Reduced hemidiaphragmatic paresis with extrafascial compared with conventional intrafascial tip placement for continuous interscalene brachial plexus block: a randomized, controlled, double-blind trial

Recent updates on interscalene brachial plexus block for shoulder surgery

Interscalene brachial plexus block (ISBPB) provides optimal analgesia for shoulder surgery. However, several limitations still exist, including the short duration of analgesia, rebound pain, a high incidence of unilateral diaphragmatic paresis, and potential risk of nerve damage, prompting the search for alternative techniques. Many alternatives to ISBPB have been studied to alleviate these concerns, and clinicians should choose an appropriate option based on the patient's condition. In this mini-review, we aimed to present recent updates on ISBPB while discussing our clinical experiences in shoulder surgery.

Comparison of pulmonary function during interscalene block vs. supraclavicular block: a single-center, double-blind, randomized trial

BACKROUND

The supraclavicular plexus block (SCB) and interscalene plexus block (ISB) have the potential to pulmonary function, the duration of the potential remains uncertain. So, we compared the effect of SCB and ISB on pulmonary function, especially the duration time.

METHODS

Ninety-six patients were finally allocated to group I and group S. The ISB and the SCB procedures were performed with ultrasound guidance before anesthesia induction. An investigator recorded the diaphragm mobility and respiratory function test indicators before the block (T₀) and at 30 min (T_{30 min}), 4 h (T₄), 8 h (T₈), and 12 h (T₁₂) after the block. The diaphragmatic paralysis rate was calculated for above timepoint. The VAS, the recovery time for the sensory and motor block, and adverse reactions within 24 h of administering the block were also recorded.

RESULTS

The recovery times of diaphragm mobility in group I were longer than those in group S. Compared with group I, group S had a significantly lower diaphragmatic paralysis rate during eupnea breathing at T_{30 min} and T₈ after the block. Similarly, group S had a significantly lower diaphragmatic paralysis rate at deep breathing at T_{30 min}, T_8, and T₁₂ after the block. The recovery times of FEV₁ and FVC in group I were longer than those in group S. The other results were not statistically significant.

CONCLUSIONS

Ultrasound-guided ISB resulted in a longer periods with a suppressive effect on pulmonary function than SCB.

TRIALS REGISTRATION

17/12/2019, ChiCTR1900028286.

What Is the Risk of Postoperative Neurologic Symptoms After Regional Anesthesia in Upper Extremity Surgery? A Systematic Review and Meta-analysis of Randomized Trials

BACKGROUND

The risk of neurologic symptoms after regional anesthesia in orthopaedic surgery is estimated to approach 3%, with long-term deficits affecting 2 to 4 per 10,000 patients. However, current estimates are derived from large retrospective or observational studies that are subject to important systemic biases. Therefore, to harness the highest quality data and overcome the challenge of small numbers of participants in individual randomized trials, we undertook this systematic review and meta-analysis of contemporary randomized trials.

QUESTIONS/PURPOSES

In this systematic review and meta-analysis of randomized trials we asked: (1) What is the aggregate pessimistic and optimistic risk of postoperative neurologic symptoms after regional anesthesia in upper extremity surgery? (2) What block locations have the highest and lowest risk of postoperative neurologic symptoms? (3) What is the timing of occurrence of postoperative neurologic symptoms (in days) after surgery?

METHODS

We searched Ovid MEDLINE, Embase, Cochrane Central Register of Controlled Trials and Cochrane Database of Systematic Reviews, Web of Science, Scopus, and PubMed for randomized controlled trials (RCTs) published between 2008 and 2019 that prospectively evaluated postoperative neurologic symptoms after peripheral nerve blocks in operative procedures. Based on the Grading of Recommendations, Assessment, Development, and Evaluation guidance for using the Risk of Bias in Non-Randomized Studies of Interventions tool, most trials registered a global rating of a low-to-intermediate risk of bias. A total of 12,532 participants in 143 trials were analyzed. Data were pooled and interpreted using two approaches to calculate the aggregate risk of postoperative neurologic symptoms: first according to the occurrence of each neurologic symptom, such that all reported symptoms were considered mutually exclusive (pessimistic estimate), and second according to the occurrence of any neurologic symptom for each participant, such that all reported symptoms were considered mutually inclusive (optimistic estimate).

RESULTS

At any time postoperatively, the aggregate pessimistic and optimistic risks of postoperative neurologic symptoms were 7% (915 of 12,532 [95% CI 7% to 8%]) and 6% (775 of 12,532 [95% CI 6% to 7%]), respectively. Interscalene block was associated with the highest risk (13% [661 of 5101] [95% CI 12% to 14%]) and axillary block the lowest (3% [88 of 3026] [95% CI 2% to 4%]). Of all symptom occurrences, 73% (724 of 998) were reported between 0 and 7 days, 24% (243 of 998) between 7 and 90 days, and 3% (30 of 998) between 90 and 180 days. Among the 31 occurrences reported at 90 days or beyond, all involved sensory deficits and four involved motor deficits, three of which ultimately resolved.

CONCLUSION

When assessed prospectively in randomized trials, the aggregate risk of postoperative neurologic symptoms associated with peripheral nerve block in upper extremity surgery was approximately 7%, which is greater than previous estimates described in large retrospective and observational trials. Most occurrences were reported within the first week and were associated with an interscalene block. Few occurrences were reported after 90 days, and they primarily involved sensory deficits. Although these findings cannot inform causation, they can help inform risk discussions and clinical decisions, as well as bolster our understanding of the evolution of postoperative neurologic symptoms after regional anesthesia in upper extremity surgery. Future prospective trials examining the risks of neurologic symptoms should aim to standardize descriptions of symptoms, timing of evaluation, classification of severity, and diagnostic methods.

LEVEL OF EVIDENCE

Level I, therapeutic study.

Regional Anesthetic and Analgesic Techniques for Clavicle Fractures and Clavicle Surgeries: Part 2-A Retrospective Study

Objective. Clavicle fracture fixation is commonly performed under general anesthesia due to the complex sensory innervation in this region which poses a challenge for anesthesiologists applying regional anesthetic (RA) techniques. In part 1 of this two-part study, we summarized the current literature describing various RA approaches in clavicle fractures and surgery. In our earlier scoping review, we surmised that a superficial or intermediate cervical plexus block (CPB) may provide analgesia for this procedure and, when combined with an interscalene brachial plexus block (ISB), can provide anesthesia to the clavicular region for surgical fixation. We performed a retrospective study, consolidating assumptions that were based on the results of our earlier scoping review. Methods. A retrospective study was conducted on 168 consecutive patients who underwent clavicle fixation surgery at a tertiary healthcare system in Singapore. We used a standardized pro forma to collate perioperative data from the electronic health records of both hospitals, including anesthetic technique, analgesic requirements, pain scores, and adverse events, up to the second postoperative day or up until discharge. Results. In our study, patients who received RA had significantly reduced pain scores and opioid requirements, compared to general anesthesia (GA) alone. Through subgroup analysis, differences were found in postoperative pain scores and opioid requirements in the following order: GA alone > GA with local infiltration analgesia > CPB > CPB plus ISB. All patients who received combined CPB and ISB had upper limb weakness in recovery, compared to none with CPB alone (p < 0.001). Of those who received an ISB either in isolation or combined with a CPB, four (9.3%) were reported to have dyspnea (within 24 h) and motor weakness that persisted beyond 12 h, compared to none for patients that received CPB alone. Conclusions. Addition of a CPB to GA for clavicle fracture fixation surgery is associated with reduced pain scores in the early postoperative period, with a lower opioid requirement compared to GA alone. In patients undergoing GA, the combination of a CPB with an ISB was associated with a small, although statistically significant, reduction in pain scores and opioid requirements compared to a CPB alone.

A randomised controlled trial in patients undergoing arthroscopic shoulder surgery comparing interscalene block with either 10 ml or 20 ml levobupivacaine 0.25

The interscalene brachial plexus block is recommended for analgesia after shoulder surgery but it may cause hemidiaphragmatic dysfunction. We tested whether ipsilateral hemidiaphragmatic contraction was better after a smaller dose of local anaesthetic without impairing analgesic effect. We randomly allocated 48 adults to 10 ml or 20 ml levobupivacaine 0.25% before arthroscopic shoulder surgery. The primary outcome was hemidiaphragmatic paralysis, defined as inspiratory thickness < 1.2 times expiratory thickness, measured by ultrasound 4 h after block. Hemidiaphragmatic paralysis was recorded for 6/24 vs. 23/24 supine participants after 10 ml vs. 20 ml levobupivacaine 0.25%, respectively, and for 4/24 vs. 23/24 sitting participants, respectively, p < 0.001 for both. Pain scores after 10 ml injectate were not worse than after 20 ml injectate. Median (IQR [range]) morphine doses in the first 24 postoperative hours after 10 ml and 20 ml levobupivacaine 0.25% were 2 (0-6 [0-23]) mg vs. 1 (0-2 [0-11]) mg, respectively, p = 0.12. No participant had a complication after 10 ml interscalene levobupivacaine, whereas seven had complications after 20 ml levobupivacaine, p = 0.009. Hemidiaphragmatic function was better after 10 ml vs. 20 ml interscalene levobupivacaine 0.25% without impairing analgesia for 24 postoperative hours.

Postoperative neurologic symptoms in the operative arm after shoulder surgery with interscalene blockade: a systematic review

OBJECTIVE

Postoperative neurologic symptoms (PONS) in the operative arm are important complications of shoulder surgery and interscalene blockade (ISB). This systematic review aimed to compare the risk of PONS between ISB and other techniques, and the relative safety of different agents used in ISB.

METHODS

Our systematic review followed Cochrane review methodology and was registered in PROSPERO. A search of MEDLINE (Ovid), EMBASE (Ovid), and CENTRAL (Wiley) from inception to June 2020 was completed. We included randomized or quasi-randomized trials of patients (> five years old) undergoing shoulder surgery with any ISB technique as an intervention, compared with any other nonregional or regional technique, or ISB of alternate composition or technique. The primary outcome was PONS (study author defined) assessed a minimum of one week after surgery.

RESULTS

Fifty-five studies totalling 6,236 participants (median, 69; range, 30-910) were included. Another 422 otherwise eligible trials were excluded because PONS was not reported. Heterogeneity in when PONS was assessed (from one week to one year) and the diagnostic criteria used precluded quantitative meta-analysis. The most common PONS definition, consisting of one or more of paresthesia, sensory deficit, or motor deficit, was only used in 16/55 (29%) trials. Risk of bias was low in 5/55 (9%) trials and high in 36/55 (65%) trials, further limiting any inferences.

CONCLUSION

These findings highlight the need for a standardized PONS outcome definition and follow-up time, along with routine, rigorous measurement of PONS in trials of ISB.

STUDY REGISTRATION

PROSPERO (CRD42020148496); registered 10 February 2020.

Impact of self-coiling catheters for continuous popliteal sciatic block on postoperative pain level and dislocation rate: a randomized controlled trial

Background

Dislocation of catheters within the tissue is a challenge in continuous regional anesthesia. A novel self-coiling catheter design is available and has demonstrated a lower dislocation rate in a cadaver model. The dislocation rate and effect on postoperative pain of these catheters in vivo has yet to be determined and were the subjects of this investigation.

Methods

After ethics committee approval 140 patients undergoing elective distal lower limb surgery were enrolled in this prospective randomized controlled trial. Preoperatively, patients were randomly assigned and received either the conventional (n = 70) or self-coiling catheter (n = 70) for ultrasound-guided popliteal sciatic nerve block in short axis view and by the in-plane approach from lateral to medial. The primary outcome was pain intensity after surgery and on the following three postoperative days. Secondary outcomes investigated were dislocation rate in situ determined by sonography, catheter movement visible from outside, opioid consumption as well as leakage at the puncture site.

Results

All catheters were successfully inserted. The study population of self-coiling catheters had significantly lower mean numeric rating scale values than the reference cohort on the first (p = 0.01) and second postoperative days (p < 0.01). Sonographic evaluation demonstrated, 42 standard catheters (60%) and 10 self-coiling catheters (14.3%) were dislocated in situ within the first three postoperative days. The externally visible movement of the catheters at insertion site did not differ significantly between groups through the third postoperative day. The opioid consumption was significantly lower in the self-coiling catheter group on the day of surgery and on the second and third postoperative days (p = 0.04, p = 0.03 and p = 0.04, respectively).

Conclusion

The self-coiling catheter offers a better postoperative pain control and a lower dislocation rate within the tissue when blocking the popliteal sciatic nerve compared to a conventional catheter. Further trials in large patient cohorts are warranted to investigate the potential beneficial effects of self-coiling catheters for other localisations and other application techniques.

Trial registration

The trial was registered at German Clinical Trials Register (DRKS) on 08/04/2020 (DRKS00020938, retrospectively registered).

The Relationship Between Postoperative Opioid Analgesia and Sleep Apnea Severity in Patients Undergoing Hip Arthroplasty: A Randomized, Controlled, Triple-Blinded Trial

PURPOSE

Residual postoperative pain after hip arthroplasty is usually treated with oral opioids. While classic opioids are associated with respiratory depression and worsening of sleep apnea, tramadol has been reported to preserve respiratory function. However, this has not been investigated in a prospective trial using respiratory polygraphy. This randomized controlled triple-blinded trial tested the hypothesis that postoperative treatment with oral opioids such as oxycodone would increase sleep apnea severity, measured with a respiratory polygraphy, compared with oral tramadol.

PATIENTS AND METHODS

Sixty patients undergoing hip arthroplasty under spinal anesthesia with 15 mg isobaric bupivacaine 0.5% were randomized to receive postoperative pain treatment with either oral oxycodone (controlled-release 10 mg every 12 hours and immediate-release 5 mg every 4 hours as needed) or oral tramadol (controlled-release 100 mg every 8 hours and immediate-release 50 mg every 4 hours as needed). Respiratory polygraphy was performed on the first postoperative night. The primary outcome was the apnea-hypopnea index in the supine position. Secondary outcomes included the oxygen desaturation index, postoperative pain scores and intravenous morphine consumption.

RESULTS

Mean supine apnea-hypopnea index on postoperative night 1 was 11.3 events.h^-1 (95% confidence interval, 4.8-17.7) in the oxycodone group and 10.7 (4.6-16.8) events.h^-1 in the tramadol group (p=0.89). There were no significant differences between the oxycodone and tramadol groups with respect to any secondary sleep-related or pain-related outcomes.

CONCLUSION

Oral oxycodone did not increase sleep apnea severity measured using respiratory polygraphy compared with oral tramadol on the first postoperative night after hip arthroplasty.

TRIAL REGISTRATION NUMBER

Clinicaltrials.gov - NCT03454217 (date of registration: 05/03/2018).

Combination of femoral triangle block and infiltration between the popliteal artery and the capsule of the posterior knee (iPACK) versus local infiltration analgesia for analgesia after anterior cruciate ligament reconstruction: a randomized controlled triple-blinded trial

BACKGROUND AND OBJECTIVES

Femoral triangle block and local infiltration analgesia are two effective analgesic techniques after anterior cruciate ligament reconstruction. Recently, the iPACK block (infiltration between the popliteal artery and the capsule of the posterior knee) has been described to relieve posterior knee pain. This randomized controlled triple-blinded trial tested the hypothesis that the combination of femoral triangle block and iPACK provides superior analgesia to local infiltration analgesia after anterior cruciate ligament reconstruction.

METHODS

Sixty patients undergoing anterior cruciate ligament reconstruction received general anesthesia and were randomly allocated to two groups: femoral triangle block and iPACK under ultrasound guidance or local infiltration analgesia. For each group, a total of 160 mg of ropivacaine was injected. Postoperative pain treatment followed a predefined protocol with intravenous morphine patient-controlled analgesia, acetaminophen, and ibuprofen. The primary outcome was cumulative intravenous morphine consumption at 24 hours postoperatively. Secondary pain-related outcomes included pain scores (Numeric Rating Scale out of 10) measured at 2 and 24 hours postoperatively. Functional outcomes, such as range of motion and quadriceps strength, were also recorded at 24 postoperative hours, and at 4 and 8 postoperative months.

RESULTS

Cumulative intravenous morphine consumption at 24 hours postoperatively was significantly reduced in the femoral triangle block and iPACK group (femoral triangle block and iPACK: 9.7 mg (95% CI: 6.7 to 12.7); local infiltration analgesia: 17.0 mg (95% CI: 11.1 to 23.0), p=0.03). Other pain-related and functional-related outcomes were similar between groups.

CONCLUSIONS

The combination of femoral triangle block and iPACK reduces intravenous morphine consumption during the first 24 hours after anterior cruciate ligament reconstruction, when compared with local infiltration analgesia, without effect on other pain-related, early, or late functional-related outcomes.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Registry (NCT03680716).

Impact of short-acting vs. standard anaesthetic agents on obstructive sleep apnoea: a randomised, controlled, triple-blind trial

Sleep apnoea is associated with negative outcomes following general anaesthesia. Current recommendations suggest using short‐acting anaesthetic agents in preference to standard agents to reduce this risk, but there is currently no evidence to support this. This randomised controlled triple‐blind trial tested the hypothesis that a combination of short‐acting agents (desflurane‐remifentanil) would reduce the postoperative impact of general anaesthesia on sleep apnoea severity compared with standard agents (sevoflurane‐fentanyl). Sixty patients undergoing hip arthroplasty under general anaesthesia were randomised to anaesthesia with desflurane‐remifentanil or sevoflurane‐fentanyl. Respiratory polygraphy was performed before surgery and on the first and third postoperative nights. The primary outcome was the supine apnoea‐hypopnoea index on the first postoperative night. Secondary outcomes were the supine apnoea‐hypopnoea index on the third postoperative night, and the oxygen desaturation index on the first and third postoperative nights. Additional outcomes included intravenous morphine equivalent consumption and pain scores on postoperative days 1, 2 and 3. Pre‐operative sleep study data were similar between groups. Mean (95%CI) values for the supine apnoea‐hypopnoea index on the first postoperative night were 18.9 (12.7–25.0) and 21.4 (14.2–28.7) events.h⁻¹, respectively, in the short‐acting and standard anaesthesia groups (p = 0.64). Corresponding values on the third postoperative night were 28.1 (15.8–40.3) and 38.0 (18.3–57.6) events.h⁻¹ (p = 0.34). Secondary sleep‐ and pain‐related outcomes were generally similar in the two groups. In conclusion, short‐acting anaesthetic agents did not reduce the impact of general anaesthesia on sleep apnoea severity compared with standard agents. These data should prompt an update of current recommendations.

Anatomy of the brachial plexus and its implications for daily clinical practice: regional anesthesia is applied anatomy

Safety and effectiveness are mandatory requirements for any technique of regional anesthesia and can only be met by clinicians who appropriately understand all relevant anatomical details. Anatomical texts written for anesthetists may oversimplify the facts, presumably in an effort to reconcile extreme complexity with a need to educate as many users as possible. When it comes to techniques as common as upper-extremity blocks, the need for customized anatomical literature is even greater, particularly because the complex anatomy of the brachial plexus has never been described for anesthetists with a focus placed on regional anesthesia. The authors have undertaken to close this gap by compiling a structured overview that is clinically oriented and tailored to the needs of regional anesthesia. They describe the anatomy of the brachial plexus (ventral rami, trunks, divisions, cords, and nerves) in relation to the topographical regions used for access (interscalene gap, posterior triangle of the neck, infraclavicular fossa, and axillary fossa) and discuss the (interscalene, supraclavicular, infraclavicular, and axillary) block procedures associated with these access regions. They indicate allowances to be made for anatomical variations and the topography of fascial anatomy, give recommendations for ultrasound imaging and needle guidance, and explain the risks of excessive volumes and misdirected spreading of local anesthetics in various anatomical contexts. It is hoped that clinicians will find this article to be a useful reference for decision-making, enabling them to select the most appropriate regional anesthetic technique in any given situation, and to correctly judge the risks involved, whenever they prepare patients for a specific upper-limb surgical procedure.

Interscalene brachial plexus block for surgical repair of clavicle fracture: a matched case-controlled study

BACKGROUND

Innervation of the clavicle is complex and debated, with scarce data on the analgesic and clinical impact of regional anaesthesia after surgical repair of clavicle fracture.

METHODS

In order to assess the analgesic efficiency of an interscalene brachial plexus block (ISB) for surgical repair of clavicle fracture, 50 consecutive patients scheduled for surgical fixation of middle/lateral clavicle fracture under general anaesthesia with ISB were prospectively enrolled. This cohort was compared to a historical control of 76 retrospective patients without regional block. The primary outcome was total intravenous morphine equivalent consumption at 2 postoperative hours. To assess the ISB impact, both an overall cohort analysis and a case-matched analysis with each ISB-treated patient matched to a Non-ISB-treated patient was performed. Matching employed a 1-to-1, nearest-neighbour approach using the Mahalanobis metric.

RESULTS

In the overall cohort, patients with ISB had significantly lower i.v. morphine equivalent consumption at 2 postoperative hours (0.7 mg (95% CI 0.1 to 1.2) versus controls 8.8 mg (95% CI 7.1 to 10.4); P <  0.0001). These results persisted after case-matching the cohorts (mean difference for the primary outcome: 8.3 mg (95% CI 6.5 to 10.0); P <  0.001).

CONCLUSIONS

ISB provides effective analgesia after surgical fixation of middle and lateral clavicle fracture. These results should help physicians in establishing an analgesic strategy for this type of surgery. Further research is needed to identify the optimal regional technique for medial third clavicle fractures and the clinically relevant contributions of the cervical and brachial plexus.

TRIAL REGISTRATION

Clinicaltrials.gov - NCT02565342, October 1st 2015.

Costoclavicular brachial plexus block reduces hemidiaphragmatic paralysis more than supraclavicular brachial plexus block: retrospective, propensity score matched cohort study

Background

Hemidiaphragmatic paralysis, a frequent complication of the brachial plexus block performed above the clavicle, is rarely associated with an infraclavicular approach. The costoclavicular brachial plexus block is emerging as a promising infraclavicular approach. However, it may increase the risk of hemidiaphragmatic paralysis because the proximity to the phrenic nerve is greater than in the classical infraclavicular approach.

Methods

This retrospective analysis compared the incidence of hemidiaphragmatic paralysis in patients undergoing costoclavicular and supraclavicular brachial plexus blocks. Of 315 patients who underwent brachial plexus block performed by a single anesthesiologist, 118 underwent costoclavicular, and 197 underwent supraclavicular brachial plexus block. Propensity score matching selected 118 pairs of patients. The primary outcome was the incidence of hemidiaphragmatic paralysis, defined as a postoperative elevation of the hemidiaphragm > 20 mm. Factors affecting the incidence of hemidiaphragmatic paralysis were also evaluated.

Results

Hemidiaphragmatic paralysis was observed in three patients (2.5%) who underwent costoclavicular and 47 (39.8%) who underwent supraclavicular brachial plexus blocks (P < 0.001; odds ratio, 0.04; 95% confidence interval, 0.01-0.13). Both the brachial plexus block approach and the injected volume of local anesthetic were significantly associated with hemidiaphragmatic paralysis.

Conclusions

The incidence of hemidiaphragmatic paralysis is significantly lower with costoclavicular than with supraclavicular brachial plexus block.

Subacromial analgesia via continuous infusion catheter vs. placebo following arthroscopic shoulder surgery: a systematic review and meta-analysis of randomized trials

BACKGROUND

Subacromial analgesia (SAA) is hypothesized to reduce pain after arthroscopic shoulder surgery by delivering a continuous infusion of local anesthetic directly to the surgical site. The purpose of this systematic review and meta-analysis was to evaluate the efficacy of SAA vs. placebo for pain relief after arthroscopic subacromial shoulder procedures.

METHODS

MEDLINE, Embase, PubMed, and the Cochrane Central Register of Controlled Trials were searched for randomized controlled trials comparing SAA with placebo after arthroscopic shoulder surgery. Outcomes collected included pain scores (converted to equivalent ordinal visual analog scores; minimal clinically important difference 1.4 cm), oral morphine equivalents used postoperatively, and catheter-related complications. Meta-analysis was performed via a random-effects model. Included trials underwent a risk of bias and quality of evidence assessment.

RESULTS

Nine studies involving 459 participants were included. There were no clinically significant changes for pain scores in SAA at 6-, 12-, 24-, and 48-hour postoperative timepoints. Patients receiving SAA used less morphine equivalents of pain medication at 12 hours only (-0.37 mg, 95% confidence interval: -0.63 to -0.11), but there was no significant difference at 24 and 48 hours. There were no major complications (infection or reoperation). Included trials demonstrated a moderate risk-of-bias, and low to very low quality of evidence for primary outcomes.

CONCLUSION

Subacromial continuous infusion of local anesthetic does not provide a clinically significant benefit compared with placebo as part of a multimodal analgesia regime after arthroscopic subacromial surgical procedures. Future, high-quality trials are required to further assess the efficacy of SAA against placebo.

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.

A randomised controlled trial of shoulder block vs. interscalene brachial plexus block for ventilatory function after shoulder arthroscopy

The shoulder block may impair ventilatory function and diaphragmatic movement less than the interscalene brachial plexus block. We randomly allocated 30 adults who underwent shoulder arthroscopy under general anaesthesia to ultrasound-guided shoulder block or interscalene block with 20 ml bupivacaine 0.5%. The primary outcome, rate of ultrasound-measured hemidiaphragmatic excursion < 25% of baseline 30 min after blockade, was reduced from 12/15 with brachial plexus block to 2/15 with shoulder block, a difference (95%CI) of 67% (40-93%), p < 0.001. The mean (SD) numeric rating scale pain scores at rest after shoulder block were higher than after interscalene block at two postoperative hours, 1.4 (1.2) vs. 0.3 (0.7), p = 0.02, but lower at 24 postoperative hours, 1.3 (1.3) vs. 3.4 (2.3), p = 0.008. Mean (SD) pain scores on movement in the shoulder and interscalene blocks were similar, with respective values of 1.9 (1.9) vs. 0.7 (1.2), p = 0.13 at two postoperative hours and 3.7 (2.3) vs. 5.3 (2.5), p = 0.41, at 24 postoperative hours.

Superior Trunk Block Provides Noninferior Analgesia Compared with Interscalene Brachial Plexus Block in Arthroscopic Shoulder Surgery

Editor’s Perspective

What We Already Know about This Topic

What This Article Tells Us That Is New

Background

Interscalene brachial plexus block of the C5–C6 roots provides highly effective postoperative analgesia after shoulder surgery but usually results in hemidiaphragmatic paresis. Injection around the superior trunk of the brachial plexus is an alternative technique that may reduce this risk. The authors hypothesized that the superior trunk block would provide noninferior postoperative analgesia compared with the interscalene block and reduce hemidiaphragmatic paresis.

Methods

Eighty patients undergoing arthroscopic shoulder surgery were randomized to receive a preoperative injection of 15 ml of 0.5% ropivacaine and 5 μg · ml−1 epinephrine around either (1) the C5–C6 nerve roots (interscalene block group) or (2) the superior trunk (superior trunk block group). The primary outcome was pain intensity 24 h after surgery measured on an 11-point numerical rating score; the prespecified noninferiority limit was 1. Diaphragmatic function was assessed using both ultrasonographic measurement of excursion and incentive spirometry by a blinded investigator before and 30 min after block completion.

Results

Seventy-eight patients completed the study. The pain score 24 h postoperatively (means ± SDs) was 1.4 ± 1.0 versus 1.2 ± 1.0 in the superior trunk block (n = 38) and interscalene block (n = 40) groups, respectively. The mean difference in pain scores was 0.1 (95% CI, −0.3 to 0.6), and the upper limit of the 95% CI was lower than the prespecified noninferiority limit. Analgesic requirements and all other pain measurements were similar between groups. Hemidiaphragmatic paresis was observed in 97.5% of the interscalene block group versus 76.3% of the superior trunk block group (P = 0.006); paresis was complete in 72.5% versus 5.3% of the patients, respectively. The decrease in spirometry values from baseline was significantly greater in the interscalene block group.

Conclusions

The superior trunk block provided noninferior analgesia compared with interscalene brachial plexus block for up to 24 h after arthroscopic shoulder surgery and resulted in significantly less hemidiaphragmatic paresis.

Diaphragm-sparing nerve blocks for shoulder surgery, revisited

Although interscalene brachial plexus block (ISB) remains the gold standard for analgesia after shoulder surgery, the inherent risks of ipsilateral phrenic nerve block and hemidiaphragmatic paralysis (HDP) limit its use in patients with preexisting pulmonary compromise. In a previous Daring Discourse (2017), our research team has identified potential diaphragm-sparing alternatives to ISB for patients undergoing shoulder surgery. In recent years, the field has been fertile with research, with the publication of multiple randomized controlled trials investigating supraclavicular blocks, upper trunk blocks, anterior suprascapular nerve blocks, costoclavicular blocks, and combined infraclavicular-suprascapular blocks. To date, the cumulative evidence (pre-2017 and post-2017) suggests that costoclavicular blocks may provide similar postoperative analgesia to ISB coupled with a 0%-incidence of HDP. However, in light of the small number of patients recruited by the single study investigating costoclavicular blocks, further confirmatory trials are required. Moreover, future investigation should also be undertaken to determine if costoclavicular blocks could achieve surgical anesthesia for shoulder surgery. Anterior suprascapular nerve blocks have been demonstrated to provide surgical anesthesia and similar analgesia to ISB. However, their risk of HDP has not been formally quantified. Of the remaining diaphragm-sparing nerve blocks, supraclavicular blocks (with local anesthetic injection posterolateral to the brachial plexus), upper trunk blocks, and combined infraclavicular-anterior suprascapular blocks merit further investigation, as they have been shown to achieve similar analgesia to ISB, coupled with an HDP incidence <10%.

Adductor canal block versus local infiltration analgesia for postoperative pain after anterior cruciate ligament reconstruction: a single centre randomised controlled triple-blinded trial

BACKGROUND

Both the adductor canal block (ACB) and local infiltration analgesia (LIA) are effective analgesic techniques after anterior cruciate ligament (ACL) reconstruction, but they have never been compared head-to-head. This randomised controlled triple-blinded trial tested the hypothesis that ACB provides superior analgesia to LIA after ACL reconstruction, with additional focus on postoperative functional outcomes.

METHODS

Of 104 enrolled ACL reconstruction patients receiving general anaesthesia, 52 were randomly allocated to either ACB under ultrasound guidance or LIA. For each intervention, ropivacaine 0.5%, 20 ml was injected. Postoperative pain treatment followed a predefined protocol with i.v. patient-controlled morphine, paracetamol, and ibuprofen. The primary outcome was cumulative i.v. morphine consumption at 24 h after operation. Secondary pain-related outcomes included resting and dynamic pain scores (numeric rating scale out of 10) measured 2, 24, and 48 h after operation and cumulative i.v. morphine consumption 2 and 48 h after operation. Early function-related outcomes evaluated were quadriceps strength, walking distance, and range of motion, all measured 24 and 48 h after operation. Late function-related outcomes were concentric quadriceps strength, single-hop test, triple-hop test, cross-over test, and Y balance test, measured at 4 and 8 postoperative months.

RESULTS

Cumulative i.v. morphine consumption at 24 h was similar between groups (ACB group: 17.1 mg [95% confidence interval, CI: 13.1, 21.2]; LIA group: 17.7 mg [95% CI: 13.2, 22.6], P=0.84). Similarly, no differences between groups were seen in the secondary pain- or function-related outcomes.

CONCLUSIONS

ACB and LIA result in equivalent postoperative opioid consumption with similar impact on postoperative pain scores and functional outcomes.

CLINICAL TRIAL REGISTRATION

NCT02524652.