A systematic review of ultrasound-guided methods for brachial plexus blockade

Comparison of the lateral sagittal and costoclavicular approaches for ultrasound-guided infraclavicular block in pediatric patients: a prospective randomized study

BACKGROUND

The lateral sagittal brachial plexus block is the most used method for pediatric upper extremity surgery, whereas the applications of costoclavicular brachial plexus block are limited. This study aimed to compare the lateral sagittal and costoclavicular approaches for the ultrasound-guided infraclavicular block in pediatric patients.

METHODS

Sixty pediatric patients aged 5...15 years undergoing hand or forearm surgery were randomly assigned to two groups. Group LS (n.ß=.ß30) received ultrasound-guided lateral sagittal block, and Group CC (n.ß=.ß30) received ultrasound-guided costoclavicular block. The block performing time, needling time, imaging time, needle visibility, number of passes, sensorial/motor block time, and postoperative pain scores were evaluated.

RESULTS

The needling time (82.90.ß...ß28.17 seconds vs. 64.77.ß...ß28.11 seconds respectively, p.ß=.ß0.004) and total block performance time (109.53 .. 29.75 seconds vs. 89.70 .. 29.98 seconds respectively, p.ß=.ß0.005) were significantly longer in Group LS than in Group CC. However, there was no significant difference between the groups in imaging time, needle visibility, number of passes, sensorial/motor block time, and postoperative pain scores (p > 0.05).

CONCLUSIONS

Costoclavicular and lateral sagittal brachial plexus blocks resulted in similar anesthetics effects. Moreover, the costoclavicular method can be a better alternative to lateral sagittal as it has a shorter block performance time.

Simulation-Based Analysis of Trial Design in Regional Anesthesia

Background

In regional anesthesia, the efficacy of novel blocks is typically evaluated using randomized controlled trials (RCTs), the findings of which are aggregated in systematic reviews and meta-analyses. Systematic review authors frequently point out the small sample size of RCTs as limiting conclusions from this literature. We sought to determine via statistical simulation if small sample size could be an expected property of RCTs focusing on novel blocks with typical effect sizes.

Methods

We simulated the conduct of a series of RCTs comparing a novel block versus placebo on a single continuous outcome measure. Simulation analysis inputs were obtained from a systematic bibliographic search of meta-analyses. Primary outcomes were the predicted number of large trials (empirically defined as N ≥ 256) and total patient enrollment.

Results

Simulation analysis predicted that a novel block would be tested in 16 RCTs enrolling a median of 970 patients (interquartile range (IQR) across 1000 simulations: 806, 1269), with no large trials. Among possible modifications to trial design, decreasing the statistical significance threshold from p < 0.05 to p < 0.005 was most effective at increasing the total number of patients represented in the final meta-analysis, but was associated with early termination of the trial sequence due to futility in block vs. block comparisons.

Conclusion

Small sample size of regional anesthesia RCTs comparing novel block to placebo is a rational outcome of trial design. Feasibly large trials are unlikely to change conclusions regarding block vs. placebo comparisons.

Regional Anesthesia in Upper-Limb Surgery

BACKGROUND

Local and regional anesthesia is associated with numerous clinical and institutional advantages relative to general anesthesia. As anesthesiologists and surgeons increasingly integrate local and regional anesthesia into their clinical practice, an understanding of the principles, evolution, and trends underpinning modern anesthetic techniques continues to be relevant.

METHODS

A review of the literature in databases Medline, PubMed, and EMBASE identified recent developments, ongoing trends, and historical milestones in upper-limb regional anesthesia.

RESULTS

Advances in regional anesthetic techniques in the last century have led to reduced postoperative pain, improved safety, and improved outcomes in upper-limb surgery. The development of ultrasound-guided techniques, as well as pharmacological advances in local anesthetic drugs and adjuncts, has further advanced the role of regional anesthesia. Wide-awake local anesthesia with no tourniquet has allowed certain procedures to be performed on select patients in outpatient and low-resource settings.

CONCLUSIONS

This review provides an overview of local and regional anesthesia in the upper-limb from its historical origins to its contemporary applications in upper-limb surgery, particularly during the COVID-19 pandemic.

Thermal Imaging to Predict Failed Supraclavicular Brachial Plexus Block: A Prospective Observational Study

Background

Successful brachial plexus blockade produces sympathetic blockade, resulting in increased skin temperature in the blocked segments. This study aimed to evaluate the accuracy of infrared thermography in predicting failed segmental supraclavicular brachial plexus block.

Methods

This prospective observational study included adult patients undergoing upper-limb surgery under supraclavicular brachial plexus block. Sensation was evaluated at the dermatomal distribution of the ulnar, median, and radial nerves. Block failure was defined as absence of complete sensory loss 30 min after block completion. Skin temperature was evaluated by infrared thermography at the dermatomal supply of the ulnar, median, and radial nerves at baseline, 5, 10, 15, and 20 min after block completion. The temperature change from the baseline measurement was calculated for each time point. Outcomes were the ability of temperature change at each site to predict failed block of the corresponding nerve using area under receiver-operating characteristic curve (AUC) analysis.

Results

Eighty patients were available for the final analysis. The AUC (95% confidence interval [CI]) for the ability of temperature change at 5 min to predict failed ulnar, median, and radial nerve block was 0.79 (0.68-0.87), 0.77 (0.67-0.86), and 0.79 (0.69-0.88). The AUC (95% CI) increased progressively and reached its maximum values at 15 min (ulnar nerve 0.98 [0.92-1.00], median nerve 0.97 [0.90-0.99], radial nerve 0.96 [0.89-0.99]) with negative predictive value of 100%.

Conclusion

Infrared thermography of different skin segments provides an accurate tool for predicting failed supraclavicular brachial plexus block. Increased skin temperature at each segment can exclude block failure in the corresponding nerve with 100% accuracy.

Impact of an extrafascial versus intrafascial injection for supraclavicular brachial plexus block on respiratory function: a randomized, controlled, double-blind trial

Introduction

Hemidiaphragmatic paresis after ultrasound-guided supraclavicular brachial plexus block is reported to occur in up to 67% of patients. We tested the hypothesis that an injection outside the brachial plexus sheath reduces the incidence of hemidiaphragmatic paresis compared with an intrafascial injection while providing similar analgesia.

Methods

Fifty American Society of Anesthesiologists I–III patients scheduled for elective upper limb surgery received a supraclavicular brachial plexus block using 30 mL of 1:1 mixture of mepivacaine 1% and ropivacaine 0.5%. The block procedures were randomized to position the needle tip either within the brachial plexus after piercing the sheath (intrafascial injection) or outside the brachial plexus sheath (extrafascial injection). The primary outcome was the incidence of hemidiaphragmatic paresis 30 min after the injection, measured by M-mode ultrasonography. Additional outcomes included time to surgery readiness, and resting and dynamic pain scores at 24 hours postoperatively (Numeric Rating Scale, 0–10).

Results

The incidence of hemidiaphragmatic paresis 30 min after the injection was 9% (95% CI 1% to 29%) and 0% (95% CI 0% to 15%) in the intrafascial and extrafascial groups respectively (p=0.14). Extrafascial injection was associated with a longer time to surgery readiness (intrafascial: 18 min (95% CI: 16 to 21 min); extrafascial: 37 min (95% CI: 31 to 42 min); p<0.001). At 24 hours, resting and dynamic pain scores were similar between groups.

Discussion

Ultrasound-guided supraclavicular brachial plexus block with an extrafascial injection does not reduce the incidence of hemidiaphragmatic paresis although it provides similar analgesia, when compared with an intrafascial injection. The longer time to surgery readiness is less compatible with contemporary operating theater efficiency requirements.

Trial registration number

NCT03957772.

Ultrasound-Guided Retroclavicular Approach to the Infraclavicular Region (RAPTIR) Brachial Plexus Block for Anterior Shoulder Reduction

BACKGROUND

Shoulder dislocations are a common presenting injury to the emergency department (ED), with anterior dislocations comprising the majority of these cases. Some patients may tolerate gentle manipulation and reduction, but many require analgesia of some type. Oral or parenteral pain medication is often used alone or in combination with procedural sedation if gentle manipulation fails to achieve reduction. Recently, this treatment algorithm has grown to include regional anesthesia as a mode of analgesia for reduction of shoulder dislocations in the form of brachial plexus blocks. It has been well described that the interscalene and supraclavicular approach to the brachial plexus can be used to assist in reduction of anterior shoulder dislocations; however, there has yet to be any published literature regarding the use of ultrasound-guided retroclavicular approach to the infraclavicular region (RAPTIR) brachial plexus blocks for shoulder reduction.

CASE REPORT

We describe three patients who presented to the ED with anterior shoulder dislocations. The RAPTIR block was performed, provided effective analgesia, and facilitated successful shoulder reduction in all three patients.Why Should an Emergency Physician Be Aware of This? The RAPTIR nerve block is a safe and effective option for analgesia in the patient with an anterior shoulder dislocation. It may have advantages over other brachial nerve blocks and avoids the risks and disadvantages of procedural sedation and opioids.

The EFSUMB Guidelines and Recommendations for Musculoskeletal Ultrasound - Part II: Joint Pathologies, Pediatric Applications, and Guided Procedures

The second part of the Guidelines and Recommendations for Musculoskeletal Ultrasound (MSUS), produced under the auspices of EFSUMB, following the same methodology as for Part 1, provides information and recommendations on the use of this imaging modality for joint pathology, pediatric applications, and musculoskeletal ultrasound-guided procedures. Clinical application, practical points, limitations, and artifacts are described and discussed for every joint or procedure. The document is intended to guide clinical users in their daily practice.

Regional haemodynamic variables and perfusion index in the evaluation of sciatic nerve block: a prospective observational trial

OBJECTIVE

We determined whether regional haemodynamics and perfusion index (PI) could be reliable indicators of a successful sciatic nerve block (SNB).

DESIGN

Prospective observational trial.

SETTING

A tertiary teaching hospital in China from April 2020 to August 2020.

PARTICIPANTS

We assessed 79 patients for eligibility to participate in this study. Nine patients were excluded for not meeting our inclusion criteria, and three patients were excluded due to missing measurements at all time points.

INTERVENTIONS

The patients underwent SNB. Pulsed-wave Doppler and PI measurements were performed.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome measure was the diagnostic power of regional haemodynamic change and PI to predict successful SNB. The secondary outcome measure was the effect of SNB on the regional haemodynamics and PI in the lower extremity.

RESULTS

We assessed 79 patients in this study and 67 patients available for the final analysis. The SNB was successful in 59 patients and failed in eight patients. There were no significant differences in demographic characteristics between the patients with successful and failed SNB. Starting from 10 min after SNB, the peak systolic velocity (PSV), end-diastolic velocity, time-averaged maximum velocity and time-averaged mean velocity of the anterior tibial artery and posterior tibial artery of patients in the successful SNB group were significantly higher than those in the failed SNB group (p<0.05). The PSV percentage increase at 10 min after SNB has great potential to predict the block success. The area under the receiver operating characteristic curve (AUC) values were 0.893 (95% CI 0.7809 to 1.000) and 0.880 (95% CI 0.7901 to 0.9699). The corresponding cut-off values were 19.22 and 35.88, respectively. The PI increased during 5-45 min intervals in patients with successful SNB. The AUC for the PI percentage increases at 10 min after SNB was 0.853 (95% CI 0.7035 to 1.000), with a cut-off value of 93.09.

CONCLUSION

The regional haemodynamic variables, PSV and PI in particular, can be used as alternative indicators for clinicians to evaluate the success of SNB objectively and early.

TRIAL REGISTRATION NUMBER

ChiCTR2000030772.

Pain management during a bromelain-based selective enzymatic debridement in paediatric and adult burn patients

BACKGROUND

Pain associated with surgical or enzymatic burn wound debridement prevents many burn centres from working outside an operating theatre, creating a burden. Alternatives for general anaesthesia to manage pain in burn patients treated with enzymatic debridements, such as regional anaesthesia, have not been studied in detail. This study explores the different possibilities for pain management during a bedside NexoBrid™ procedure.

MATERIAL AND METHODS

We performed a single-centre retrospective study that included 82 paediatric, adolescent, and adult patients with deep dermal and full-thickness burns treated bedside with NexoBrid™ under regional or general anaesthesia. Outcome measures were pain during the NexoBrid™ procedure, the safety of the anaesthesia and the NexoBrid™ procedure, logistics of the bedside NexoBrid™ procedure, and time to wound closure.

RESULTS

Forty-three patients in the adult group (43/67, 64%) only presented with burn wounds on one upper or the one or two lower extremities. In 29 of them (29/43, 67%), a NexoBrid™ procedure was performed under regional anaesthesia, which resulted in low pain levels without any adverse events. All seven patients in the paediatric group, where only one upper or one or two lower limbs were involved (7/15, 47%), underwent a NexoBrid™ procedure performed under regional anaesthesia where no adverse events were reported. In these children, the use of regional anaesthesia was associated with a significant decrease in time to wound closure (average treatment effect on the treated = -22.5 days, p = 0.021).

CONCLUSION

This study highlights that regional anaesthesia administered at the bedside should be the method of choice for pain management during NexoBrid™ procedures because often, it can be adequately and safely performed in all age groups. This approach will reduce the burden on operating theatres. A flow chart has been developed to guide pain management during a NexoBrid™ procedure.

Determination of the minimum effective volume of bupivacaine for ultrasound-guided infraclavicular brachial plexus block: a prospective, observer-blind, controlled study

Background

We aimed to determine the minimum effective volume (MEV) of 0.5% bupivacaine for infraclavicular brachial plexus block.

Methods

We assigned patients to volume groups consisting of five consecutive patients. Local anesthetic was sequentially reduced from a starting dose of 30 mL by 2 mL to form the volume groups. Five patients were included in each volume group, and at least 3 of 5 injections had to be successful to consider the volume of the anesthetic as sufficient. The study ended when the anesthetic volume of a group was determined to be unsuccessful (two or fewer successful blocks). Block was successful if the patient reported a sensorial block score of 7 or more on an 8-point scale and sensorial and motor block's total score of 14 on a 16-point scale.

Results

The MEV of 0.5% bupivacaine for infraclavicular brachial plexus block was 14 mL. A successful block was achieved in all patients (n = 45) in 9 volume groups, which received 30 mL down to 14 mL. Three blocks were unsuccessful in the 12-mL group. Time to onset of block and time to first postoperative anesthetic administration was 15 (10–15) min and more than 24 h in the 30-mL bupivacaine group, but 40 (30–45) min and 14 (10–24) h were determined for the 14-mL group, respectively.

Conclusions

The MEV of 0.5% bupivacaine for ultrasound-guided infraclavicular brachial plexus block was 14 mL. However, this low-dose block has a long onset time of 40 (30–45) min on average.

A preliminary animal study on the prediction of nerve block success using ultrasonographic parameters

This study aimed to evaluate the diagnostic value of ultrasonographic parameters as an indicator for predicting regional nerve block success. Ultrasound-guided sciatic nerve block was performed in seven dogs using either 2% mepivacaine (nerve-block group) or saline (sham-block group). The cross-sectional area (CSA), nerve blood flow (NBF), and shear wave velocity (SWV) of the sciatic nerve (SWVN), SWV of the biceps femoris muscle (SWVM), and their ratio (SWVNMR) were measured at 0, 30, 60, and 90 min after the nerve block as well as the change rate of each parameter from the baseline. A receiver operating characteristic (ROC) curve analysis was performed to determine the diagnostic value of each parameter in the prediction of nerve block success. No significant changes were observed in the CSA or NBF in association with the nerve block. The SWVN and SWVNMR in the nerve-block group were significantly higher than those in the sham-block group at 90 min and at 30, 60, and 90 min, respectively (p < 0.05). The change rates of SWVN and SWVNMR in the nerve-block group were significantly higher than those in the sham-block group at all time points (p < 0.05). The ROC curve analysis showed that SWVN had a moderate diagnostic accuracy (area under the curve [AUC], 0.779), whereas SWVNMR and change rates of SWVN and SWVNMR had a high diagnostic accuracy (AUC, 0.947, 0.998, and 1.000, respectively). Ultrasonographic evaluation of the SWVN and SWVNMR could be used as indicators for predicting nerve block success.

Complications associated with three brachial plexus blocking techniques: Systematic review and meta-analysis

BACKGROUND

Brachial plexus block has become one of the most widely-used anaesthetic techniques in the world for upper limb anaesthesia. There are three different brachial blocks techniques: supraclavicular, infraclavicular and axillary block. However, its execution is not exempt from possible clinical complications, and it is not clear which of these is associated with a lower complication rate and greater anaesthetic success.

MATERIALS AND METHODS

Systematic review and meta-analysis following the Cochrane and Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines to identify controlled clinical trials reporting the three techniques. The main outcome was the incidence of anaesthetic complications, and the secondary ones were an anaesthetic success, time of performance and anaesthetic latency.

RESULTS

25 controlled clinical trials, with 2012 patient, were included. The methodological quality of the included studies is moderate to high. For the main outcome, the main complication reported was a vascular puncture, followed by transient neurological injury, symptomatic diaphragmatic paralysis and pneumothorax. No differences were found in complications associated with the three anaesthetic techniques. Additionally, no differences were found regarding anaesthetic success.

CONCLUSIONS

Anesthetic complications associated with the three brachial block techniques are low, with no medium and long-term sequelae; however, none of the three techniques seems to be superior among them to reduce these complications. All three techniques are highly successful when performed using ultrasound imaging.

Sedoanalgesia Versus Infraclavicular Block for Closed Reduction of Pediatric Forearm Fracture in Emergency Department: Prospective Randomized Study

OBJECTIVE

Procedural sedoanalgesia is commonly used in pediatric patients in the emergency department (ED) for interventional procedures, diagnosis, and treatment. However, this method causes serious systemic complications, such as respiratory and cardiac depression. To minimize these complications, ultrasound-guided regional anesthesia methods have been used in recent years. We aimed to compare the use of procedural sedoanalgesia (PSA) and infraclavicular block (ICB) in the pain management of pediatric patients who underwent closed reductions of forearm fractures.

MATERIALS AND METHODS

This prospective, randomized, clinical study included patients aged 3 to 15 years who presented to the ED with forearm fractures. The patients were divided into 2 groups: the procedural sedoanalgesia group (group PSA, n = 30) and ultrasound-guided ICB group (group ICB, n = 30). Pain scores of the patients were evaluated using the Wong-Baker FACES Scale before and during the procedure. Pain scores and parental and operator satisfaction were compared between the groups.

RESULTS

There was no statistical significance in terms of demographic data. The pain scores observed during the procedures were significantly higher in the group PSA than in the group ICB (3.07 ± 1.55 vs 0.47 ± 0.86, respectively; P < 0.001). The parental and operator satisfaction of the ICB group was significantly higher than that of the PSA group (P < 0.001).

CONCLUSIONS

Ultrasound-guided ICB is a safe and effective method in the management of pain during closed reduction of forearm fracture in pediatric patients in EDs. It can be used safely in emergency rooms and has a high level of both parental and operator satisfaction.

An Evaluation of Complications Following Ultrasound-Guided Regional Block Anesthesia in Outpatient Hand Surgery

Background: Ultrasound-guided (USG) assistance has contributed to the acceptance of regional anesthesia as a safe and efficient alternative to traditional general anesthesia. However, limited data exist regarding the safety of supraclavicular blocks used in common hand surgery procedures. The purpose of this retrospective study was to evaluate a large sample of cases to determine the effectiveness and complication rate of supraclavicular nerve blocks and confirm the safety of its use within the ambulatory surgery center (ASC) setting. Methods: Nerve blocks for the upper extremity were performed via the supraclavicular approach using the USG technique. Records were analyzed for all patients monitored during the immediate postoperative recovery and step-down phases at the ASC and contacted by phone or evaluated within 2 weeks at their first postoperative visit. Adverse outcomes related to the regional block anesthesia were identified via phone interview or postoperative surgical visit and documented. Results: In all, 713 records were reviewed with 56% female (n = 398) and 44% male (n = 315) patients. Of the 713 cases, 4 adverse events were identified (0.6%, 95% confidence interval [%]), including 2 abnormal reactions to the nerve block and 2 incomplete blocks with inadequate pain control. Conclusions: This study is the first report to evaluate a large sample of outpatient hand procedures at a high-volume ASC. We can report no clinically significant pulmonary or neurovascular complications with the use of USG supraclavicular nerve block techniques, further supporting its establishment as a safe and efficient procedure, yielding a low complication rate.

An ultrasound-guided subparaneural approach to the sciatic nerve in the dog: a cadaver study

OBJECTIVE

To describe the gross and microscopic anatomy of the sciatic nerve paraneural sheath and to report an ultrasound (US)-guided subparaneural approach to the sciatic nerve in dogs, comparing two different volumes of injectate.

STUDY DESIGN

Prospective, randomized, anatomical study.

ANIMALS

A group of nine middle-sized adult Mongrel canine cadavers (18 limbs).

METHODS

The sciatic nerves of three pelvic limbs of two canine cadavers were identified, exposed and isolated between the greater trochanter and the popliteal fossa for gross anatomical and microscopic examination. An additional three pelvic limbs were surgically dissected on the lateral surface of the limb; the sciatic nerves were isolated, and a 26 gauge over-the-needle catheter was inserted through the paraneural sheath under direct visualization. A methylene blue solution was then slowly injected into the subparaneural compartment through the catheter under US visualization using an 8-13 MHz linear-array transducer. Subsequently, 12 pelvic limbs (six cadavers) were randomly allocated to one of two groups; using US-guided percutaneous subparaneural approach, either 0.1 or 0.05 mL kg^-1of a 1:1 solution of methylene blue and 0.5% bupivacaine was injected. The spread of the dye solution and the amount of nerve staining were macroscopically scored. The stained sciatic nerves with their sheaths were then harvested for microscopic examination.

RESULTS

The paraneural sciatic nerve sheath was easily identified distinct from the nerve trunk both macroscopically and with US visualization, and microscopically. Complete staining was achieved in five of six (83.3%) sciatic nerves in each group; no difference was found in the amount of staining between the two groups. Microscopically, no signs of sciatic nerve intraneural injection were observed.

CONCLUSIONS AND CLINICAL RELEVANCE

The US-guided subparaneural injection of 0.05 mL kg^-1 of a dye injectate resulted in satisfactory nerve staining without evidence of sciatic nerve intraneural injection.

Comparison of ultrasound-guided supraclavicular and costoclavicular brachial plexus block using a modified double-injection technique: a randomized non-inferiority trial

Ultrasound-guided costoclavicular block (CC-approach) is a recently described brachial plexus block (BPB) and an alternative approach to the supraclavicular approach (SC-approach). The relevant sonoanatomy is analogous in terms of the brachial plexus and its adjacent artery for both approaches. In the present study, we hypothesized that the two approaches will result in similar block dynamics when used the modified double-injection (MDI) technique. One hundred and twelve patients were randomly allocated to receive either a SC- or CC-approach with MDI technique. In the CC group, half the volume was injected adjacent to the medial cord of the brachial plexus, the procedure was guided by ultrasound and verified by nerve stimulator, subsequently the second half was injected close to the lateral cord. In the SC group, the MDI technique was carried out as described in our previous study. Sensory and motor blockade of all four terminal nerves were assessed with a 3-point scale. The primary outcome was the proportion of complete sensory blockade at 15 min with a predefined non-inferiority margin of −13%. The proportion of subjects at 15 min was comparable between the SC group and the CC group (91 vs 87%, absolute difference: −3%). No significant differences were found for complete motor blockade and onset times of the individual nerves within 30 min, and block-related serious adverse events (all P>0.05). We conclude that the MDI technique applied to a costoclavicular and supraclavicular block resulted in similar block dynamics. In addition, it may provide a promising alternative technique when considering the use of multipoint injection.

Advances in regional anaesthesia and acute pain management: a narrative review

Regional anaesthesia has undergone several exciting advances in the past few decades. Ultrasound-guided techniques of peripheral nerve blockade have become the gold standard thanks to the associated improvements in efficacy, ease of performance and safety. This has increased the accessibility and utilisation of regional anaesthesia in the anaesthesia community at large and is timely given the mounting evidence for its potential benefits on various patient-centred outcomes, including major morbidity, cancer recurrence and persistent postoperative pain. Ultrasound guidance has also paved the way for refinement of the technical performance of existing blocks concerning simplicity and safety, as well as the development of new regional anaesthesia techniques. In particular, the emergence of fascial plane blocks has further broadened the application of regional anaesthesia in the management of painful conditions of the thorax and abdomen. The preliminary results of investigations into these fascial plane blocks are promising but require further research to establish their true value and role in clinical care. One of the challenges that remains is how best to prolong regional anaesthesia to maximise its benefits while avoiding undue harm. There is ongoing research into optimising continuous catheter techniques and their management, intravenous and perineural pharmacological adjuncts, and sustained-release local anaesthetic molecules. Finally, there is a growing appreciation for the critical role that regional anaesthesia can play in an overall multimodal anaesthetic strategy. This is especially pertinent given the current focus on eliminating unnecessary peri-operative opioid administration.

Clinical indications for image guided interventional procedures in the musculoskeletal system: a Delphi-based consensus paper from the European Society of Musculoskeletal Radiology (ESSR)-part III, nerves of the upper limb

BACKGROUND

Image-guided interventional procedures of the nerves are commonly performed by physicians from different medical specialties, although there is a lack of clinical indications for these types of procedures. This Delphi-based consensus provided a list of indications on image-guided interventional procedures for nerves of the upper limb based on updated published evidence.

METHODS

An expert panel of 45 members of the Ultrasound and Interventional Subcommittees of the ESSR participated in this Delphi-based consensus study. After revision of the published papers on image-guided interventional procedures for nerves of the upper limb updated to September 2018, the experts drafted a list of statements according to the Oxford Centre for evidence-based medicine levels of evidence. Consensus on statements regarding clinical indications was considered as strong when more than 95% of experts agreed, and broad if more than 80% agreed.

RESULTS

Ten statements were drafted on procedures for nerves of the upper limb. Only two statements reached the highest level of evidence (ultrasound guidance is a safe and effective method for brachial plexus block; ultrasound-guided non-surgical approaches are safe and effective methods to treat carpal tunnel syndrome in the short term, but there is sparse evidence on the mid- and long-term effectiveness of these interventions). Strong consensus was obtained on 6/10 statements (60%), while 4/10 statements reached broad consensus (40%).

CONCLUSIONS

This Delphi-based consensus study reported poor evidence on image-guided interventional procedures for nerves of the upper limb. Sixty percent of statements on clinical indications provided by the expert board reached a strong consensus.

KEY POINTS

• An expert panel of the ESSR provided 10 evidence-based statements on clinical indications for image-guided interventional procedures for nerves of the upper limb • Two statements reached the highest level of evidence • Strong consensus was obtained on 6/10 statements (60%), while 4/10 statements reached broad consensus (40%).

Thermochromic nail polish as a novel indicator to predict infraclavicular brachial plexus block success: A prospective cohort study

BACKGROUND

Skin temperature measurements after peripheral nerve block can be used as an easy and objective method to help predict block success. Thermochromic nail polishes are popular cosmetic products especially among young women. The colour change of nail polish is based on a thermochromic reaction as the temperature changes.

OBJECTIVE

The aim of this study was to test the hypothesis that the success of infraclavicular brachial plexus blocks (IBPBs) can be predicted by the colour change in thermochromic nail polish, which depends on skin temperature changes.

DESIGN

A prospective cohort study.

SETTING

Training and research hospital from December 2018 to March 2019.

PATIENTS

A total of 50 patients who received IBPB for forearm, wrist or hand surgery were included.

MAIN OUTCOME MEASURES

Thermochromic nail polish was applied to the nails of both hands of all patients before the block. Reaction of the nail polish in both hands was photographed immediately after application of nail polish and at 30 min after performing the block. The digital photographs of each patient were evaluated by observers. To evaluate the validity of the colour change in nail polish in predicting a successful IBPB, sensitivity, specificity, positive and negative predictive values and positive and negative likelihood ratios were estimated.

RESULTS

The positive predictive value for colour change in thermochromic nail polish predicting a successful IBPB was 96% [95% confidence interval (CI) 90 to 98] and sensitivity was 94% (95% CI 87 to 97). Fleiss kappa value showed substantial agreement (0.76; 95% CI 0.59 to 0.93) in the assessment of interobserver agreement.

CONCLUSION

The current study demonstrates that the colour change in thermochromic nail polish is a valid and reliable indicator for the prediction of block success.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT03767868.

Retroclavicular vs supraclavicular brachial plexus block for distal upper limb surgery: a randomised, controlled, single-blinded trial

BACKGROUND

Regional anaesthesia for upper limb surgery is routinely performed with brachial plexus blocks. A retroclavicular brachial plexus block has recently been described, but has not been adequately compared with another approach. This randomised controlled single-blinded trial tested the hypothesis that the retroclavicular approach, when compared with the supraclavicular approach, would increase the success rate.

METHODS

One hundred and twenty ASA physical status 1-3 patients undergoing distal upper limb surgery were randomised to receive an ultrasound-guided retroclavicular or supraclavicular brachial plexus block with 30 mL of a 1:1 mixture of mepivacaine 1% and ropivacaine 0.5%, using a single-injection technique without needle tip repositioning. The primary outcome was block success rate 30 min after local anaesthetic injection, defined as a composite score of 14 of 16 points, inclusive of sensory and motor components. Secondary outcomes included needling time, time to first opioid request, oxycodone consumption, and pain scores (numeric rating scale, 0-10) at 24 h postoperatively.

RESULTS

Success rates were 98.3% [95% confidence interval (CI): 90.8%, 99.9%] and 98.3% [95% CI: 90.9%, 99.9%] in the supraclavicular and retroclavicular groups, respectively (P=0.99). The mean needling time was reduced in the supraclavicular group [supraclavicular: 5.0 (95% CI: 4.7, 5.4) min; retroclavicular: 6.0 (95% CI: 5.4, 6.6) min; P=0.006]. The mean time to first opioid request was similar between groups [supraclavicular: 439 (95% CI: 399, 479) min; retroclavicular: 447 (95% CI: 397, 498) min; P=0.19] as were oxycodone consumption [supraclavicular: 10.0 (95% CI: 6.5, 13.5 mg; retroclavicular: 7.9 (95% CI: 4.8, 11.0) mg; P=0.80] and pain scores at 24 h postoperatively [supraclavicular: 1.2 (95% CI: 2.1, 2.7); retroclavicular: 1.5 (95% CI: 1.6, 2.4); P=0.09].

CONCLUSIONS

Ultrasound-guided retroclavicular and supraclavicular brachial plexus blocks share identical success rates, while providing similar pain relief. Reduced needling time in the supraclavicular approach is not clinically relevant.

CLINICAL TRIAL REGISTRATION

NCT02641613.

Comparison of peripheral nerve blockade characteristics between non-diabetic patients and patients suffering from diabetic neuropathy: a prospective cohort study

Animal data have demonstrated increased block duration after local anaesthetic injections in diabetic rat models. Whether the same is true in humans is currently undefined. We, therefore, undertook this prospective cohort study to test the hypothesis that type-2 diabetic patients suffering from diabetic peripheral neuropathy would have increased block duration after ultrasound-guided popliteal sciatic nerve block when compared with patients without neuropathy. Thirty-three type-2 diabetic patients with neuropathy and 23 non-diabetic control patients, scheduled for fore-foot surgery, were included prospectively. All patients received an ultrasound-guided popliteal sciatic nerve block with a 30 ml 1:1 mixture of lidocaine 1% and bupivacaine 0.5%. The primary outcome was time to first opioid request after block procedure. Secondary outcomes included the time to onset of sensory blockade, and pain score at rest on postoperative day 1 (numeric rating scale 0-10). These outcomes were analysed using an accelerated failure time regression model. Patients in the diabetic peripheral neuropathy group had significantly prolonged median (IQR [range]) time to first opioid request (diabetic peripheral neuropathy group 1440 (IQR 1140-1440 [180-1440]) min vs. control group 710 (IQR 420-1200 [150-1440] min, p = 0.0004). Diabetic peripheral neuropathy patients had a time ratio of 1.57 (95%CI 1.10-2.23, p < 0.01), experienced a 59% shorter time to onset of sensory blockade (median time ratio 0.41 (95%CI 0.28-0.59), p < 0.0001) and had lower median (IQR [range]) pain scores at rest on postoperative day 1 (diabetic peripheral neuropathy group 0 (IQR 0-1 [0-5]) vs. control group 3 (IQR 0-5 [0-9]), p = 0.001). In conclusion, after an ultrasound-guided popliteal sciatic nerve block, patients with diabetic peripheral neuropathy demonstrated reduced time to onset of sensory blockade, with increased time to first opioid request when compared with patients without neuropathy.

Ultrasonic navigation – a single way for identification of brachial plexus nerves in patient with severe vascular pathology

The article discusses the successful experience of using ultrasound imaging of the brachial plexus nerves to perform a supraclavicular block of the brachial plexus with an additional block of n. cutaneus brachii medialis and n. intercostobrachialis in a patient with severe vascular pathology with lack of sensitivity and movements in the hand. The authors describe this technique in detail.

Medial approach of ultrasound-guided costoclavicular plexus block and its effects on regional perfussion

INTRODUCTION

Ultrasound-guided infraclavicular block in the costoclavicular space located between the clavicle and the first rib, reaches the secondary trunks when they are clustered together and lateral to the axillary artery. This block is most often performed through a lateral approach, the difficulty being finding the coracoid process an obstacle and guiding the needle towards the vessels and pleura. A medial approach, meaning from inside to outside, will avoid these structures. Traditionally the assessment of a successful block is through motor or sensitive responses but a sympathetic fibre block can also be evaluated measuring the changes in humeral artery blood flow, skin temperature and/or perfusion index.

OBJECTIVE

To describe the medial approach of the ultrasound-guided costoclavicular block evaluating its development by motor and sensitive response and measurement of sympathetic changes.

MATERIALS AND METHODS

Description of the technique and administration of 20ml of contrast in a fresh cadaver model, evaluating the distribution with CT-scan and sagittal sections of the anatomic piece. Subsequently in a clinical phase, including 11 patients, we evaluated the establishment of motor, sensitive and sympathetic blocks. We evaluated the sympathetic changes reflected by humeral artery blood flow, skin temperature and distal perfusion index.

RESULTS

In the anatomical model the block was conducted without difficulties, showing an adequate periclavicular distribution of the contrast in the CT-scan and in sagittal sections, reaching the interscalenic space as far as the secondary trunks. Successful blocks were observed in 91% of patients after 25minutes. All the parameters reflecting sympathetic block increased significantly. The humeral artery blood flow showed an increase from 108 ± 86 to 188±141ml/min (P=.05), skin temperature from 32.1±2 to 32.8±9°C (P=.03) and perfusion index from 4±3 to 9±5 (P=.003).

CONCLUSIONS

The medial approach of the ultrasound-guided costoclavicular block is anatomically feasible, with high clinical effectiveness using 20ml of 1.5% mepivacaine. The sympathetic block can be evaluated with all three parameters studied.

Comparison of Supraclavicular and Infraclavicular Brachial Plexus Block: A Systemic Review of Randomized Controlled Trials

BACKGROUND

Supraclavicular (SC) and infraclavicular (IC) brachial plexus block (BPB) are commonly used for upper extremity surgery. Recent clinical studies have compared the effect of SC- and IC-BPB, but there have been controversies over spread of sensory blockade in each of the 4 peripheral nerve branches of brachial plexus.

METHODS

This study included a systemic review, using the Medline and EMBASE database from their inceptions through March 2016. Randomized controlled trials (RCTs) comparing SC- and IC-BPB were included. The prespecified primary outcome was the incidences of incomplete sensory blockade in each of the 4 terminal nerve branches of brachial plexus. Secondary outcome included the incidence of successful blockade, performance time, onset of sensory block, duration of analgesia, and complication rates.

RESULTS

Ten RCTs involving 676 patients were included. Pooled analyses showed the incidence of incomplete block at 30 minutes in radial nerve territory was significantly higher in IC-BPB, favoring SC-BPB (risk ratio 0.39; 95% confidence interval [0.17-0.88], P = .02, I = 0%). However, subgroup analysis according to the number of injections of IC-BPB showed that double or triple injections IC-BPB yielded no difference in the incomplete radial block. Furthermore, the incidence of incomplete ulnar block at 30 minutes was significantly lower in IC-BPB when using double or triple injection IC-BPB. There was no difference in the secondary outcomes between SC- and IC-BPB groups, with the exception of complication rates. The incidence of paresthesia/pain on local anesthetic injection, phrenic nerve palsy, and Horner syndrome was significantly higher in the SC group, favoring IC-BPB.

CONCLUSIONS

This meta-analysis demonstrated that IC-BPB showed a significantly high incidence of incomplete radial nerve sensory block at 30 minutes, which may be avoided by double or triple injection. Furthermore, IC-BPB with multiple injection technique showed significantly lower incidence of incomplete ulnar block than SC-BPB. There were no differences in the incidence of successful blockade, block onset, and duration of analgesia between SC- and IC-BPB. Procedure-related paresthesia/pain and adjacent nerve-related complications were more frequent in SC-BPB. However, because of the small sample size, publication bias remains a concern when interpreting our results. Further studies with sufficient sample size and reporting large number of outcomes are required.

Low-Volume Brachial Plexus Block Providing Surgical Anesthesia for Distal Arm Surgery Comparing Supraclavicular, Infraclavicular, and Axillary Approach: A Randomized Observer Blind Trial

Background. Distal arm surgery is widely performed under regional anesthesia with brachial plexus block. The preponderance of evidence for the efficacy relies upon injection of local anesthetic in excess of 30 mL. We aimed to compare three different ultrasound-guided brachial plexus block techniques restricting the total volume to 20 mL. Methods. 120 patients were prospectively randomized to ultrasound-guided brachial plexus block with 20 mL ropivacaine 0.75% at either the supraclavicular, infraclavicular, or axillary level. Multiinjection technique was performed with all three approaches. Primary outcome measure was performance time. Results. Performance time and procedural pain were similar between groups. Needle passes and injection numbers were significantly reduced in the infraclavicular group (P < 0.01). Nerve visibility was significantly reduced in the axillary group (P = 0.01). Success-rate was significantly increased in the supraclavicular versus the axillary group (P < 0.025). Total anesthesia-related time was significantly reduced in the supraclavicular compared to the infraclavicular group (P < 0.01). Block duration was significantly increased in the infraclavicular group (P < 0.05). No early adverse effects occurred. Conclusion. Supraclavicular and infraclavicular blocks exhibited favorable characteristics compared to the axillary block. Supraclavicular brachial plexus block with the multiinjection intracluster technique exhibited significantly reduced total anesthesia-related time and higher success rate without any early adverse events.