Buprenorphine added to levobupivacaine enhances postoperative analgesia of middle interscalene brachial plexus block

Combination of different local anesthetic adjunct for supraclavicular brachial plexus block after arthroscopic shoulder surgery: a prospective randomized controlled trial

BACKGROUND

Acute pain is a major concern after arthroscopic shoulder surgery, supraclavicular brachial plexus blockade has shown favorable postoperative analgesic effects. However, its duration of analgesia does not meet clinical needs. We aimed to explore whether the combination of different local anesthetic adjunct can prolong the analgesic duration of supraclavicular brachial plexus block for arthroscopic shoulder surgery.

METHODS

In this prospective randomized controlled trial, we allocated 80 patients into four groups: Group DMD (dexamethasone 10 mg + ropivacaine 100 mg + dexmedetomidine 50 µg + magnesium sulfate 250 mg), Group DM (ropivacaine 100 mg + dexmedetomidine 50 µg + magnesium sulfate 250 mg), Group M (ropivacaine 100 mg + magnesium sulfate 250 mg) and Group D (ropivacaine 100 mg + dexmedetomidine 50 µg). The primary outcome was the time to first request for analgesia. Secondary outcome measures included cumulative opioid consumption at 6, 12, 18, 24, and 48 h postoperatively, VAS scores at 6, 12, 18, 24, and 48 h postoperatively and so on.

RESULTS

The time to first request for analgesia in Group DMD was significantly longer than Group DM (P = 0.011) and Group M (P = 0.003). The cumulative opioid consumption at 18 h postoperatively in Group DMD was significantly lower than in Group DM (P = 0.002) and Group M (P = 0.007). The cumulative opioid consumption at 24 h postoperatively in Group DMD was significantly lower than in Group DM (P = 0.016). The VAS score at 6 h postoperatively in Group DMD was significantly lower than in Group DM and Group M. The VAS score at 12 h postoperatively in Group DMD was significantly lower than in Group M. For American Shoulder and Elbow Surgeons Score, Group DMD had a better score than Group DM and Group D.

CONCLUSIONS

The analgesic efficacy of supraclavicular brachial plexus blockade combined with dexamethasone, magnesium sulfate, and dexmedetomidine is significantly superior to the combination of magnesium sulfate and dexmedetomidine, and significantly superior to the use of magnesium sulfate alone.

TRIAL REGISTRATION

This trial was registered in Chinese Clinical Trial Registry. (ChiCTR2200061181, Date of registration: June 15, 2022, http://www.chictr.org.cn ).

A Historical Analysis of Randomized Controlled Trials in the Management of Pain in Rotator Cuff Tears

The aim of this analysis was to assess the quality of reporting of randomized controlled trials (RCTs) relating to pain management in rotator cuff (RC) tears. This review evaluated the quality of the studies in the literature regarding this topic through the use of some factors and trends. The online databases used to search all RCTs on the topic of RC surgery were Medline, Scopus, CINAHL, EMBASE, and CENTRAL. This research was completed in September 2020. To assess the quality of reports, the Consolidated Standards of Reporting Trials (CONSORT) and the modified Coleman methodology score (MCMS) were used. From the research, 262 articles emerged. Finally, 79 studies were included in this historical analysis. There were no statistically significant changes in MCMS across trials that included or did not include a CONSORT diagram (p = 0.10). A statistically significant difference in MCMS was discovered between papers produced prior to 2009 and publications produced after 2015 (p = 0.03). There was no association between the number of checklist items for each article and the Coleman score. During the years there has been a significant increase in both quantity and quality of RCTs relating to pain in RC tears.

Dexamethasone Addition to Popliteal Nerve Blocks: Effects on Duration of Analgesia and Incidence of Postoperative Nerve Complication

Background. The purpose of this prospective, double-blinded randomized control pilot study was to evaluate the effect of adjunctive dexamethasone on analgesia duration and the incidence of postoperative neuropathic complication. Peripheral nerve blocks are an effective adjunct to decrease postoperative pain in foot and ankle surgery, and any possible modalities to augment their efficacy is of clinical utility. Methods. Patients were randomly assigned to a control group (n = 25) receiving nerve blocks of bupivacaine and epinephrine or an experimental group (n = 24) with an adjunctive 8 mg dexamethasone. The patients, surgeons, and anesthesiologists were all blinded to allocation. Patients had a minimum 1 year postoperative follow-up. Results. Forty-nine patients completed the protocol. There was no statistically significant difference in analgesia duration (P = .38) or postoperative neuropathic complication incidence (P = .67) between the 2 groups. Conclusions. The addition of dexamethasone to popliteal nerve blocks does not appear to affect analgesia duration or incidence of postoperative neuropathic complications. However, our study was underpowered, and we recommend a larger scale prospective study for validation.Levels of Evidence: Level II: Prospective, randomized control pilot study.

Perioperative pain management for shoulder surgery: evolving techniques

Improving management of postoperative pain following shoulder surgery is vital for optimizing patient outcomes, length of stay, and decreasing addiction to narcotic medications. Multimodal analgesia (ie, controlling pain via multiple different analgesic methods with differing mechanisms) is an ever-evolving approach to enhancing pain control perioperatively after shoulder surgery. With a variety of options for the shoulder surgeon to turn to, this article succinctly reviews the pros and cons of each approach and proposes a potential pain management algorithm.

A Historical Analysis of Randomized Controlled Trials in Rotator Cuff Tears

Background and objectives: Our research aimed to evaluate the quality of reporting of randomized controlled trials (RCTs) linked to rotator cuff (RC) tears. The present study analyzed factors connected to the quality of the RCTs and trends in the quality of reporting through time. Materials and Methods: The online databases used to search all RCTs on the topic of RC surgery completed until March 2020 were PubMed and Ovid (MEDLINE). The quality of reporting was evaluated using the modified Coleman methodology score (MCMS) and the consolidated standards of reporting trials (CONSORT). Results: The online search found 957 articles. Finally, 183 studies were included in the quantitative synthesis. A total of 97 (53%) of 183 studies had a level of evidence I and 86 (47%) of 183 studies had a level of evidence II, according to the Oxford Center of Evidence Based Medicine (EBM). A statistically significant difference in MCMS between articles written before 2010 and articles written after 2010 was found. Articles written after 2010 had, on average, the highest Coleman score. The average number of CONSORT checklist items for each article across all analyzed RCTs was 21.67. The 37 studies completed up to 2010 averaged a number of checklist items of 19.97 and the studies completed between 2011 and 2019 averaged a number of checklist items of 22.10. A statistically significant difference in the number of checklist items between articles written before 2010 and articles written after 2010 was found. Articles written after 2010 had on average more checklist items. However, low correlation (0.26) between the number of checklist items for each article and the respective Coleman score was found. On the other hand, articles with the CONSORT diagram had a significantly high Coleman score. Conclusions: An improvement in the quantity and quality of RCTs relating to RC surgery over the analyzed period was found.

National Trends in Use of Regional Anesthesia and Postoperative Patterns of Opioid Prescription Filling in Shoulder Arthroscopy: A Procedure-Specific Analysis in Patients With or Without Recent Opioid Exposure

Background

There are few large database studies on national trends in regional anesthesia for various arthroscopic shoulder procedures and the effect of nerve blocks on the postoperative rate of opioid prescription filling.

Hypothesis

The use of regional nerve block will decrease the rate of opioid prescription filling after various shoulder arthroscopic procedures. Also, the postoperative pattern of opioid prescription filling will be affected by the preoperative opioid prescription-filling history.

Study Design

Cohort study; Level of evidence, 3.

Methods

Patient data from Humana, a large national private insurer, were queried via PearlDiver software, and a retrospective review was conducted from 2007 through 2015. Patients undergoing arthroscopic shoulder procedures were identified through Current Procedural Terminology codes. Nerve blocks were identified by relevant codes for single-shot and indwelling catheter blocks. The blocked and unblocked cases were age and sex matched to compare the pain medication prescription-filling pattern. Postoperative opioid trends (up to 6 months) were compared by regression analysis.

Results

We identified 82,561 cases, of which 54,578 (66.1%) included a peripheral nerve block. Of the patients who received a block, 508 underwent diagnostic shoulder arthroscopy; 2449 had labral repair; 4746 had subacromial decompression procedure; and 12,616 underwent rotator cuff repair. The percentage of patients undergoing a nerve block increased linearly over the 9-year study period (R ² = 0.77; P = .002). After matching across the 2 cohorts, there was an identical trend in opioid prescription filling between blocked and unblocked cases (P = .95). When subdivided by procedure, there was no difference in the trends between blocked and unblocked cases (P = .52 for diagnostic arthroscopies; P = .24 for labral procedures; P = .71 for subacromial decompressions; P = .34 for rotator cuff repairs). However, when preoperative opioid users were isolated, postoperative opioid prescription filling was found to be less common in the first 2 weeks after surgery when a nerve block was given versus not given (P < .001).

Conclusion

An increasing percentage of shoulder arthroscopies are being performed with regional nerve blocks. However, there was no difference in patterns of filled postoperative opioid prescriptions between blocked and unblocked cases, except for the subgroup of patients who had filled an opioid prescription within 1 to 3 months prior to shoulder arthroscopy. Future research should focus on recording the amount of prescribed opioids consumed in national databases to reinforce our strategy against the opioid epidemic.

PROSPECT guideline for rotator cuff repair surgery: systematic review and procedure-specific postoperative pain management recommendations

Rotator cuff repair can be associated with significant and difficult to treat postoperative pain. We aimed to evaluate the available literature and develop recommendations for optimal pain management after rotator cuff repair. A systematic review using procedure-specific postoperative pain management (PROSPECT) methodology was undertaken. Randomised controlled trials published in English from 1 January 2006 to 15 April 2019 assessing postoperative pain after rotator cuff repair using analgesic, anaesthetic or surgical interventions were identified from MEDLINE, Embase and Cochrane Databases. Out of 322 eligible studies identified, 59 randomised controlled trials and one systematic review met the inclusion criteria. Pre-operative and intra-operative interventions that improved postoperative pain were paracetamol, cyclo-oxygenase-2 inhibitors, intravenous dexamethasone, regional analgesia techniques including interscalene block or suprascapular nerve block (with or without axillary nerve block) and arthroscopic surgical technique. Limited evidence was found for pre-operative gabapentin, perineural adjuncts (opioids, glucocorticoids, or α-2-adrenoceptor agonists added to the local anaesthetic solution) or postoperative transcutaneous electrical nerve stimulation. Inconsistent evidence was found for subacromial/intra-articular injection, and for surgical technique-linked interventions, such as platelet-rich plasma. No evidence was found for stellate ganglion block, cervical epidural block, specific postoperative rehabilitation protocols or postoperative compressive cryotherapy. The analgesic regimen for rotator cuff repair should include an arthroscopic approach, paracetamol, non-steroidal anti-inflammatory drugs, dexamethasone and a regional analgesic technique (either interscalene block or suprascapular nerve block with or without axillary nerve block), with opioids as rescue analgesics. Further randomised controlled trials are required to confirm the influence of the recommended analgesic regimen on postoperative pain relief.

Effect of addition of buprenorphine or dexamethasone to levobupivacaine on postoperative analgesia in ultrasound guided transversus abdominis plane block in patients undergoing unilateral inguinal hernia repair: a prospective randomized double blind controlled trial

BACKGROUND

The transversus abdominis plane (TAP) block is an effective technique to block the thoracolumbar nerves innervating the anterolateral abdominal wall. This study was conducted to evaluate the analgesic efficacy and opioid consumption with the use of perineural buprenorphine or dexamethasone in TAP blocks after unilateral inguinal hernioplasties.

METHODS

This prospective, randomized, double-blinded, placebo-controlled study enrolled 93 patients scheduled for unilateral inguinal hernioplasty, followed by an ultrasound-guided TAP block. The participants were randomized into 3 groups (31 patients each). Group L received 20 ml 0.25% levobupivacaine + 1 ml normal saline (NS); group LB, 20 ml 0.25% levobupivacaine + 0.3 mg (1 ml) buprenorphine; and group LD, 20 ml 0.25% levobupivacaine + 4 mg (1 ml) dexamethasone. The patients were observed postoperatively for 24 h for first rescue analgesic requirement, total rescue analgesic consumption, and pain scores on the numeric rating scale (NRS).

RESULTS

The time to first rescue analgesic requirement was significantly longer in Group LB than in groups LD and L (688.87 ± 36.11 min, 601.45 ± 39.85 min, and 383.06 ± 36.21 min, respectively; P < 0.001). The mean total tramadol consumption in the first 24 h was the lowest in group LB (P < 0.001, L vs. LB / LD). Groups LB and LD displayed significantly lower NRS scores than group L (P < 0.001 both).

CONCLUSIONS

Levobupivacaine with perineural buprenorphine in a TAP block after unilateral open inguinal hernioplasty facilitates prolonged analgesia and reduced requirement for rescue analgesics compared to perineural dexamethasone, without significant side effects.

Efficacy of Adding Dexmedetomidine to Intra-articular Levobupivacaine on Postoperative Pain after Knee Arthroscopy

Background and Aims:

Intrarticular ingection of local anesthetics in the knee joint decreases postoperative pain after knee arthrosopy. Dexmedetomidine an α₂ agonist has sedative and analgesic effects and decreases postoperative pain after knee arthroscopy when injected intraarticulary. Levobubivacaine is a long acting local anesthetic with less toxicity than bubivacaine. We compared the analgesic effects of dexmedetomidine when added to intraarticular levobupivacaine in patients posted for knee arthroscopy.

Methods:

Data were first tested for normality by Kolmogorov–Smirnov test. Study was done on 90 patients. Patients were divided into 3 groups 30 patients each. Group (C) received 50 ml saline only as a control group. Group (L) received 50 ml 0.25% levobupivacaine. Group (L/D) received 50 ml 0.25% levobupivacaine and dexmedetomidine 1μg.kg-1. (VAS) score was used to assess postoperative pain. Time of first pethidine demand and total dose of pethidine in the first 24 h were recorded, also postoperative complications such as pruritis, nausea and vomiting. SPSS version 16 was used for data analysis. P < 0.05 was considered significant.

Results:

Postoperative VAS sore at different intervals was less in Group LD than Group L than Group C, time to the first pethedine injection in (min) was longer (39 ± 6, 31 ± 7, 21 ± 6), and total pethedine dose given (mg) was lower (36 ± 9.8, 64 ± 19, 102 ± 24) in Group LD than Group L than Group C respectively.

Conclusion:

Adding dexmedetomidine to intraarticular levobupivacaine in patients undergoing knee arthroscopy provides more analgesic effect with lower pain scores than levobupivacaine alone with less use of postoperative analgesics during the first 24 h.

Comparative evaluation of anaesthetic efficacy and haemodynamic effects of a combination of isobaric bupivacaine with buprenorphine vs. isobaric levobupivacaine with buprenorphine for spinal anaesthesia - A double blinded randomised clinical trial

Background and Aims

Bupivacaine is the most frequently used local anaesthetic for spinal anaesthesia, however, use of levobupivacaine in clinical practice has advanced recently. This study aimed to compare the anaesthetic potency and haemodynamic effects of intrathecal bupivacaine with buprenorphine versus levobupivacaine with buprenorphine in infraumbilical surgeries.

Methods

This prospective randomised double blind study was conducted in seventy patients aged 18-65 years, American Society of Anesthesiologists grade I-II, scheduled for lower abdominal and lower limb surgery under spinal anaesthesia. The patients either received 0.5% isobaric racemic bupivacaine 3 ml with 2 μg/kg of buprenorphine (Group B) or 0.5% isobaric levobupivacaine 3 ml with 2 μg/kg of buprenorphine (Group L). The time for onset of sensory block between the two groups was the priomary end-point. Other measurements included haemodynamic variables, sensory and motor blockade characteristics, postoperative analgesia, and complications in the first 24 h.

Results

There was no significant difference in the onset of sensory block between the two groups. Sensory and motor blockade characteristics were similar between the two groups. However, there was significant fall in the heart rate at 5 min in Group B compared to Group L. There was statistically significant fall in systolic blood pressure in group B compared to Group L from 5 min up to 60 min and fall in diastolic blood pressure from 10 min to 45 min.

Conclusion

Our study showed that onset of sensory block is similar between isobaric levobupivacaine with buprenorphine 37 38 and isobaric bupivacaine with buprenorphine.

Interscalene Block with and without Intraoperative Local Infiltration with Liposomal Bupivacaine in Shoulder Arthroplasty: A Randomized Controlled Trial

BACKGROUND

Interscalene brachial plexus blockade (ISBPB) is an effective anesthetic technique for shoulder arthroplasty; however, "rebound pain" can increase the patient's postoperative pain experience and narcotic usage. Exparel (liposomal bupivacaine) injected into the soft tissues at the surgical site has theoretical efficacy for up to 72 hours after administration. The purpose of this study was to evaluate postoperative pain scores and narcotic consumption following shoulder arthroplasty performed with either ISBPB alone or ISBPB and intraoperative Exparel.

METHODS

Seventy-eight patients undergoing primary shoulder arthroplasty were randomized to receive an ISBPB with Exparel (39 patients) or without Exparel (39 patients). The primary outcome variable was morphine equivalent units (MEUs) consumed over the first 24 hours after surgery. Secondary outcomes included intraoperative narcotic administration and visual analog scale (VAS) scores for pain (at 0, 8, 16, 24, 48, and 72 hours after surgery).

RESULTS

There were no significant demographic differences between the ISBPB and ISBPB + Exparel groups. Total narcotic consumption over the first 24 hours after surgery was significantly lower in the ISBPB group compared with the ISBPB + Exparel group (mean and standard deviation, 18.9 ± 25.6 MEU versus 35.3 ± 36.7 MEU, p = 0.009). VAS pain scores did not differ significantly between groups at any time point during the first 72 hours after surgery.

CONCLUSIONS

Patients treated with Exparel required significantly more postoperative narcotics and demonstrated no significant reduction in pain scores over the first 72 hours after primary shoulder arthroplasty. Exparel does not appear to have substantial value when added to a pain protocol that includes an ISBPB.

LEVEL OF EVIDENCE

Therapeutic Level l. See Instructions for Authors for a complete description of levels of evidence.

In patients undergoing fast track total knee arthroplasty, addition of buprenorphine to a femoral nerve block has no clinical advantage: A prospective, double-blinded, randomized, placebo controlled trial

BACKGROUND

Several adjuvants have been proposed to prolong the effect of peripheral nerve blocks, one of which is buprenorphine. In this randomized double blinded placebo controlled trial we studied whether the addition of buprenorphine to a femoral nerve block prolongs analgesia in patients undergoing total knee arthroplasty in a fast track surgery protocol.

METHODS

The treatment group (B) was given an ultrasound-guided femoral nerve block with ropivacaine 0.2% and 0.3mg buprenorphine. We choose to use 2 control groups. Group R was given a femoral nerve block with ropivacaine 0.2% only. Group S also received 0.3 mg buprenorphine subcutaneously. Only patients with a successful block were enrolled in the study.

RESULTS

We found no difference in our primary outcome parameter of time to first rescue analgesic. We found lower opioid use and better sleep quality the first postoperative night in patients receiving buprenorphine perineurally or subcutaneously. Buprenorphine did not lead to any significant change in pain or mobilization. We found a high overall incidence of nausea and vomiting.

CONCLUSION

In patients undergoing total knee arthroplasty, in the setting of a fast track surgery protocol, the addition of buprenorphine to a femoral nerve block did not prolong analgesia.

Adjuvant Agents in Regional Anesthesia in the Ambulatory Setting

PURPOSE OF REVIEW

A majority of surgical practice has involved ambulatory centers with the number of outpatient operations in the USA doubling to 26.8 million per year. Local anesthesia delivery provides numerous benefits, including increased satisfaction, earlier discharge, and reduction in unplanned hospital admission. Further, with the epidemic of opioid mediated overdoses, local anesthesia can be a key tool in providing an opportunity to reduce the need for other analgesics postoperatively.

RECENT FINDINGS

Adjuvants such as epinephrine and clonidine enhance local anesthetic clinical utility. Further, dexmedetomidine prolongs regional blockade duration effects. There has also been a significant interest recently in the use of dexamethasone. Studies have demonstrated a significant prolongation in motor and sensory block with perineural dexamethasone. Findings are conflicting as to whether intravenous dexamethasone has similar beneficial effects. However, considering the possible neurotoxicity effects, which perineural dexamethasone may present, it would be prudent not to consider intravenously administered dexamethasone to prolong regional block duration. Many studies have also demonstrated neurotoxicity from intrathecally administered midazolam. Therefore, midazolam as an adjuvant is not recommended. Magnesium prolongs regional block duration but related to paucity of studies as of yet, cannot be recommended. Tramadol yields inconsistent results and ketamine is associated with psychotomimetic adverse effects. Buprenorphine consistently increases regional block duration and reduce opioid requirements by a significant amount. Future studies are warranted to define best practice strategies for these adjuvant agents. The present review focuses on the many roles of local anesthetics in current ambulatory practice.

Postoperative pain control after arthroscopic rotator cuff repair

Arthroscopic rotator cuff repair (ARCR) can provide excellent clinical results for patients who fail to respond to conservative management of symptomatic rotator cuff tears. ARCR, however, can be associated with severe postoperative pain and discomfort that requires adequate analgesia. As ARCR continues to shift toward being performed as an outpatient procedure, it is incumbent on physicians and ambulatory surgical centers to provide appropriate pain relief with minimal side effects to ensure rapid recovery and safe discharge. Although intravenous and oral opioids are the cornerstone of pain management after orthopedic procedures, they are associated with drowsiness, nausea, vomiting, and increased length of hospital stay. As health care reimbursements continue to become more intimately focused on quality, patient satisfaction, and minimizing of complications, the need for adequate pain control with minimal complications will continue to be a principal focus for providers and institutions alike. We present a review of alternative modalities for pain relief after ARCR, including cryotherapy, intralesional anesthesia, nerve blockade, indwelling continuous nerve block catheters, and multimodal anesthesia. In choosing among these modalities, physicians should consider patient- and system-based factors to allow the efficient delivery of analgesia that optimizes recovery and improves patient satisfaction.

Neurotoxicity of common peripheral nerve block adjuvants

PURPOSE OF REVIEW

This review outlines the analgesic role of perineural adjuvants for local anesthetic nerve block injections, and evaluates current knowledge regarding whether adjuvants modulate the neurocytologic properties of local anesthetics.

RECENT FINDINGS

Perineural adjuvant medications such as dexmedetomidine, clonidine, buprenorphine, dexamethasone, and midazolam play unique analgesic roles. The dosing of these medications to prevent neurotoxicity is characterized in various cellular and in-vivo models. Much of this mitigation may be via reducing the dose of local anesthetic used while achieving equal or superior analgesia. Dose-concentration animal models have shown no evidence of deleterious effects. Clinical observations regarding blocks with combined bupivacaine-clonidine-buprenorphine-dexamethasone have shown beneficial effects on block duration and rebound pain without long-term evidence of neurotoxicity. In-vitro and in-vivo studies of perineural clonidine and dexmedetomidine show attenuation of perineural inflammatory responses generated by local anesthetics.

SUMMARY

Dexmedetomidine added as a peripheral nerve blockade adjuvant improves block duration without neurotoxic properties. The combined adjuvants clonidine, buprenorphine, and dexamethasone do not appear to alter local anesthetic neurotoxicity. Midazolam significantly increases local anesthetic neurotoxicity in vitro, but when combined with clonidine-buprenorphine-dexamethasone (sans local anesthetic) produces no in-vitro or in-vivo neurotoxicity. Further larger-species animal testing and human trials will be required to reinforce the clinical applicability of these findings.

Upper extremity nerve block: how can benefit, duration, and safety be improved? An update

Upper extremity blocks are useful as both sole anaesthesia and/or a supplement to general anaesthesia and they further provide effective postoperative analgesia, reducing the need for opioid analgesics. There is without doubt a renewed interest among anaesthesiologists in the interscalene, supraclavicular, infraclavicular, and axillary plexus blocks with the increasing use of ultrasound guidance. The ultrasound-guided technique visualising the needle tip and solution injected reduces the risk of side effects, accidental intravascular injection, and possibly also trauma to surrounding tissues. The ultrasound technique has also reduced the volume needed in order to gain effective block. Still, single-shot plexus block, although it produces effective anaesthesia, has a limited duration of postoperative analgesia and a number of adjuncts have been tested in order to prolong analgesia duration. The addition of steroids, midazolam, clonidine, dexmedetomidine, and buprenorphine has been studied, all being off-label when administered by perineural injection, and the potential neurotoxicity needs further study. The use of perineural catheters is an effective option to improve and prolong the postoperative analgesic effect.

Upper extremity plexus blocks have an obvious place as a sole anaesthetic technique or as a powerful complement to general anaesthesia, reducing the need for analgesics and hypnotics intraoperatively, and provide effective early postoperative pain relief. Continuous perineural infusion is an effective option to prolong the effects and improve postoperative quality.

Buprenorphine, Clonidine, Dexamethasone, and Ropivacaine for Interscalene Nerve Blockade: A Prospective, Randomized, Blinded, Ropivacaine Dose-Response Study

OBJECTIVE

This study investigated interscalene block for shoulder arthroplasty with various ropivacaine concentrations in the presence of clonidine, dexamethasone, and buprenorphine. The goal was prolonged analgesia with minimal motor blockade.

DESIGN

Prospective, double-blind, randomized controlled trial.

SETTING

University-affiliated orthopedic hospital.

METHODS

Patients (20/group) received acetaminophen, ketorolac, pregabalin, opioids, and "Control"; interscalene block, 0.375% ropivacaine, intravenous additives (buprenorphine, clonidine, dexamethasone); "High Dose"; 0.375% ropivacaine, perineural additives; "Medium Dose"; 0.2% ropivacaine, perineural additives; and "Low Dose"; 0.1% ropivacaine, perineural additives.

RESULTS

Pain with movement at 24 hours was 4.9 ± 2.5 (mean ± standard deviation [SD]) (Control), 4.5 ± 3.0 (High Dose), 3.4 ± 1.8 (Medium Dose), 4.2 ± 2.4 (Low Dose). The difference between Medium Dose and Control was -1.5 (95% CI: -2.9, -0.1) (P = 0.040). Median time until need for opioids was 16.1 hours (Control) vs 23.7 hours (High Dose); hazard ratio 0.37 [95% CI: 0.17, 0.79]. High Dose had less pain with movement the morning after surgery, vs Control; 2.9 ± 2.5 vs 4.9 ± 2.7; P = 0.027. Pain with movement in the Post-Anesthesia Care Unit was higher in Low Dose, vs Control; 0.9 ± 1.4 vs 0 ± 0, P = 0.009. Low Dose had superior hand strength in the Post-Anesthesia Care Unit (mean ± SD of pre-operative strength: 44.0 ± 20.3%) compared to Control (27.5 ± 24.5%) (P = 0.031).

CONCLUSIONS

For maximum pain reduction, combining perineural additives with ropivacaine 0.375% or 0.2% is suggested. To minimize motor blockade, perineural additives can be combined with ropivacaine, 0.1%.

Local Anesthetic Peripheral Nerve Block Adjuvants for Prolongation of Analgesia: A Systematic Qualitative Review

Background

The use of peripheral nerve blocks for anesthesia and postoperative analgesia has increased significantly in recent years. Adjuvants are frequently added to local anesthetics to prolong analgesia following peripheral nerve blockade. Numerous randomized controlled trials and meta-analyses have examined the pros and cons of the use of various individual adjuvants.

Objectives

To systematically review adjuvant-related randomized controlled trials and meta-analyses and provide clinical recommendations for the use of adjuvants in peripheral nerve blocks.

Methods

Randomized controlled trials and meta-analyses that were published between 1990 and 2014 were included in the initial bibliographic search, which was conducted using Medline/PubMed, Cochrane Central Register of Controlled Trials, and EMBASE. Only studies that were published in English and listed block analgesic duration as an outcome were included. Trials that had already been published in the identified meta-analyses and included adjuvants not in widespread use and published without an Investigational New Drug application or equivalent status were excluded.

Results

Sixty one novel clinical trials and meta-analyses were identified and included in this review. The clinical trials reported analgesic duration data for the following adjuvants: buprenorphine (6), morphine (6), fentanyl (10), epinephrine (3), clonidine (7), dexmedetomidine (7), dexamethasone (7), tramadol (8), and magnesium (4). Studies of perineural buprenorphine, clonidine, dexamethasone, dexmedetomidine, and magnesium most consistently demonstrated prolongation of peripheral nerve blocks.

Conclusions

Buprenorphine, clonidine, dexamethasone, magnesium, and dexmedetomidine are promising agents for use in prolongation of local anesthetic peripheral nerve blocks, and further studies of safety and efficacy are merited. However, caution is recommended with use of any perineural adjuvant, as none have Food and Drug Administration approval, and concerns for side effects and potential toxicity persist.

Buprenorphine for postoperative analgesia: Axillary brachial plexus block versus intramuscular administration in a placebo-controlled trial

Background and Aims:

Peripheral administration of opioids has been suggested for prolongation of regional analgesia. This prospective, randomized, double-blind placebo-controlled study was undertaken to compare the effect of regional (axillary brachial plexus block [ABPB]) versus intramuscular (IM) buprenorphine (2 μg/kg) in adults.

Material and Methods:

Seventy-five adults undergoing upper limb surgery received ABPB with local anaesthetic (15 ml 0.5% bupivacaine, 15 ml 2% lignocaine with adrenaline 1:200,000, 9 ml normal saline [NS]). In addition, regional group RB (n = 25) received buprenorphine 2 μg/kg in ABPB and 1 ml NS IM. Systemic Group SB (n = 25) received 1 ml NS in ABPB and buprenorphine 2 μg/kg IM. Group C (n = 25) received 1 ml NS in ABPB and IM. Onset, duration of sensory and motor block, hemodynamic parameters, sedation score, pain scores using visual analog scale, duration of postoperative analgesia, rescue analgesic (RA) requirement, adverse events, and patient satisfaction were noted.

Results:

Demographics, onset and duration of sensory, motor block were similar. RB group had longest duration of analgesia (20.61 ± 1.33 h) compared to SB (10.91 ± 0.90 h) and control group (5.86 ± 0.57 h) (P < 0.05 RB vs. SB/C and SB vs. C). RA requirement was highest in the control group and least in RB group (P = 0.000 RB vs. SB/C and SB vs. C). SB group had a maximum number of side effects (P = 0.041, SB vs. RB/C). Patient satisfaction was highest with group RB (P < 0.05 RB vs. SB/C, and P = 0.06 SB vs. C).

Conclusion:

Buprenorphine 2 μg/kg in axillary plexus block provides significantly prolonged analgesia with less RA requirement and greater patient satisfaction compared to IM administration. This is highly suggestive of action on peripheral opioid receptors.

Efficacy of intraarticular application of ketamine or ketamine-levobupivacaine combination on post-operative pain after arthroscopic meniscectomy

PURPOSE

To evaluate the efficacy of intraarticular injection of ketamine or ketamine plus levobupivacaine on post-operative analgesia in patients undergoing arthroscopic meniscectomy.

METHODS

A prospective, randomized, double-blind study was performed on 60 patients aged 18-65 years who planned to undergo elective arthroscopic meniscectomy. The patients were divided into three groups: the ketamine group (n = 20) received 1.0 mg/kg of intraarticular ketamine in 20 ml of normal saline, the ketamine-levobupivacaine group (n = 20) received 0.5 mg/kg of intraarticular ketamine plus 50.0 mg of 0.25 % levobupivacaine in 20 ml of normal saline, and the control group (n = 20) received 20 ml of intraarticular normal saline. A visual analogue scale (VAS) was used to determine the efficacy of analgesia at 1, 2, 4, 6, 8, 12, and 24 h post-operatively.

RESULTS

There were statistically significant differences in the median VAS scores among the three groups according to Bonferroni adjustment at all time points (p < 0.01), with the exception of 6 and 24 h post-operatively. The median VAS scores at 1, 2, and 4 h post-operatively were higher in the control group than in the two treatment groups (p < 0.001). The median VAS scores in the control group at 1, 2, 4, 6, 8, and 12 h post-operatively and those in the ketamine group at 4, 8, and 12 h post-operatively were significantly higher than those in the ketamine-levobupivacaine group (p < 0.05).

CONCLUSION

Intraarticular ketamine provides effective post-operative analgesia. Addition of intraarticular levobupivacaine to ketamine may provide better amelioration of pain after outpatient arthroscopic meniscectomy.

Additives to local anesthetics for peripheral nerve blocks or local anesthesia: a review of the literature

SUMMARY 

A multitude of studies have focused on individual additives to local anesthetics and their effect on quality, onset, duration, spread and selectivity, as well as the potential toxic effects of their use. This review aims to give a broad overview of the current evidence in this developing field, based on beneficial and adverse effects of these drugs. We discuss the limitations of the available data and hope to convey implications and future perspectives for clinicians and researchers alike.