Addition of Dexamethasone and Buprenorphine to Bupivacaine Sciatic Nerve Block: A Randomized Controlled Trial

Primary outcomes and anticipated effect sizes in randomised clinical trials assessing adjuncts to peripheral nerve blocks: A scoping review

BACKGROUND

Prolonging effects of adjuncts to local anaesthetics in peripheral nerve blocks have been demonstrated in randomised clinical trials. The chosen primary outcome and anticipated effect size have major impact on the clinical relevance of results in these trials. This scoping review aims to provide an overview of frequently used outcomes and anticipated effect sizes in randomised trials on peripheral nerve block adjuncts.

METHODS

For our scoping review, we searched MEDLINE, Embase and CENTRAL for trials assessing effects of adjuncts for peripheral nerve blocks published in 10 major anaesthesia journals. We included randomised clinical trials assessing adjuncts for single-shot ultrasound-guided peripheral nerve blocks, regardless of the type of interventional adjunct and control group, local anaesthetic used and anatomical localization. Our primary outcome was the choice of primary outcomes and corresponding anticipated effect size used for sample size estimation. Secondary outcomes were assessor of primary outcomes, the reporting of sample size calculations and statistically significant and non-significant results related to the anticipated effect sizes.

RESULTS

Of 11,854 screened trials, we included 59. The most frequent primary outcome was duration of analgesia (35/59 trials, 59%) with absolute and relative median (interquartile range) anticipated effect sizes for adjunct versus placebo/no adjunct: 240 min (180-318) and 30% (25-40) and for adjunct versus active comparator: 210 min (180-308) and 17% (15-28). Adequate sample size calculations were reported in 78% of trials. Statistically significant results were reported for primary outcomes in 45/59 trials (76%), of which 22% did not reach the anticipated effect size.

CONCLUSION

The reported outcomes and associated anticipated effect sizes can be used in future trials on adjuncts for peripheral nerve blocks to increase methodological homogeneity.

Spinal Anesthesia With Peripheral Nerve Block Versus General Anesthesia With Peripheral Nerve Block for Elective Foot and Ankle Surgeries: A Retrospective Single-Center Study

Peripheral nerve blocks are the regional techniques in orthopedic surgeries to control postoperative pain and have early discharge from hospital. However, anesthesia protocols for foot and ankle surgeries of institutes do not include multimodal analgesics including peripheral nerve blocks. The objective of the study was to compare spinal anesthesia with peripheral nerve block against general anesthesia with peripheral nerve block for elective foot and ankle surgeries. Patients have treated for elective foot and ankle surgery under general anesthesia (using propofol, 0.05 mg/kg dezocine, and 1% sevoflurane; GA cohort, n = 112) or spinal anesthesia (using 0.5% bupivacaine, propofol, and 0.05 mg/kg dezocine; SA cohort, n = 132) or patients have treated for elective for foot and ankle surgery under general anesthesia (GL cohort, n = 115) or spinal anesthesia (SL cohort, n = 160) with the use of peripheral nerve block (the sciatic nerve blocks and adductor canal nerve blocks using 0.25% bupivacaine and 0.1 mg/kg dexamethasone). Propofol was administered in fewer amounts if anesthesia was used with the peripheral nerve block. Patients of the GL cohort were transferred to ward 36 minutes (mean) earlier than those of the SL cohort. None of the patients of the GL and the SL cohorts have received intraoperative opioid(s) for the management of pain. Patients of the GL and the SL cohorts have reported postoperative falls within 1 day after surgeries during movement. Patients of the SL cohort experienced more frequently difficulty with sleeping. Patients of the GL and the GA cohorts have reported nausea and vomiting. Only patients of the GL cohort were required usage of vasoactive drugs. The study provides information to anesthesiologists and surgeons regarding anesthesia techniques for elective foot and ankle surgeries for better surgical outcomes (Technical Efficacy Stage: 4).

A Comprehensive Enhanced Recovery Pathway for Rotator Cuff Surgery Reduces Pain, Opioid Use, and Side Effects

BACKGROUND

Patients often have moderate to severe pain after rotator cuff surgery, despite receiving analgesics and nerve blocks. There are many suggested ways to improve pain after rotator cuff surgery, but the effects of adopting a pathway that includes formal patient education, a long-acting nerve block, and extensive multimodal analgesia are unclear.

QUESTIONS/PURPOSES

(1) Does adoption of a clinical pathway incorporating patient education, a long-acting nerve block, and preemptive multimodal analgesia reduce the worst pain during the first 48 hours after surgery compared with current standard institutional practices? (2) Does adoption of the pathway reduce opioid use? (3) Does adoption of the pathway reduce side effects and improve patient-oriented outcomes?

METHODS

From September 2018 to January 2020, 281 patients scheduled for arthroscopic ambulatory rotator cuff surgery were identified for this paired sequential prospective cohort study. Among patients in the control group, 177 were identified, 33% (58) were not eligible, for 11% (20) staff was not available, 56% (99) were approached, 16% (29) declined, 40% (70) enrolled, and 40% (70) were analyzed (2% [4] lost to follow-up for secondary outcomes after postoperative day 2). For patients in the pathway cohort, 104 were identified, 17% (18) were not eligible, for 11% (11) staff was not available, 72% (75) were approached, 5% (5) declined, 67% (70) enrolled, and 67% (70) were analyzed (3% [3] lost to follow-up for secondary outcomes after postoperative day 2). No patients were lost to follow-up for primary outcome; for secondary outcomes, four were lost in the control group and three in the pathway group after postoperative day 2 (p = 0.70). The initial 70 patients enrolled received routine care (control group), and in a subsequent cohort, 70 patients received care guided by a pathway (pathway group). Of the 205 eligible patients, 68% (140) were included in the analysis. This was not a study comparing two tightly defined protocols but rather a study to determine whether adoption of a pathway would alter patient outcomes. For this reason, we used a pragmatic (real-world) study design that did not specify how control patients would be treated, and it did not require that all pathway patients receive all components of the pathway. We developed the pathway in coordination with a group of surgeons and anesthesiologists who agreed to apply the pathway as much as was viewed practical for each individual patient. Patients in both groups received a brachial plexus nerve block with sedation. Major differences between the pathway and control groups were: detailed patient education regarding reasonable pain expectations with a goal of reducing opioid use (no formal educational presentation was given to the control), a long-acting nerve block using bupivacaine with dexamethasone (control patients often received shorter-acting local anesthetic without perineural dexamethasone), and preemptive multimodal analgesia including intraoperative ketamine, postoperative acetaminophen, NSAIDs, and gabapentin at bedtime, with opioids as needed (control patients received postoperative opioids but most did not get postoperative NSAIDS and no controls received gabapentin or separate prescriptions for acetaminophen). The primary outcome was the numerical rating scale (NRS) worst pain with movement 0 to 48 hours after block placement. The NRS pain score ranges from 0 (no pain) to 10 (worst pain possible). The minimum clinically important difference (MCID) [12] for NRS that was used for calculation of the study sample size was 1.3 [18], although some authors suggest 1 [13] or 2 [5] are appropriate; if we had used an MCID of 2, the sample size would have been smaller. Secondary outcomes included NRS pain scores at rest, daily opioid use (postoperative day 1, 2, 7, 14), block duration, patient-oriented pain questions (postoperative day 1, 2, 7, 14), and patient and physician adherence to pathway.

RESULTS

On postoperative day 1, pathway patients had lower worst pain with movement (3.3 ± 3.1) compared with control patients (5.6 ± 3.0, mean difference -2.7 [95% CI -3.7 to -1.7]; p < 0.001); lower scores were also seen for pain at rest (1.9 ± 2.3 versus 4.0 ± 2.9, mean difference -2.0 [95% CI -2.8 to -1.3]; p < 0.001). Cumulative postoperative opioid use (0-48 hours) was reduced (pathway oral morphine equivalent use was 23 ± 28 mg versus 44 ± 35 mg, mean difference 21 [95% CI 10 to 32]; p < 0.01). The greatest difference in opioid use was in the first 24 hours after surgery (pathway 7 ± 12 mg versus control 21 ± 21 mg, mean difference -14 [95% CI -19 to -10]; p < 0.01). On postoperative day 1, pathway patients had less interference with staying asleep compared with control patients (0.5 ± 1.6 versus 2.6 ± 3.3, mean difference -2.2 [95% CI -3.3 to -1.1]; p < 0.001); lower scores were also seen for interference with activities (0.9 ± 2.3 versus 1.9 ± 2.9, mean difference -1.1 [95% CI -2 to -0.1]; p = 0.03). Satisfaction with pain treatment on postoperative day 1 was higher among pathway patients compared with control patients (9.2 ± 1.7 versus 8.2 ± 2.5, mean difference 1.0 [95% CI 0.3 to 1.8]; p < 0.001). On postoperative day 2, pathway patients had lower nausea scores compared with control patients (0.3 ± 1.1 versus 1 ± 2.1, mean difference -0.7 [95% CI -1.2 to -0.1]; p = 0.02); lower scores were also seen for drowsiness on postoperative day 1 (1.7 ± 2.7 versus 2.6 ± 2.6, mean difference -0.9 [95% CI - 1.7 to -0.1]; p = 0.03).

CONCLUSION

Adoption of the pathway was associated with improvement in the primary outcome (pain with movement) that exceeded the MCID. Patients in the pathway group had improved patient-oriented outcomes and fewer side effects. This pathway uses multiple analgesic drugs, which may pose risks to elderly patients, in particular. Therefore, in evaluating whether to use this pathway, clinicians should weigh the effect sizes against the potential risks that may emerge with large scale use, consider the difficulties involved in adapting a pathway to local practice so that pathway will persist, and recognize that this study only enrolled patients among surgeons and the anesthesiologists that advocated for the pathway; results may have been different with less enthusiastic clinicians. This pathway, based on a long-lasting nerve block, multimodal analgesia, and patient education can be considered for adoption.

LEVEL OF EVIDENCE

Level II, therapeutic study.

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.

Role of dexmedetomidine as adjuvant in postoperative sciatic popliteal and adductor canal analgesia in trauma patients: a randomized controlled trial

Background

The effect of dexmedetomidine as an adjuvant in the adductor canal block (ACB) and sciatic popliteal block (SPB) on the postoperative tramadol-sparing effect following spinal anesthesia has not been evaluated.

Methods

In this randomized, placebo-controlled study, ninety patients undergoing below knee trauma surgery were randomized to either the control group, using ropivacaine in the ACB + SPB; the block Dex group, using dexmedetomidine + ropivacaine in the ACB + SPB; or the systemic Dex group, using ropivacaine in the ACB + SPB + intravenous dexmedetomidine. The primary outcome was a comparison of postoperative cumulative tramadol patient-controlled analgesia (PCA) consumption at 48 hours. Secondary outcomes included time to first PCA bolus, pain score, neurological assessment, sedation score, and adverse effects at 0, 5, 10, 15, and 60 minutes, as well as 4, 6, 12, 18, 24, 30, 36, 42, and 48 hours after the block.

Results

The mean ± standard deviation of cumulative tramadol consumption at 48 hours was 64.83 ± 51.17 mg in the control group and 41.33 ± 38.57 mg in the block Dex group (P = 0.008), using Mann–Whitney U-test. Time to first tramadol PCA bolus was earlier in the control group versus the block Dex group (P = 0.04). Other secondary outcomes were comparable.

Conclusions

Postoperative tramadol consumption was reduced at 48 hours in patients receiving perineural or systemic dexmedetomidine with ACB and SPB in below knee trauma surgery.

The efficacy of dexamethasone on pain management for knee arthroscopy: A meta-analysis of randomized controlled trials

INTRODUCTION

The impact of dexamethasone on pain management for knee arthroscopy remains controversial. We conduct a systematic review and meta-analysis to explore the influence of dexamethasone for knee arthroscopy.

METHODS

We search PubMed, EMbase, Web of science, EBSCO, and Cochrane library databases through October 2018 for randomized controlled trials (RCTs) assessing the effect of dexamethasone on pain intensity for patients with dental implant. This meta-analysis is performed using the random-effect model.

RESULTS

Four RCTs involving 228 patients are included in the meta-analysis. Overall, compared with control group for knee arthroscopy, dexamethasone supplementation has no notable effect on pain scores at 4 to 6 hours (Std. MD = 0.99; 95% CI = -2.97 to 4.95; P = .62), but exerts significantly favorable promotion to pain scores at 12 hours (Std. MD = -1.06; 95% CI = -1.43 to -0.69; P < .00001), duration of block (Std. MD = 1.87; 95% CI = 0.65 to 3.10; P = .003), time to first analgesic requirement (Std. MD = 0.90; 95% CI = 0.51 to 1.29; P < .00001), analgesic consumption (Std. MD = -1.62; 95% CI = -2.31 to -0.93; P < .00001), and patient satisfaction (Std. MD = 1.15; 95% CI = 0.73 to 1.58; P < .00001).

CONCLUSIONS

Dexamethasone supplementation has importantly positive influence on pain control for knee arthroscopy.

Comparison of Single-Agent Versus 3-Additive Regional Anesthesia for Foot and Ankle Surgery

BACKGROUND

This study compared the results of regional blocks containing a single anesthetic, bupivacaine, with those containing bupivacaine and 3 additives (buprenorphine, clonidine, and dexamethasone) in patients undergoing foot and ankle surgery.

METHODS

Eighty patients undergoing foot and ankle surgery over a 9-month period were prospectively enrolled and randomized to receive a peripheral nerve block containing either a single anesthetic (SA) or one with 3 additives (TA). Patients, surgeons, and anesthesiologists were blinded to the groups. Patients maintained pain diaries and were evaluated at 1 and 12 weeks postoperatively. Fifty-six patients completed the study.

RESULTS

The TA group had a longer duration of analgesic effect than the SA group (average 82 vs 34 hours, P < .05). Forty-eight hours after surgery, 93% of SA blocks, compared with 34% of TA blocks, had completely worn off. The TA group had a longer duration of sensory effects. At 3 months, 10 of 26 (38.5%) TA patients, compared with 3 of 30 (10%) SA patients, reported postoperative neurologic symptoms. Pain scores in both groups were not statistically different at 1 week or 3 months after surgery. Patients in both groups were similarly satisfied with their blocks.

CONCLUSION

Both types of nerve blocks provided equivalent pain control and patient satisfaction in patients undergoing foot and ankle surgery. The 3-additive agent blocks were associated with a longer duration of pain relief and a longer duration of numbness, as well as higher rates of postoperative neurologic symptoms. Longer pain relief may be obtained at the cost of prolonged sensory deficits.

LEVEL OF EVIDENCE

Level II, prospective comparative study.

Peripheral nerve catheters: A critical review of the efficacy

Continuous peripheral nerve blocks are commonly used for postoperative analgesia after surgery. However, catheter failure may occur due to either primary (incorrect insertion) or secondary reasons (displacement, obstruction, disconnection). Catheter failure results in unanticipated pain, need for opioid use, and risk of readmission or delay in hospital discharge. This review aimed to assess definition and frequency of catheter failure, and discuss the alternatives to prolong duration of single-shot nerve blocks. A literature search was performed on peripheral catheters reporting failure as the main outcome measure. Thirty-three studies met the selection criteria, comprising 2711 catheters. Literature review suggests that peripheral nerve catheters have clinically significant failure rate when the assessment is performed using an objective (imaging) method. Subjective methods of assessment (without imaging) may underestimate the incidence of catheter failure.

What Pain Levels Do TSA Patients Experience When Given a Long-acting Nerve Block and Multimodal Analgesia?

BACKGROUND

The pain experience for total shoulder arthroplasty (TSA) patients in the first 2 weeks after surgery has not been well described. Many approaches to pain management have been used, with none emerging as clearly superior; it is important that any approach minimizes postoperative opioid use.

QUESTIONS/PURPOSES

(1) With a long-acting nerve block and comprehensive multimodal analgesia, what are the pain levels after TSA from day of surgery until postoperative day (POD) 14? (2) How many opioids do TSA patients take from the day of surgery until POD 14? (3) What are the PainOUT responses at POD 1 and POD 14, focusing on side effects from opioids usage?

METHODS

From January 27, 2017 to December 6, 2017, 154 TSA patients were identified as potentially eligible for this prospective, institutional review board-approved observational study. Of those, 46 patients (30%) were excluded (either because they were deemed not appropriate for the study, research staff were not available, patients were not eligible, or they declined to participate), and another six (4%) had incomplete followup data and could not be studied, leaving 102 patients (66%) for analysis here. Median preoperative pain with movement was 7 (interquartile range [IQR], 5-9) and 13 of 102 patients used preoperative opioids. All patients received a single-injection bupivacaine interscalene block with adjuvant clonidine, dexamethasone, and buprenorphine. Multimodal analgesia included acetaminophen, NSAIDs, and opioids. The primary outcome was the Numerical Rating Scale (NRS) pain score with movement on POD 14. The NRS pain score ranges from 0 (no pain) to 10 (worst pain possible). Secondary outcomes included NRS pain scores at rest and with movement (day of surgery, and PODs 1, 3, 7 and 14), daily analgesic use from day of surgery to POD 14 (both oral and intravenous), Opioid-Related Symptom Distress Scale (which assesses 12 symptoms ranging from 0 to 4, with 4 being the most distressing; the composite score is the mean of the 12 symptom-specific scores) on POD 1, and the PainOut questionnaire on POD 1 and POD 14. The PainOut questionnaire includes questions rating nausea, drowsiness, itching from 0 (none) to 10 (severe), as well as rating difficulty staying asleep from 0 (does not interfere) to 10 (completely interferes).

RESULTS

The median NRS pain scores with movement were 2 (IQR, 0-5) on POD 1, 5 (IQR, 3-6) on POD 3, and the pain score was 3 (IQR, 1-5) on POD 14. Median total opioid use (converted to oral morphine equivalents) was 16 mg (4-50 mg) for the first 24 hours, 30 mg (8-63 mg) for the third, and 0 mg (0-20 mg) by the eighth 24-hour period, while the most frequent number of activations of the intravenous patient-controlled analgesia device was 0. Median PainOut scores on POD 1 and POD 14 for sleep interference, nausea, drowsiness and itching were 0, and the median composite Opioid-Related Symptom Distress Scale score on day 1 was 0.3 (IQR, 0.1-0.5).

CONCLUSIONS

Clinicians using this protocol, which combines a long-acting, single-injection nerve block with multimodal analgesia, can inform TSA patients that their postoperative pain will likely be less than their preoperative pain, and that on average they will stop using opioids after 7 days. Future research could investigate what the individual components of this protocol contribute. Larger cohort studies or registries would document the incidence of rare complications. Randomized controlled trials could directly compare analgesic effectiveness and cost-benefits for this protocol versus alternative strategies, such as perineural catheters or liposomal bupivacaine. Perhaps most importantly, future studies could seek ways to further reduce peak pain and opioid usage on POD 2 and POD 3.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Lower extremity regional anesthesia: essentials of our current understanding

The advent of ultrasound guidance has led to a renewed interest in regional anesthesia of the lower limb. In keeping with the American Society of Regional Anesthesia and Pain Medicine's ongoing commitment to provide intensive evidence-based education, this article presents a complete update of the 2005 comprehensive review on lower extremity peripheral nerve blocks. The current review article strives to (1) summarize the pertinent anatomy of the lumbar and sacral plexuses, (2) discuss the optimal approaches and techniques for lower limb regional anesthesia, (3) present evidence to guide the selection of pharmacological agents and adjuvants, (4) describe potential complications associated with lower extremity nerve blocks, and (5) identify informational gaps pertaining to outcomes, which warrant further investigation.

Single-Injection Adductor Canal Block With Multiple Adjuvants Provides Equivalent Analgesia When Compared With Continuous Adductor Canal Blockade for Primary Total Knee Arthroplasty: A Double-Blinded, Randomized, Controlled, Equivalency Trial

BACKGROUND

Peripheral nerve blockade is used to provide analgesia for patients undergoing total knee arthroplasty. This study compared a single-injection adductor canal block (SACB) with adjuvants to continuous adductor canal blockade (CACB). The hypothesis was that the 2 groups would have equivalent analgesia at 30 hours after neural blockade.

METHODS

This was a double-blinded, randomized, controlled, equivalency trial. Sixty patients were randomized to either the SACB group (20 mL of 0.25% bupivacaine, 1.67 mcg/mL of clonidine, 2 mg of dexamethasone, 150 mcg of buprenorphine, and 2.5 mcg/mL of epinephrine) or the CACB group (20 mL 0.25% of bupivacaine injection with 2.5 mcg/mL of epinephrine followed by an 8 mL/h infusion of 0.125% bupivacaine continued through postoperative day 2). The primary outcome was movement pain scores at 30 hours using the numeric rating scale (NRS). The secondary outcomes included serial postoperative NRS pain scores (rest and movement every 6 hours), opioid consumption, time to first opioid administration, ability to straight leg raise, patient satisfaction, length of stay, and the incidence of nausea/vomiting.

RESULTS

An intention-to-treat analysis included 59 patients. The NRS pain scores with movement were equivalent at 30 hours (SACB 5.5 ± 2.8 vs CACB 5.7 ± 2.9 [mean NRS ± standard deviation]; mean difference 0.2 [-1.5 to 1.0 {90% confidence interval}]). All NRS pain scores were equivalent until 42 hours (rest) and 48 hours (rest and movement) with the CACB group having lower pain scores. Other secondary outcomes were not statistically different.

CONCLUSION

An SACB provides equivalent analgesia for up to 36 hours after block placement when compared with a CACB for patients undergoing total knee arthroplasty, though a CACB was favored at 42 hours and beyond.

The Incidence of Complications Is Low Following Foot and Ankle Surgery for Which Peripheral Nerve Blocks Are Used for Postoperative Pain Management

BACKGROUND

The incidence of neurologic complications from foot and ankle surgery utilizing regional anesthesia is not well established.

QUESTIONS/PURPOSES

The purpose of this study was to prospectively determine the incidence of neurologic and peripheral nerve block (PNB) site complications on a busy foot and ankle service that utilizes ankle blocks (ABs) and popliteal blocks (POPs).

PATIENTS AND METHODS

This prospective observational study included patients undergoing foot and ankle surgery with ABs or POPs. Block choice was determined by surgeon's preference. Patients were assessed for complications during postoperative visits at 2, 6, and 12 weeks. The relation of each complication to the block was scored by a surgeon and anesthesiologist.

RESULTS

From October 2012 to October 2014, 2516 patients underwent 2704 surgeries. There were 195 complications (7.2%) considered neurologic or at the PNB site. The incidence of serious complications was 0.7%. A higher complication rate was reported for POPs (8.8%) than for ABs (2.5%). However, when analysis was limited to forefoot surgery, this difference was not significant. Dexamethasone use was associated with increased complications for POPs. Only 5 of the 195 total complications, and 2 of 20 serious complications, were deemed to have been likely caused by the block by both the surgeon and anesthesiologist reviewer.

CONCLUSIONS

The incidences of neurologic or block-related complications and serious complications were 7.2 and 0.7%, respectively, most without a clear surgical vs. nerve block etiology. The higher complication rate for POPs using perineural dexamethasone should be interpreted cautiously in light of the lack of randomization and likely confounders.

Comparison of Dexamethasone and Buprenorphine as Adjuvant in Ultrasound-guided Brachial Plexus Blocks: A Randomized Controlled Trial

Introduction:

Effective postoperative analgesia is imperative for orthopedic surgeries to enhance recovery and facilitate early ambulation. Various additives have been used as adjuvants with local anesthetics in peripheral nerve blocks to provide postoperative analgesia. The aim of this study is to compare the duration of postoperative analgesia with buprenorphine and dexamethasone when administered as an adjuvant during ultrasound-guided brachial plexus blocks.

Methodology:

Sixty adult patients undergoing various upper arm surgeries were recruited for the study after acquiring ethics committee clearance. They were randomized into two groups of thirty; Group B was given ultrasound-guided supraclavicular block with 10 ml 2% lignocaine with adrenaline and 15 ml 0.5% bupivacaine and 4 mg dexamethasone as adjuvant. Group B was given the same amount of local anesthetics with 0.3 mg buprenorphine as the adjuvant. The duration of postoperative analgesia and incidence of adverse events if any were noted.

Results:

Both groups were comparable in demographics, time for onset of sensory, and motor block. The duration of postoperative analgesia was 17.4 ± 3.4 h in the buprenorphine group and 18 ± 3.49 h in the dexamethasone group. None of the patients had significant adverse effects. A single dose of buprenorphine and dexamethasone administered perineurally can provide significant postoperative analgesia for upper limb surgeries.

The effect of perineural dexamethasone on duration of sciatic nerve blockade: a randomized, double-blind study

BACKGROUND

Major hindfoot and ankle surgery is associated with severe postoperative pain, which is effectively alleviated by combined sciatic and saphenous nerve blockade. Local anaesthetics with added dexamethasone consistently prolongs the duration of pain relief compared to local anaesthetics alone. However, whether the extended duration of pain relief is due to an effect on duration of sensorimotor block per se vs. systemic absorption of the dexamethasone is still not fully elucidated. We aimed to investigate the postoperative duration of sensorimotor blockade with either dexamethasone or saline added to bupivacaine-epinephrine.

METHODS

Fifty six patients scheduled for surgery were randomly assigned to a popliteal sciatic nerve block of 18 ml 0.5% bupivacaine-epinephrine with either 2 ml of 0.4% dexamethasone or 2 ml 0.9% normal saline added. Sensory and motor functions were tested every 30 min until normalized nerve functions. Primary outcome was time until complete return of sensorimotor functions.

RESULTS

Mean (SD) time until return of normal sensory and motor functions was 26 (6) vs. 16 (4) hours, P < 0.001, postponing block remission by 10 (95% CI: 8-13) hours. Mean (SD) time until first opioid request was 34 (11) vs. 15 (7) hours, P < 0.001, extending first opioid request by 19 (95% CI: 13-25) hours. Total oral morphine equivalents administered 0-48 h differed significantly between the two groups by 39 (95% CI: 23-55) mg.

CONCLUSIONS

Addition of 8 mg dexamethasone to 0.5% bupivacaine-epinephrine significantly prolongs the duration of sensorimotor popliteal sciatic nerve blockade, and reduces pain and opioid consumption in patients after major hind foot and ankle surgery.

Efficacy of perineural dexamethasone with ropivacaine in adductor canal block for post-operative analgesia in patients undergoing total knee arthroplasty: A randomized controlled trial

Adductor canal block (ACB) is an effective analgesic alternative to femoral nerve block after total knee arthroplasty (TKA). The aim of the present study was to investigate whether addition of dexamethasone to ropivacaine for ACB is able to prolong analgesia and reduce pain. Study participants were randomized into groups receiving ACB with either 0.5% ropivacaine + normal saline (control group; n=93) or 0.5% ropivacaine + 8 mg dexamethasone (dexamethasone group; n=93). All patients were subjected to identical peri-operative management. Patients were assessed for the duration of analgesia by the return of pinprick sensation. A numerical rating scale, ranging from 0 to 10, was used to assess post-operative pain at 6, 12, 18, 24 and 48 h. Opioid use was recorded. Serum C-reactive protein and interleukin-6 levels were measured at 3, 6, 12, 24 and 48 h after surgery. The results revealed that the duration of sensory block was significantly longer in the dexamethasone group (23.42±3.35 vs. 14.67±2.96 h in control group, P<0.05). The dexamethasone group also had significantly lower pain scores at 6, 12, 18 and 24 h after surgery (all P<0.001), and at 48 h, pain was comparable in the two groups. Reduction in post-operative pain was associated with a decrease in serum C-reactive protein. Morphine use in the first 24 h after surgery was also lower in the dexamethasone group (4.23±1.80 vs. 8.42±2.44 mg in control group, P<0.05). In conclusion, addition of dexamethasone to ropivacaine for ACB was able to prolong the duration of analgesia and decreased early post-operative pain following TKA.

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.

Impacts of triamcinolone acetonide on femoral head chondrocytic structures in lumbosacral plexus block

Objective: To investigate impacts of triamcinolone acetonide (TRI) on femoral head chondrocytic (FHC) structures when used for lumbosacral plexus block (LPB). Methods: A total of 32 6-month-old New Zealand white rabbits were selected (averagely weighing 2.75–3.25 kg) and added TRI into nerve block solution for LPB. The rabbit were randomly divided into four groups: group A1: 2.5 ml × 2 times, group A2 2.5 ml × 4 times, group B1 5 ml × 2 times, and group B2 5 ml × 4 times; the time interval among the injection was 5 days, and the structural changes of FHC were the observed using 50/100/200 light microscope; the modified Mankin pathological scoring was also performed for the evaluation. Results: There exhibited significant microscopic changes of FHC structures between the rabbits performed LPB and the normal rabbits, among which group B2 exhibited the most serious FHC damages, and the Mankin pathological score in group B2 was much higher than those in the other three groups, and the scores of the experimental group were higher than the control group. Conclusions: The addition of TRI in LPB can damage the FHC structures, and large-dose (5 ml/once) and long-course (four times) will result in more serious injuries.

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.