The Effect of Fixation Technique on Continuous Interscalene Nerve Block Catheter Success: A Randomized, Double-Blind Trial

Comparison of the Analgesic Efficacy between Arthroscopically Placed Continuous Suprascapular Nerve Block and Ultrasound-guided Continuous Superior Trunk Block: A Double-blinded Randomized Controlled Trial

BACKGROUND

Single-shot suprascapular nerve block and superior trunk block have been reported to provide a noninferior analgesic effect after shoulder surgery with a lesser incidence of hemidiaphragmatic paresis compared with interscalene brachial plexus block. This study hypothesized that continuous suprascapular nerve block provides noninferior analgesia with minimal effects on diaphragmatic movement compared with continuous superior trunk block in patients undergoing arthroscopic shoulder surgery.

METHODS

100 patients were randomized undergoing arthroscopic shoulder surgery between December 2020 and October 2021 into continuous suprascapular nerve block and continuous superior trunk block groups. Before the surgery, patients received either a single-shot superior trunk block or subomohyoid suprascapular nerve block. Thereafter, a superior trunk catheter was inserted by anesthesiologists in patients in the continuous superior trunk block group, and a posterior suprascapular nerve catheter was inserted with arthroscopic assistance during the surgery by surgeon in the continuous suprascapular nerve block group. The primary outcome was the postoperative pain score at postoperative 24 h, and the incidence of hemidiaphragmatic paresis was also compared.

RESULTS

Overall, 98 patients were included in the final analysis. The worst and resting pain scores at postoperative 24 h in the continuous suprascapular nerve block group were inferior compared with those in the continuous superior trunk block group in the test with a noninferiority margin of 1 (worst pain score: mean difference, 0.9; 95% CI, 0.1 to 1.7; resting pain score: mean difference, 0.5; 95% CI, 0.0 to 1.0). However, the continuous suprascapular nerve block group had a significantly lower incidence of hemidiaphragmatic paresis at postoperative 24 h than the continuous superior trunk block group.

CONCLUSIONS

Continuous suprascapular nerve block provides statistically inferior analgesia compared to the continuous superior trunk block; however, the continuous suprascapular nerve block had a minimal effect on the phrenic nerve function.

EDITOR’S PERSPECTIVE

Ten years of clinical experience with cyanoacrylate glue for venous access in a 1300-bed university hospital

In the past decade, cyanoacrylate glue has been progressively introduced into the clinical practice of venous access devices used for different purposes. Glue has been used to increase device stabilisation (to reduce the risk of catheter dislodgement), to seal the exit site (to both reduce local bleeding and decrease the risk of bacterial contamination) and to close skin incisions required for the insertion of tunnelled catheters or totally implanted venous ports. For many of these purposes, the efficacy and cost-effectiveness of cyanoacrylate glue has been demonstrated, while some indications are still controversial. This article reports on 10 years of clinical experience with cyanoacrylate glue in a large university hospital, and provides a narrative review of the scientific evidence on the benefits of glue in venous access that has been accumulating over the past decade.

Comparison of continuous and single interscalene block for quality of recovery score following arthroscopic rotator cuff repair

BACKGROUND

Continuous interscalene brachial plexus block (CISB) is well known to reduce postoperative pain and to improve patient satisfaction. However, the effect of CISB on the quality of postoperative recovery is unknown. We Compared the quality of recovery from arthroscopic rotator cuff repair in patients who received CISB or single interscalene brachial plexus block (SISB).

METHODS

This prospective non-randomized controlled trial with propensity score matching enrolled 134 patients undergoing arthroscopic surgery for rotator cuff repair. Each patient received an interscalene block before surgery. One group had a catheter insertion 30 min after the end of surgery and started patient-controlled regional analgesia (PCRA, n = 49). The other group received intravenous patient-controlled analgesia (IV-PCA, n = 85). The primary outcome was the quality of recovery (QoR-40) score. Also, postoperative analgesia, sleep quality, and postoperative complications were evaluated.

RESULTS

The two groups had similar QoR-40 score on postoperative day-1 (POD1), but the PCRA group had a significantly greater QoR-40 score on POD2 (156.0, IQR: 143.0, 169.0 vs. 171.0, IQR: 159.0, 178.0; p < 0.001). The IV-PCA group received more analgesics during the 2 days after surgery, especially during night-time, and had a higher prevalence of sleep disturbances. The time to first additional analgesics request was significantly longer in PCRA group (14 hours, 95% CI: 13-16 vs. 44 hours, 95% CI: 28-not applicable). The incidence of postoperative nausea and vomiting significantly lower in the PCRA group (16.3% vs 46.9%, p = 0.002).

CONCLUSION

CISB showed a higher quality of recovery score than SISB with IV-PCA in arthroscopic rotator cuff repair, probably related to the effective analgesia, improved sleep quality, and reduced opioid-related complications.

Decreasing leakage during continuous femoral nerve catheter fixation using 2-octyl cyanoacrylate glue (Dermabond®): a randomized controlled trial

BACKGROUND

Continuous peripheral nerve catheters (CPNCs) have been used for postoperative pain relief. A common problem encountered with CPNCs is pericatheter leakage, which can lead to dressing adhesive failure. Frequent dressing changes increase the risk of catheter dislodgement and infections. Adhesive glue is effective in securing the peripheral nerve catheter and decreasing leakage around the catheter insertion site. This study aimed to evaluate the incidence of pericatheter leakage with fixation using 2-octyl cyanoacrylate glue (Dermabond®) as compared to sterile strips.

METHODS

Thirty patients undergoing unilateral total knee arthroplasty (TKA) with continuous femoral nerve catheter for postoperative analgesia were randomized into the catheter fixation with 2-octyl cyanoacrylate glue (Dermabond®) group or the sterile strip group. The primary outcome was the incidence of pericatheter leakage. Secondary outcomes included the frequent of catheter displacement, the difficulty of catheter removal, pain score and patient satisfaction.

RESULTS

The incidence of pericatheter leakage at 24 and 48 h was 0% versus 93 and 0% versus 100% in the Dermabond® and sterile strip groups, respectively (P < 0.001). The incidence of displacement at 24 and 48 h was 6.7% versus 93.3 and 6.7% versus 100% in the Dermabond® and sterile strip, respectively (P < 0.001). There was no difference in numeric rating scale, difficulty of catheter removal, or satisfaction scores between groups.

CONCLUSIONS

Catheter fixation with 2-octyl cyanoacrylate glue (Dermabond®) decreased the incidence of pericatheter leakage, as well as catheter displacement, over 48 h as compared to sterile strip fixation.

TRIAL REGISTRATION

This trial was registered on Thai clinical trial registry: TCTR20200228002 , registered 24 February 2020- Retrospectively registered.

Effectiveness of securing central venous catheters with topical tissue adhesive in patients undergoing cardiac surgery: a randomized controlled pilot study

BACKGROUND

Central venous catheters (CVCs) play an important role during cardiac surgery. Topical tissue adhesives form a thin film of coating that becomes bound to keratin in the epidermis. The advantage of this "super glue" lies in its antimicrobial activity. This study aimed to evaluate fixation of CVCs with topical tissue adhesive in patients (prone to bleed) undergoing cardiac surgery regarding its ability to reduce the incidence of pericatheter leakage.

METHODS

This randomized controlled trial included 150 patients > 15 years of age who were (1) scheduled to undergo elective cardiac surgery, (2) required CVC insertion at the internal jugular vein, and (3) scheduled for transfer postoperatively to the cardiac intensive care unit. We randomly assigned patients to a topical tissue adhesive group (TA) or a standard control group (SC). The primary outcome was a change in dressing immediately postoperatively due to pericatheter blood oozing. Secondary outcomes were the number of dressings, total dressings per catheter day, and composite outcome of catheter failure within 3 days. Both intention-to-treat and per-protocol analyses were performed. Seven patients violated the protocol (three TA patients and four SC patients).

RESULTS

Regarding the primary outcome, the SC group exhibited a significantly increased incidence of dressing change immediately postoperatively due to pericatheter leakage compared with the TA group in both the intention-to-treat analysis (5.33% vs 18.67%, RR 0.25 [95% CI 0.08 to 0.79], P = 0.012) and the per-protocol analysis (5.56% vs 16.90%, RR 0.289 [95% CI 0.09 to 0.95], P = 0.031). No significant differences were noted in the number of dressings, total dressings per catheter day, or composite outcome of catheter failure within 3 days between the two groups. Multiple logistic regression analysis was performed to adjust baseline characteristics that were different in the per-protocol analysis. The results showed that the risk ratio of immediate postoperative dressing change in TA patients was 0.25 compared to the SC group ([95% CI 0.07 to 0.87], P = 0.029) in the per-protocol analysis.

CONCLUSION

The use of a topical tissue adhesive can reduce the incidence of immediate postoperative pericatheter blood oozing.

TRIAL REGISTRATION

TCTR20180608004 , retrospectively registered on June 06, 2018.

Incidence and effects of postoperative migration of interscalene catheter tips placed using ultrasound-guided anterior and posterior approaches

BACKGROUND

Continuous interscalene brachial plexus block (CISB) provides analgesia after shoulder surgery. However, even a catheter securely fixed at the insertion site may be susceptible to migration, precluding the block from working consistently. We examined to see if catheter tip migration would occur with no catheter-at-skin change after anterior and posterior approaches to CISB in patients undergoing shoulder surgery, and compared the incidence rate and pain scores between approaches and between catheters with and without tip migration, respectively.

METHODS

Patients were randomly assigned to receive CISB using either anterior or posterior approach. Catheter tip was observed using a cross-sectional view. The rates of catheter tip migration with no catheter-at-skin change at 24 h after the two approaches were calculated and compared, and pain scores were compared between catheters with and without tip migration after each approach.

RESULTS

Fifty-four patients were analyzed. Catheter tip migration occurred at 24 h at a similar rate after both approaches (anterior approach 40.7% versus posterior approach 33.3%, p = 0.78). Worst pain score was significantly higher for 24 h in patients whose catheter tip had migrated as compared with those whose catheter had not migrated after anterior (median [IQR] 53 [42-73] versus 18 [0-50], p = 0.003) and posterior approaches (median [IQR] 63 [57-81] versus 29 [3-47], p < 0.0001).

CONCLUSION

In patients undergoing shoulder surgery, an interscalene catheter tip can migrate after both anterior and posterior approaches at a similar rate, even if the catheter insertion length is not changed. The tip migration does decrease the analgesic effect of CISB.

Effects of local dexmedetomidine administration on the neurotoxicity of ropivacaine for sciatic nerve block in rats

Dexmedetomidine, used as an adjuvant to local anesthetics (LAs), may prolong the duration of peripheral nerve block. However, the effect of dexmedetomidine on the neurotoxicity of LAs is not completely understood. The present study was designed to investigate the efficacy of two doses of dexmedetomidine as an adjuvant to ropivacaine and its protective effect against the neurotoxicity of LAs. Paw withdrawal thermal latency testing was used to detect the sensory blockade. Extensor postural thrust testing was used to detect the motor blockade. The results demonstrated that the addition of dexmedetomidine to ropivacaine prolonged the duration of sensory and motor blockade in a dose-dependent manner compared with ropivacaine alone. TUNEL staining was performed to examine apoptosis. Western blotting was used to detect the Cleaved caspase-3 expression levels. The results showed that the addition of dexmedetomidine to ropivacaine decreased the rate of apoptosis and caspase-3 expression levels in a dose-dependent manner compared with ropivacaine alone (P<0.05). In addition, the rate of apoptosis and caspase-3 expression levels were significantly lower in the high-dose dexmedetomidine group compared with the low-dose dexmedetomidine group (P<0.05). The results suggested that the addition of dexmedetomidine to ropivacaine for sciatic nerve block in rats not only prolonged the duration of sensory and motor block of the sciatic nerve, but also markedly alleviated ropivacaine-induced neurotoxicity by decreasing caspase-3-dependent sciatic nerve cell apoptosis. Furthermore, the present study indicated that dexmedetomidine was more effective at a dose of 20 µg/kg compared with 6 µg/kg.

Suture-method versus Through-the-needle Catheters for Continuous Popliteal-sciatic Nerve Blocks

Background

The basic perineural catheter design has changed minimally since inception, with the catheter introduced through or over a straight needle. The U.S. Food and Drug Administration recently cleared a novel perineural catheter design comprising a catheter attached to the back of a suture-shaped needle that is inserted, advanced along the arc of its curvature pulling the catheter past the target nerve, and then exited through the skin in a second location. The authors hypothesized that analgesia would be noninferior using the new versus traditional catheter design in the first two days after painful foot/ankle surgery with a primary outcome of average pain measured with the Numeric Rating Scale.

Methods

Subjects undergoing painful foot or ankle surgery with a continuous supraparaneural popliteal-sciatic nerve block 5 cm proximal to the bifurcation were randomized to either a suture-type or through-the-needle catheter and subsequent 3-day 0.2% ropivacaine infusion (basal 6 ml/h, bolus 4 ml, lockout 30 min). Subjects received daily follow-up for the first four days after surgery, including assessment for evidence of malfunction or dislodgement of the catheters.

Results

During the first two postoperative days the mean ± SD average pain scores were lower in subjects with the suture-catheter (n = 35) compared with the through-the-needle (n = 35) group (2.7 ± 2.4 vs. 3.4 ± 2.4) and found to be statistically noninferior (95% CI, −1.9 to 0.6; P &lt; 0.001). No suture-style catheter was completely dislodged (0%), whereas the tips of three (9%) traditional catheters were found outside of the skin before purposeful removal on postoperative day 3 (P = 0.239).

Conclusions

Suture-type perineural catheters provided noninferior analgesia compared with traditional catheters for continuous popliteal-sciatic blocks after painful foot and ankle surgery. The new catheter design appears to be a viable alternative to traditional designs used for the past seven decades.

Editor’s Perspective

What We Already Know about This Topic

What This Article Tells Us That Is New

Suture Catheter for Rescue Perineural Catheter Placement When Unable to Position a Conventional Through-the-Needle Catheter: A Case Report

The main purported benefit of suture-style catheters is the ability to secure the catheter at 2 sites, thereby decreasing the likelihood of catheter dislodgement. An additional benefit is the ability to precisely control the placement of the orifice to infuse local anesthetic. Here we present the case of a patient undergoing open ankle surgery for whom placement of a conventional through-the-needle popliteal sciatic perineural catheter for postoperative analgesia was attempted. Despite multiple attempts, the catheter repeatedly advanced beyond the nerve. Placement of a suture catheter was then attempted, and the catheter was successfully placed on the first attempt.

Continuous Transversus Abdominis Plane Block for Primary Open Inguinal Hernia Repair: A Randomized, Double-Blind, Placebo-Controlled Trial

OBJECTIVE

Patients undergoing open inguinal hernia repair may experience moderate to severe postoperative pain. We assessed opioid consumption in subjects who received a continuous transversus abdominis plane block in addition to standard multimodal analgesia.

DESIGN

Randomized, double-blind, placebo-controlled.

SETTING

Tertiary academic medical center.

SUBJECTS

Adult patients undergoing open inguinal hernia repair at Virginia Mason Medical Center. A total of 90 patients were enrolled.

METHODS

Subjects presenting for surgery were randomized to receive either a continuous transversus abdominis plane block or a subcutaneous sham block. The primary outcome was opioid consumption within the first 48 hours after surgery. Secondary outcomes included pain scores, activities assessment scores, and opioid-related adverse events. Multimodal analgesia utilized in both groups included acetaminophen, nonsteroidal anti-inflammatory drugs, and surgical local anesthetic infiltration.

RESULTS

Eighty-two subjects, 42 from the block group and 40 from the sham group, completed the study, per protocol. The intention-to-treat analysis demonstrated no difference in 48-hour postoperative oxycodone equivalent consumption between the block and sham groups (27.8 mg ± 26.8 vs 32 mg ± 39.2, difference -4.4 mg, P = 0.55). There was a statistically significant reduction in pain scores at 24 hours in the block group. There were no other differences in secondary outcomes.

CONCLUSIONS

Continuous transversus abdominis plane blocks provide modest improvements in pain after open inguinal hernia repair but fail to significantly reduce opioid consumption or improve functional activity levels in the setting of multimodal analgesia use.

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.

Postoperative epidural analgesia versus systemic analgesia for thoraco-lumbar spine surgery in children

BACKGROUND

Spine surgery may be associated with severe acute postoperative pain. Compared with systemic analgesia alone, epidural analgesia may offer better pain control. However, epidural analgesia has sometimes been associated with rare but serious complications. Therefore, it is critical to quantify the real benefits of epidural analgesia over other modes of pain treatment.

OBJECTIVES

To assess the effectiveness and safety of epidural analgesia compared with systemic analgesia for acute postoperative pain control after thoraco-lumbar spine surgery in children.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase and Cumulative Index to Nursing and Allied Health Literature on 14 November 2018, together with the references lists of related reviews and retained trials, and two trials registers.

SELECTION CRITERIA

We included all randomized controlled trials performed in children undergoing any type of thoraco-lumbar spine surgery comparing epidural analgesia with systemic analgesia for postoperative pain. We applied no language or publication status restriction.

DATA COLLECTION AND ANALYSIS

We assessed risk of bias of included trials using the Cochrane tool. We analysed data using random-effects models. We rated the quality of the evidence according to the GRADE scale.

MAIN RESULTS

We included 11 trials (559 participants) in the review, and seven trials (249 participants) in the analysis: 140 participants received epidural analgesia and 109 received systemic analgesia.Most studies included adolescents. Three trials included in the analysis contained some participants older than 18 years. The types of surgery were posterior spinal fusion for idiopathic scoliosis (nine trials), anterior correction for idiopathic scoliosis (one trial), or selective dorsal rhizotomy in children with cerebral palsy (one trial). The mean numbers of vertebrae operated on were between nine and 14.5 and the mean numbers of spinal levels were between three and four and a half. The length of surgery varied between three and six and a half hours.Compared with systemic analgesia, epidural analgesia reduced pain at rest at all time points. At six to eight hours, the mean pain score on a 0 to 10 scale with systemic analgesia was 3.1 (standard deviation 0.7) and with epidural analgesia was -1.32 points (95% confidence interval (CI) -1.83 to -0.82; 4 studies, 116 participants; moderate-quality evidence). At 72 hours, the mean pain score with epidural analgesia was equivalent to a -0.8 point reduction on a 0 to 10 scale (standardized mean difference (SMD) -0.65, 95% CI -1.19 to -0.10; 5 studies, 157 participants; moderate-quality evidence).Return of gastrointestinal functionThere was no difference for nausea and vomiting between groups (risk ratio (RR) 0.87, 95% CI 0.58 to 1.30; 6 studies, 215 participants; low-quality evidence). One study found epidural analgesia with local anaesthetics may have increased the number of participants who had their first flatus within 48 hours (RR 1.63, 95% CI 1.08 to 2.47; 30 participants; very low-quality evidence). Two studies found epidural analgesia with local anaesthetics may have increased the number of participants in whom first bowel movement occurred within 48 hours (RR 11.52, 95% CI 2.36 to 56.26; 60 participants; low-quality evidence). It was uncertain whether epidural analgesia reduced the time to first bowel movement (MD 0.09 days, 95% CI -0.32 to 0.50; 1 study, 60 participants; very low-quality evidence) and time to first liquid ingestion following epidural infusion of an opioid alone or a local anaesthetic plus an opioid (mean difference (MD) -5.02 hours, 95% CI -13.15 to 3.10; 2 studies, 56 participants; very low-quality evidence). Epidural analgesia with local anaesthetics may have increased the risk of having first solid food ingestion within 48 hours (RR 7.00, 95% CI 1.91 to 25.62; 1 study, 30 participants; very low-quality evidence).Secondary outcomesIt was uncertain whether there was a difference in time to ambulate (MD 0.08 days, 95% CI -0.24 to 0.39; 1 study, 60 participants; very low-quality evidence) and hospital length of stay (MD -0.29 days, 95% CI -0.69 to 0.10; 2 studies, 89 participants; very low-quality evidence). Two studies found participants were more satisfied when treated with epidural analgesia (MD 1.62 on a scale from 0 to 10, 95% CI 1.26 to 1.97; 60 participants; very low-quality evidence). It was unclear whether there was a difference in parent satisfaction for epidural analgesia with an opioid alone (MD 0.60, 95% CI -0.81 to 2.01; 1 trial, 27 participants; very low-quality evidence).ComplicationsIt was uncertain whether there was a difference in the risk of complications such as: respiratory depression (risk difference (RD) -0.05, 95% CI -0.16 to 0.05; 4 studies, 126 participants; very low-quality evidence); wound infection (RD 0.01, 95% CI -0.05 to 0.08; 2 trials, 93 participants; very low-quality evidence); epidural abscess (RD 0, 95% CI -0.05 to 0.05; 3 trials, 120 participants; very low-quality evidence); and neurological complications (RD 0.01, 95% CI -0.04 to 0.06; 4 studies, 151 participants; very low-quality evidence).

AUTHORS' CONCLUSIONS

There is moderate- and low-quality evidence that there may be a small additional reduction in pain up to 72 hours after surgery with epidural analgesia compared with systemic analgesia. Two very small studies showed epidural analgesia with local anaesthetic alone may accelerate the return of gastrointestinal function. The safety of this technique in children undergoing thoraco-lumbar surgery is uncertain due to the very low-quality of the evidence. The study in 'Studies awaiting classification' may alter the conclusions of the review once assessed.

Optimizing the securement of epidural catheters: an in vitro trial

Introduction

Epidural anesthesia is frequently used to provide postoperative analgesia following major surgical procedures. Secure fixation of the epidural catheter is necessary to prevent premature dislodgment and loss of epidural analgesia. Using an in vitro model, the current prospective study evaluates different types of dressings for securement of an epidural catheter by quantifying the force in Newtons (N) required for dislodgment using a digital force gage.

Methods

Four methods of epidural catheter securement were used on a simulator mannequin: 1) Suresite^® Window Clear Dressing, 2) Op-Site Post-Op^® Visible Dressing, 3) Steri-Strips^® and Suresite Window Clear Dressing, and 4) Steri-Strips and Op-Site Post-Op Visible Dressing. Each method of securement was assessed 10 times to calculate the mean force required to dislodge the catheter. Mean force of dislodgment for each method was compared using parametric tests.

Results

The force (mean ± SD) required for catheter dislodgment for the four methods was 14.0±2.9, 2, 10.7±1.5, 8.6±2.3, and 9.6±2.2 N, respectively. The pairwise difference showed that the Suresite Window Clear Dressing was the best securement method when compared with other methods.

Conclusion

Our study demonstrates the advantage of the Suresite Window Clear Dressing in securing the epidural catheter. Future clinical trials are needed to validate these findings.

Comparison of Anterior Suprascapular, Supraclavicular, and Interscalene Nerve Block Approaches for Major Outpatient Arthroscopic Shoulder Surgery

Background

The interscalene nerve block provides analgesia for shoulder surgery, but is associated with diaphragm paralysis. One solution may be performing brachial plexus blocks more distally. This noninferiority study evaluated analgesia for blocks at the supraclavicular and anterior suprascapular levels, comparing them individually to the interscalene approach.

Methods

One hundred-eighty-nine subjects undergoing arthroscopic shoulder surgery were recruited to this double-blind trial and randomized to interscalene, supraclavicular, or anterior suprascapular block using 15 ml, 0.5% ropivacaine. The primary outcome was numeric rating scale pain scores analyzed using noninferiority testing. The predefined noninferiority margin was one point on the 11-point pain scale. Secondary outcomes included opioid consumption and pulmonary assessments.

Results

All subjects completed the study through the primary outcome analysis. Mean pain after surgery was: interscalene = 1.9 (95% CI, 1.3 to 2.5), supraclavicular = 2.3 (1.7 to 2.9), suprascapular = 2.0 (1.4 to 2.6). The primary outcome, mean pain score difference of supraclavicular–interscalene was 0.4 (–0.4 to 1.2; P = 0.088 for noninferiority) and of suprascapular–interscalene was 0.1 (–0.7 to 0.9; P = 0.012 for noninferiority). Secondary outcomes showed similar opioid consumption with better preservation of vital capacity in the anterior suprascapular group (90% baseline [P &lt; 0.001]) and the supraclavicular group (76% [P = 0.002]) when compared to the interscalene group (67%).

Conclusions

The anterior suprascapular block, but not the supraclavicular, provides noninferior analgesia compared to the interscalene approach for major arthroscopic shoulder surgery. Pulmonary function is best preserved with the anterior suprascapular nerve block.

Optimal dose of perineural dexmedetomidine for interscalene brachial plexus block to control postoperative pain in patients undergoing arthroscopic shoulder surgery: A prospective, double-blind, randomized controlled study

BACKGROUND

Adjuvant perineural dexmedetomidine can be used to prolong the analgesic effect of interscalene brachial plexus block (ISB). We investigated the optimal dose of dexmedetomidine in ISB for postoperative analgesia in patients undergoing arthroscopic shoulder surgery.

METHODS

One hundred patients scheduled for elective shoulder arthroscopic surgery were enrolled in this randomized, double-blind study. Ultrasound-guided ISB was performed before general anesthesia using 22 mL of ropivacaine 0.5% combined with 1, 1.5, or 2 μg/kg of dexmedetomidine (group D1, D2, and D3, respectively) or with normal saline as a control (group R, n = 25 per group). The primary outcome was the duration of analgesia (DOA), numeric pain rating scale (NRS), and consumption of additional analgesics during 36 h after ISB. Secondary outcome included durations of motor and sensory block (DOM and DOS), hemodynamic variables and sedation and dyspnea scores.

RESULTS

Ninety-seven patients completed the study. The DOS, DOM, and DOA were significantly longer in the dexmedetomidine groups than in group R. The DOA was significantly longer in group D3 than in groups D1 (P = .026) and D2 (P = .039). The DOA was 808.13 ± 179.97, 1032.60 ± 288.14, 1042.04 ± 188.13, and 1223.96 ± 238.06 min in groups R, D1, D2, and D3, respectively. The NRS score was significantly higher in group R than in the dexmedetomidine groups 12 h after ISB (P < .001) and significantly lower in group D3 than in the other groups 18 h after ISB (P = .02). The incidence of hypotension was higher in groups D2 and D3 than in group R during surgery (P = .008 and P = .011, respectively). There were no significant differences in consumption of rescue analgesics, sedation, and dyspnea scores between the study groups.

CONCLUSION

Perineural dexmedetomidine 2 μg/kg could be the optimal dose in ISB for arthroscopic shoulder surgery in that it provides an adequate DOA. However, this dose was associated with increased risk of hypotension.