Comparison of intravenous versus perineural dexamethasone as a local anaesthetic adjunct for peripheral nerve blocks in the lower limb: A meta-analysis and systematic review.

BACKGROUND: As a local anaesthetic adjunct, the systemic absorption of perineural dexamethasone in the lower limb could be restricted because of decreased vascularity when compared with the upper limb. OBJECTIVES: To compare the pharmacodynamic characteristics of intravenous and perineural dexamethasone in the lower limb. DESIGN: Systematic review of randomised controlled trials with meta-analysis. DATA SOURCES: Systematic search of Central, Google Scholar, Ovid Embase and Ovid Medline to 18 July 2023. ELIGIBILITY CRITERIA: Randomised controlled trials, which compared the intravenous with perineural administration of dexamethasone as a local anaesthetic adjunct in peripheral nerve blocks for surgery of the lower limb. RESULTS: The most common peripheral nerve blocks were femoral, sciatic and ankle block. The local anaesthetic was long acting in all trials and the dose of dexamethasone was 8 mg in most trials. The primary outcome, the duration of analgesia, was investigated by all nine trials (n = 546 patients). Overall, compared with intravenous dexamethasone, perineural dexamethasone increased the duration of analgesia from 19.54 to 22.27 h, a mean difference [95% confidence interval (CI) of 2.73 (1.07 to 4.38) h; P = 0.001, I2 = 87]. The quality of evidence was moderate owing to serious inconsistency. However, analysis based on the location of the peripheral nerve block, the type of local anaesthetic or the use of perineural adrenaline showed no difference in duration between intravenous and perineural dexamethasone. No differences were shown for any of the secondary outcomes related to efficacy and side effects. CONCLUSION: In summary, moderate evidence supports the superiority of perineural dexamethasone over intravenous dexamethasone in prolonging the duration of analgesia. However, this difference is unlikely to be clinically relevant. Consideration of the perineural use of dexamethasone should recognise that this route of administration remains off label.

Impact of spinal versus general anaesthesia on perioperative obstructive sleep apnoea severity in patients undergoing hip arthroplasty: a post hoc analysis of two randomised controlled trials.

BACKGROUND: Recommendations suggest favouring regional over general anaesthesia to reduce impact on postoperative sleep apnoea severity, but there is currently no evidence to support this. We compared the impact of general vs spinal anaesthesia on postoperative sleep apnoea severity and assessed the evolution of sleep apnoea severity up to the third postoperative night. METHODS: This post hoc analysis used pooled data from two previous randomised controlled trials in patients undergoing total hip arthroplasty under general or spinal anaesthesia (n=96), without performing a preliminary power analysis. All participants underwent respiratory polygraphy before surgery and on the first and third postoperative nights. The primary outcomes were the supine apnoea-hypopnea index on the first postoperative night and the evolution of the supine apnoea-hypopnea index up to the third postoperative night. Secondary outcomes included the oxygen desaturation index on the first and third postoperative nights. RESULTS: In the general and spinal anaesthesia groups, mean (95% confidence interval) values for the supine apnoea-hypopnoea index on the first postoperative night were 20 (16-25) and 21 (16-26) events h-1 (P=0.82), respectively; corresponding values on the third postoperative night were 34 (22-45) and 35 (20-49) events h-1 (P=0.91). The generalised estimating equations model showed a significant time effect. Secondary outcomes were similar in the two groups. CONCLUSIONS: Use of spinal anaesthesia compared with general anaesthesia was not associated with a reduction in postoperative sleep apnoea severity, which was worse on the third postoperative night. CLINICAL TRIAL REGISTRATION: NCT02717780 and NCT02566226.

Efficacy and safety of intrathecal diamorphine: a systematic review and meta-analysis with meta-regression and trial sequential analysis.

BACKGROUND: Intrathecal diamorphine is believed to provide postoperative analgesia but is associated with adverse effects such as nausea and vomiting. There is little evidence of synthesis regarding intrathecal diamorphine in the contemporary literature. We performed a systematic review, meta-analysis with meta-regression and trial sequential analysis to determine the magnitude of intrathecal diamorphine efficacy and safety. METHODS: We systematically searched the literature for trials comparing intrathecal diamorphine with a control group in patients undergoing all types of surgery. The primary efficacy and safety outcomes were intravenous morphine consumption and incidence of postoperative nausea and vomiting at 24 h following surgery, respectively. RESULTS: Twelve trials were identified, which included data for 712 patients. Intrathecal doses of diamorphine ranged from 100 µg to 2500 µg. Intravenous morphine consumption at 24 h postoperatively was significantly reduced in the intrathecal diamorphine group, with a mean difference (95%CI) of -8 mg (-11 to -6), I2 = 93%, p < 0.001. There was a significant difference between three intrathecal diamorphine dosing subgroups but without correlation: mean differences (95%CI) -1 mg (-3-0), -26 mg (-40 to -11) and -6 mg (-15-4) in patients receiving doses of 0-200 µg, 201-400 µg and > 400 µg, respectively (p = 0.003). Intrathecal diamorphine increased postoperative nausea and vomiting with a risk ratio (95%CI) of 1.37 (1.19-1.58), I2 = 7%, p < 0.001. There were no differences in postoperative nausea and vomiting between the three intrathecal diamorphine dosing subgroups. There was no correlation observed with meta-regression of the primary efficacy and safety outcomes. The quality of evidence for all outcomes was very low. CONCLUSION: There is very low level of evidence that intrathecal diamorphine provides effective analgesia after surgery, while increasing postoperative nausea and vomiting with doses > 200 µg.

Intravenous versus perineural dexamethasone to prolong analgesia after interscalene brachial plexus block: a systematic review with meta-analysis and trial sequential analysis.

BACKGROUND: The efficacy of perineural vs intravenous dexamethasone as a local anaesthetic adjunct to increase duration of analgesia could be particular to specific peripheral nerve blocks because of differences in systemic absorption depending on the injection site. Given this uncertainty, we performed a systematic review with meta-analysis and trial sequential analysis comparing dexamethasone administered perineurally or intravenously combined with local anaesthetic for interscalene brachial plexus block. METHODS: Following a search of various electronic databases, we included 11 trials (1145 patients). The primary outcome was the duration of analgesia defined as the time between peripheral nerve block or onset of sensory blockade and the time to first analgesic request or initial report of pain. RESULTS: The primary outcome, duration of analgesia, was greater in the perineural dexamethasone group, with a mean difference (95% confidence interval) of 122 (62-183) min, I2=73%, P<0.0001. Trial sequential analysis indicated that firm evidence had been reached. The quality of evidence was downgraded to low, mainly because of moderate inconsistency and serious publication bias. No significant differences were present for any of the secondary outcomes, except for onset time of sensory and motor blockade and resting pain score at 12 h, but the magnitude of differences was not clinically relevant. CONCLUSIONS: There is low-quality evidence that perineural administration of dexamethasone as a local anaesthetic adjunct increases duration of analgesia by an average of 2 h compared with intravenous injection for interscalene brachial plexus block. Given the limited clinical relevance of this difference, the off-label use of perineural administration, and the risk of drug crystallisation, we recommend intravenous dexamethasone administration. SYSTEMATIC REVIEW PROTOCOL: PROSPERO (CRD42023466147).

Research priorities in regional anaesthesia: where should we focus?

Using a modified Delphi technique, an international group of regional anaesthetists generated a list of top research priorities in regional anaesthesia. The list of unanswered research questions was created from a questionnaire completed by >500 anaesthetists and distilled into 11 priorities grouped into four themes: clinical practice and efficacy, pain management, technology and equipment, and training and assessment.

Research priorities in regional anaesthesia: an international Delphi study.

BACKGROUND: Regional anaesthesia use is growing worldwide, and there is an increasing emphasis on research in regional anaesthesia to improve patient outcomes. However, priorities for future study remain unclear. We therefore conducted an international research prioritisation exercise, setting the agenda for future investigators and funding bodies. METHODS: We invited members of specialist regional anaesthesia societies from six continents to propose research questions that they felt were unanswered. These were consolidated into representative indicative questions, and a literature review was undertaken to determine if any indicative questions were already answered by published work. Unanswered indicative questions entered a three-round modified Delphi process, whereby 29 experts in regional anaesthesia (representing all participating specialist societies) rated each indicative question for inclusion on a final high priority shortlist. If ≥75% of participants rated an indicative question as 'definitely' include in any round, it was accepted. Indicative questions rated as 'definitely' or 'probably' by <50% of participants in any round were excluded. Retained indicative questions were further ranked based on the rating score in the final Delphi round. The final research priorities were ratified by the Delphi expert group. RESULTS: There were 1318 responses from 516 people in the initial survey, from which 71 indicative questions were formed, of which 68 entered the modified Delphi process. Eleven 'highest priority' research questions were short listed, covering themes of pain management; training and assessment; clinical practice and efficacy; technology and equipment. CONCLUSIONS: We prioritised unanswered research questions in regional anaesthesia. These will inform a coordinated global research strategy for regional anaesthesia and direct investigators to address high-priority areas.

Femoral vs sciatic nerve block to provide analgesia after medial open wedge high tibial osteotomy in the setting of multimodal analgesia: A randomized, controlled, single-blinded trial.

STUDY OBJECTIVE: Medial open wedge high tibial osteotomy (MOW HTO) is associated with moderate to severe postoperative pain. The proximal part of the tibia is innervated by branches from the femoral nerve anteriorly and the sciatic nerve posteriorly. There is a paucity of information regarding the optimal peripheral nerve block for postoperative analgesia with minimal impact on motor function. This study tested the hypothesis that a femoral nerve block provides superior analgesia to a sciatic nerve block after MOW HTO in the setting of multimodal analgesia. DESIGN: Randomized controlled single-blind trial. SETTING: Operating room, postoperative recovery area and ward, up to 6 postoperative months. PATIENTS: Fifty patients undergoing MOW HTO. INTERVENTIONS: Interventions were femoral or sciatic nerve block under ultrasound guidance. For each intervention, a total of 100 mg of ropivacaine was injected. Postoperative pain treatment followed a pre-defined protocol with intravenous patient-controlled analgesia of morphine, paracetamol, and ibuprofen. MEASUREMENTS: The primary outcome was intravenous morphine consumption at 24 h postoperatively. Secondary outcomes included rest and dynamic pain scores (on a numeric rating scale out of 10) at 2, 24 and 48 h postoperatively. Functional outcomes included the Short Form-12, Knee injury and Osteoarthritis Outcome Score, and International Knee Documentation Committee (IKDC) scores measured at 6 months postoperatively. MAIN RESULTS: Mean [95% confidence interval] i.v. morphine consumption at 24 postoperative hours were 24 mg [15 mg,33 mg] in the femoral nerve block group and 24 mg [16 mg,32 mg] in the sciatic nerve block group (p = 0.98). There were no significant differences in the secondary outcomes between groups. CONCLUSIONS: This trial failed to demonstrate that a femoral nerve block provides superior analgesia to a sciatic nerve block after MOW HTO under general anesthesia in the setting of multimodal analgesia. There was no significant difference in quality of life and functional outcomes at 6 months postoperatively between groups. Trial registry number:Clinicaltrials.com - NCT05728294; Kofam.ch - SNCTP000003048 | BASEC2018-01774.

Duration of analgesia after forefoot surgery compared between an ankle and a sciatic nerve block at the popliteal crease: A randomised controlled single-blinded trial.

BACKGROUND: Forefoot surgery is associated with severe postoperative pain. Ankle and sciatic nerve blocks provide satisfactory postoperative analgesia after forefoot surgery, but little is known on their respective duration of analgesia. OBJECTIVE: This randomised controlled, single-blinded trial tested the hypothesis that after forefoot surgery in the setting of multimodal analgesia, an ankle block provides analgesia superior to that of a sciatic nerve block at the popliteal crease. DESIGN: A randomised controlled study. SETTING: A single centre study in a university hospital in Switzerland, from September 2018 to November 2022. PATIENTS: From 91 patients scheduled for forefoot surgery, 60 met the inclusion criteria of which 56 completed the protocol and their data were available for analysis. Exclusion criteria were existing sciatic nerve deficit, pre-existing peripheral neuropathy, chronic pain diagnosis, pregnancy, or identified contraindications to peripheral nerve block. INTERVENTION: Patients undergoing forefoot surgery were randomly allocated to either a multi-injection ankle block (partly under ultrasound guidance) or a sciatic nerve block at the popliteal crease (under ultrasound guidance) combined with a saphenous nerve block at the ankle. Patients in each group received a total of 30 ml of ropivacaine 0.5% and a multimodal analgesic regimen inclusive of dexamethasone, paracetamol, ketorolac then ibuprofen. MAIN OUTCOME MEASURE: The primary outcome was duration of analgesia, defined as time to first morphine request. RESULTS: Mean ±â€ŠSD duration of analgesia was 15.4 ±â€Š8.0 h in the ankle block group and 20.0 ±â€Š10.3 h in the sciatic nerve block group ( P  = 0.32). Of note, 15 of 26 (58%) and 24 of 30 (80%) patients of the ankle and sciatic nerve block groups did not request any morphine ( P  = 0.09). Other secondary outcomes were similar between groups. CONCLUSION: Compared with the ankle block, the sciatic nerve block at the popliteal crease does not provide a longer duration of analgesia in patients undergoing forefoot surgery in the setting of multimodal analgesia. TRIAL REGISTRATION: Clinicaltrials.com identifier: NCT03683342.

Standardizing nomenclature in regional anesthesia: an ASRA-ESRA Delphi consensus study of upper and lower limb nerve blocks.

BACKGROUND: Inconsistent nomenclature and anatomical descriptions of regional anesthetic techniques hinder scientific communication and engender confusion; this in turn has implications for research, education and clinical implementation of regional anesthesia. Having produced standardized nomenclature for abdominal wall, paraspinal and chest wall regional anesthetic techniques, we aimed to similarly do so for upper and lower limb peripheral nerve blocks. METHODS: We performed a three-round Delphi international consensus study to generate standardized names and anatomical descriptions of upper and lower limb regional anesthetic techniques. A long list of names and anatomical description of blocks of upper and lower extremities was produced by the members of the steering committee. Subsequently, two rounds of anonymized voting and commenting were followed by a third virtual round table to secure consensus for items that remained outstanding after the first and second rounds. As with previous methodology, strong consensus was defined as ≥75% agreement and weak consensus as 50%-74% agreement. RESULTS: A total of 94, 91 and 65 collaborators participated in the first, second and third rounds, respectively. We achieved strong consensus for 38 names and 33 anatomical descriptions, and weak consensus for five anatomical descriptions. We agreed on a template for naming peripheral nerve blocks based on the name of the nerve and the anatomical location of the blockade and identified several areas for future research. CONCLUSIONS: We achieved consensus on nomenclature and anatomical descriptions of regional anesthetic techniques for upper and lower limb nerve blocks, and recommend using this framework in clinical and academic practice. This should improve research, teaching and learning of regional anesthesia to eventually improve patient care.

Single-bolus injection of local anesthetic, with or without continuous infusion, for interscalene brachial plexus block in the setting of multimodal analgesia: a randomized controlled unblinded trial.

INTRODUCTION: Previous trials favored a continuous interscalene brachial plexus block over a single injection for major shoulder surgery. However, these trials did not administer a multimodal analgesic regimen. This randomized, controlled unblinded trial tested the hypothesis that a continuous infusion of local anesthetic for an interscalene brachial plexus block still provides superior analgesia after major shoulder surgery when compared with a single injection in the setting of multimodal analgesia, inclusive of intravenous dexamethasone, magnesium, acetaminophen and ketorolac. METHODS: Sixty patients undergoing shoulder arthroplasty or arthroscopic rotator cuff repair were randomized to receive a bolus of ropivacaine 0.5%, 20 mL, with or without a continuous infusion of ropivacaine 0.2% 4-8 mL/hour, for an interscalene brachial plexus block. Patients were provided with intravenous morphine patient-controlled analgesia. The primary outcome was cumulative intravenous morphine consumption at 24 hours postoperatively. Secondary outcomes included pain scores at rest and on movement, and functional outcomes, measured over 48 hours after surgery. RESULTS: Median (IQR) cumulative intravenous morphine consumption at 24 hours postoperatively was 10 mg (4-24) in the continuous infusion group and 14 mg (8-26) in the single injection group (p=0.74). No significant between-group differences were found for any of the secondary outcomes. CONCLUSIONS: A continuous infusion of local anesthetic for an interscalene brachial plexus block does not provide superior analgesia after major shoulder surgery when compared with a single injection in the setting of multimodal analgesia, inclusive of intravenous dexamethasone, magnesium, acetaminophen and ketorolac. The findings of this study are limited by performance and detection biases. TRIAL REGISTRATION NUMBER: NCT04394130.

Regional anesthesia in the emergency department outside the operating theatre.

PURPOSE OF REVIEW: Moderate to severe pain is common and remains a significant problem in the emergency department and regional anesthesia provides optimal and safe pain relief. This review aims to discuss the benefits, indications of the most common ultrasound-guided regional anesthesia techniques that can be provided by clinicians in the emergency department as part of multimodal analgesia. We will also comment on the education and training for effective and safe ultrasound-guided regional anesthesia in the emergency department. RECENT FINDINGS: The emergence of multiple new fascial plane blocks that provide easier to learn alternatives, yet effective analgesia for specific patient groups can now safely be taught and utilized in the emergency department. SUMMARY: Emergency physicians are perfectly placed to utilize the advantages of ultrasound-guided regional anesthesia. Various techniques can now be employed to cover most of the painful injuries presenting to the emergency department, thus modifying the morbidity and outcomes of emergency patients. Some of the new techniques require minimal training, provide safe and effective pain relief with low risk of complications. Ultrasound-guided regional anesthetic techniques should form an integral part of the curriculum of emergency department physicians.

Local anaesthetic adjuncts for peripheral nerve blockade.

PURPOSE OF REVIEW: Moderate-to-severe pain is common and remains a significant problem. Compared with opioid analgesia alone, single-shot peripheral nerve blockade has been associated with improved pain relief and the potential of decreased side effects. Single-shot nerve blockade, however, is limited by its relatively short duration of action. In this review, we aim to summarize the evidence related to local anaesthetic adjuncts for peripheral nerve blockade. RECENT FINDINGS: Dexamethasone and dexmedetomidine exhibit characteristics that most closely resemble the ideal local anaesthetic adjunct. In upper limb block, dexamethasone has been demonstrated to be superior to dexmedetomidine regardless of administration route for the duration of sensory and motor blockade as well as the duration of analgesia. No clinically significant differences between intravenous and perineural dexamethasone were found. Perineural and intravenous dexamethasone have the potential to prolong sensory blockade to a greater extent than motor blockade. The evidence indicates that the mechanism of action of perineural dexamethasone in upper limb block is systemic in nature. Unlike perineural dexmedetomidine, intravenous dexmedetomidine has not been shown to result in differences in the characteristics of regional blockade compared with local anaesthetic alone. SUMMARY: Intravenous dexamethasone is the local anaesthetic adjunct of choice, increasing the duration of sensory and motor blockade as well as the duration of analgesia by 477, 289 and 478 min, respectively. In view of this, we recommend consideration of the intravenous administration of dexamethasone at a dose of 0.1-0.2 mg/kg for all patients undergoing surgery whatever the level of postoperative pain, mild, moderate or severe. Further research should focus on the potential synergism of action between intravenous dexamethasone and perineural dexmedetomidine.

Management of adverse effects of intrathecal opioids in acute pain.

Intrathecal opioids have been used for several decades in different clinical settings. They are easy to administer and provide many benefits in clinical practice, such as better quality of spinal anaesthesia, prolonged postoperative analgesia, decreased postoperative analgesic requirements and early mobilisation. Several lipophilic and hydrophilic opioids are available for intrathecal administration, either in combination with general anaesthesia or as adjuncts to local anaesthetics. Adverse effects after intrathecal lipophilic opioids administration are predominantly short-lived and benign. In contrast, intrathecal hydrophilic opioids may have potentially serious adverse effects, the most feared of which is respiratory depression. In this review, we will focus on the contemporary evidence regarding intrathecal hydrophilic opioids and present their adverse effects and how to manage them.

Intracellular Zinc Trafficking during Crotalus atrox Venom Wound Development.

In this study, we examined zinc trafficking in human umbilical vein endothelial cells (HUVEC) stimulated with Crotalus atrox (CA venom) snake venom. We utilized MTS cytotoxicity assays to monitor the cytotoxic range of CA venom. HUVEC monolayers stimulated with 10 µg/mL CA venom for 3 h displayed cellular retraction, which coincided with 53.0 ± 6.5 percent viability. In contrast, venom concentrations of 100 µg/mL produced a complete disruption of cellular adherence and viability decreased to 36.6 ± 1.0. The zinc probe Fluozin-3AM was used to detect intracellular zinc in non-stimulated controls, HUVEC stimulated with 10 µg/mL CA venom or HUVEC preincubated with TPEN for 2 h then stimulated with 10 µg/mL CA venom. Fluorescent intensity analysis returned values of 1434.3 ± 197.4 for CA venom demonstrating an increase of about two orders of magnitude in labile zinc compared to non-stimulated controls. Endothelial response to CA venom induced a 96.1 ± 3.0- and 4.4 ± 0.41-fold increase in metallothionein 1X (MT1X) and metallothionein 2A (MT2A) gene expression. Zinc chelation during CA venom stimulation significantly increased cell viability, suggesting that the maintenance of zinc homeostasis during envenomation injury improves cell survival.

The postoperative analgesic efficacy of liposomal bupivacaine versus long-acting local anaesthetics for peripheral nerve and field blocks: A systematic review and meta-analysis, with trial sequential analysis.

BACKGROUND: Liposomal bupivacaine is claimed by the manufacturer to provide analgesia for up to 72 h postoperatively. OBJECTIVES: To compare the postoperative analgesic efficacy of liposomal bupivacaine versus long-acting local anaesthetics for peripheral nerve or field blocks. DESIGN: A systematic review and meta-analysis with trial sequential analysis. DATA SOURCES: MEDLINE, Embase and Web of Science, among others, up to June 2022. ELIGIBILITY CRITERIA: We retrieved randomised controlled trials comparing liposomal bupivacaine versus bupivacaine, levobupivacaine or ropivacaine for peripheral nerve and field blocks after all types of surgery. Our primary endpoint was rest pain score (analogue scale 0 to 10) at 24 h. Secondary endpoints included rest pain score at 48 and 72 h, and morphine consumption at 24, 48 and 72 h. RESULTS: Twenty-seven trials including 2122 patients were identified. Rest pain scores at 24 h were significantly reduced by liposomal bupivacaine with a mean difference (95% CI) of -0.9 (-1.4 to -0.4), I2  = 87%, P  < 0.001. This reduction in pain scores persisted at 48 h and 72 h with mean differences (95% CI) of -0.7 (-1.1 to -0.3), I2  = 82%, P  = 0.001 and -0.7 (-1.1 to -0.3), I2  = 80%, P  < 0.001, respectively. There were no differences in interval morphine consumption at 24 h ( P  = 0.15), 48 h ( P  = 0.15) and 72 h ( P  = 0.07). The quality of evidence was moderate. CONCLUSIONS: There is moderate level evidence that liposomal bupivacaine reduces rest pain scores by 0.9 out of 10 units, when compared with long-acting local anaesthetics at 24 hours after surgery, and by 0.7 up to 72 hours after surgery.

Sensory block duration after spinal anaesthesia supplemented with intravenous dexamethasone: a randomised controlled double-blinded trial.

BACKGROUND: Intravenous dexamethasone prolongs duration of analgesia or sensory block after injection of local anaesthetics close to peripheral nerves by an average of 8 h. Uncertainty remains on the potential increase in the duration of sensory block after spinal anaesthesia. The objective of this randomised controlled double-blinded trial was to investigate whether dexamethasone i.v. prolongs the sensory block of spinal anaesthesia with bupivacaine when compared with a control group. METHODS: Of 50 patients undergoing lower limb osteoarticular surgery under spinal anaesthesia with isobaric bupivacaine 15 mg i.t. with morphine 100 µg i.t. were randomised to receive either dexamethasone 0.15 mg kg-1 i.v. or normal saline 3 ml i.v. The primary outcome was duration of sensory block defined as the time elapsed between injection of the local anaesthetic in the intrathecal space and the regression of sensory block by two dermatomes compared with the highest dermatome blocked. Secondary outcomes included intravenous morphine consumption, pain scores at rest and on movement, postoperative nausea and vomiting, and blood glucose at 2, 24, and 48 h. RESULTS: Median duration of sensory block was 135 (105-225) min in the dexamethasone group and 158 (135-240 min) in the control group (P=0.19). Patients in the dexamethasone group received less morphine at 24 h, had significantly less postoperative nausea and vomiting at 2 h and 24 h, and had increased blood glucose at 24 h. Other secondary outcomes were similar between groups. CONCLUSION: Intravenous dexamethasone did not prolong the sensory block of spinal anaesthesia with isobaric bupivacaine. However, it reduced morphine consumption and rate of postoperative nausea and vomiting at 24 h, at the expense of an increased blood glucose. CLINICAL TRIAL REGISTRATION: NCT03527576 (Clinicaltrials.gov).

Core outcome set for peripheral regional anesthesia research: a systematic review and Delphi study.

BACKGROUND/IMPORTANCE: There is heterogeneity among the outcomes used in regional anesthesia research. OBJECTIVE: We aimed to produce a core outcome set for regional anesthesia research. METHODS: We conducted a systematic review and Delphi study to develop this core outcome set. A systematic review of the literature from January 2015 to December 2019 was undertaken to generate a long list of potential outcomes to be included in the core outcome set. For each outcome found, the parameters such as the measurement scale, timing and definitions, were compiled. Regional anesthesia experts were then recruited to participate in a three-round electronic modified Delphi process with incremental thresholds to generate a core outcome set. Once the core outcomes were decided, a final Delphi survey and video conference vote was used to reach a consensus on the outcome parameters. RESULTS: Two hundred and six papers were generated following the systematic review, producing a long list of 224 unique outcomes. Twenty-one international regional anesthesia experts participated in the study. Ten core outcomes were selected after three Delphi survey rounds with 13 outcome parameters reaching consensus after a final Delphi survey and video conference. CONCLUSIONS: We present the first core outcome set for regional anesthesia derived by international expert consensus. These are proposed not to limit the outcomes examined in future studies, but rather to serve as a minimum core set. If adopted, this may increase the relevance of outcomes being studied, reduce selective reporting bias and increase the availability and suitability of data for meta-analysis in this area.

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.