Rational Perioperative Opioid Management in the Era of the Opioid Crisis

Knowledge, attitudes and practices of pain management among Taiwanese physicians in a reformed 2-year postgraduate training programme: a cross-sectional questionnaire survey

BACKGROUND

Taiwan implemented a reformed 6-year medical education in 2013, with a subsequent 2-year postgraduate training programme starting in August 2019. This study investigated the perceptions of acute and chronic pain management in postgraduate physicians.

METHODS

In late July 2023, a cross-sectional questionnaire survey was conducted of Taiwanese physicians who had almost completed their postgraduate 2-year or 1-year training and those who were starting a postgraduate programme in early August 2023. This survey evaluated their knowledge, attitude and clinical experience related to opioid-based pain management and their perceptions of the opioid crisis in the United States and Taiwan.

RESULTS

Of the 197 postgraduate physicians, 169 (85.8%) responded to the survey. Physicians who had received postgraduate 2-year (n = 48) and 1-year (n = 51) training had a deeper understanding of opioids (p < 0.001) and exhibited greater confidence in acute and chronic pain management (both p < 0.001) compared with those who were just starting a postgraduate programme (n = 70). Of the included physicians, 92 (54.4%) were aware of the ongoing opioid crisis in the United States, but only 28 (16.6%) disagreed with the notion of a current opioid problem in Taiwan. Approximately 27.8% had never heard of multimodal analgesia, and 86.4% expressed a need for further pain management education.

CONCLUSIONS

The postgraduate training programme in Taiwan provides enhanced knowledge of opioids and improves physicians' levels of confidence in acute and chronic pain management. However, only one-sixth of postgraduate physicians are aware that Taiwan does not have an opioid problem.

Opioid Dose Variation in Cardiac Surgery: A Multicenter Study of Practice

BACKGROUND

Although high-opioid anesthesia was long the standard for cardiac surgery, some anesthesiologists now favor multimodal analgesia and low-opioid anesthetic techniques. The typical cardiac surgery opioid dose is unclear, and the degree to which patients, anesthesiologists, and institutions influence this opioid dose is unknown.

METHODS

We reviewed data from nonemergency adult cardiac surgeries requiring cardiopulmonary bypass performed at 30 academic and community hospitals within the Multicenter Perioperative Outcomes Group registry from 2014 through 2021. Intraoperative opioid administration was measured in fentanyl equivalents. We used hierarchical linear modeling to attribute opioid dose variation to the institution where each surgery took place, the primary attending anesthesiologist, and the specifics of the surgical patient and case.

RESULTS

Across 30 hospitals, 794 anesthesiologists, and 59,463 cardiac cases, patients received a mean of 1139 (95% confidence interval [CI], 1132-1146) fentanyl mcg equivalents of opioid, and doses varied widely (standard deviation [SD], 872 µg). The most frequently used opioids were fentanyl (86% of cases), sufentanil (16% of cases), hydromorphone (12% of cases), and morphine (3% of cases). 0.6% of cases were opioid-free. 60% of dose variation was explainable by institution and anesthesiologist. The median difference in opioid dose between 2 randomly selected anesthesiologists across all institutions was 600 µg of fentanyl (interquartile range [IQR], 283-1023 µg). An anesthesiologist's intraoperative opioid dose was strongly correlated with their frequency of using a sufentanil infusion (r = 0.81), but largely uncorrelated with their use of nonopioid analgesic techniques (|r| < 0.3).

CONCLUSIONS

High-dose opioids predominate in cardiac surgery, with substantial dose variation from case to case. Much of this variation is attributable to practice variability rather than patient or surgical differences. This suggests an opportunity to optimize opioid use in cardiac surgery.

Effects of perioperative oxycodone as the sole opioid on immunity within a multi-modal analgesia framework in patients undergoing cervical cancer surgery: A randomised controlled trial

Background and Aims

Current views on oxycodone's effects on immunity are inconsistent. Our objective was to compare the effects of perioperative oxycodone as the sole opioid in a multi-modal analgesia regimen with conventional opioid regimens on immunity in cervical cancer.

Methods

In this randomised controlled trial (RCT), patients scheduled for laparoscopic radical hysterectomy for cervical cancer were randomised to receive either oxycodone (Group O) or conventional opioid regimens (Group C). The primary outcome was the CD4+/CD8+ ratios postoperatively at 24 and 48 h. Student's t-test was used for normally distributed variables, the non-parametric Wilcoxon test for non-normally distributed variables, and Chi-square/Fisher's exact test for qualitative variables, with differences significant set at P < 0.05.

Results

We included 56 patients in the final analysis. The postoperative CD4+/CD8+ ratios were comparable between groups. However, the mean arterial pressures (MAPs) at extubation and 5 minutes thereafter were lower in Group O than in Group C (both P < 0.001), as were the heart rates (HRs) (P = 0.001 and 0.018, respectively). Within 24 h postoperatively, the visual analogue scale (VAS) scores for resting and movement-evoked pain were lower in Group O than in Group C (all P < 0.001), and the same was observed at 48 h postoperatively (both P = 0.002), as was the incidence of catheter-related bladder discomfort (P = 0.001). The VASs for postoperative analgesia satisfaction were higher in Group O than in Group C (P = 0.006).

Conclusion

In laparoscopic surgery for cervical cancer, perioperative oxycodone as the sole opioid within a multi-modal analgesia framework does not yield anticipated benefits in immunopreservation compared to conventional opioid regimens but improves postoperative pain management and haemodynamic stability.

Effects of Serratus Anterior Plane Block on Early Recovery from Thoracoscopic Lung Resection: A Randomized, Blinded, Placebo-controlled Trial

BACKGROUND

The efficacy of serratus anterior plane block for treatment of pain after minimally invasive thoracic surgery remains unclear. This trial assesses the impact of serratus anterior plane block on postoperative opioid consumption and on measures of early recovery after thoracoscopic lung resection.

METHODS

Patients undergoing minimally invasive anatomic lung resection at a single center were randomized to undergo serratus anterior plane block with 40 ml injectate containing bupivacaine 0.25%, clonidine 100 μg, and dexamethasone 4 mg (serratus anterior plane block group) or sham block with 40 ml normal saline (placebo group) at the conclusion of surgery. The primary outcome was cumulative intravenous morphine equivalents during the first 24 h postoperatively. Secondary outcomes were intravenous morphine equivalents, pain scores at rest and with cough, inspiratory volume on incentive spirometry, incidence of nausea or vomiting during the first 48 h postoperatively, Quality of Recovery-15 score on postoperative day 7, and length of stay.

RESULTS

Using the protocol-specified intention-to-treat analysis, the median (interquartile range) intravenous morphine equivalents was 10.6 (5.0 to 27.1) mg in serratus anterior plane block patients (n = 46) versus 18.8 (9.9 to 29.6) mg in placebo patients (n = 46; 32% reduction; ratio, 0.68 [95% CI, 0.44 to 1.06]; P = 0.085). Of the secondary outcomes, only the composite pain with cough scores differed significantly in the serratus anterior plane block group by a coefficient of -0.41 (95% CI, -0.81 to -0.01; P = 0.044). A sensitivity as-treated analysis reported median (interquartile range) intravenous morphine equivalents of 10.0 (5.0 to 27.2) mg in serratus anterior plane block patients (n = 44) versus 19.9 (10.4 to 29.0) mg in placebo patients (n = 48; 36% reduction; ratio, 0.64 [95% CI, 0.41 to 1.00]; P = 0.048).

CONCLUSIONS

The protocol-specified intention-to-treat analysis demonstrated that serratus anterior plane block did not result in a significant reduction in opioid consumption when added to a multimodal analgesic regimen after thoracoscopic anatomic lung resection. The sensitivity as-treated analysis showed a significant and modest clinical reduction in the primary outcome that warrants further investigation.

EDITOR’S PERSPECTIVE

Multimodal Analgesia and Outcomes in Hysterectomy Surgery-A Population-Based Analysis

Objective: We aimed to investigate the impact of multimodal analgesia on postoperative complications and opioid prescription on a national level. Methods: This retrospective cross-sectional study included n = 1,307,923 hysterectomies (01/2006-12/2022, Premier Healthcare claims data). Multimodal analgesia was defined as opioid use with the addition of non-opioid analgesic modes, grouped into four categories: opioid-only and 1, 2, or 3 or more additional non-opioid analgesics. Multivariable regression models measured associations between multimodal categories and outcomes (composite/respiratory/cardiac/gastrointestinal/genitourinary, and CNS complications, oral morphine milligram equivalents [MME], and length of hospital stay [LOS]). Odds ratios (OR) and 95% confidence intervals (CI) are reported. Results: Overall, 84.3% (1,102,812/1,307,923) received multimodal analgesia, of which 58.9%, 28.0%, and 13.1% received 1, 2, or 3 or more additional non-opioid analgesics, respectively. The odds of any composite complication (any ≥1 complication) decreased with the addition of 1, 2, 3, or more analgesic modalities (versus opioid-only): OR 0.66 (CI 0.64; 0.68), OR 0.63 (CI 0.61; 0.66), OR 0.65 (CI 0.62; 0.67), respectively. Similar patterns existed for respiratory, cardiac, and genitourinary complications. Opioid prescription decreased incrementally with 1,2, 3, or more non-opioid analgesic modalities by 9.51 mg (CI 11.16; 7.86) and 15.29 mg (CI 17.21; 13.37) and 29.35 mg (CI 31.79; 26.91) cumulative MME. LOS was reduced by 0.52 days (CI 0.54; 0.51), 0.49 days (CI 0.51; 0.47), and 0.40 days (CI 0.43; 0.38), respectively. Costs were reduced by $765 (CI 817; 714) or $479 (CI 539; 419) with 1 or 2 multimodal modes. Conclusions: These findings suggest substantial benefits of multimodal analgesia, including significant decreases in serious complications (especially respiratory, cardiac, and genitourinary), opioid consumption, and hospitalizations. Multimodal analgesia may facilitate safe and efficient pain management with optimized opioid consumption.

Pharmacokinetics and Safety of Oliceridine Fumarate Injection in Chinese Patients with Chronic Non-Cancer Pain: A Phase I, Single-Ascending-Dose, Open-Label Clinical Trial

Background

Oliceridine is a novel G protein-biased ligand μ-opioid receptor agonist. This study aimed to assess the pharmacokinetics and safety profile of single-ascending doses of oliceridine fumarate injection in Chinese patients with chronic non-cancer pain.

Methods

Conducted as a single-center, open-label trial, this study administered single doses of 0.75, 1.5, and 3.0 mg to 32 adult participants. The trial was conducted in two parts. First, we conducted a preliminary test comprising the administration of a single dose of 0.75mg to 2 participants. Then, we conducted the main trial involving intravenous administration of escalating doses of oliceridine fumarate (0.75 to 3 mg) to 30 participants. Pharmacokinetic (PK) parameters were derived using non-compartmental analysis. Additionally, the safety evaluation encompassed the monitoring of adverse events (AEs).

Results

32 participants were included in the PK and safety analyses. Following a 2-min intravenous infusion of oliceridine fumarate injection (0.75, 1.5, or 3 mg), Cmax and Tmax ranged from 51.293 to 81.914 ng/mL and 0.034 to 0.083 h, respectively. AUC0-t and half-life (t1/2) increased more than proportionally with dosage (1.85-2.084 h). Treatment emergent adverse events (TEAEs) were found to be consistent with the commonly reported adverse effects of opioids, both post-administration and as documented in the original trials conducted in the United States. Critically, no serious adverse events were observed.

Conclusion

Oliceridine demonstrated comparable PK parameters and a consistent PK profile in the Chinese population, in line with the PK results observed in the original trials conducted in the United States. Oliceridine was safe and well tolerated in Chinese patients with chronic non-cancer pain at doses ranging from 0.75 mg to 3.0 mg.

Trial Registration

The trial is registered at chictr.org.cn (ChiCTR2100047180).

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

EDITOR’S PERSPECTIVE

Continuous peripheral nerve blocks for analgesia following painful ambulatory surgery: a review with focus on recent developments in infusion technology

PURPOSE OF REVIEW

Continuous peripheral nerve blocks (cPNB) decrease pain scores and opioid consumption while improving patient satisfaction following ambulatory surgery. This review focuses on the history and evolution of ambulatory cPNBs, recent developments in infusion technology that may prolong the duration of analgesia, optimal choice of cPNB for various surgical procedures, and novel analgesic modalities that may prove to be alternatives or supplements to cPNBs.

RECENT FINDINGS

The primary factor limiting the duration of an ambulatory cPNB is the size of the local anesthetic reservoir. Recent evidence suggests the use of automated boluses, as opposed to continuous infusions, may decrease the rate of consumption of local anesthetic and, thereby, prolong the duration of analgesia. Utilizing a long-acting local anesthetic (e.g. ropivacaine) for initial block placement and an infusion start-delay timer may further increase this duration.

SUMMARY

Patients undergoing painful ambulatory surgery are likely to have less pain and require fewer opioid analgesics when receiving a cPNB for postoperative analgesia. Advances in electronic pumps used for cPNBs may increase the duration of these benefits.

Association of Intraoperative Opioid Administration With Postoperative Pain and Opioid Use

IMPORTANCE

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

OBJECTIVE

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

DESIGN, SETTING, AND PARTICIPANTS

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

EXPOSURES

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

MAIN OUTCOMES AND MEASURES

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

RESULTS

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

CONCLUSIONS AND RELEVANCE

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

A multidisciplinary opioid-reduction pathway for robotic prostatectomy: outcomes at year one

BACKGROUND

Opioid use has come under increasing scrutiny, driven in part by the opioid crisis and growing concerns that up to 6% of opioid-naïve patients may become chronic opioid users. This has resulted in a revaluation of perioperative practice. For this reason, we implemented a multidisciplinary pathway to reduce perioperative opioid usage through education and standardization of practice.

METHODS

A single-centre retrospective evaluation was performed after 1 year, comparing the outcomes to those of the 2 years prior to pathway implementation. Comparisons were made between pre- vs. post pathway change by 2:1 propensity matching between cohorts. Univariate linear regression models were created using demographic variables with those that were p < 0.15 included in the final model and using post-operative opioid use (in oral morphine equivalents, OME) as the primary outcome.

RESULTS

We found that intraoperative opioid use was significantly decreased 38.2 mg (28.3) vs. 18.0 mg (40.4) oral morphine equivalents (OME), p < .001, as was post-operative opioid use for the duration of the hospitalization, 46.3 mg (49.5) vs. 35.49 mg (43.7) OME, p = 0.002. In subgroup analysis of those that received some intraoperative opioids (n = 152) and those that received no opioids (n = 34), we found that both groups required fewer opioids in the post-operative period 47.0 mg (47.7) vs. 32.4 mg (40.6) OME, p = 0.001, + intraoperative opioids, 62.4 mg (62.9) vs. 35.8 mg (27.7) OME, p = 0.13, - intraoperative opioids. Time to discharge from the PACU was reduced in both groups 215 min (199) vs. 167 min (122), p < 0.003, + intraoperative opioids and 253 min (270) vs. 167 min (105), p = 0.028, - intraoperative opioids. The duration of time until meeting discharge criteria from PACU was 221 min (205) vs. 170 min (120), p = 0.001. Hospital length of stay (LOS) was significantly reduced 1.4 days (1.3) vs. 1.2 days (0.8), p = 0.005. Both sub-groups demonstrated reduced hospital LOS 1.5 days (1.4) vs. 1.2 days (0.8), p = 0.0047, + intraoperative opioids and 1.7 days (1.6) vs. 1.3 days (0.9), p = 0.0583, - intraoperative opioids. Average pain scores during PACU admission and post-PACU until discharge were not statistically different between cohorts.

CONCLUSIONS

These findings underscore the effectiveness of a multidisciplinary approach to reduce opioids. Furthermore, it demonstrates improved patient outcomes as measured by both shorter PACU and almost 50% reduction in perioperative opioid use whilst maintaining similar analgesia as indicated by patient-reported pain scores.

Efficacy and Safety of Sufentanil Infusion for Postoperative Analgesia in Cancer Surgery: A Retrospective Cohort Study

Background Opioids have long been the cornerstone of drugs used for perioperative analgesia. Sufentanil has an advantageous pharmacological profile for its use in continuous intravenous (IV) infusion, yet remains poorly described. Our institution has implemented analgesia protocols with IV sufentanil infusions for cancer surgery with appropriate monitoring. The aim of this study was to evaluate the efficacy and safety of IV sufentanil infusion. Methods A single-center retrospective cohort study was conducted through the analysis of patients' records and the acute pain service database. Inclusion criteria were adult patients admitted for elective cancer surgery and with postoperative IV sufentanil infusion during one year period. Descriptive and inferential statistical analysis was performed by using Software SPSS Statistics (IBM Corp., Armonk USA): Kruskal-Wallis, Mann-Whitney, Chi-square and Fisher tests; Bonferroni chi-square residual analysis, binary logistic regression; p<0.05. Results The study population of 304 patients had a median age of 66 years (22-91) and 229 (75.3%) were men. 38 (12.5%) were chronic opioid users. Head and neck/otorhinolaryngology (ORL) surgery was performed in 155 (51.0%) and abdominopelvic surgery in 123 (40.5%). The median days of IV sufentanil infusion were 2 (1-13). At rest and with movement, analgesia was considered good, i.e., over 90% of patients with visual analogue scale (VAS) pain score ≤ 3. We found that patients submitted to musculoskeletal surgery had higher VAS pain scores; this group also presented older patients with higher American Society of Anesthesiologists (ASA) physical status classification and more chronic opioid users (p<0.05). 144 patients (47.4%) had at least one adverse effect related to IV sufentanil infusion, notably transient and not requiring any specific treatment. These patients were older and had longer infusion periods (p<0.05). 237 (98.3%) of the adverse effects occurred during the first 3 days and the most common were: sedation (n=104, 42.8%), hypotension (n=32, 13.2%), hypoxemia (n=31, 12.8%) and nausea/vomiting (n=25, 10.3%). The reported incidence of respiratory depression was 2.9% (n=9), with three patients (1%) requiring advanced treatment. Conclusion Multimodal analgesic protocols with IV sufentanil infusions provided good postoperative analgesia for head and neck/ORL and abdominopelvic cancer surgeries. The adverse effects associated with the IV sufentanil infusions were mild and mainly managed with opioid dose reductions. Our study showed that this approach can be a safe option for postoperative multimodal analgesia in cancer surgery with appropriate monitoring in high-dependency units.

Respiratory Effects of Biased Ligand Oliceridine in Older Volunteers: A Pharmacokinetic-Pharmacodynamic Comparison with Morphine

BACKGROUND

Oliceridine is a G protein-biased µ-opioid, a drug class that is associated with less respiratory depression than nonbiased opioids, such as morphine. The authors quantified the respiratory effects of oliceridine and morphine in elderly volunteers. The authors hypothesized that these opioids differ in their pharmacodynamic behavior, measured as effect on ventilation at an extrapolated end-tidal Pco2 at 55 mmHg, V̇E55.

METHODS

This four-arm double-blind, randomized, crossover study examined the respiratory effects of intravenous 0.5 or 2 mg oliceridine and 2 or 8 mg morphine in 18 healthy male and female volunteers, aged 55 to 89 yr, on four separate occasions. Participants' CYP2D6 genotypes were determined, hypercapnic ventilatory responses were obtained, and arterial blood samples were collected before and for 6 h after treatment. A population pharmacokinetic-pharmacodynamic analysis was performed on V̇E55, the primary endpoint; values reported are median ± standard error of the estimate.

RESULTS

Oliceridine at low dose was devoid of significant respiratory effects. High-dose oliceridine and both morphine doses caused a rapid onset of respiratory depression with peak effects occurring at 0.5 to 1 h after opioid dosing. After peak effect, compared with morphine, respiratory depression induced by oliceridine returned faster to baseline. The effect-site concentrations causing a 50% depression of V̇E55 were 29.9 ± 3.5 ng/ml (oliceridine) and 21.5 ± 4.6 ng/ml (morphine), the blood effect-site equilibration half-lives differed by a factor of 5: oliceridine 44.3 ± 6.1 min and morphine 214 ± 27 min. Three poor CYP2D6 oliceridine metabolizers exhibited a significant difference in oliceridine clearance by about 50%, causing higher oliceridine plasma concentrations after both low- and high-dose oliceridine, compared with the other participants.

CONCLUSIONS

Oliceridine and morphine differ in their respiratory pharmacodynamics with a more rapid onset and offset of respiratory depression for oliceridine and a smaller magnitude of respiratory depression over time.

EDITOR’S PERSPECTIVE

Efficacy of pericapsular nerve group (PENG) block on perioperative pain management in elderly patients undergoing hip surgical procedures: a protocol for a systematic review with meta-analysis and trial sequential analysis

INTRODUCTION

An increasing number of elderly patients suffer from hip diseases associated with moderate to severe perioperative pain during the accelerating global ageing process. Optimal analgesia can decrease perioperative complications and facilitate elderly patients' perioperative recovery. Pericapsular nerve group (PENG) block is a relatively new, analgesia adequate and motor-sparing block technique for perioperative pain management of hip diseases. However, the efficacy of PENG block remains unclear as the limited clinical evidence. Then, we will perform a protocol for a systematic review and meta-analysis to identify the efficacy of PENG block for perioperative pain management.

METHODS AND ANALYSIS

PubMed, Ovid Medline, Cochrane Library, Embase, Web of Science, China National Knowledge Infrastructure, Chinese BioMedical Literature, Wanfang and VIP databases will be searched from inception to August 2022 to identify randomised controlled trials of elderly patients accepting PENG block for hip diseases. The primary outcome will be the pain intensity after pain management. Secondary outcomes will be quadriceps strength, perioperative rescue analgesia information and perioperative complications. Assessment of heterogeneity will be primarily inspected by forest plots. If there is no indication of funnel plot asymmetry, a random-effects meta-analysis will be performed. The Cochrane risk-of-bias tool, Grading of Recommendations Assessment, Development and Evaluation and trial sequential analysis will be conducted to evaluate the evidence quality and control the random errors. Funnel plots and Egger's regression test will be performed to evaluate publication bias.

ETHICS AND DISSEMINATION

Ethical approval was not required for this systematic review protocol. The results will be disseminated through peer-reviewed publications.

PROSPERO REGISTRATION NUMBER

CRD42022313895.

Opioid-Free Anesthesia: The Pros and Cons

Appropriate perioperative pain control is essential to aid in patients' recovery after surgery; however, acute postsurgical pain remains poorly treated and there continues to be an overreliance on opiates. Perioperative pain control starts in the operating room, and opiate-free anesthesia (OFA), where no opiates are used intraoperatively, has been proposed as a feasible strategy to further minimize opiates in the perioperative period. In this article, we address the potential benefits and shortcomings of OFA, while exploring tools available to accomplish multimodal anesthesia and ideally OFA, and the evidence behind the techniques proposed.

Effects of Intraoperative Opioid Administration on Postoperative Pain and Pain Threshold: A Randomized Controlled Study

Fentanyl and short-acting remifentanil are often used in combination. We evaluated the effect of intraoperative opioid administration on postoperative pain and pain thresholds when the two drugs were used. Patients who underwent gynecological laparoscopic surgery were randomly assigned into two groups (15 patients each) to receive either sufficient (group A) or minimum (group B) fentanyl (maximum estimated effect site concentration: A: 7.86 ng/mL, B: 1.5 ng/mL). The estimated effect site concentration at the end of surgery was adjusted to the same level (1 ng/mL). Patients in both groups also received continuous intravenous remifentanil during surgery. The primary outcome was the pressure pain threshold, as evaluated by a pressure algometer 3 h postoperatively. The pressure pain threshold at 3 h postoperatively was 51.1% (95% CI: [44.4–57.8]) in group A and 56.6% [49.5–63.6] in group B, assuming a preoperative value of 100% (p = 0.298). There were no significant differences in pressure pain threshold and numeric rating scale scores between the groups after surgery. The pain threshold decreased significantly in both groups at 3 h postoperatively compared to preoperative values, and recovered at 24 h. Co-administration of both opioids caused hyperalgesia regardless of fentanyl dose.

Analgesic and Anesthetic Efficacy of Rocuronium/Sugammadex in Otorhinolaryngologic Surgery: A Propensity Score-Matched Analysis

The use of rocuronium/sugammadex in otorhinolaryngologic surgery improves intubation conditions and surgical rating scales. This study primarily aimed to evaluate the effect of the combination of rocuronium and sugammadex on intraoperative anesthetic consumption. The secondary outcomes were the intraoperative and postoperative morphine milligram equivalent (MME) consumption, duration of intraoperative hypertension, extubation time, incidence of delayed extubation and postoperative nausea and vomiting, pain score, and length of stay. A total of 2848 patients underwent otorhinolaryngologic surgery at a tertiary medical center in southern Taiwan. After applying the exclusion criteria, 2648 of these cases were included, with 167 and 2481 in the rocuronium/sugammadex and cisatracurium/neostigmine groups, respectively. To reduce potential bias, 119 patients in each group were matched by propensity scores for sex, age, body weight, and type of surgery. We found that the rocuronium/sugammadex group was associated with significant preservation of the intraoperative sevoflurane and MME consumption, with reductions of 14.2% (p = 0.009) and 11.8% (p = 0.035), respectively. The use of the combination of rocuronium and sugammadex also significantly increased the dose of intraoperative labetalol (p = 0.002), although there was no significant difference in intraoperative hypertensive events between both groups. In conclusion, our results may encourage the use of the combination of rocuronium and sugammadex as part of volatile-sparing and opioid-sparing anesthesia in otorhinolaryngologic surgery.

Perioperative Opioids, the Opioid Crisis, and the Anesthesiologist

This review summarizes current evidence related to perioperative opioid prescription fulfillment and use and discusses the role of personalized anesthesia care in mitigating opioid-related harms without compromising analgesia.

Opioid-free anesthesia in oncologic surgery: the rules of the game

BACKGROUND

Opioids are frequently used in the postoperative period due to their analgesic properties. While these drugs reduce nociceptive somatic, visceral, and neuropathic pain, they may also lead to undesirable effects such as respiratory depression, urinary retention, nausea and vomiting, constipation, itching, opioid-induced hyperalgesia, tolerance, addiction, and immune system disorders. Anesthesiologists are in the critical position of finding balance between using opioids when they are necessary and implementing opioid-sparing strategies to avoid the known harmful effects. This article aims to give an overview of opioid-free anesthesia.

MAIN BODY

This paper presents an overview of opioid-free anesthesia and opioid-sparing anesthetic techniques. Pharmacological and non-pharmacological strategies are discussed, highlighting the possible advantages and drawbacks of each approach.

CONCLUSIONS

Choosing the best anesthetic protocol for a patient undergoing cancer surgery is not an easy task and the available literature provides no definitive answers. In our opinion, opioid-sparing strategies should always be implemented in routine practice and opioid-free anesthesia should be considered whenever possible. Non-pharmacological strategies such as patient education, while generally underrepresented in scientific literature, may warrant consideration in clinical practice.

Current Issues in the Use of Opioids for the Management of Postoperative Pain: A Review

Importance

Uncontrolled and indiscriminate prescribing of opioids has led to an opioid crisis that started in North America and spread throughout high-income countries. The aim of this narrative review was to explore some of the current issues surrounding the use of opioids in the perioperative period, focusing on drivers that led to escalation of use, patient harms, the move away from using self-reported pain scores alone to assess adequacy of analgesia, concerns about the routine use of controlled-release opioids for the management of acute pain, opioid-free anesthesia and analgesia, and prescription of opioids on discharge from hospital.

Observations

The origins of the opioid crisis are multifactorial and may include good intentions to keep patients pain free in the postoperative period. Assessment of patient function may be better than unidimensional numerical pain scores to help guide postoperative analgesia. Immediate-release opioids can be titrated more easily to match analgesic requirements. There is currently no good evidence to show that opioid-free anesthesia and analgesia affects opioid prescribing practices or the risk of persistent postoperative opioid use. Attention should be paid to discharge opioid prescribing as repeat and refill prescriptions are risk-factors for persistent postoperative opioid use. Opioid stewardship is paramount, and many governments are passing legislation, while statutory bodies and professional societies are providing advice and guidance to help mitigate the harm caused by opioids.

Conclusions and Relevance

Opioids remain a crucial part of many patients' journey from surgery to full recovery. The last few decades have shown that unfettered opioid use puts patients and societies at risk, so caution is needed to mitigate those dangers. Opioid stewardship provides a multilayered structure to allow continued safe use of opioids as part of broad pain management strategies for those patients who benefit from them most.

Opioids and Public Health: The Prescription Opioid Ecosystem and Need for Improved Management

While U.S. opioid prescribing has decreased 38% in the past decade, opioid deaths have increased 300%. This opioid paradox is poorly recognized. Current approaches to opioid management are not working, and new approaches are needed. This article reviews the outcomes and shortcomings of recent U.S. opioid policies and strategies that focus primarily or exclusively on reducing or eliminating opioid prescribing. It introduces concepts of a prescription opioid ecosystem and opioid pool, and it discusses how the pool can be influenced by supply-side, demand-side, and opioid returns factors. It illuminates pressing policy needs for an opioid ecosystem that enables proper opioid stewardship, identifies associated responsibilities, and emphasizes the necessity of making opioid returns as easy and common as opioid prescribing, in order to minimize the size of the opioid pool available for potential diversion, misuse, overdose, and death. Approaches are applicable to opioid prescribing in general, and to opioid prescribing after surgery.

The opioid epidemic from the acute care hospital front line

Prescription opioid use has risen steeply for over two decades, driven primarily by advocacy for better management of chronic non-cancer pain, but also by poor opioid stewardship in the management of acute pain. Inappropriate prescribing, among other things, contributed to the opioid 'epidemic' and striking increases in patient harm. It has also seen a greater proportion of opioid-tolerant patients presenting to acute care hospitals. Effective and safe management of acute pain in opioid-tolerant patients can be challenging, with higher risks of opioid-induced ventilatory impairment and persistent post-discharge opioid use compared with opioid-naive patients. There are also increased risks of some less well known adverse postoperative outcomes including infection, earlier revision rates after major joint arthroplasty and spinal fusion, longer hospital stays, higher re-admission rates and increased healthcare costs. Increasingly, opioid-free/opioid-sparing techniques have been advocated as ways to reduce patient harm. However, good evidence for these remains lacking and opioids will continue to play an important role in the management of acute pain in many patients.Better opioid stewardship with consideration of preoperative opioid weaning in some patients, assessment of patient function rather than relying on pain scores alone to assess adequacy of analgesia, prescription of immediate release opioids only and evidence-based use of analgesic adjuvants are important. Post-discharge opioid prescribing should be contingent on an assessment of patient risk, with short-term only use of opioids. In partnership with pharmacists, nursing staff, other medical specialists, general practitioners and patients, anaesthetists remain ideally positioned to be involved in opioid stewardship in the acute care setting.

Practice Patterns and Variability in Intraoperative Opioid Utilization: A Report From the Multicenter Perioperative Outcomes Group

BACKGROUND

Opioids remain the primary mode of analgesia intraoperatively. There are limited data on how patient, procedural, and institutional characteristics influence intraoperative opioid administration. The aim of this retrospective, longitudinal study from 2012 to 2016 was to assess how intraoperative opioid dosing varies by patient and clinical care factors and across multiple institutions over time.

METHODS

Demographic, surgical procedural, anesthetic technique, and intraoperative analgesia data as putative variables of intraoperative opioid utilization were collected from 10 institutions. Log parenteral morphine equivalents (PME) was modeled in a multivariable linear regression model as a function of 15 covariates: 3 continuous covariates (age, anesthesia duration, year) and 12 factor covariates (peripheral block, neuraxial block, general anesthesia, emergency status, race, sex, remifentanil infusion, major surgery, American Society of Anesthesiologists [ASA] physical status, non-opioid analgesic count, Multicenter Perioperative Outcomes Group [MPOG] institution, surgery category). One interaction (year by MPOG institution) was included in the model. The regression model adjusted simultaneously for all included variables. Comparison of levels within a factor were reported as a ratio of medians with 95% credible intervals (CrI).

RESULTS

A total of 1,104,324 cases between January 2012 and December 2016 were analyzed. The median (interquartile range) PME and standardized by weight PME per case for the study period were 15 (10-28) mg and 200 (111-347) μg/kg, respectively. As estimated in the multivariable model, there was a sustained decrease in opioid use (mean, 95% CrI) dropping from 152 (151-153) μg/kg in 2012 to 129 (129-130) μg/kg in 2016. The percent of variability in PME due to institution was 25.6% (24.8%-26.5%). Less opioids were prescribed in men (130 [129-130] μg/kg) than women (144 [143-145] μg/kg). The men to women PME ratio was 0.90 (0.89-0.90). There was substantial variability in PME administration among institutions, with the lowest being 80 (79-81) μg/kg and the highest being 186 (184-187) μg/kg; this is a PME ratio of 0.43 (0.42-0.43).

CONCLUSIONS

We observed a reduction in intraoperative opioid administration over time, with variability in dose ranging between sexes and by procedure type. Furthermore, there was substantial variability in opioid use between institutions even when adjusting for multiple variables.

Low Incidence of Opioid-Induced Respiratory Depression Observed with Oliceridine Regardless of Age or Body Mass Index: Exploratory Analysis from a Phase 3 Open-Label Trial in Postsurgical Pain

INTRODUCTION

Advanced age and obesity are reported to increase the risk of opioid-induced respiratory depression (OIRD). Oliceridine, an intravenous opioid, is a G-protein-biased agonist at the µ-opioid receptor that may provide improved safety. The recent phase 3 ATHENA open-label, multicenter study evaluated postoperative use of oliceridine in patients with moderate-to-severe acute pain. This exploratory analysis of the ATHENA data examined the incidence of OIRD in older (≥ 65 years) and/or obese (BMI ≥ 30 kg/m2) patients and analyzed risk factors of OIRD.

METHODS

Patients aged ≥ 18 years with a score ≥ 4 on an 11-point numeric pain rating scale (NPRS) received IV oliceridine as needed via bolus dosing and/or patient-controlled analgesia (PCA). OIRD occurring within 48 h of last dose of oliceridine was defined using two established definitions: (1) naloxone use, (2) respiratory rate < 10 breaths per minute and/or oxygen saturation < 90%.

RESULTS

A total of 724 surgical patients with a mean age of 54.5 ± 15.9 years and a mean NRS score of 6.2 ± 2.1 were included in this analysis; 33.3% (241/724) were ≥ 65 years of age and 46.3% (335/724) had BMI (body mass index) ≥ 30 kg/m2. The overall OIRD incidence was 13.7% with no patients requiring naloxone. The OIRD incidence was similar in the elderly and younger adults' cohorts [10.8 vs. 15.1%, OR 0.68 (0.42, 1.1), p = 0.11], and in obese and non-obese groups [14.0 vs. 13.4%, OR 1.06 (0.69, 1.62), p = 0.80]. In patients that were both elderly and obese (n = 120), the incidence was 10.8%. The multivariate analysis identified baseline NRS ≥ 6 [OR 1.6 (1.0, 2.4), p = 0.0499], PCA administration [OR 1.9 (1.2, 3.1), p = 0.005], and concomitant use of benzodiazepines and/or gabapentinoids [OR 1.6 (1.0, 2.6), p = 0.045], as being associated with OIRD.

CONCLUSIONS

Postoperative oliceridine use in patients with advanced age and/or increased BMI was not associated with increased risk of OIRD.

Percutaneous cryoneurolysis for acute pain management: current status and future prospects

Introduction: Conventional nerve blocks utilize local anesthetic drugs to provide pain relief for hours or days following surgery or trauma. However, postoperative and trauma pain can last weeks or months. Ultrasound-guided percutaneous cryoneurolysis is an anesthetic modality that offers substantially longer pain relief compared to local anesthetic-based nerve blocks.Areas covered: In this review, we discuss the history, mechanism of action, and use of ultrasound-guided percutaneous cryoneurolysis by anesthesiologists in the setting of acute pain management.Expert opinion: Ultrasound-guided percutaneous cryoneurolysis offers the potential to provide weeks or months of pain relief following surgery or trauma. Compared to continuous local anesthetic-based peripheral nerve blocks, currently the gold standard for providing long duration postoperative analgesia, cryoneurolysis has benefits that include: 1) longer duration measured in weeks or months rather than days; 2) no external reservoir of local anesthetic to be carried by the patient; 3) no risk of infection; and 4) no risk of catheter dislodgement. However, cryoneurolysis can induce a prolonged motor block in addition to the sensory block, decreasing the appropriate indications to those in which potential sensory and motor deficits are acceptable. Additionally, cryoneurolysis of multiple nerves can have a substantial time requirement relative to conventional nerve blocks.

Perioperative Opioid Administration

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

Surgery and opioids: evidence-based expert consensus guidelines on the perioperative use of opioids in the United Kingdom

There are significant concerns regarding prescription and misuse of prescription opioids in the perioperative period. The Faculty of Pain Medicine at the Royal College of Anaesthetists have produced this evidence-based expert consensus guideline on surgery and opioids along with the Royal College of Surgery, Royal College of Psychiatry, Royal College of Nursing, and the British Pain Society. This expert consensus practice advisory reproduces the Faculty of Pain Medicine guidance. Perioperative stewardship of opioids starts with judicious opioid prescribing in primary and secondary care. Before surgery, it is important to assess risk factors for continued opioid use after surgery and identify those with chronic pain before surgery, some of whom may be taking opioids. A multidisciplinary perioperative care plan that includes a prehabilitation strategy and intraoperative and postoperative care needs to be formulated. This may need the input of a pain specialist. Emphasis is placed on optimum management of pain pre-, intra-, and postoperatively. The use of immediate-release opioids is preferred in the immediate postoperative period. Attention to ensuring a smooth care transition and communication from secondary to primary care for those taking opioids is highlighted. For opioid-naive patients (patients not taking opioids before surgery), no more than 7 days of opioid prescription is recommended. Persistent use of opioid needs a medical evaluation and exclusion of chronic post-surgical pain. The lack of grading of the evidence of each individual recommendation remains a major weakness of this guidance; however, evidence supporting each recommendation has been rigorously reviewed by experts in perioperative pain management.

In the Arms of Morpheus without Morphia; Mitigating the United States Opioid Epidemic by Decreasing the Surgical Use of Opioids

The opioid epidemic is a major public health issue in the United States. Exposure of opioid naïve-patients to opioids in the perioperative period is a well-documented source of continued use with one in 20 opioid-naïve surgical patients continuing to use opioids beyond 90 days. There is no association with magnitude of surgery, major versus minor, and the strongest predictor of continued use is surgical exposure. Causal factors include over reliance on opioids for intraoperative and postoperative analgesia and excessive ambulatory opioid prescribing. Opioid-induced hyperalgesia can paradoxically result from intraoperative (anesthesia controlled) opioid administration. Increasing size of initial prescription is a strong predictor of continued use necessitating procedure specific supplies limited to under 3-days. Alternative multimodal pain management (non-opioid medications and regional anesthesia) that limit opioid use must be a high priority with opioids reserved for severe breakthrough pain. Barriers to implementation of opioid-sparing pathways include reluctance to adopt protocols and apprehension about opioid elimination. Considering the number of surgeries performed annually in the United States, perioperative physicians must aggressively address modifiable factors in surgical patients. Patient care pathways need to be constructed collaboratively by surgeons and anesthesiologists with continuing feedback to optimize patient outcomes including iatrogenic opioid dependence.

An international multidisciplinary consensus statement on the prevention of opioid-related harm in adult surgical patients

This international multidisciplinary consensus statement was developed to provide balanced guidance on the safe peri-operative use of opioids in adults. An international panel of healthcare professionals evaluated the literature relating to postoperative opioid-related harm, including persistent postoperative opioid use; opioid-induced ventilatory impairment; non-medical opioid use; opioid diversion and dependence; and driving under the influence of prescription opioids. Recommended strategies to reduce harm include pre-operative assessment of the risk of persistent postoperative opioid use; use of an assessment of patient function rather than unidimensional pain scores alone to guide adequacy of analgesia; avoidance of long-acting (modified-release and transdermal patches) opioid formulations and combination analgesics; limiting the number of tablets prescribed at discharge; providing deprescribing advice; avoidance of automatic prescription refills; safe disposal of unused medicines; reducing the risk of opioid diversion; and better education of healthcare professionals, patients and carers. This consensus statement provides a framework for better prescribing practices that could help reduce the risk of postoperative opioid-related harm in adults.

Acute postoperative pain management with percutaneous peripheral nerve stimulation: the SPRINT neuromodulation system

INTRODUCTION

Ultrasound-guided percutaneous peripheral nerve stimulation (PNS) may be used to treat acute postoperative pain for various types of surgeries. This modality avoids several limitations of traditional local anesthetic-based peripheral nerve blocks including avoidance of motor blockade and sensory deficits.

AREAS COVERED

In this review, we discuss the use of SPRINT (SPR Therapeutics, Cleveland, OH) neuromodulation system in the setting of acute postoperative pain management.

EXPERT OPINION

PNS is a novel modality in regional anesthesia that has much promise in reducing overall opioid use after surgery. Placement of PNS is very similar to that of catheter-based regional anesthesia techniques. Ultrasound is used to guide the percutaneously placed introducer needle in proximity to the target nerve. There are several benefits of PNS over catheter-based approaches, including: 1) avoidance of motor or sensory blockade; 2) no medication bag required to be carried; and 3) electric leads may be kept in situ safely for up to 60 days. While several proof-of-concept studies have been published highlighting its use in various types of surgeries, large high-quality randomized controlled trials are still needed.

Perioperative Gabapentinoids: Deflating the Bubble

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