Multimodal Analgesia

Addition of Surgeon-Administered Adductor Canal Infiltration to the Periarticular Infiltration in Total Knee Arthroplasty: Effect on Pain and Early Outcomes

BACKGROUND

Our aim was to study the additive effect of surgeon-administered adductor canal infiltration (SACI) over routine periarticular infiltration (PAI) on pain control [morphine consumption and pain score by the visual analog scale (VAS)] and early function [flexion and Timed Up and Go (TUG) test] post-total knee arthroplasty (TKA).

METHODS

We prospectively randomized 60 patients into 2 groups. Group I patients received the standard PAI, whereas in Group II, the patients received a SACI in addition to the PAI. The total volume of the injected drug and the postoperative pain management protocol were the same for all. The number of doses of patient-controlled analgesia (PCA) used for breakthrough pain was recorded as PCA consumption. For early function, flexion and the TUG test were used. The VAS score and PCA consumption were compared between the 2 groups by using analyses of variance with post hoc tests as indicated. The TUG test and flexion were compared using Student t tests. The level of significance was set at 0.05.

RESULTS

The PCA consumption in the first 6 hours was significantly higher in Group I (P = .04). The VAS at 6 hours was significantly lower in Group II (P = .042). The TUG test was comparable between the 2 groups preoperatively (P = .72) at 24 hours (P = .60) and 48 hours (P = .60) post-TKA. The flexion was comparable between the 2 groups preoperatively (P = .85) at 24 hours (P = .48) and 48 hours (P = .79) post-TKA.

CONCLUSIONS

Adding a SACI to PAI provides improved pain relief and reduces opioid consumption without affecting early function post-TKA. A SACI avoids the need for an anesthesiologist or specialized equipment with no added operating time and minimal added cost. We recommend routine use of SACI for all patients undergoing TKA.

Virtual reality for postsurgical pain management: An explorative randomized controlled study

BACKGROUND

Virtual reality (VR) is a promising tool in a multimodal analgesic approach; however, evidence regarding virtual reality for postsurgical pain is limited. This study investigates the initial effectiveness and feasibility of self-administered virtual reality in postsurgical pain management.

METHODS

Patients reporting a postsurgical pain score ≥4 were randomized for control or VR, stratified for 3 interventions with varying levels of immersion and interaction. Subjects were instructed to use virtual reality as add-on treatment at least 3 times a day for 10 minutes on days 2 till 4 postoperatively. Primary outcome was the mean daily pain intensity. Results of pain scores were related to patient and intervention characteristics, to explore which characteristics interact with virtual reality effects. Secondary outcomes were analgesic use, anxiety, stress, and feasibility.

RESULTS

One hundred patients were included in the analyses: 37 in the control group and 63 for VR. VR did not demonstrate a significant effect on self-reported pain scores (P = .43), nor were specific patient or intervention characteristics associated with greater VR effects. Analgesic usage did not differ between groups. However, there was a trend toward greater cumulative percentages of patients achieving a 30% pain reduction, and significantly lower daily experienced stress (P = .01) and anxiety (P = .03) levels in VR intervention groups. VR was used less than prescribed, mainly because of illness and pain. Adverse events included disorientation, nausea, and fatigue.

CONCLUSIONS

This explorative study did not demonstrate initial effectiveness of VR as add-on pain treatment regarding pain and analgesic use; however, VR positively affected stress and anxiety. VR is safe and suitable for a wide target audience, and feasibility differed between interventions. Personalizing and improving VR technology may enhance its effectiveness.

Effects of buccal acupuncture on postoperative analgesia in elderly patients undergoing laparoscopic radical gastrectomy: a randomized controlled trial

Objective

This study aimed to evaluate the efficacy and safety of buccal acupuncture on postoperative analgesia, perioperative stress response and adverse events in elderly patients undergoing laparoscopic radical gastrectomy.

Methods

It was a prospective, outcome assessor-blinded, randomized controlled trial, involving 90 patients aged 65-80 years who were treated with an elective laparoscopic radical gastrectomy. They were randomly assigned to buccal acupuncture group (Group B) and control group (Group C). Buccal acupuncture was applied to patients of Group B before the induction of general anesthesia, while no additional application was given to those in Group C. Patient-controlled intravenous analgesia (PCIA) with sufentanil was postoperatively performed in both groups. Sufentanil consumption and the Visual Analog Scale (VAS) score within 48 h postoperatively were assessed as primary outcomes. Secondary outcomes included peripheral levels of stress markers, intraoperative consumptions of anesthetic drugs and postoperative recovery.

Results

Patients in Group B presented significantly lower VAS scores within 24 h and less consumption of sufentanil within 48 h postoperatively (both p < 0.01). The awaking time, time to extubation and length of stay were significantly shorter in Group B than in Group C (p = 0.005, 0.001 and 0.028, respectively). Compared with Group C, stress response and inflammatory response within 24 h postoperatively were also significantly milder in Group B.

Conclusion

The use of buccal acupuncture before general anesthesia induction favors the postoperative analgesic effect and recovery in elderly patients undergoing laparoscopic radical gastrectomy, the mechanism of which involves relieving postoperative stress response and inflammatory response.

Clinical trial registration

This study was registered in the Chinese Clinical Trial Registry (www.chictr.org.cn) on 15/06/2023 (ChiCTR2300072500).

Cannabinoid Analgesia in Postoperative Pain Management: From Molecular Mechanisms to Clinical Reality

Postoperative pain (POP) is a challenging clinical phenomenon that affects the majority of surgical patients and demands effective management to mitigate adverse outcomes such as persistent pain. The primary goal of POP management is to alleviate suffering and facilitate a seamless return to normal function for the patient. Despite compelling evidence of its drawbacks, opioid analgesia remains the basis of POP treatment. Novel therapeutic approaches rely on multimodal analgesia, integrating different pharmacological strategies to optimize efficacy while minimizing adverse effects. The recognition of the imperative role of the endocannabinoid system in pain regulation has prompted the investigation of cannabinoid compounds as a new therapeutic avenue. Cannabinoids may serve as adjuvants, enhancing the analgesic effects of other drugs and potentially replacing or at least reducing the dependence on other long-term analgesics in pain management. This narrative review succinctly summarizes pertinent information on the molecular mechanisms, clinical therapeutic benefits, and considerations associated with the plausible use of various cannabinoid compounds in treating POP. According to the available evidence, cannabinoid compounds modulate specific molecular mechanisms intimately involved in POP. However, only two of the eleven clinical trials that evaluated the efficacy of different cannabinoid interventions showed positive results.

Acupoint Stimulation for Pain Control in Enhanced Recovery After Surgery: Systematic Review and Meta-Analysis

Introduction: Postoperative pain control is a challenge in enhanced recovery after surgery (ERAS). The current study reviewed the efficacy and safety of incorporating acupoint stimulation for postoperative pain control in ERAS. Methods: Ten databases for relevant randomized controlled trials (RCTs) published in English or Mandarin Chinese were searched from 1997 to 2022. The quality of each article was appraised using the Cochrane Collaboration Risk of Bias Criteria and the modified Jadad Scale. The primary outcome was pain control, measured using the visual analog scale 24 h after surgery. Results: Eleven trials met the eligibility criteria and were included in the study. Acupoint stimulation was found more effective than control treatments in terms of pain intensity (standardized mean difference [SMD] -0.94; 95% confidence interval [CI] -1.35 to -0.53), analgesic drug consumption (SMD -1.87; 95% CI -2.98 to -0.75), postoperative nausea (PON; SMD 0.31; 95% CI 0.13 to 0.73), postoperative vomiting (POV; SMD 0.57; 95% CI 0.11 to 2.92), and PON and POV (PONV; SMD 0.29; 95% CI 0.16 to 0.53). The Zusanli (ST36) and Neiguan (PC6) were the most-used acupoints in the included trials (8/11). The reported adverse reaction was only one case of bruising. Discussion: Acupoint stimulation improved pain control in patients undergoing ERAS more than control treatments. The findings provide an evidence-based premise for incorporating acupoint stimulation into ERAS strategies. More rigorous RCTs are needed in the future.

Novel drug-drug salt crystals of metformin with ibuprofen or naproxen: Improved solubility, dissolution rate, and synergistic antinociceptive effects

As the monotherapy of available analgesics is usually accompanied by serious side effects or limited efficacy in the management of chronic pain, multimodal analgesia is widely used to achieve improved benefit-to-risk ratios in clinic. Drug-drug salts are extensively researched to optimize the physicochemical properties of active pharmaceutical ingredients (APIs) and achieve clinical benefits compared with individual APIs or their combination. New drug-drug salt crystals metformin-ibuprofen (MET-IBU) and metformin-naproxen (MET-NAP) were prepared from metformin (MET) and two poorly water-soluble anti-inflammatory drugs (IBU and NAP) by the solvent evaporation method. The structures of these crystals were confirmed by single crystal and powder X-ray diffraction, Hirshfeld surface, Fourier transform infrared spectroscopy and thermal analysis. Both MET-IBU and MET-NAP showed significantly improved solubility and intrinsic dissolution rate than the pure IBU or NAP. The stability test indicated that MET-IBU and MET-NAP have excellent physical stability under stressing test (10 days) and accelerated conditions (3 months). Moreover, isobolographic analysis suggested that MET-IBU and MET-NAP exerted potent and synergistic antinociceptive effects in λ-Carrageenan-induced inflammatory pain in mice, and both of them had an advantage in rapid pain relief. These results demonstrated the potential of MET-IBU and MET-NAP to achieve synergistic antinociceptive effects by developing drug-drug salt crystals.

National Trends in Orthopaedic Pain Management from 2016 to 2020

INTRODUCTION

Effective pain management is vital in orthopaedic care, impacting postoperative recovery and patient well-being. This study aimed to discern national and regional pain prescription trends among orthopaedic surgeons through Medicare claims data, using geospatial analysis to ascertain opioid and nonopioid usage patterns across the United States.

METHODS

Physician-level Medicare prescription databases from 2016 to 2020 were filtered to orthopaedic surgeons, and medications were categorized into opioids, muscle relaxants, anticonvulsants, and NSAIDs. Patient demographics were extracted from a Medicare provider demographic data set, while county-level socioeconomic metrics were obtained primarily from the American Community Survey. Geospatial analysis was conducted using Geoda software, using Moran I statistic for cluster analysis of pain medication metrics. Statistical trends were analyzed using linear regression, Mann-Whitney U test, and multivariate logistic regression, focusing on prescribing rates and hotspot/coldspot identification.

RESULTS

Analysis encompassed 16,505 orthopaedic surgeons, documenting more than 396 million days of pain medication prescriptions: 57.42% NSAIDs, 28.57% opioids, 9.84% anticonvulsants, and 4.17% muscle relaxants. Annually, opioid prescriptions declined by 4.43% ( P < 0.01), while NSAIDs rose by 3.29% ( P < 0.01). Opioid prescriptions dropped by 210.73 days yearly per surgeon ( P < 0.005), whereas NSAIDs increased by 148.86 days ( P < 0.005). Opioid prescriptions were most prevalent in the West Coast and Northern Midwest regions, and NSAID prescriptions were most prevalent in the Northeast and South regions. Regression pinpointed spine as the highest and hand as the lowest predictor for pain prescriptions.

DISCUSSION

On average, orthopaedic surgeons markedly decreased both the percentage of patients receiving opioids and the duration of prescription. Simultaneously, the fraction of patients receiving NSAIDs dramatically increased, without change in the average duration of prescription. Opioid hotspots were located in the West Coast, Utah, Colorado, Arizona, Idaho, the Northern Midwest, Vermont, New Hampshire, and Maine. Future directions could include similar examinations using non-Medicare databases.

Effects of a Modified Long-Acting Cocktail on Analgesia and Enhanced Recovery After Total Hip Arthroplasty: A Double-Blinded Randomized Clinical Trial

BACKGROUND

We compared the efficacy and safety of a modified cocktail for postoperative analgesia and early functional rehabilitation in patients undergoing total hip arthroplasty (THA).

METHODS

Magnesium sulfate and sodium bicarbonate were added to a cocktail of ropivacaine, epinephrine, and dexamethasone. Primary outcome measures were visual analog scale (VAS) pain scores at various intervals after surgery, morphine consumption for rescue analgesia after surgery, and time to first rescue analgesia. Secondary outcomes were hip function after surgery, daily walking distance, quadriceps muscle strength, and the incidence of postoperative adverse reactions.

RESULTS

Morphine consumption was significantly lower in the modified cocktail group than in the control group in the first 24 hours after surgery (6.2 ± 6.0 versus 14.2 ± 6.4 mg, P < .001), as was total morphine consumption (10.0 ± 8.6 versus 19.2 ± 10.1 mg, P < .001). The duration of the first rescue analgesia was significantly prolonged (23.7 ± 10.3 versus 11.9 ± 5.8 mg, P < .001). Morphine consumption was also reduced in the magnesium sulfate and sodium bicarbonate groups over a 24-hour period compared to the control group (P < .001). The modified cocktail group had significantly lower resting VAS pain scores than the control group within 24 hours after surgery (P < .050). The VAS pain scores during movement within 12 hours after surgery were also lower (P < .050). The experimental groups showed better hip range of motion (P < .050) and longer walking distance (P < .050) on the first postoperative day, and levels of inflammatory markers were significantly reduced. The incidence of postoperative adverse reactions was similar among the 4 groups.

CONCLUSIONS

The modified cocktail with a new adjuvant can prolong the duration of postoperative analgesia, reduce the dosage of rescue analgesics, and accelerate early postoperative functional recovery in patients undergoing THA.

Remifentanil-induced hyperalgesia in healthy volunteers: a systematic review and meta-analysis of randomized controlled trials

ABSTRACT

Recent literature suggests that the withdrawal of remifentanil (RF) infusion can be associated with hyperalgesia in clinical and nonclinical settings. We performed a systematic review and a meta-analysis of randomized controlled trials with cross-over design, to assess the effect of discontinuing RF infusion on pain intensity and areas of hyperalgesia and allodynia in healthy volunteers. Nine studies were included. The intervention treatment consisted in RF infusion that was compared with placebo (saline solution). The primary outcome was pain intensity assessment at 30 ± 15 minutes after RF or placebo discontinuation, assessed by any pain scale and using any quantitative sensory testing. Moreover, postwithdrawal pain scores were compared with baseline scores in each treatment. Secondary outcomes included the areas (% of basal values) of hyperalgesia and allodynia. Subjects during RF treatment reported higher pain scores after discontinuation than during treatment with placebo [standardized mean difference (SMD): 0.50, 95% confidence interval (CI): 0.03-0.97; P = 0.04, I 2 = 71%]. A significant decrease in pain scores, compared with baseline values, was found in the placebo treatment (SMD: -0.87, 95% CI: -1.61 to -0.13; P = 0.02, I 2 = 87%), but not in the RF treatment (SMD: -0.28, 95% CI: -1.18 to 0.62; P = 0.54, I 2 = 91%). The area of hyperalgesia was larger after RF withdrawal (SMD: 0.55; 95% CI: 0.27-0.84; P = 0.001; I 2 = 0%). The area of allodynia did not vary between treatments. These findings suggest that the withdrawal of RF induces a mild but nonclinically relevant degree of hyperalgesia in HVs, likely linked to a reduced pain threshold.

Latest Advances in Regional Anaesthesia

Training and expertise in regional anaesthesia have increased significantly in tandem with increased interest over the past two decades. This review outlines the most recent advances in regional anaesthesia and focuses on novel areas of interest including fascial plane blocks. Pharmacological advances in the form of the prolongation of drug duration with liposomal bupivacaine are considered. Neuromodulation in the context of regional anaesthesia is outlined as a potential future direction. The growing use of regional anaesthesia outside of the theatre environment and current thinking on managing the rebound plane after regional block regression are also discussed. Recent relevant evidence is summarised, unanswered questions are outlined, and priorities for ongoing investigation are suggested.

Thoracolumbar Interfascial Plane (TLIP) block verses other paraspinal fascial plane blocks and local infiltration for enhanced pain control after spine surgery: a systematic review

Spinal surgeries are accompanied by excessive pain due to extensive dissection and muscle retraction during the procedure. Thoracolumbar interfascial plane (TLIP) blocks for spinal surgeries are a recent addition to regional anesthesia to improve postoperative pain management. When performing a classical TLIP (cTLIP) block, anesthetics are injected between the muscle (m.) multifidus and m. longissimus. During a modified TLIP (mTLIP) block, anesthetics are injected between the m. longissimus and m. iliocostalis instead. Our systematic review provides a comprehensive evaluation of the effectiveness of TLIP blocks in improving postoperative outcomes in spinal surgery through an analysis of randomized controlled trials (RCTs).We conducted a systematic review based on the PRISMA guidelines using PubMed and Scopus databases. Inclusion criteria required studies to be RCTs in English that used TLIP blocks during spinal surgery and report both outcome measures. Outcome data includes postoperative opioid consumption and pain.A total of 17 RCTs were included. The use of a TLIP block significantly decreases postoperative opioid use and pain compared to using general anesthesia (GA) plus 0.9% saline with no increase in complications. There were mixed outcomes when compared against wound infiltration with local anesthesia. When compared with erector spinae plane blocks (ESPB), TLIP blocks often decreased analgesic use, however, this did not always translate to decreased pain. The cTLIP and mTLP block methods had comparable postoperative outcomes but the mTLIP block had a significantly higher percentage of one-time block success.The accumulation of the current literature demonstrates that TLIP blocks are superior to non-block procedures in terms of analgesia requirements and reported pain throughout the hospitalization in patients who underwent spinal surgery. The various levels of success seen with wound infiltration and ESPB could be due to the nature of the different spinal procedures. For example, studies that saw superiority with TLIP blocks included fusion surgeries which is a more invasive procedure resulting in increased postoperative pain compared to discectomies.The results of our systematic review include moderate-quality evidence that show TLIP blocks provide effective pain control after spinal surgery. Although, the application of mTLIP blocks is more successful, more studies are needed to confirm that superiority of mTLIP over cTLIP blocks. Additionally, further high-quality research is needed to verify the potential benefit of TLIP blocks as a common practice for spinal surgeries.

Chronic postsurgical pain (CPSP): an underestimated problem after incisional hernia treatment

BACKGROUND

Chronic postsurgical pain (CPSP) is a potential long-term problem following open incisional hernia repair which may affect the quality of life of patients despite successful anatomical repair of the hernia. The aim of this manuscript was to identify the incidence and outcome of patients following open incisional hernia repair in respect of risk factors to develop CPSP.

METHODS

A single-center retrospective analysis of patients who underwent open incisional hernia repair between 2015 and 2021 was performed. Pre-existing conditions (e.g., diabetes mellitus and malignancy), hernia complexity, postoperative complications, and postoperative pain medication were analyzed using the local database. Quality of life and CPSP were assessed using the EuraHS Quality of Life (QoL) questionnaire.

RESULTS

A total of 182 cases were retrospectively included in a detailed analysis based on the complete EuraHS (QoL) questionnaire. During the average follow-up period of 46 months, this long-term follow-up revealed a 54.4% incidence of CPSP and including a rate of 14.8% for severe CPSP (sCPSP) after open incisional hernia surgery. The complexity of the hernia and the demographic variables were not different between the group with and without CPSP. Patients with CPSP reported significantly reduced QoL. The analgesics score which includes the need of pain medication in the initial days after surgery was significantly higher in patients with CPSP than in those without (no CPSP: 2.86 vs. CPSP: 3.35; p = 0.047).

CONCLUSION

The presence of CPSP after open incisional hernia repair represents a frequent and underestimated long-term problem which has been not been recognized to this extent before. CPSP impairs QoL in these patients. Patients at risk to develop CPSP can be identified in the perioperative setting by the need of high doses of pain medication using the analgesics score. Possibly timely adjustment of pain medication, even in the domestic setting, could alleviate the chronicity or severity of CPSP.

Celecoxib Decreases the Need for Rescue Analgesics after Total Knee Arthroplasty: A Meta-Analysis

This systematic review and meta-analysis aimed to evaluate the analgesic efficacy and adverse effects of celecoxib after total knee arthroplasty. Keywords in the PubMed and Scopus databases were used to find article abstracts. Each included clinical trial was assessed using the Cochrane Collaboration risk of bias tool, and we extracted data on postoperative pain assessment using the Visual Analogue Scale (VAS) at rest, ambulation, and active range of motion, rescue analgesic intake, and adverse effects. Inverse variance tests with mean differences were used to analyze the numerical variables. The Mantel-Haenszel statistical method and the odds ratio were used to evaluate the dichotomous data. According to this qualitative assessment (n = 482), two studies presented conclusions in favor of celecoxib (n = 187), one showed similar results between celecoxib and the placebo (n = 44), and three clinical trials did not draw conclusions as to the effectiveness of celecoxib versus the placebo (n = 251). Moreover, the evaluation of the rescue analgesic intake showed that the patients receiving celecoxib had a lower intake compared to patients receiving a placebo (n = 278, I2 = 82%, p = 0.006, mean difference = -6.89, 95% IC = -11.76 to -2.02). In conclusion, the pooled analysis shows that administration of celecoxib alone results in a decrease in rescue analgesic consumption compared to a placebo after total knee surgery.

Single Dose Intravenous Paracetamol versus Placebo in Postorthognathic Surgery Pain: A Randomized Clinical Trial

Background

The postorthognathic surgery patients experienced moderate to severe pain and could be at risk for opioid-related side effects. The aim of this study was to evaluate the efficacy of a single dose of intravenous paracetamol to control postorthognathic surgery pain and reduce opioid consumption.

Methods

The patients were randomized into two groups. The study group received intravenous paracetamol and the control group received a placebo immediately postoperation. The visual analogue pain scale (VAS) at 1-, 4-, 8-, 12-, 16-, 20-, and 24 -h postoperatively, morphine consumption, side effects from morphine, and patient satisfaction were analyzed.

Results

Sixty-two patients (thirty-one patients in each group) were included. The postoperative VAS in the study group was significantly lower than those in the control group (p value <0.001) at all time points. The total postoperative morphine consumption in the study group (45.1 ± 21.2 mcg/kg) was significantly lower compared with the control group (136.5 ± 49.9 mcg/kg) (p value <0.001). Patient satisfaction was significantly higher in the study group (4.7 ± 0.5 out of 5 points) than in the control group (4.1 ± 0.7 out of 5 points) (p value <0.001). The incidence of nausea and vomiting was significantly lower in the study group compared with the control group (p value <0.001 and 0.002, respectively).

Conclusion

A single dose of intravenous paracetamol as part of multimodal analgesia was effective for postorthognathic surgery pain. It provided significant benefits to patients, including reduced pain scores, decreased opioid consumption, reduced nausea and vomiting, and improved satisfaction. This trial is registered with TCTR20210908002.

Duloxetine reduces opioid consumption and pain after total hip or knee arthroplasty: a meta-analysis of randomized controlled trials

PURPOSE

There is no consensus in the current literature on the analgesic role of duloxetine after total hip arthroplasty (THA) or total knee arthroplasty (TKA). Thus, we designed this meta-analysis to reveal the analgesic effectiveness and safety of duloxetine in TKA or THA.

METHODS

As of October 2022, two authors (L.C. and W.Q.J.) independently searched five main databases (EMBASE, Web of Science, PubMed, Cochrane Library, and Google Scholar) to find relevant studies. Duloxetine vs. placebo in randomized controlled trials (RCTs) for THA or TKA were included. We set perioperative total opioid consumption as the primary outcome. Secondary outcomes included resting or dynamic pain scores over time, gastrointestinal adverse events, neurological adverse events, and other adverse reactions.

RESULTS

Eight RCTs with 695 patients were incorporated in our study. This meta-analysis showed high evidence that duloxetine was effective in reducing perioperative opioid consumption (Standard mean difference [SMD] = - 0.50, 95% confidence intervals [CI]: -0.70 to - 0.31, P < 0.00001) and low to moderate evidence that duloxetine could reduce pain within three weeks after surgery. Low to high evidence showed no differences between the two groups for most adverse events. Substantial evidence suggests that duloxetine can reduce nausea and vomiting after surgery (Risk ratio [RR] = 0.69, 95% CI: 0.50 to 0.95, P = 0.02, I2 = 4%). However, moderate evidence suggested that duloxetine might be associated with increased postoperative drowsiness (RR = 1.83, 95% CI: 1.08 to 3.09, P = 0.02, I2 = 0%).

CONCLUSION

Duloxetine reduced overall opioid consumption in the perioperative period and relieved pain within three weeks after surgery without increasing the risk of adverse drug events. Duloxetine can be part of a multimodal management regimen in patients with THA and TKA.

Are There Any Advantages of the Low Opioid Anaesthesia and Non-Opioid Postoperative Analgesia Protocol: A Clinical Observational Study

Purpose

The methods of perioperative analgesia and pain control have changed. The principle of opioid-based analgesia has been modified to multimodal analgesia, followed by LOA (low opioid anaesthesia) and OFA (opioid-free anaesthesia). The aim was to describe the effects of LOA on nausea, vomiting, and pain control during general anaesthesia and postoperative period after laparoscopic cholecystectomy.

Patients and Methods

The protocol included the study group-40 patients received low-opioid anaesthesia (LOA), and the control group-40 patients received general anaesthesia with opioid analgesia (OA). The scheme of LOA was based on ketamine, lidocaine, magnesium sulfate, paracetamol, and metamizole. The OA was based on standard opioid (fentanyl) administration in induction and maintenance phase due to clinical observation. Postoperative analgesia included 1g of paracetamol and 1g of metamizol intravenously, with a 6-hour interval between doses.

Results

Significant differences in the pain score in the periods of 2-6, 6-12, and 12-24 hours after anaesthesia between the groups were noticed (p < 0.001). Moreover, a significant difference in the frequency of nausea (p = 0.005) and vomiting (p = 0.04) between groups were presented. Nausea occurred in 54.05% of OA group, while in the LOA group, it occurred in a 23.08%. Vomiting occurred in 32.43% of control group, while in the study group, it occurred in 12.82% of patients.

Conclusion

The LOA protocol was more beneficial in reducing nausea and vomiting than the opioid-based method of anaesthesia. The LOA protocol of general anaesthesia during laparoscopic cholecystectomy and non-opioid postoperative analgesia have better outcomes in pain control, as well as nausea and vomiting, and improve postoperative patient comfort. The LOA protocol during anaesthesia and non-opioid postoperative analgesia should be considered in routine practice.

Transitional Pain Service: Optimizing Complex Surgical Patients

PURPOSE OF REVIEW

The care of patients with complex postsurgical pain can be challenging and burdensome for the healthcare system. Transitional pain service (TPS) is a relatively new concept and has not been widely adopted in the USA. This article explores the benefits and barriers of transitional pain services and describes the development of a TPS at our institution.

RECENT FINDINGS

Evidence from a few institutions that have adopted TPS has shown decreased postsurgical opioid consumption for patients on chronic opioids and decreased incidence of chronic postsurgical opioid use for opioid-naïve patients. The development of a transitional pain service may improve outcomes for these complex patients by providing longitudinal and multidisciplinary perioperative pain care. In this article, we describe the implementation of a TPS at a tertiary medical center. Our TPS model involves a multidisciplinary team of anesthesiologists, pain psychologists, surgeons, and advanced practice providers. We provide longitudinal care, including preoperative education and optimization; perioperative multimodal analgesic care; and longitudinal follow-up for 90 days post-procedure. With our TPS service, we aim to reduce long-term opioid use and improve functional outcomes for our patients.

Efficacy, safety, and side effects of oliceridine in acute postoperative pain, a protocol for a systematic review and meta-analysis

This will be the first meta-analysis on the efficacy, safety, and side effects of oliceridine on postoperative pain. Our aim with this work is to evaluate the clinical utility of this relatively new substance in a broad postoperative context. Oliceridine is a new so-called bias opioid that is approved for severe pain requiring an opioid. Due to its biased agonism, it is said to have fewer side effects than conventional opioids. This systematic review and meta-analysis will analyze the efficacy, safety, and side effects of oliceridine compared to placebo or morphine in acute postoperative pain for up to 72 hours. In January 2024, an extensive search in various databases will be performed without restrictions for randomized controlled trials with at least single blinding. After data extraction, data will be pooled and meta-analytic calculations performed. A random-effects model will be used. Dichotomous data will be presented as risk ratio and continuous data as standardized mean difference. Dose-dependent side effects will be evaluated with meta-regression. Heterogeneity will be assessed via the Q statistic and prediction interval in case of a sufficient number of included studies. Publication bias will be examined using funnel plot and Duval and Tweedie's trim and fill method.

Postoperative Magnesium Sulfate Repletion Decreases Narcotic Use in Abdominal-Based Free Flap Breast Reconstruction

BACKGROUND

 Microsurgical breast reconstruction after mastectomy is now the standard of care for breast cancer patients. However, the costs and resources involved in free flap reconstruction can vary across different medical settings. To enhance patient outcomes in a cost-effective manner, we investigated the effect of intravenous magnesium sulfate (IV Mg) on postoperative opioid usage in this context.

METHODS

 A retrospective chart review was performed on all consecutive patients who underwent abdominal-based free flap breast reconstruction in a single institute following an enhanced recovery after surgery (ERAS) protocol. Patients who received IV Mg were compared with those who did not receive supplementation. Serum magnesium levels at different time points, narcotic consumption in units of oral morphine milligram equivalents (MMEs), and other postoperative recovery parameters were compared.

RESULTS

 Eighty-two patients were included. Those who received IV Mg on postoperative day 0 (n = 67) showed significantly lower serum magnesium levels before repletion (1.5 vs. 1.7 mg/dL, p = 0.004) and significantly higher levels on postoperative day 1 after repletion (2.2 vs. 1.7 mg/dL, p = 0.0002) compared to patients who received no magnesium repletion (n = 13). While both groups required a similar amount of narcotics on postoperative day 0 (20.2 vs. 13.2 MMEs, p = 0.2), those who received IV Mg needed significantly fewer narcotics for pain control on postoperative day 1 (12.2 MMEs for IV Mg vs. 19.8 MMEs for No Mg, p = 0.03). Recovery parameters, including maximal pain scores, postoperative mobilization, and length of hospital stay, did not significantly differ between the two groups.

CONCLUSION

 This is the first study to describe the potential analgesic benefits of routine postoperative magnesium repletion in abdominal-based free flap reconstruction. Further research is necessary to fully understand the role of perioperative magnesium supplementation as part of an ERAS protocol.

Boosting open-label placebo effects in acute induced pain in healthy adults (BOLPAP-study): study protocol of a randomized controlled trial

Introduction

Pain is a highly prevalent symptom in the hospital setting, but treatment options remain limited. Harnessing the placebo effect in an ethical manner could provide a new possibility to reduce pain in clinical practice. So called open-label placebos (OLP) have been shown to elicit significant effects in reducing acute pain. But, before implementation, more knowledge concerning the properties of OLPs is needed. This study aims to assess the duration of analgesic effects from OLP and to determine the possibility of boosting such effects.

Methods and analysis

This is the protocol of an ongoing (first patient enrolled in March 2023) single-site randomized trial investigating OLPs in two parts (i.e., substudies). In both parts, pain will be induced in healthy adults using an intradermal electrical stimulation model. Participants in Part 1 will have two study visits: An interventional visit with one OLP injection accompanied by an evidence-based treatment rationale and a control visit with no treatment. For Part 2, participants will be randomized into three groups: (1) A fixed-time "Booster" group including one single repetition of the OLP injection at a fixed time point, (2) an on-demand "Booster" group including one single repetition of the OLP injection on-demand, and (3) a control group who will receive just one OLP injection. Differences in pain ratings over time (using the Numeric Rating Scale) will be analyzed with several two-sample t-tests. The time point for a fixed-time "Booster" in Part 2 will be derived from Part 1 with additional statistical tools such as a broken-stick mixed-effect model.

Discussion

This study aims to further characterize the analgesic effects of OLPs. In doing so, it will provide valuable information needed for later implementation of OLPs in clinical practice, where they could play a role in multimodal analgesic concepts.

Ethics and dissemination

The "Ethikkommission Nordwest- und Zentralschweiz" (BASEC 2023-00296) approved the study protocol. Results of the analysis will be submitted for publication in a peer-reviewed journal.

Clinical Trial Registration

This study is registered at ClinicalTrials.gov (NCT05819476) and is listed in the Swiss National Registry at kofam.ch (SNCTP000005470).

Ultrasound-guided medial branch of the superior laryngeal nerve block to reduce peri-operative opioids dosage and accelerate patient recovery

BACKGROUND

To explore whether the medial branch block of superior laryngeal nerve can reduce the stress response of patients undergoing intubation and further reduce the dosage of opioids.

METHODS

80 patients undergoing gynecological laparoscopic surgery were selected, and randomly divided into 4 groups. All patients in the experimental groups received bilateral internal branch of superior laryngeal nerve block and transversus abdominis plane block. But the dosage of sufentanil used for anesthesia induction in the group A, B, and C was 0.4, 0.2, and 0μg/kg, respectively. Group D do not underwent supralaryngeal nerve block and the dosage of sufentanil was 0.4μg/kg. The heart rate (HR) and mean arterial pressure(MAP) were recorded at the time of entering the operating room(T1), before intubation after induction(T2), immediately after intubation(T3), 5min after intubation(T4), before extubation(T5), immediately after extubation(T6), 5min after extubation(T7). We also recorded the stay time in the recovery room, the number of cases of postoperative sore throat, the number of cases of nausea and vomiting, the first intestinal exhaust time, the length of hospital stay after operation.

RESULTS

The HR of group A, C and D at T3 was significantly higher than that at T2(P < 0.01), while the HR of group B had no significant change. The HR of group A, C and D at T4 was lower than that at T3(P < 0.01), while the HR of group B had no obvious change. The HR of group C and D at T3 was significantly higher than that at T1 (P < 0.01). The MAP of group A and D at T4 was significantly lower than that at T1 (P<0.001). The first postoperative intestinal exhaust time in group A, B and C was significantly shorter than that in group D. The length of hospital stay after operation in group B and C was shorter than that in group D.

CONCLUSIONS

Ultrasound-guided superior laryngeal nerve block combined with 0.2μg/kg sufentanil can reduce the intubation reaction, have better hemodynamic stability, reduce the first postoperative intestinal exhaust time and postoperative hospital stay, thereby accelerating the postoperative recovery of patients.

Comparative retrospective review of perioperative analgesia using ultrasound-guided programmed intermittent erector spinae plane block for video-assisted thoracoscopic lobectomy

BACKGROUND

The retrospective cohort study was conducted to estimate the opioid-sparing anesthesia and limited side-effects with ultrasound (US)-guided ESPB using programmed intermittent bolus (PIB) or continuous infusion (CI) and standard opioid-based anesthesia in patients undergoing video-assisted thoracoscopic lobectomy (VATS).

METHODS

Patients underwent VATS were stratified into either control group or one of the two ESPB groups in a 1:2:2 ratio depending on whether PIB was implemented or not. The primary endpoint was intra- and post-operative opioids consumption over the first 48 h following surgery.

RESULTS

A total of 180 cases were included in the analysis. Cumulative perioperative opioid administration was found to be significantly different between PIB, CI and control group (both p < 0.001), and between PIB and CI group (p = 0.028). More specifically, the mean was 305.30 ± 51.35 mg, 339.68 ± 56.07 mg and 468.91 ± 79.84 mg in PIB, CI and control group. NRS scores at rest across all postoperative times were comparable in two ESPB groups, while significantly lower than control group, however, scores during exercising at postoperative 3, 6, 12 h were significantly lower in PIB group as compared to CI group. A wider anesthetized dermatomes with PIB was observed at 6, 24 and 48 h as opposed to the CI. The mean of levobupivacaine plasma concentration was significantly lower for PIB at postoperative 0.5, 12, 24 and 48 h after initiation than CI. However, local anesthetic toxicity was not observed in any of the two ESPB groups.

CONCLUSIONS

When US-guided ESPB using PIB was performed preoperatively, it contributed to the minimization of intra- and post-operative opioid consumption due to better analgesia with a wider anesthetic dermatome opposed to conventional CI, whereas, it was also associated with lower risk of local anesthetic toxicity because of lower plasma concentration of levobupivacaine.

The Pain Management of Trauma Patients in the Emergency Department

The vast majority of injured patients suffer from pain. Systematic assessment of pain on admission to the emergency department (ED) is a cornerstone of translating the best treatment strategies for patient care into practice. Pain must be measured with severity scales that are validated in clinical practice, including for specific populations (such as children and older adults). Although primary care ED of trauma patients focuses on resuscitation, diagnosis and treatment, pain assessment and management remains a critical element as professionals are not prepared to provide effective and early therapy. To date, most EDs have pain assessment and management protocols that take into account the patient's hemodynamic status and clinical condition and give preference to non-pharmacological approaches where possible. When selecting medications, the focus is on those that are least disruptive to hemodynamic status. Pain relief may still be necessary in hemodynamically unstable patients, but caution should be exercised, especially when using opioids, as absorption may be impaired or shock may be exacerbated. The analgesic dose of ketamine is certainly an attractive option. Fentanyl is clearly superior to other opioids in initial resuscitation and treatment as it has minimal effects on hemodynamic status and does not cause central nervous system depression. Inhaled analgesia techniques and ultrasound-guided nerve blocks are also increasingly effective solutions. A multimodal pain approach, which involves the use of two or more drugs with different mechanisms of action, plays an important role in the relief of trauma pain. All EDs must have policies and promote the adoption of procedures that use multimodal strategies for effective pain management in all injured patients.

Analgesic Efficacy of COX-2 Inhibitors in Periodontal Surgery: A Systematic Review and Meta-Analysis

The objective of this systematic review and meta-analysis was to evaluate the analgesic efficacy of COX-2 inhibitors versus other drugs in periodontal surgery. Two researchers searched PubMed, Google Scholar, ACM Digital, BASE, EBSCOhost, Scopus, or Web of Science for clinical trials using various combinations of words. All articles that met the selection criteria were assessed using the Cochrane Collaboration’s risk of bias tool. For data analysis, the inverse variance and mean difference statistical method was used with Review Manager 5.3 software for Windows. According to the conclusion of each study (qualitative evaluation), only one clinical trial had results in favor of a COX-2 inhibitor when compared to placebo, one clinical study informed that a COX-2 was better that an active control, four studies showed similar analgesic efficacy to active controls, and one clinical study informed the analgesic effect of one celecoxib-caffeine combination in comparison with celecoxib alone and placebo (n = 337). The COX-2 inhibitors showed a decrease in the rescue analgesic consumption (n = 138; I2 = 15%; mean difference = −0.31; 95%CIs = −0.6 to −0.01), and lower pain intensity at four hours (n = 178; I2 = 0%; mean difference = −2.25; 95%CIs = −2.94 to −1.55; p = 0.00001) when compared to active controls after periodontal surgery. In conclusion, the data indicate that COX-2 agents produce better pain relief in comparison to placebo and other drugs after periodontal surgery.

Flupirtine and antihistamines exert synergistic anti-nociceptive effects in mice

RATIONALE

Drug combinations are commonly used in pain management, which can produce potent analgesic effects with reduced dosage and adverse effects.

OBJECTIVE

This study was designed to evaluate the anti-nociceptive effects and adverse effects of new combinations of flupirtine (a Kv7 potassium channel opener) and antihistamines (promethazine, fexofenadine) on acute and chronic pain in mice, and the possible mechanisms behind the synergistic analgesic effects were preliminarily investigated.

METHODS

In acetic acid writhing test, carrageenan-induced inflammatory pain model, and paclitaxel-induced neuropathic pain model, the interaction indexes (γ) between flupirtine and antihistamines were determined by isobolographic analysis. Furthermore, the Kv7 channel blocker XE991 was used to determine whether the effects of single agents and drug combinations on paclitaxel- and carrageenan-induced mechanical allodynia were mediated by Kv7 channels. Finally, hepatotoxicity markers, liver histopathology, and the rotarod test were used to investigate the adverse effects of drugs in combination doses.

RESULTS

The interaction indexes of flupirtine-promethazine and flupirtine-fexofenadine in all the above three pain models were lower than 1. The analgesic effects of flupirtine (13 mg/kg), promethazine (5 mg/kg), fexofenadine (20 mg/kg), and their combinations were antagonized significantly by XE991 (3 mg/kg). And the adverse effects of flupirtine and antihistamines in combination doses were not significantly different from the vehicle group.

CONCLUSIONS

Flupirtine and antihistamines produced synergistic analgesic effects in all the above pain models. The analgesic effects of antihistamines were partially mediated by Kv7/M channels, and the activation of Kv7/M channels may be partly responsible for the synergistic analgesic effects between flupirtine and antihistamines.

Efficacy of Lidocaine Infusion in High-Risk Vascular Surgery—A Randomized, Double-Blind, Placebo-Controlled Single-Center Clinical Trial

Background: In perioperative pain control, adjuvants such as lidocaine can reduce opioid consumption in a specific type of surgery. The aim of this single-center prospective double-blinded randomized controlled trial was to determine opioid consumption in the perioperative period in patients receiving continuous lidocaine infusion. Methods: Patients undergoing elective abdominal aorta and/or iliac arteries open surgery were randomized into two groups to receive 1% lidocaine or placebo at the same infusion rate based on ideal body weight (bolus of 0.15 mL/kg during the induction of anesthesia followed by continuous infusion of 0.2 mL/kg/h during surgery; postoperatively 0.1 mL/kg/h for 24 h) additionally to standard opioid analgesia. Results: Total opioid consumption within 24 h after surgery was 89.2 mg (95%CI 80.9–97.4) in the lidocaine and 113.1 mg (95%CI 102.5–123.6) in the placebo group (p = 0.0007). Similar findings were observed in opioid consumption intraoperatively (26.7 mg (95%CI 22.2–31.3) vs. 35.1 mg (95%CI 29.1–41.2), respectively, p = 0.029) and six hours postoperatively (47.5 mg (IQR 37.5–59.5) vs. 60 mg (IQR 44–83), respectively, p = 0.01). Conclusions: In high-risk vascular surgery, lidocaine infusion as an adjunct to standard perioperative analgesia is effective. It may decrease opioid consumption by more than 20% during the first 24 h after surgery, with no serious adverse effects noted during the study period.

Sciatic Nerve Block Combined with Flurbiprofen Inhibits Spinal Cord Inflammation and Improves Postoperative Pain in Rats with Plantar Incision

Background and Purpose

Peripheral nerve block is often used to relieve postoperative pain. But the effect of nerve block on inflammatory response is not fully understood. Spinal cord is the primary center of pain processing. This study is to investigate the effect of single sciatic nerve block on the inflammatory response of the spinal cord in rats with plantar incision and the combined effect with flurbiprofen.

Methods

The plantar incision was used to establish a postoperative pain model. Single sciatic nerve block, intravenous flurbiprofen or the combination of both were used for intervention. The sensory and motor functions after nerve block and incision were evaluated. The changes of IL-1β, IL-6, TNF-α, microglia and astrocytes in the spinal cord were examined by qPCR and immunofluorescence respectively.

Results

Sciatic nerve block with 0.5% ropivacaine in rats induced sensory block for 2h and motor block for 1.5h. In the rats with plantar incision, the single sciatic nerve block did not alleviate postoperative pain or inhibit the activation of spinal microglia and astrocytes, but the levels of IL-1β and IL-6 in spinal cord were decreased when the nerve block wore off. The combined effect of a single sciatic nerve block and intravenous flurbiprofen not only decreased the levels of IL-1β, IL-6, and TNF-α, but also relieved the pain and alleviated the activation of microglia and astrocytes.

Conclusion

The single sciatic nerve block cannot improve postoperative pain or inhibit the activation of spinal cord glial cells, but can reduce the expression of spinal inflammatory factors. Nerve block combined with flurbiprofen can inhibit spinal cord inflammation and improve postoperative pain. This study provides a reference for rational clinical application of nerve block.

Integrated Analgesic Care in the Current Human Monkeypox Outbreak: Perspectives on an Integrated and Holistic Approach Combining Old Allies with Innovative Technologies

Monkeypox (MPX) is a zoonotic infection caused by an orthopoxvirus that is endemic to Central and Western Africa. The MPX virus is a part of the same family of viruses as the variola virus, which causes smallpox. Since May 2022, there has been a global increase in the incidence of MPX infections in multiple countries where the illness is not usually prevalent. A growing number of publications have emphasized on the need for increased awareness among all health professionals for the rapid recognition and diagnosis of this disease and for proper public health measures. However, atypical presentations and occurrence of uncommon symptoms receive less than the desired attention. More specifically, MPX infection related nociceptive symptoms are currently underexposed. Nevertheless, reports from the current outbreak have revealed that (severe) pain is one of the major causes for distress and even hospitalization in these patients. As for all serious pain conditions, an integrated, multidisciplinary, and holistic approach is indicated. This approach should be multimodal and include non-pharmacological therapies alongside pharmacological approaches. Health care professionals should be aware of available alternatives when first choice analgesic therapies fail. Protocols for identification of pain type and prolonged monitoring of clinical status should be implemented to improve patient well-being during acute infection, but also prevent chronic nociceptive syndromes.