Acute Pain Is Associated With Chronic Opioid Use After Total Knee Arthroplasty

The effect of adductor canal block on outcomes of total knee arthroplasty: A single centre, historical cohort study

Background

Adductor canal blocks (ACBs) have been associated with reduced pain following total knee arthroplasty (TKA). There is a paucity of evidence regarding whether these early differences impact longer term outcomes. This study aimed to identify whether using ACB in TKA was associated with improvements in both early and late outcomes.

Methods

Patients who underwent a unilateral TKA between 2021 and 2022 were retrospectively assessed for pain scores, time to first mobilization and opioid use over the first 72 h. At 6 weeks, complications, pain scores and opioid use were assessed. At 12 months validated patient reported outcome measures (PROMs) and patient satisfaction with their surgery were assessed.

Results

262 unilateral TKA, of whom 129 received ACB (ACB group) and 133 did not (control group) were assessed. The ACB group had significantly lower median day 1 pain (median difference -0.44 (-0.09 to -0.79), p = 0.015). There was no significant difference between groups for pain after 24 h, time to mobilization or opioid use over 72 h. There was no significant difference in pain (p = 0.892), opioid use (p = 0.913) or complications (p = 0.348) at 6 weeks, or median change in PROMs (p = 0.436 and p = 0.307), opioid use (p = 0.187), or satisfaction with surgery (p = 0.262) at 12 months.

Conclusion

ACBs were associated with a clinically insignificant difference in median pain on day 1. there was no association with pain after 24 h, opioid use, time to mobilization or longer term outcomes. Our findings do not support the use of routine ACB during TKA.

Pain profiles and opioid consumption following joint replacement surgery: a prospective observational cohort study

PURPOSE

We sought to analyze postoperative discharge opioid prescription, consumption, and pain over three months following total hip arthroplasty (THA) and total knee arthroplasty (TKA).

METHODS

We conducted a prospective observational study in patients undergoing THA and TKA at two centres in Toronto, ON, Canada. We contacted study participants at two, six, and 12 weeks after discharge to collect data on analgesic satisfaction, pain relief, time point of stopping opioids, quantity of unconsumed opioid pills, quality of pain, and mental health. We also evaluated patient factors that may have contributed to a higher opioid consumption or dissatisfaction with the analgesic prescription at six weeks.

RESULTS

The median [interquartile range] opioid pill count prescribed at the time of discharge for the 443 participants was 60 [50-80]. At 12 weeks after surgery, 33.9% of participants had more than one-third of their prescribed quantity remaining. Three-quarters of the cohort indicated that pain relief after arthroplasty was appropriate at all postoperative follow-ups. The incidence of neuropathic pain reduced from 24.1% before TKA or THA to 4.3% at 12 weeks after arthroplasty. Female sex (odds ratio [OR], 1.78; 95% confidence interval [CI], 1.08 to 2.95; P = 0.03), a history of preoperative opioid use (OR, 2.46; 95% CI, 1.25 to 5.1; P = 0.01), and TKA vs THA (OR, 2.46; 95% CI, 1.47 to 4.17; P = 0.001) were associated with higher opioid consumption at six weeks after arthroplasty.

CONCLUSION

A discharge prescription of 60 opioid pills may be excessive for patients undergoing THA or TKA. Identifying patients with risk factors for higher postoperative opioid consumption may result in more appropriate analgesic regimens.

Preoperative peripheral nerve blocks are not independently associated with improved functional outcome, patient satisfaction, or risk of chronic pain at one year following knee arthroplasty

Aims

Control of acute pain following knee arthroplasty (KA) with a perioperative peripheral nerve block (PNB) may improve functional outcomes and reduce the risk of chronic postoperative knee pain (CPKP). The aims of this study were to assess whether a PNB influences patient-reported outcomes and risk of CPKP at one year following KA.

Methods

A retrospective study was conducted over a two-year period and included 3,338 patients who underwent KA, of whom 1,434 (43.0%) had a lower limb PNB. A total of 2,588 patients (77.6%) completed and returned their one-year follow-up questionnaire. The Oxford Knee Score (OKS) and pain component (OKS-PS), EuroQol five-dimension questionnaire (EQ-5D), and EQ-visual analogue scale (VAS) were collected preoperatively and at one year postoperatively. Patient satisfaction was also recorded at one year. The OKS-PS was used to define CPKP at one year.

Results

The PNB group were younger (mean difference (MD) 0.7 years, 95% CI 0.0 to 1.3; p = 0.039), had a worse OKS (MD 0.7, 95% CI 0.1 to 1.3; p = 0.027), and were more likely to have had a spinal anaesthesia relative to a general anaesthetic (odds ratio 4.2, 95% CI 3.23 to 5.45; p < 0.001). When adjusting for confounding factors, patients in the PNB group had a significantly reduced improvement in their OKS (MD -0.9, 95% CI -1.6 to -0.1; p = 0.022), which may not be clinically meaningful. There were no significant differences in the OKS-PS (p = 0.068), EQ-5D (p = 0.313), or EQ-VAS (0.855) between the groups when adjusting for confounding factors. When adjusting for confounding factors using binary regression analysis, there were no differences in patient satisfaction (p = 0.132) or in the risk of CPKP (p = 0.794) according to PNB group.

Conclusion

PNBs were independently associated with worse knee-specific outcomes, but whether these are clinically meaningful is not clear, as the difference was less than the minimal clinically important difference. Furthermore, PNBs were not independently associated with differences in health-related quality of life, patient satisfaction, or risk of CPKP.

Regional Anesthesia Decreases Inpatient But Not Outpatient Opioid Demand in Ankle and Distal Tibia Fracture Surgery

INTRODUCTION

Regional anesthesia (RA) is commonly used in ankle and distal tibia fracture surgery. However, the pragmatic effects of this treatment on inpatient and outpatient opioid demand are unclear. The hypothesis was that RA would decrease inpatient opioid consumption and have little effect on outpatient demand in patients undergoing ankle and distal tibia fracture surgery compared with patients not receiving RA.

METHODS

All patients aged 18 years and older undergoing ankle and distal tibia fracture surgery at a single institution between July 2013 and July 2018 were included in this study (n = 1310). Inpatient opioid consumption (0-72 hours postoperatively) and outpatient opioid prescribing (1 month preoperatively to 90 days postoperatively) were recorded in oxycodone 5-mg equivalents (OEs). Adjusted models were used to evaluate the impact of RA versus no RA on inpatient and outpatient opioid demand.

RESULTS

Patients without RA had higher rates of high-energy mechanism of injury, additional injuries, open fractures, and additional surgery compared with patients with RA. Adjusted models demonstrated decreased inpatient opioid consumption in patients with RA (12.1 estimated OEs without RA vs 8.8 OEs with RA from 0 to 24 hours postoperatively, P < .001) but no significant difference after that time (9.7 vs 10.4 from 24 to 48 hours postoperatively, and 9.5 vs 8.5 from 48 to 72 hours postoperatively). Estimated cumulative outpatient opioid demand was significantly increased in patients receiving RA at all time points (112.5 OEs without RA vs 137.3 with RA from 1 month preoperatively to 2 weeks, 125.6 vs 155.5 OEs to 6 weeks, and 134.6 vs 163.3 OEs to 90 days, all P values for RA <.001).

DISCUSSION

In ankle and distal tibia fracture surgery, RA was associated with decreased early inpatient opioid demand but significantly increased outpatient demand after adjusting for baseline patient and treatment characteristics. This study encourages the use of RA to decrease inpatient opioid use, although there was a worrisome increase in outpatient opioid demand.

LEVEL OF EVIDENCE

Level III: Retrospective, therapeutic cohort study.

Comparing modalities of opioid education in patients undergoing total knee arthroplasty: a randomized pilot trial

BACKGROUND

Patients undergoing total knee arthroplasty (TKA) experience significant postoperative pain and routinely require opioids, yet they often lack knowledge regarding appropriate use and handling of these medications. Evidence suggests that educational interventions in various formats may help reinforce proper usage and improve postoperative pain control. The aim of this study is to compare the institution standard of care (webinar) with two novel educational interventions-one in-person and the other a video recording-that focus specifically on the use of opioids and pain control.

METHODS

This prospective, randomized pilot study included 42 patients undergoing TKA. Patients were randomized into one of three groups: (1) webinar: 50 min virtual session standard of care at Hospital for Special Surgery (HSS), (2) in-person education, or (3) video education. The primary outcomes of this study were the number of opioid refill requests through postoperative day (POD) 30 and POD 60. The secondary outcomes evaluated Numerical Rating Scale (NRS) pain scores, opioid consumption in oral morphine equivalents (OME), surveys on medication usage and opioid knowledge, reported medication storage and disposal. We hypothesize that the novel educational interventions, presented either in-person or by video, will lead to a decrease in opioid refills within 60 days compared with current education delivered through virtual webinar.

RESULTS

No significant differences were found among groups in the number of opioid refill requests, average NRS pain score, or OME consumption at any time point. Opioid refill requests ranged from 0% to 16.7% at POD 30 (Fisher's exact test, p=0.625) and from 0% to 8.3% at POD 60 (p=1.000). The median opioid refill request was zero requests per group from POD 21 to 60 (webinar 0 (0.0, 0.0), in-person 0 (0.0, 0.0), video 0 (0.0, 0.0), Kruskal-Wallis test, p=0.381). Average NRS pain scores were 5 or below for all groups on POD 1, 7 and 14. By POD 7, all groups had an average daily intake OME of 14 or below.

CONCLUSIONS

Overall, patients in each group did well with postoperative pain management after TKA and had minimal opioid refill requests. There were no statistically significant differences in outcomes of NRS pain scores or opioid usage among groups suggesting that educational interventions were similarly effective. As a pilot trial, study demonstrated successful recruitment and retention of participants, and important feedback was elicited from patients regarding education, as well. Of note, this was a pilot study and was likely underpowered to detect a difference.

TRIAL REGISTRATION NUMBER

NCT05593341.

Personal versus therapist perioperative music intervention: a randomized controlled trial

INTRODUCTION

Music interventions can alleviate patient anxiety and improve post-surgical satisfaction. However, it remains uncertain whether personal music preferences affect efficacy. The authors tested whether personal music intervention with patient-selected songs played ad libitum is more effective than standard therapist-designed treatment with classical music.

METHODS

A prospective, parallel-group, single-blinded, randomized controlled trial with 229 participants (aged 18-60 years) previously scheduled for elective surgery. Data analyses followed a modified intention-to-treat principle. The patients were randomized into three groups: Standard care without music (Control), therapist-designed classic music treatment (TT), or personal music intervention with patient-selected songs played ad libitum by the patient (PI). All patients received standard post-anaesthesia care, and music intervention was started upon arrival at the post-anaesthesia care unit. Primary outcomes were anxiety and overall satisfaction at discharge. In contrast, secondary outcomes were systolic blood pressure during music intervention, the sleep quality of the night after surgery, and the occurrence of postoperative nausea and vomiting within the first 24 h after surgery.

RESULTS

Compared with therapist-designed music treatment, personal intervention decreased systolic blood pressure (T 0 : 124.3±13.7, 95% CI:121-127.7; T 20min : 117.6±10.4, 95% CI:115-120.1; T 30min : 116.9±10.6, 95% CI:114.3-119.4), prevented postoperative nausea and vomiting (Control: 55.9%, TT: 64.6%, PI: 77.6%), including severe postoperative nausea (VAS score>4; Control: 44.1%; TT: 33.8%; PI: 20.9%) and severe emesis (Frequency≥3, Control: 13.2%; TT: 7.7%; PI: 4.5%). None of the treatments affected sleep quality at night after surgery (Median, Q1-Q3, Control: 3, 1-3; TT: 3, 1-4; PI: 3, 1-3.5). Personal, but not therapist, music intervention significantly prevented anxiety (Control: 36.4±5.9, 95% CI:35.0-37.9; TT: 36.2±7.1, 95% CI: 34.4-37.9; PI: 33.8±5.6, 95% CI: 32.4-35.2) and emesis (Control: 23.9%; TT: 23.4%; PI: 13.2%) and improved patient satisfaction (Median, Q1-Q3, C: 8, 6-8; TT: 8, 7-9; PI: 8, 7-9).

CONCLUSIONS

Personal music intervention improved postoperative systolic blood pressure, anxiety, nausea, emesis, and overall satisfaction, but not sleep quality, as compared to therapist-designed classic intervention.

Regional anesthesia improves inpatient but not outpatient opioid demand in tibial shaft fracture surgery

BACKGROUND

Patients undergoing operative treatment of tibial shaft fractures have considerable pain largely managed with opioids. Regional anesthesia (RA) has been increasingly used to reduce perioperative opioid use.

METHODS

This was a retrospective study of 426 patients that underwent operative treatment of tibial shaft fractures with and without RA. Inpatient opioid consumption and 90-day outpatient opioid demand were measured.

RESULTS

RA significantly decreased inpatient opioid consumption for 48 h post-operatively (p = 0.008). Neither inpatient use after 48 h nor outpatient opioid demand differed in patients with RA (p > 0.05).

CONCLUSIONS

RA may help with inpatient pain control and reduce opioid use in tibial shaft fracture.

LEVEL OF EVIDENCE

Level III, retrospective, therapeutic cohort study.

Shared decision-making for postoperative opioid prescribing and preoperative pain management education decreases excess opioid burden

INTRODUCTION

Managing postoperative pain requires an individualized approach in order to balance adequate pain control with risk of persistent opioid use and narcotic abuse associated with inappropriately outsized narcotic prescriptions. Shared decision-making has been proposed to address individual pain management needs. We report here the results of a quality improvement initiative instituting prescribing guidelines using shared decision-making and preoperative pain expectation and management education to decrease excess opioid pills after surgery and improve patient satisfaction.

METHODS

Pre-intervention prescribing habits were obtained by retrospective review perioperative pharmacy records for patients undergoing general surgeries in the 24 months prior to initiation of intervention. Patients scheduled to undergo General Surgery procedures were given a survey at their preoperative visit. Preoperative education was performed by the surgical team as a part of the Informed Consent process using a standardized handout and patients were asked to choose the number of narcotic pills they wished to obtain within prescribing recommendations. Postoperative surveys were administered during or after their 2-week postoperative visit.

RESULTS

131 patients completed pre-intervention and post-intervention surveys. The average prescription size decreased from 12.29 oxycodone pills per surgery prior to institution of pathway to 6.80 pills per surgery after institution of pathway (p < 0.001). The percentage of unused pills after surgery decreased from an estimated 70.5% pre-intervention to 48.5% (p < 0.001) post-intervention. 61.1% of patients with excess pills returned or planned to return medication to the pharmacy with 16.8% of patients reporting alternative disposal of excess medication. Patient-reported satisfaction was higher with current surgery compared to prior surgeries (p < 0.001).

CONCLUSION

Institution of procedure-specific prescribing recommendations and preoperative pain management education using shared decision-making between patient and provider decreases opioid excess burden, resulting in fewer unused narcotic pills entering the community. Furthermore, allowing patients to participate in decision-making with their provider results in increased patient satisfaction.

Predictors of continued opioid use 6 months after total joint arthroplasty: a multi-site study

PURPOSE

Continued opioid use after total knee and hip arthroplasty (TKA/THA) is well-documented and associated with both surgical and patient-reported factors. Research examining the combined effects of a multitude of factors on continued, and even chronic, opioid use in a systematic algorithmic manner is lacking. This study prospectively evaluated the combined effect of patient-related and surgical factors associated with continued opioid use after TKA/THA.

METHODS

From 2016 to 2018, 198 participants undergoing TKA or THA were recruited from two tertiary care facilities. Participants completed surveys before surgery and at 2 weeks, 1, 3, and 6 months following surgery. A LASSO approach, followed by an exhaustive covariate selection procedure, was used to build a multivariable mixed-effects logistic regression model estimating the odds ratio of continued postoperative opioid use based on surgical factors and patient-reported factors.

RESULTS

Approximately half of the participants underwent either TKA (49%) or THA (51%). Preoperatively, 15% of participants reported taking opioid medication. Opioid use decreased from 68% at 2-week follow-up to 7% by 6 months. In addition, preoperative opioid use (95% CI 1.07-4.37), increased pain (95% CI 1.21-1.62), elevated preoperative Pain Catastrophizing Scale scores (95% CI 1.01-1.04), lower Physical Function scores (95% CI 0.87-0.95), and participants undergoing TKA, compared to THA, (95% CI 0.25-0.67) were found to be significantly associated with continued postoperative opioid use up to 6 months.

CONCLUSION

Preoperative opioid use, average pain, reduced physical function, and TKA were significantly associated with continued postoperative opioid use. Findings illustrate the need for preoperative and longitudinal assessment of patient-reported outcomes to mitigate poor postoperative pain outcomes.

LEVEL OF EVIDENCE

II.

Regional anesthesia does not decrease inpatient or outpatient opioid demand in distal femur fracture surgery

INTRODUCTION

Regional anesthesia (RA) is sometimes used to decrease pain and opioid consumption in distal femur fractures. However, the real-world impact of RA on inpatient opioid consumption and outpatient opioid demand is not well known. The hypothesis of this study is that RA would be associated with decreased inpatient opioid consumption and outpatient opioid demand.

METHODS

This study evaluated inpatient post-operative opioid consumption (0-24 h, 24-48 h, 48-72 h) and outpatient opioid demand (discharge to 2 weeks, 6 weeks, and 90 days) in all patients ages 18 and older undergoing operative treatment of distal femur fractures at a single institution from 7/2013 to 7/2018 (n = 230). Unadjusted and adjusted multivariable models were used to evaluate the impact of RA and other baseline patient and operative characteristics on inpatient opioid consumption and outpatient opioid demand.

RESULTS

Adjusted models demonstrated a small, significant increase in inpatient opioid consumption in patients with RA compared to no RA (4.7 estimated OE's without RA vs 6.2 OE's with RA from 24- to 48-h post-op, p < 0.05) but otherwise no significant differences at other timepoints (6.7 estimated OE's without RA vs 6.9 OE's with RA from 0- to 24-h post-op and 4.5 vs 4.4 from 48- to 72-h post-op, p > 0.05). Estimated cumulative outpatient opioid demand was significantly higher in patients with RA from discharge to 6 weeks and to 90 days (55.8 OE's without RA vs 63.9 with RA from discharge to 2 weeks, p > 0.05; 74.9 vs 95.1 OE's to 6 weeks, and 85 vs 113.1 OE's to 90 days, p < 0.05).

DISCUSSION

In distal femur fracture surgery, RA was associated with increased inpatient and outpatient opioid demand after adjusting for baseline patient and treatment characteristics. These results call into question the routine use of RA in distal femur fractures.

LEVEL OF EVIDENCE

Level III, retrospective, therapeutic cohort study.

The duration of postoperative analgesic use after total knee arthroplasty and nomogram for predicting prolonged analgesic use

Background

Total knee arthroplasty is currently a reliable treatment for end-stage knee osteoarthritis. However, chronic postsurgical pain (CPSP) is substantially thought to reduce patient satisfaction. NSAID-based oral analgesics were used to manage CPSP, but research on the duration of postoperative analgesic use (DAU) and prolonged analgesic use (PAU) are presently scarce.

Methods

Preoperative, perioperative, and one-year or above postoperative follow-up data were collected from 162 patients who underwent total knee arthroplasty between 1 June 2018 and 1 March 2019, and the DAU and the discontinuation time of each patient after discharge were recorded. Observational statistical analysis, diagnostic test, and predictive nomogram construction were performed on the collected data.

Results

The 3-month DAU has good diagnostic utility for poor outcome of postoperative months twelve (POM12). The constructed nomogram shows that gender, preoperative Numeric Rating Scale (NRS) movement pain scores, duration of surgery, postoperative days three (POD3) moderate to severe movement pain, and POD3 pain rescue medication were significant prognostic predictors of PAU after discharge. The area under the curve (AUC) of the 3-month, 6-month, and 12-month nomogram receiver operating characteristic (ROC) curves were calculated to be 0.741, 0.736, and 0.781.

Conclusion

PAU was defined as more than three months of NSAID-based oral analgesic use after TKA. Prognostic predictors of PAU after TKA were identified, and visualized nomogram was plotted and evaluated. The evaluation indicated that the prediction model had the good predictive ability and was a valuable tool for predicting PAU after discharge.

Preoperative Care Assessment of Need Scores Are Associated With Postoperative Mortality and Length of Stay in Veterans Undergoing Knee Replacement

Background

Care Assessment of Need (CAN) scores predicting 90-day mortality and hospitalization are automatically computed each week for patients receiving care at Veterans Health Administration facilities. While currently used only by primary care teams for care coordination, we explored their value as a perioperative risk stratification tool before major elective surgery.

Methods

We collected relevant demographic and perioperative data along with perioperative CAN scores for veterans who underwent total knee replacement between July 2014 and December 2015. We examined score distribution, relationships of preoperative CAN 1-year mortality scores with 1-year postoperative mortality and index hospital length of stay (LOS), and patterns of mortality.

Results

Among 8206 patients, 1-year mortality was 1.4% (110 patients), and CAN scores exhibited near-normal distribution. Median scores among survivors were significantly higher than those of in nonsurvivors (45 vs 75; P < .001). The Kaplan-Meier curves showed an approximately 4-fold higher rate of death at 1 year in the highest tercile for 1-year mortality CAN scores compared with those with lower scores (2.0% vs 0.5% respectively; P < .001). Locally estimated scatterplot smoothing curves revealed a significant and nonlinear increase in hospital LOS across preoperative CAN scores.

Conclusions

Although designed for ambulatory care use, CAN scores can identify patients at high risk for mortality and extended hospital LOS in an elective surgery population. The CAN scores may prove valuable in supporting informed decision making and preoperative planning in high-risk and vulnerable populations. Further study is needed to confirm the validity of CAN scores and compare them to other more widely used surgical risk calculators.

Regional anesthesia does not decrease opioid demand in pelvis and acetabulum fracture surgery

INTRODUCTION

Patients with pelvic and acetabular fractures often have considerable pain in the perioperative period. Regional anesthesia (RA) including peripheral nerve blocks and spinal analgesia may reduce pain. However, the real-world impact of these modalities on inpatient opioid consumption and outpatient opioid demand is largely unknown. The purpose of this study was to evaluate the impact of perioperative RA on inpatient opioid consumption and outpatient opioid demand.

METHODS

This is a retrospective, observational review of inpatient opioid consumption and outpatient opioid demand in all patients ages 18 and older undergoing operative fixation of pelvic and acetabular fractures at a single Level, I trauma center from 7/1/2013-7/1/2018 (n = 205). Unadjusted and adjusted analyses were constructed to evaluate the impact of RA on inpatient opioid consumption and outpatient opioid demand while controlling for age, sex, race, body mass index (BMI), smoking, chronic opioid use, ASA score, injury mechanism, additional injuries, open injury, and additional inpatient surgery.

RESULTS

Adjusted models demonstrated increases in inpatient opioid consumption in patients with RA (12.6 estimated OE's without RA vs 16.1 OE's with RA from 48 to 72 h post-op, p < 0.05) but no significant differences at other timepoints (17.5 estimated OE's without RA vs 16.8 OE's with RA from 0 to 24 h post-op, 15.3 vs 17.1 from 24 to 48 h post-op, p > 0.05). Estimated cumulative outpatient opioid demand was significantly higher in patients with RA at discharge to 90 days post-op (and 156.8 vs 207.9 OE's to 90 days, p < 0.05) but did not differ significantly before that time (121.5 OE's without RA vs 123.9 with RA from discharge to two weeks, 145.2 vs 177.2 OE's to 6 weeks, p > 0.05).

DISCUSSION

In pelvis and acetabulum fracture surgery, RA was associated with increased inpatient and outpatient opioid demand after adjusting for baseline patient and treatment characteristics. Regional anesthesia may not be beneficial for these patients.

A Multimodal Pain Management Protocol Including Preoperative Cryoneurolysis for Total Knee Arthroplasty to Reduce Pain, Opioid Consumption, and Length of Stay

Background

A retrospective analysis was conducted to determine if cryoneurolysis of superficial genicular nerves combined with standard care decreased postoperative opioids and pain after total knee arthroplasty (TKA).

Methods

Data from patients who underwent TKA at a single center were analyzed. Patients who received standardized cryoneurolysis before TKA were compared with a historical control group including patients who underwent TKA without cryoneurolysis. Both groups received a similar perioperative multimodal pain management protocol. The primary outcome was opioid intake at various time points from hospital stay to 6 weeks after discharge. Additional outcomes included pain, length of stay, and range of motion.

Results

The analysis included 267 patients (cryoneurolysis group: n = 169; control group: n = 98). During the hospital stay, the cryoneurolysis group had 51% lower daily morphine milligram equivalents (MMEs) (47 vs 97 MMEs; ratio estimate, 0.49 [95% confidence interval (CI), 0.43-0.56]; P < .0001) and 22% lower mean pain score (ratio estimate, 0.78 [95% CI, 0.70-0.88]; P < .0001) vs the control group. The cryoneurolysis group received significantly fewer cumulative MMEs, including discharge prescriptions, than the control group at week 2 (855 vs 1312 MMEs; ratio estimate, 0.65 [95% CI, 0.59-0.73]; P < .0001) and week 6 (894 vs 1406 MMEs; ratio estimate, 0.64 [95% CI, 0.57-0.71]; P < .0001). The cryoneurolysis group had significant 44% reduction in overall length of stay (P < .0001) and greater flexion degree at discharge (P < .0001).

Conclusions

Addition of preoperative cryoneurolysis to a multimodal pain management protocol reduced opioids and in-hospital pain and optimized outcomes during the 6-week recovery period after TKA.

Defining success in regional anaesthesia

Utilisation of regional anaesthesia is increasing globally; however, it remains challenging to determine the overall benefit of individual regional anaesthesia procedures. Like any peri-operative intervention, the benefit to the patient and healthcare system must outweigh any patient risk or resource implications. This review aims to identify markers of success in regional anaesthesia, categorise these into an objective framework and rationalise suggestions on how measuring outcomes in regional anaesthesia can be used to develop the widespread performance of this evolving subspecialty. This framework of measuring success of regional anaesthesia contains four pillars: patient-centred, population-centred, healthcare-centred and training-centred outcomes. Each pillar of success contains several outcomes which provide a structure for the measurement and development of regional anaesthesia success on a global scale.

Predictors of the use of analgesic drugs 1 year after joint replacement: a single-center analysis of 13,000 hip and knee replacements

BACKGROUND

Pain persists in a moderate number of patients following hip or knee replacement surgery. Persistent pain may subsequently lead to the prolonged consumption of analgesics after surgery and expose patients to the adverse drug events of opioids and NSAIDs, especially in older patients and patients with comorbidities. This study aimed to identify risk factors for the increased use of opioids and other analgesics 1 year after surgery and focused on comorbidities and surgery-related factors.

METHODS

All patients who underwent a primary hip or knee replacement for osteoarthritis from 2002 to 2013 were identified. Redeemed prescriptions for acetaminophen, non-steroidal anti-inflammatory drugs (NSAIDs), and opioids (mild and strong) were collected from a nationwide Drug Prescription Register. The user rates of analgesics and the adjusted risks ratios for analgesic use 1 year after joint replacement were calculated.

RESULTS

Of the 6238 hip replacement and 7501 knee replacement recipients, 3591 (26.1%) were still using analgesics 1 year after surgery. Significant predictors of overall analgesic use (acetaminophen, NSAID, or opioid) were (risk ratio (95% CI)) age 65-74.9 years (reference < 65), 1.1 (1.03-1.2); age > 75 years, 1.2 (1.1-1.3); female gender, 1.2 (1.1-1.3); BMI 30-34.9 kg/m2 (reference < 25 kg/m2), 1.1 (1.04-1.2); BMI > 35 kg/m2, 1.4 (1.3-1.6); and a higher number of comorbidities (according to the modified Charlson Comorbidity Index score), 1.2 (1.1-1.4). Diabetes and other comorbidities were not significant independent predictors. Of the other clinical factors, the preoperative use of analgesics, 2.6 (2.5-2.8), and knee surgery, 1.2 (1.1-1.3), predicted the use of analgesics, whereas simultaneous bilateral knee replacement (compared to unilateral procedure) was a protective factor, 0.86 (0.77-0.96). Opioid use was associated with obesity, higher CCI score, epilepsy, knee vs hip surgery, unilateral vs bilateral knee operation, total vs unicompartmental knee replacement, and the preoperative use of analgesics/opioids.

CONCLUSIONS

Obesity (especially BMI > 35 kg/m2) and the preoperative use of analgesics were the strongest predictors of an increased postoperative use of analgesics. It is remarkable that also older age and higher number of comorbidities predicted analgesic use despite these patients being the most vulnerable to adverse drug events.

The Effect of Intraoperative Methadone Compared to Morphine on Postsurgical Pain: A Meta-Analysis of Randomized Controlled Trials

Methods

We performed a quantitative systematic review of randomized controlled trials in PubMed, Embase, Cochrane Library, and Google Scholar electronic databases. Meta-analysis was performed using the random effects model, weighted mean differences (WMD), standard deviation, 95% confidence intervals, and sample size. Methodological quality was evaluated using Cochrane Collaboration's tool.

Results

Seven randomized controlled trials evaluating 337 patients across different surgical procedures were included. The aggregated effect of intraoperative methadone on postoperative opioid consumption did not reveal a significant effect, WMD (95% CI) of −0.51 (−1.79 to 0.76), (P=0.43) IV morphine equivalents. In contrast, the effect of methadone on postoperative pain demonstrated a significant effect in the postanesthesia care unit, WMD (95% CI) of −1.11 (−1.88 to −0.33), P=0.005, and at 24 hours, WMD (95% CI) of −1.35 (−2.03 to −0.67), P < 0.001.

Conclusions

The use of intraoperative methadone reduces postoperative pain when compared to morphine. In addition, the beneficial effect of methadone on postoperative pain is not attributable to an increase in postsurgical opioid consumption. Our results suggest that intraoperative methadone may be a viable strategy to reduce acute pain in surgical patients.

APOLLO-2: A Randomized, Placebo and Active-Controlled Phase III Study Investigating Oliceridine (TRV130), a G Protein-Biased Ligand at the μ-Opioid Receptor, for Management of Moderate to Severe Acute Pain Following Abdominoplasty

Objectives

The clinical utility of conventional IV opioids is limited by the occurrence of opioid‐related adverse events. Oliceridine is a novel G protein–biased μ‐opioid receptor agonist designed to provide analgesia with an improved safety and tolerability profile. This phase III, double‐blind, randomized trial (APOLLO‐2 [NCT02820324]) evaluated the efficacy and safety of oliceridine for acute pain following abdominoplasty.

Methods

Patients received a loading dose of either placebo, oliceridine (1.5 mg), or morphine (4 mg), followed by demand doses via patient‐controlled analgesia (0.1, 0.35, or 0.5 mg oliceridine; 1 mg morphine; or placebo) with a 6‐minute lockout interval. The primary endpoint was the proportion of treatment responders over 24 hours for oliceridine regimens compared to placebo. Secondary outcomes included a predefined composite measure of respiratory safety burden (RSB, representing the cumulative duration of respiratory safety events) and the proportion of treatment responders vs. morphine.

Results

A total of 401 patients were treated with study medication. Effective analgesia was observed for all oliceridine regimens, with responder rates of 61.0%, 76.3%, and 70.0% for the 0.1‐, 0.35‐, and 0.5‐mg regimens, respectively, compared with 45.7% for placebo (all P < 0.05) and 78.3% for morphine. Oliceridine 0.35‐ and 0.5‐mg demand dose regimens were equi‐analgesic to morphine using a noninferiority analysis. RSB showed a dose‐dependent increase across oliceridine regimens (mean hours [standard deviation], 0.1 mg: 0.43 [1.56]; 0.35 mg: 1.48 [3.83]; 0.5 mg: 1.59 [4.26]; all comparisons not significant at P > 0.05 vs. placebo: 0.60 [2.82]). The RSB measure for morphine was 1.72 (3.86) (P < 0.05 vs. placebo). Gastrointestinal adverse events increased in a dose‐dependent manner across oliceridine demand dose regimens (0.1 mg: 49.4%; 0.35 mg: 65.8%; 0.5 mg: 78.8%; vs. placebo: 47.0%; and morphine: 79.3%). In comparison to morphine, the proportion of patients experiencing nausea or vomiting was lower with the 2 equi‐analgesic dose regimens of 0.35 and 0.5 mg oliceridine.

Conclusions

Oliceridine is a safe and effective IV analgesic for the relief of moderate to severe acute postoperative pain in patients undergoing abdominoplasty. Since the low‐dose regimen of 0.1 mg oliceridine was superior to placebo but not as effective as the morphine regimen, safety comparisons to morphine are relevant only to the 2 equi‐analgesic dose groups of 0.35 and 0.5 mg, which showed a favorable safety and tolerability profile regarding respiratory and gastrointestinal adverse effects compared to morphine. These findings support that oliceridine may provide a new treatment option for patients with moderate to severe acute pain where an IV opioid is warranted.

APOLLO-1: a randomized placebo and active-controlled phase III study investigating oliceridine (TRV130), a G protein-biased ligand at the µ-opioid receptor, for management of moderate-to-severe acute pain following bunionectomy

Purpose

Oliceridine is a novel G protein-biased µ-opioid receptor agonist designed to provide intravenous (IV) analgesia with a lower risk of opioid-related adverse events (ORAEs) than conventional opioids.

Patients and methods

APOLLO-1 (NCT02815709) was a phase III, double-blind, randomized trial in patients with moderate-to-severe pain following bunionectomy. Patients received a loading dose of either placebo, oliceridine (1.5 mg), or morphine (4 mg), followed by demand doses via patient-controlled analgesia (0.1, 0.35, or 0.5 mg oliceridine, 1 mg morphine, or placebo). The primary endpoint compared the proportion of treatment responders through 48 hours for oliceridine regimens and placebo. Secondary outcomes included a composite measure of respiratory safety burden (RSB, representing the cumulative duration of respiratory safety events) and the proportion of treatment responders vs morphine.

Results

Effective analgesia was observed for all oliceridine regimens, with responder rates of 50%, 62%, and 65.8% in the 0.1 mg, 0.35 mg, and 0.5 mg regimens, respectively (all P<0.0001 vs placebo [15.2%]; 0.35 mg and 0.5 mg non-inferior to morphine). RSB showed a dose-dependent increase across oliceridine regimens (mean hours [SD]: 0.1 mg: 0.04 [0.33]; 0.35 mg: 0.28 [1.11]; 0.5 mg: 0.8 [3.33]; placebo: 0 [0]), but none were statistically different from morphine (1.1 [3.03]). Gastrointestinal adverse events also increased in a dose-dependent manner in oliceridine regimens (0.1 mg: 40.8%; 0.35 mg: 59.5%; 0.5 mg: 70.9%; placebo: 24.1%; morphine: 72.4%). The odds ratio for rescue antiemetic use was significantly lower for oliceridine regimens compared to morphine (P<0.05).

Conclusion

Oliceridine is a novel and effective IV analgesic providing rapid analgesia for the relief of moderate-to-severe acute postoperative pain compared to placebo. Additionally, it has a favorable safety and tolerability profile with regard to respiratory and gastrointestinal adverse effects compared to morphine, and may provide a new treatment option for patients with moderate-to-severe postoperative pain where an IV opioid is required.