available for researchers internal and external to the A2CPS Consortium to advance understanding of the transition from acute to chronic postsurgical pain.

Risk factors of chronic opioid use after surgical procedures in noncancer patients: A nationwide case-control study

BACKGROUND

Surgery is an indication for opioid prescription in noncancer patients, and chronic use of opioids is associated with overdose and abuse.

OBJECTIVES

We aimed to evaluate the prevalence and risk factors associated with chronic opioid use (COU) following surgery among noncancer patients.

DESIGN

A nationwide case-control study.

SETTING

Retrospective analysis of the annual national patient sample data from 2012 to 2018 in South Korea.

PATIENTS

Adults without cancer who had undergone surgery and received noninjectable opioids during hospital stay.

MAIN OUTCOME MEASURES

COU during 3 months following surgery.

RESULTS

A total of 15 543 participants were included, and the prevalence overall and in opioid-naïve users was 8.1 and 5.7%, respectively. Prior exposure patterns of opioids [intermittent user, adjusted odds ratio (aOR) 2.35; 95% CI, 2.00 to 2.77, and continuous user, aOR 8.58; 95% CI, 6.54 to 11.24] and concomitant use of benzodiazepine (in continuous user, aOR 18.60; 95% CI 11.70 to 29.55) were strongly associated with COU compared with naïve users. Morphine milligram equivalent, type of opioid strength at discharge and prescription of nonopioid analgesics at discharge were also associated with COU. Compared with minor surgery, knee (aOR 1.49; 95% CI 1.17 to 1.89), spine (aOR 1.65; 95% CI 1.33 to 2.06) and shoulder (aOR 2.54; 95% CI 1.97 to 3.27) procedures showed a significantly positive association with COU. Sensitivity analysis in opioid-naïve patients showed similar results.

CONCLUSION

About 8.1% of noncancer patients who had undergone surgery and were prescribed noninjectable opioids became chronic opioid users in Korea. Identified risk factors could be used to derive strategies for safe opioid use in noncancer patients in the future.

The Efficacy and Safety of Celecoxib for Pain Management After Total Knee Arthroplasty: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background

This study aimed to determine the efficacy and safety of celecoxib for pain management after total knee arthroplasty (TKA).

Methods

PubMed, EMBASE, Web of Science, and the Cochrane Central Register of Controlled Trials (CENTRAL) were searched to identify eligible randomized controlled trials (RCTs) that compared celecoxib with a placebo in term of pain control efficacy after TKA. Primary outcomes included pain scores at 24, 48, and 72 h after TKA. Secondary outcomes included the active range of motion (ROM) at 24, 48,72 h, and 7 days postoperatively, morphine consumption over 72 h after TKA, incidence of postoperative nausea and vomiting (PONV), and total blood loss after surgery. Data analysis was conducted using RevMan version 5.3.

Results

Five RCTs involving 593 participants were included in the study. Compared with a placebo, celecoxib significantly reduced visual analog scale (VAS) scores at rest at 24 h [mean difference (MD) = −0.72; 95% confidence interval (CI), −1.27 to −0.17; I² = 82%; P = 0.01], 48 h (MD = −1.51; 95% CI, −2.07 to −0.95; I² = 0%; P < 0.00001), and 72 h (MD = −1.30; 95% CI, −2.07 to −0.54; I² = 82%; P = 0.0009) after TKA, decreased morphine consumption over postoperative 72 h (MD = −0.73; 95% CI, −0.96 to −0.51; I² = 96%; P < 0.00001), and increased active ROM at 48 h (MD = 13.23; 95% CI, 7.79 to 18.67; I² = 0%; P < 0.00001), 72 h (MD = 6.52; 95% CI, 4.95 to 8.10; I² = 68%; P < 0.00001), and 7 days (MD = 7.98; 95% CI, 3.64 to 12.31; I² = 68%; P = 0.0003) after the operation. No significant difference was found in the active ROM at 24 h (MD = 7.60; 95% CI, −6.14 to 21.34; I² = 94%; P = 0.28) and the incidence of PONV after surgery [risk ratio (RR) = 0.66; 95% CI, 0.40 to 1.09; I² = 0%; P = 0.11].

Conclusion

The administration of celecoxib is an effective and safe strategy for postoperative analgesia after TKA.

Factors affecting sufentanil consumption for intravenous controlled analgesia after hepatectomy: retrospective analysis

Background

Pain control after hepatectomy is usually achieved by opioids. There are significant individual differences in the amount of opioids used after hepatectomy, and the metabolism of opioids is liver-dependent. The purpose of our study was to explore the possible risk factors for opioid consumption during the first 48 h after surgery.

Methods

In a retrospective study design involving 562 patients undergoing open or laparoscopic hepatectomy, all patients were treated with intravenous patient-controlled analgesia (IV-PCA) along with continuous and bolus doses of sufentanil for a duration of 48 h after surgery during the time period of August 2015 and February 2019. The primary endpoint was high sufentanil consumption 48 h after hepatectomy, and patients were divided into two groups: those with or without a high PCA sufentanil dosage depending on the third quartile (Q3). The secondary endpoint was the effect of a high PCA sufentanil dosage on various possible clinical risk factors. The relevant parameters were collected, and correlation and multivariate regression analyses were performed.

Results

The median operation time was 185 min (range, 115–250 min), and the median consumption of sufentanil 48 h after the operation was 91 μg (IQR, 64.00, 133.00). Factors related to the consumption of sufentanil at 48 h after hepatectomy included age, operation time, blood loss, intraoperative infusion (red blood cells and fresh-frozen plasma), pain during movement after surgery (day 1 and day 2), preoperative albumin, and postoperative blood urea nitrogen. Age (≤ 60 and > 60 years), extent of resection (minor hepatic resection and major hepatic resection), surgical approach (laparoscope and open) and operation time (min) were independent risk factors for sufentanil consumption at 48 h postoperatively.

Conclusion

Age younger than 60 years, major hepatic resection, an open approach and a longer operation are factors more likely to cause patients to require higher doses of sufentanil after hepatectomy, and the early identification of such patients can increase the efficacy of perioperative pain management.

Identifying risk factors that increase analgesic requirements at discharge among patients with burn injuries

Patients with burn injuries require large doses of opioids and gabapentinoids to achieve pain control and are often discharged from hospital with similar amounts. This study aimed to identify patient risk factors that increase analgesic requirements among patients with burn injuries and to determine the relationship between opioid and gabapentinoid use. Patient charts from July 1, 2015 - 2018 were reviewed retrospectively to determine analgesic requirements 24 hours before discharge. Linear mixed regression models were performed to determine patient risk factors (age, gender, history of substance misuse, total body surface area of burn, length of stay in hospital, history of psychiatric illness, or surgical treatment) that may increase analgesic requirements. This study found that patients with a history of substance misuse (p = 0.01) or who were managed surgically (p = 0.01) required higher doses of opioids at discharge. Similarly, patients who had undergone surgical debridement required more gabapentinoids (p < 0.001). For every percent increase in TBSA, patients also required 14 mg more gabapentinoids (p = 0.01). In contrast, older patients (p = 0.006) and those with a longer hospital stay (p = 0.009) required fewer amounts of gabapentinoids before discharge. By characterizing factors that increase analgesic requirements at discharge, burn care providers may have a stronger understanding of which patients are at greater risk of developing chronic opioid or gabapentinoid misuse. The quantity and duration of analgesics prescribed at discharge may then be tailored according to these patient specific risk factors.

The Impact of Psychological Factors and Their Treatment on the Results of Total Knee Arthroplasty

➤

There is a growing body of evidence implicating psychosocial factors, including anxiety, depression, kinesiophobia, central sensitization, and pain catastrophizing, as negative prognostic factors following total knee arthroplasty (TKA).

➤

Symptoms of anxiety and depression likely represent risk factors for negative outcomes in patients undergoing TKA. However, few studies have assessed the impact of preoperative interventions for these conditions on postoperative outcomes.

➤

The Tampa Scale of Kinesiophobia and the Central Sensitization Inventory have demonstrated value in the diagnosis of kinesiophobia and central sensitization. Higher preoperative indices of kinesiophobia and central sensitization predict worse patient-reported outcomes postoperatively.

➤

Although evidence is limited, cognitive-behavioral therapy for kinesiophobia and duloxetine for central sensitization may help to diminish the negative impact of these preoperative comorbidities. It is important to note, however, that outside the realm of TKA, cognitive-behavioral therapy has been recognized as a more effective treatment for central sensitization than medical treatment.

➤

Awareness of these issues will allow surgeons to better prepare patients regarding postoperative expectations in the setting of a comorbid psychosocial risk factor. Further research into the role of preoperative assessment and possible treatment of these conditions in patients undergoing TKA is warranted.

Inpatient Opioid Consumption Variability following Total Knee Arthroplasty: Analysis of 4,038 Procedures

This study examined an early iteration of an inpatient opioid administration-reporting tool, which standardized patient opioid consumption as an average daily morphine milligram equivalence per surgical encounter (MME/day/encounter) among total knee arthroplasty (TKA) recipients. The objective was to assess the variability of inpatient opioid administration rates among surgeons after implementation of a multimodal opioid sparing pain protocol. We queried the electronic medical record at our institution for patients undergoing elective primary TKA between January 1, 2016 and June 30, 2018. Patient demographics, inpatient and surgical factors, and inpatient opioid administration were retrieved. Opioid consumption was converted into average MME for each postoperative day. These MME/day/encounter values were used to determine mean and variance of opioids prescribed by individual surgeons. A secondary analysis of regional inpatient opioid consumption was determined by patient zip codes. In total, 23 surgeons performed 4,038 primary TKA. The institutional average opioid dose was 46.24 ± 0.75 MME/day/encounter. Average intersurgeon (IS) opioid prescribing ranged from 17.67 to 59.15 MME/day/encounter. Intrasurgeon variability ranged between ± 1.01 and ± 7.51 MME/day/encounter. After adjusting for patient factors, the average institutional MME/day/encounter was 38.43 ± 0.42, with average IS variability ranging from 18.29 to 42.84 MME/day/encounter, and intrasurgeon variability ranging between ± 1.05 and ± 2.82 MME/day/encounter. Our results suggest that there is intrainstitutional variability in opioid administration following primary TKA even after controlling for potential patient risk factors. TKA candidates may benefit from the implementation of a more rigid standardization of multimodal pain management protocols that can control pain while minimizing the opioid burden. This is a level of evidence III, retrospective observational analysis.

Perioperative medicine role in painful knee prosthesis prevention

Total knee arthroplasty is one of the most frequently performed orthopaedic surgeries. However, up to 20% of patients develop persistent postoperative pain. Persistent postoperative pain may be an extension of acute postoperative pain, but can also occur after more than 3 months without symptoms. Risk factors associated with persistent postoperative pain after arthroplasty have now been characterised within the patient's perioperative context (preoperative, intraoperative and postoperative), and can be grouped under genetic, demographic, clinical, surgical, analgesic, inflammatory and psychological factors. Identification and prevention of persistent postoperative pain through a multimodal and biopsychosocial approach is essential in the context of perioperative medicine, and has been shown to prevent or ameliorate postoperative pain.

Morphine pretreatment protects against cerebral ischemic injury via a cPKCγ-mediated anti-apoptosis pathway

It has been reported that morphine pretreatment (MP) can exert neuroprotective effects, and that protein kinase C (PKC) participates in the initiation and development of ischemic/hypoxic preconditioning in the brain. However, it remains unknown whether PKC is involved in MP-induced neuroprotection. The aim of the present study, which included in vivo and in vitro experiments, was to determine whether the conventional γ isoform of PKC (cPKCγ) was involved in the protective effects of MP against cerebral ischemic injury. The present study included an in vivo experiment using a mouse model of middle cerebral artery occlusion and an in vitro experiment using neuroblastoma N2a cells with oxygen-glucose deprivation (OGD). Furthermore, a cPKCγ antagonist, Go6983, was used to determine the involvement of cPKCγ in the protective effects of MP against cerebral ischemic injury. In the in vivo experiment, neurological deficits, ischemic infarct volume, neural cell damage, apoptosis and caspase-3 activation were evaluated. In the in vitro experiment, flow cytometry was used to determine the activation of caspase-3 in N2a cells with OGD. It was found that MP protected against cerebral ischemic injury. However, intracerebroventricular injection of the cPKCγ antagonist before MP attenuated the neuroprotective effect of MP and increased the activation of cleaved caspase-3. These findings suggested that MP may provide protection against cerebral ischemic injury via a cPKCγ-mediated anti-apoptosis pathway.

During capsaicin-induced central sensitization, brush allodynia is associated with baseline warmth sensitivity, whereas mechanical hyperalgesia is associated with painful mechanical sensibility, anxiety and somatization

BACKGROUND

Mechanical hyperalgesia and allodynia incidence varies considerably amongst neuropathic pain patients. This study explored whether sensory or psychological factors associate with mechanical hyperalgesia and brush allodynia in a human experimental model.

METHODS

Sixty-six healthy volunteers (29 male) completed psychological questionnaires and participated in two quantitative sensory testing (QST) sessions. Warmth detection threshold (WDT), heat pain threshold (HPT) and suprathreshold mechanical pain (STMP) ratings were measured before exposure to a capsaicin-heat pain model (C-HP). After C-HP exposure, brush allodynia and STMP were measured in one session, whilst mechanical hyperalgesia was measured in another session.

RESULTS

WDT and HPT measured in sessions separated by 1 month demonstrated significant but moderate levels of reliability (WDT: ICC = 0.5, 95%CI [0.28, 0.77]; HPT: ICC = 0.62, 95%CI [0.40, 0.77]). Brush allodynia associated with lower WDT (z = -3.06, p = 0.002; ϕ = 0.27). Those with allodynia showed greater hyperalgesia intensity (F = 7.044, p = 0.010, η_p ²  = 0.107) and area (F = 9.319, p = 0.004, η_p ²  = 0.163) than those without allodynia. No psychological self-report measures were significantly different between allodynic and nonallodynic groups. Intensity of hyperalgesia in response to lighter mechanical stimuli was associated with lower HPT, higher STMP ratings and higher Pain Sensitivity Questionnaire scores at baseline. Hyperalgesia to heavier probe stimuli associated with state anxiety and to a lesser extent somatic awareness. Hyperalgesic area associated with lower baseline HPT and higher STMP ratings. Hyperalgesic area was not correlated with allodynic area across individuals.

CONCLUSIONS

These findings support research in neuropathic pain patients and human experimental models that peripheral sensory input and individual sensibility are related to development of mechanical allodynia and hyperalgesia during central sensitization, whilst psychological factors play a lesser role.

SIGNIFICANCE

We evaluated differential relationships of psychological and perceptual sensitivity to the development of capsaicin-induced mechanical allodynia and hyperalgesia. Fifty percent of healthy volunteers failed to develop mechanical allodynia. Baseline pain sensitivity was greater in those developing allodynia and was related to the magnitude and area of hyperalgesia. State psychological factors, whilst unrelated to allodynia, were related to mechanical hyperalgesia. This supports that the intensity of peripheral sensory input and individual sensibility are related to development of mechanical allodynia and hyperalgesia during central sensitization, whilst psychological factors play a lesser role.

Drug Utilization for Pain Management during Perioperative Period of Total Knee Arthroplasty in China: A Retrospective Research Using Real-World Data

Background and Objective: Total knee arthroplasty (TKA) is one of the most painful procedures and perioperative pain usually requires the use of many analgesics to relieve it. The appropriate use of analgesics to relieve patient pain is an important issue of TKA. To characterize the drug utilization for pain management during perioperative period of TKA in China using real-world data of electronic medical records. Materials and Methods: This research used the data of all inpatients who received TKA at 145 hospitals covered 31 provinces in China from 1 January 2016 to 31 December 2018. The exclusion criteria included pregnancy and cancer diagnosis. In the analysis of drug utilization mode (DUM), medicines were classified into 5 groups: non-steroidal anti-inflammatory drugs (NSAIDs), opioids, non-opioid central analgesics, acetaminophen and others. Results: Among the 2017 patients included in this study, there were 1537 (76.20%) female and 480 (23.80%) male, aged 65.77 ± 7.73 years. Regarding the surgery characteristics, 1658 (82.20%) were unilateral; 1220 (60.49%) was graded Level 4; 1312 (65.05%) used local anesthesia as the main anesthesia method, and 1450 (71.89%) lasted for more than 2 h. The most common DUM was “NSAIDs + opioids” (55.92%), followed by “NSAIDs only” (17.85%), and “NSAIDs + Opioids + Non-opioid central analgesics” (17.15%). The results of the Chi-square test showed that differences in DUM were associated with surgery types, surgery levels, surgery duration, and types of anesthesia used. Up to 81.14% of the total drug expenses for pain management was spent on NSAIDs. Due to the limitation of database, this study could not subdivide operation stages, anesthesia methods, dosage forms of drugs. Conclusion: In China, the use of analgesics in perioperative period of TKA was diversified and influenced by a number of surgery characteristics. The rational use of analgesics should be considered in combination with surgery type, surgery level, surgery duration and anesthesia method.

Predictors of Acute Postsurgical Pain following Gastrointestinal Surgery: A Prospective Cohort Study

Background

Several predictors have been shown to be independently associated with chronic postsurgical pain for gastrointestinal surgery, but few studies have investigated the factors associated with acute postsurgical pain (APSP). The aim of this study was to identify the predictors of APSP intensity and severity through investigating demographic, psychological, and clinical variables.

Methods

We performed a prospective cohort study of 282 patients undergoing gastrointestinal surgery to analyze the predictors of APSP. Psychological questionnaires were assessed 1 day before surgery. Meanwhile, demographic characteristics and perioperative data were collected. The primary outcomes are APSP intensity assessed by numeric rating scale (NRS) and APSP severity defined as a clinically meaningful pain when NRS ≥4. The predictors for APSP intensity and severity were determined using multiple linear regression and multivariate logistic regression, respectively.

Results

112 patients (39.7%) reported a clinically meaningful pain during the first 24 hours postoperatively. Oral morphine milligram equivalent (MME) consumption (β 0.05, 95% CI 0.03–0.07, p < 0.001), preoperative anxiety (β 0.12, 95% CI 0.08–0.15, p < 0.001), and expected postsurgical pain intensity (β 0.12, 95% CI 0.06–0.18, p < 0.001) were positively associated with APSP intensity. Furthermore, MME consumption (OR 1.15, 95% CI 1.10–1.21, p < 0.001), preoperative anxiety (OR 1.33, 95% CI 1.21–1.46, p < 0.001), and expected postsurgical pain intensity (OR 1.36, 95% CI 1.17–1.57, p < 0.001) were independently associated with APSP severity.

Conclusion

These results suggested that the predictors for APSP intensity following gastrointestinal surgery included analgesic consumption, preoperative anxiety, and expected postsurgical pain, which were also the risk factors for APSP severity.

Investigating the True Effect of Psychological Variables Measured Prior to Arthroplastic Surgery on Postsurgical Outcomes: A P-Curve Analysis

Patients' presurgical psychological profiles have been posited to predict pain and function following arthroplastic surgery of the hip and knee. Nevertheless, findings are conflicting, and this may be rooted in biased reporting that makes the determination of evidential value difficult. This ambiguity may have negative consequences for researchers and governmental agencies, as these rely on findings to accurately reflect reality. P-Curve analyses were used to establish the presence of evidential value and selective reporting in a sample of studies examining the effect of presurgical psychological predictors on outcomes following knee and hip arthroplastic surgery. A systematic search of the literature revealed 26 relevant studies. The examined sets of studies indicate that there is evidential value for the effect of depression on pain intensity and function, anxiety on pain intensity and function, pain catastrophizing on pain intensity, as well as the combined effects of all psychological predictors on pain intensity and function. The presence of evidential value was inconclusive for the effect of optimism on pain intensity. There were no signs that any results were influenced by biased reporting. The results highlight the importance of patients' psychological profiles in predicting surgical outcomes, which represent a promising avenue for future treatment approaches. PERSPECTIVE: The effects of P-hacking are difficult to detect and might be at the root of conflicting findings pertaining to the predictive properties of presurgical psychological variables on postsurgical outcomes. P-Curve analysis allows the determination of evidential value underlying these relationships and detection of P-hacking to ensure that findings are not the result of selective reporting.

Six-year trends in postoperative prescribing and use of multimodal analgesics following total hip and knee arthroplasty: A single-site observational study of pain management

BACKGROUND

Guidelines for acute postoperative pain management recommend administering analgesics in multimodal combination to facilitate synergistic benefit, reduce opioid requirements and decrease side-effects. However, limited observational research has examined the extent to which multimodal analgesics are prescribed and administered postoperatively following joint replacement.

METHODS

In this longitudinal study, we used three-point prevalence surveys to observe the 6-year trends in prescribing and use of multimodal analgesics on the orthopaedic wards of a single Australian private hospital. We collected baseline postoperative data from total hip and knee arthroplasty patients in May/June 2010 (Time 1, n = 86), and follow-up data at 1 year (Time 2, n = 199) and 5 years (Time 3, n = 188). During the follow-up, data on prescribing practices were presented to anaesthetists.

RESULTS

We found a statistically significant increase in the prescribing (p < 0.001) and use (p < 0.001) of multimodal analgesics over time. The use of multimodal analgesics was associated with lower rest pain (p = 0.027) and clinically significant reduction in interference with activities (p < 0.001) and sleep (p < 0.001). However, dynamic pain was high and rescue opioids were likely under-administered at all time points. Furthermore, while patients reported high levels of side-effects, use of adjuvant medications was low.

CONCLUSIONS

We observed significant practice change in inpatient analgesic prescribing in favour of multimodal analgesia, in keeping with contemporary recommendations. Surveys, however, appeared to identify a clinical gap in the bedside assessment and management of breakthrough pain and medication side-effects, requiring additional targeted interventions.

SIGNIFICANCE

Evaluation of 6-year trends in a large Australian metropolitan private hospital indicated substantial growth in postoperative multimodal analgesic prescribing. In the context of growing global awareness concerning multimodal analgesia, findings suggested diffusion of best-evidence prescribing into clinical practice. Findings indicated the effects of postoperative multimodal analgesia in real-world conditions outside of experimental trials. Postoperative multimodal analgesia in the clinical setting was only associated with a modest reduction in rest pain, but substantially reduced interference from pain on activities and sleep.

The role of regional analgesia in personalized postoperative pain management

Pain management plays a fundamental role in enhanced recovery after surgery pathways. The concept of multimodal analgesia in providing a balanced and effective approach to perioperative pain management is widely accepted and practiced, with regional anesthesia playing a pivotal role. Nerve block techniques can be utilized to achieve the goals of enhanced recovery, whether it be the resolution of ileus or time to mobilization. However, the recent expansion in the number and types of nerve block approaches can be daunting for general anesthesiologists. Which is the most appropriate regional technique to choose, and what skills and infrastructure are required for its implementation? A multidisciplinary team-based approach for defining the goals is essential, based on each patient's needs, and incorporating patient, surgical, and social factors. This review provides a framework for a personalized approach to postoperative pain management with an emphasis on regional anesthesia techniques.

Variations in postoperative opioid prescribing by day of week and duration of hospital stay

BACKGROUND

Studies demonstrate wide variation in postoperative opioid prescribing and that patients are at risk of chronic opioid abuse after surgery. The factors that influence prescribing, however, remain obscure. This study investigates whether day of the week or the postoperative day at the time of discharge impacts prescribing patterns.

METHODS

We identified patients who underwent commonly performed procedures at our institution from January 2014 through April 2019 and analyzed the relationship between postoperative opioids prescribed (oral morphine milligram equivalents) and both the day of the week and the postoperative day at discharge.

RESULTS

In ambulatory operations (n = 13,545), each day progressing from Monday was associated with increased morphine milligram equivalents prescribed on discharge (P = .0080). For inpatient cases (n = 10,838), surgeons prescribed more morphine milligram equivalents at discharge in the latter half of the week and during the weekend (P = .0372). Every additional postoperative day at discharge was associated with a +19.25 morphine milligram equivalent prescribed (P < .0001).

CONCLUSION

More opioids were prescribed on discharges later in the week and after prolonged hospital stays perhaps to avoid patients running out of medication. Providers may unintentionally allow such non-clinical factors to influence postoperative opioid prescribing. Increased awareness of these inadvertent biases may help decrease excess prescribing of potentially addicting opioids after an operation.

Persistent Opioid Use After Hysterectomy in the United States, 2005-2015

OBJECTIVE

To assess variables associated with opioid prescriptions filled perioperatively after hysterectomy and the risk of prolonged opioid use through 1 year after hysterectomy.

METHODS

In this retrospective cohort study, we used the 2005-2015 IBM MarketScan databases to identify women aged at least 18 years who underwent hysterectomy. For opioid use, we identified filled prescriptions for opioid medications. We excluded women with prevalent opioid use, defined as an opioid prescription filled 180 to 30 days preoperatively or at least two prescriptions filled in the 30 days before surgery. We defined perioperative opioid use as any opioid prescription filled within 30 days before or 7 days after surgery. We used log-binomial regression to identify independent predictors of perioperative opioid prescription fill. To assess the risk of long-term opioid use, we estimated the proportion of women with ongoing monthly opioid prescriptions through 12 months after surgery and the proportion of women with any opioid prescription 3-6 months after surgery, mimicking published estimates.

RESULTS

Among 569,634 women who underwent hysterectomy during the study period, 176,537 (30.9%) were excluded owing to prevalent opioid use. We found that 331,322 (84.3%) women filled a perioperative opioid prescription, with median quantity of 30 pills (interquartile range 25-40), and that younger (adjusted risk ratio [adjRR]18-24 0.91) and older (adjRR65-74 0.84; adjRR75+ 0.70) patients were less likely to receive a perioperative prescription compared with women aged 45-54. The proportion of women with continuous monthly fills of opioids through 2, 3, 6, and 12 months after surgery was 1.40%, 0.34%, 0.06%, and 0.02%, respectively.

CONCLUSION

Most women who underwent hysterectomy in the United States from 2005 to 2015 filled a perioperative opioid prescription with a median quantity of 30 pills. The risk of prolonged opioid use through 6 months is quite low, at 0.06% or 1 in 1,547.

Assessment of Persistent and Prolonged Postoperative Opioid Use Among Patients Undergoing Plastic and Reconstructive Surgery

Importance

Although the development of persistent opioid use after surgical procedures has garnered much attention in recent years, large-scale studies characterizing patterns of persistent opioid use among patients undergoing plastic and reconstructive surgery procedures are lacking.

Objective

To assess the prevalence of immediate and long-term postoperative opioid use after plastic and reconstructive surgery procedures.

Design, Setting, and Participants

In this population-based cohort study, patients who underwent 5 classes of plastic and reconstructive procedures (nasal, eye, breast, abdomen, and soft tissue reconstruction) between January 1, 2007, and December 31, 2015, were identified using IBM MarketScan Commercial and Medicare Supplemental research databases. Patients were excluded if they were younger than 18 years, lacked continuous insurance coverage for 1 year preoperatively and postoperatively, had a second anesthesia event within 1 year postoperatively, and filled an opioid prescription within the year prior to surgery.

Main Outcomes and Measures

Analgesic prescription patterns in the immediate postoperative period. The primary outcome was rates of persistent opioid use (opioid prescriptions filled 90-180 days postoperatively). The secondary outcome was rates of prolonged opioid use (opioid prescriptions filled 90-180 days postoperatively and again 181-365 days postoperatively). Explanatory variables included patient demographics, procedure type, and relevant comorbidities.

Results

Of the 466 677 patients who met inclusion criteria, 96 397 (45.3%) were men, and the mean (SD) age was 46.8 (17.7) years. Furthermore, 212 387 (54.6%) of the patients filled prescriptions for postoperative analgesics, with 212 387 (91.5%) of analgesic prescriptions filled being for opioids. Persistent opioid use occurred in 30 865 (6.6%) patients (5.1%-13.5% across procedure classes), while prolonged opioid use occurred in 10 487 (2.3%) patients (1.7%-5.6% across procedure classes). Patients who filled prescriptions for opioids in the perioperative period were significantly more likely to exhibit persistent (odds ratio [OR], 2.87; 95% CI, 2.80-2.94) and prolonged (OR, 2.90; 95% CI, 2.77-3.02) opioid use than those who did not fill perioperative opioid prescriptions, with the greatest odds for persistent use found in patients who underwent breast (OR, 4.36; 95% CI, 4.10-4.63) and nasal (OR, 3.51; 95% CI, 3.30-3.73) procedures. On multivariable logistic regression analysis, independent risk factors for persistent and prolonged opioid use included perioperative opioid use, procedure type, and prior-year mental health (depression and anxiety) and substance abuse diagnoses.

Conclusions and Relevance

Given the significant risk of persistent opioid use after plastic and reconstructive procedures, it is imperative to develop best practices guidelines for postoperative opioid prescription practices in this population.

Level of Evidence

NA.

Postoperative intravenous parecoxib sodium followed by oral celecoxib post total knee arthroplasty in osteoarthritis patients (PIPFORCE): a multicentre, double-blind, randomised, placebo-controlled trial

OBJECTIVES

To evaluate the morphine-sparing effects of the sequential treatment versus placebo in subjects undergoing total knee arthroplasty (TKA), the effects on pain relief, inflammation control and functional rehabilitation after TKA and safety.

DESIGN

Double-blind, pragmatic, randomised, placebo-controlled trial.

SETTING

Four tertiary hospitals in China.

PARTICIPANTS

246 consecutive patients who underwent elective unilateral TKA because of osteoarthritis (OA).

INTERVENTIONS

Patients were randomised 1:1 to the parecoxib/celecoxib group or the control group. The patients in the parecoxib/celecoxib group were supplied sequential treatment with intravenous parecoxib 40 mg (every 12 hours) for the first 3 days after surgery, followed by oral celecoxib 200 mg (every 12 hours) for up to 6 weeks. The patients in the control group were supplied with the corresponding placebo under the same instructions.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary endpoint was the cumulative opioid consumption at 2 weeks post operation (intention-to-treat analysis). Secondary endpoints included the Knee Society Score, patient-reported outcomes and the cumulative opioid consumption.

RESULTS

The cumulative opioid consumption at 2 weeks was significantly smaller in the parecoxib/celecoxib group than in the control group (median difference, 57.31 (95% CI 34.66 to 110.33)). The parecoxib/celecoxib group achieving superior Knee Society Scores and EQ-5D scores and greater Visual Analogue Scale score reduction during 6 weeks. Interleukin 6, erythrocyte sedation rate and C-reactive protein levels were reduced at 72 hours, 2 weeks and 4 weeks and prostaglandin E2 levels were reduced at 48 hours and 72 hours in the parecoxib/celecoxib group compared with the placebo group. The occurrence of adverse events (AEs) was significantly lower in the parecoxib/celecoxib group.

CONCLUSIONS

The sequential intravenous parecoxib followed by oral celecoxib regimen reduces morphine consumption, achieves better pain control and functional recovery and leads to less AEs than placebo after TKA for OA.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov (ID: NCT02198924).

Risk Factors for Moderate to Severe Pain during the First 24 Hours after Laparoscopic Bariatric Surgery While Receiving Intravenous Patient-Controlled Analgesia

Objective

To investigate the incidence of and risk factors for moderate to severe pain during the first 24 hours after laparoscopic bariatric surgery.

Materials and Methods

This retrospective study included morbidly obese patients who underwent laparoscopic sleeve gastrectomy or Roux-en-Y gastric bypass at a single institution between June 2016 and July 2018. Demographic, clinical, operative, and postoperative pain data from the postanesthesia care unit (PACU) and ward were analyzed. Intravenous patient-controlled analgesia (IV-PCA) was commenced before PACU discharge.

Results

Ninety-seven patients were included. The mean age was 38.60 ± 12.27 years, and the mean BMI was 45.04 ± 8.42 kg/m², and 69% were female. The incidence of moderate to severe pain was 75%. Moderate to severe pain during the first 24 hours was associated with young age, female sex, postoperative administration of NSAIDs, first pain score greater than 3 on arrival at the PACU, and inadequate pain control at PACU discharge. A multivariate analysis revealed that inadequate pain control at PACU discharge was the only factor independently associated with moderate to severe pain during the first 24 hours postoperatively (p=0.011). From PACU discharge to the end of postoperative day 3, moderate to severe pain at the end of each 24-hour period was a significant predictor of moderate to severe pain in the subsequent 24-hour period (p=0.011, p < 0.001, and p=0.004, respectively).

Conclusions

Moderate to severe pain was experienced by 75% of patients undergoing laparoscopic bariatric surgery and receiving IV-PCA after PACU discharge. Inadequate pain control at PACU discharge was the only independent risk factor for moderate to severe pain during the first 24 hours postoperatively.

Quantitative sensory testing and predicting outcomes for musculoskeletal pain, disability, and negative affect: a systematic review and meta-analysis

Hypersensitivity due to central pain mechanisms can influence recovery and lead to worse clinical outcomes, but the ability of quantitative sensory testing (QST), an index of sensitisation, to predict outcomes in chronic musculoskeletal disorders remains unclear. We systematically reviewed the evidence for ability of QST to predict pain, disability, and negative affect using searches of CENTRAL, MEDLINE, EMBASE, AMED, CINAHL, and PubMed databases up to April 2018. Title screening, data extraction, and methodological quality assessments were performed independently by 2 reviewers. Associations were reported between baseline QST and outcomes using adjusted (β) and unadjusted (r) correlations. Of the 37 eligible studies (n = 3860 participants), 32 were prospective cohort studies and 5 randomised controlled trials. Pain was an outcome in 30 studies, disability in 11, and negative affect in 3. Meta-analysis revealed that baseline QST predicted musculoskeletal pain (mean r = 0.31, 95% confidence interval [CI]: 0.23-0.38, n = 1057 participants) and disability (mean r = 0.30, 95% CI: 0.19-0.40, n = 290 participants). Baseline modalities quantifying central mechanisms such as temporal summation and conditioned pain modulation were associated with follow-up pain (temporal summation: mean r = 0.37, 95% CI: 0.17-0.54; conditioned pain modulation: mean r = 0.36, 95% CI: 0.20-0.50), whereas baseline mechanical threshold modalities were predictive of follow-up disability (mean r = 0.25, 95% CI: 0.03-0.45). Quantitative sensory testing indices of pain hypersensitivity might help develop targeted interventions aiming to improve outcomes across a range of musculoskeletal conditions.