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.

Ambulatory total hip and knee arthroplasty: a literature review and perioperative considerations

PURPOSE

Total joint arthroplasty (TJA), particularly for the hip and knee, is one of the most commonly performed surgical procedures. The advancement/evolution of surgical and anesthesia techniques have allowed TJA to be performed on an ambulatory/same-day discharge basis. In this Continuing Professional Development module, we synthesize the perioperative evidence that may aid the development of successful ambulatory TJA pathways.

SOURCE

We searched MEDLINE, Embase, CENTRAL, and the Cochrane Database of Systematic Reviews for ambulatory or fast-track TJA articles. In the absence of direct evidence for the ambulatory setting, we extrapolated the evidence from the in-patient TJA literature.

PRINCIPAL FINDINGS

Patient selection encompassing patient, medical, and social factors is fundamental for successful same-day discharge of patients following TJA. Evidence for the type of intraoperative anesthesia favours neuraxial technique for achieving same day discharge criteria and reduced perioperative complications. Availability of short-acting local anesthetic for neuraxial anesthesia would affect the anesthetic choice. Nonetheless, modern general anesthesia with multimodal analgesia and antithrombotics in a well selected population can be considered. Regional analgesia forms an integral part of the multimodal analgesia regime to reduce opioid consumption and facilitate same-day hospital discharge, reducing hospital readmission. For ambulatory total knee arthroplasty, a combination of adductor canal block with local anesthetic periarticular infiltration provided is a suitable regional analgesic regimen.

CONCLUSION

Anesthesia for TJA has evolved as such that same-day discharge will become the norm for selected patients. It is essential to establish pathways for early discharge to prevent adverse effects and readmission in this population. As more data are generated from an increased volume of ambulatory TJA, more robust evidence will emerge for the ideal anesthetic components to optimize outcomes.

The Incidence and Predictors of Failed Spinal Anesthesia After Intrathecal Injection of Local Anesthetic for Cesarean Delivery: A Single-Center, 9-Year Retrospective Review

BACKGROUND

The incidence of failed spinal anesthesia varies widely in the obstetric literature. Although many risk factors have been suggested, their relative predictive value is unknown. The primary objective of this retrospective cohort study was to determine the incidence of failed spinal anesthesia for cesarean deliveries at a tertiary care obstetric hospital, and its secondary objectives were to identify predictors of failed spinal anesthesia in the obstetrics population and quantify their relative importance in a predictive model for failure.

METHODS

With local institutional ethics committee approval, a retrospective review of our hospital database identified the incidence of failed spinal anesthesia for 5361 cesarean deliveries between 2010 and 2019. We performed a multivariable analysis to assess the association of predictors with failure and a dominance analysis to assess the importance of each predictor.

RESULTS

The incidence of failed spinal anesthesia requiring an alternative anesthetic was 2.1%, with conversion to general anesthesia occurring in 0.7% of surgeries. Supplemental analgesia or sedation was provided to an additional 2.0% of women. The most important predictors of a failed spinal anesthetic were previous cesarean delivery (odds ratio [OR], 11.33; 95% confidence interval [CI], 7.09-18.20; P < .001), concomitant tubal ligation (OR, 8.23; 95% CI, 3.12-19.20; P < .001), lower body mass index (BMI) (kg·m -2 , OR, 0.94; 95% CI, 0.90-0.98; P = .005), and longer surgery duration (minutes, OR, 1.02; 95% CI, 1.01-1.03; P = .006). Previous cesarean delivery was the most significant risk factor, contributing to 9.6% of the total 17% variance predicted by all predictors examined.

CONCLUSIONS

Spinal anesthesia failed to provide a pain-free surgery in 4.1% of our cesarean deliveries. Previous cesarean delivery was the most important predictor of spinal failure. Other important predictors included tubal ligation, lower BMI, and longer surgery duration.

Comparative efficacy and safety of non-neuraxial analgesic techniques for midline laparotomy: a systematic review and frequentist network meta-analysis of randomised controlled trials

BACKGROUND

Fascial plane blocks provide effective analgesia after midline laparotomy; however, the most efficacious technique has not been determined. We conducted a systematic review and network meta-analysis of randomised controlled trials to synthesise the evidence with respect to pain, opioid consumption, and adverse events.

METHODS

We searched Ovid MEDLINE, Embase, Cochrane Central, and Scopus databases for studies comparing commonly used non-neuraxial analgesic techniques for midline laparotomy in adult patients. The co-primary outcomes of the study were 24-h cumulative opioid consumption and 24-h resting pain score, reported as i.v. morphine equivalents and 11-point numerical rating scale, respectively. We performed a frequentist meta-analysis using a random-effects model and a cluster-rank analysis of the co-primary outcomes.

RESULTS

Of 6115 studies screened, 67 eligible studies were included (n=4410). Interventions with the greatest reduction in 24-h cumulative opioid consumption compared with placebo/no intervention were single-injection quadratus lumborum block (sQLB; mean difference [MD] -16.1 mg, 95% confidence interval [CI] -29.9 to -2.3, very low certainty), continuous transversus abdominis plane block (cTAP; MD -14.0 mg, 95% CI -21.6 to -6.4, low certainty), single-injection transversus abdominis plane block (sTAP; MD -13.7 mg, 95% CI -17.4 to -10.0, low certainty), and continuous rectus sheath block (cRSB; MD -13.2 mg, 95% CI -20.3 to -6.1, low certainty). Interventions with the greatest reduction in 24-h resting pain score were cRSB (MD -1.2, 95% CI -1.8 to -0.6, low certainty), cTAP (MD -1.0, 95% CI -1.7 to -0.2, low certainty), and continuous wound infusion (cWI; MD -0.7, 95% CI -1.1 to -0.4, low certainty). Clustered-rank analysis including the co-primary outcomes showed cRSB and cTAP blocks to be the most efficacious interventions.

CONCLUSIONS

Based on current evidence, continuous rectus sheath block and continuous transversus abdominis plane block were the most efficacious non-neuraxial techniques at reducing 24-h cumulative opioid consumption and 24-h resting pain scores after midline laparotomy (low certainty). Future studies should compare techniques for upper vs lower midline laparotomy and other non-midline abdominal incisions.

CLINICAL TRIAL REGISTRATION

PROSPERO Registration Number: CRD42021269044.

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.

Reducing rebound pain severity after arthroscopic shoulder surgery under general anesthesia and interscalene block: a two-centre randomized controlled trial of pre-emptive opioid treatment compared with placebo

PURPOSE

Although a single-injection interscalene block provides effective early postoperative analgesia following shoulder surgery, patients may experience "rebound pain" when the block resolves. Our objective was to determine if oral hydromorphone (2 mg) given six hours after a single-injection interscalene block for arthroscopic shoulder surgery leads to a clinically significant reduction in the severity of rebound pain.

METHODS

After approval from research ethics boards, we conducted a two-centre, parallel-group, double-blind, randomized, placebo-controlled superiority trial. Patients received preoperative interscalene block, general anesthesia, and either hydromorphone or placebo six hours after the block. The primary outcome was the worst pain score in the first 24 hr postoperatively, measured on an 11-point (0-10) numerical rating scale.

RESULTS

A total of 73 participants were randomly assigned to either the hydromorphone or placebo group. There was no statistically significant difference in the mean (standard deviation) worst pain score within 24 hr between the hydromorphone and placebo groups (6.5 [2.4] vs 5.9 [2.3]; mean difference, 0.6; 95% confidence interval, -0.5 to 1.8). Similarly, we did not find any significant difference in the pain trajectory, opioid use, or incidence of nausea and vomiting between the groups. The mean time to worst pain was 14.6 hr, and the mean time to first rescue analgesia was 11.3 hr after interscalene block.

CONCLUSION

Hydromorphone 2 mg given six hours after interscalene block did not reduce the severity of rebound pain postoperatively compared with placebo in patients undergoing arthroscopic shoulder surgery.

STUDY REGISTRATION

ClinicalTrials.gov (NCT02939209); registered 19 October 2016.

Preoperative assessment of postoperative delirium: a cross-sectional study of patients and anesthesiologists in Canada

PURPOSE

We sought to evaluate 1) patient- and anesthesiologist-reported rates of postoperative delirium (POD) risk discussion during preoperative meetings, 2) patients' and anesthesiologists' ratings of the importance of POD, and 3) predictors of patient-reported discussion of POD risk during preoperative meetings.

METHODS

In this multicentre two-part cross-sectional survey study, patients ≥ 65 yr scheduled to undergo elective noncardiac surgery completed a five-minute survey after preoperative anesthesia consultation. Patients were asked about their perception of POD importance, and whether they discussed or were assessed for POD risk. Anesthesiologists were surveyed using self-administered surveys circulated via institutional email lists. Anesthesiologists were asked about the frequency of POD risk assessment and discussion in older adults, tools used, and perception of POD-screening barriers.

RESULTS

Four hundred and twelve (of 510 approached) patients (50% male; mean age, 73 yr) and 267 anesthesiologists (of 1,205 invited via e-mail) participated in this study conducted in five Canadian hospitals. Postoperative delirium screening and discussion was reported by 88/412 (22%) patients and 229/267 (86%) anesthesiologists. Postoperative delirium was rated as "somewhat-extremely" important by 64% of patients. A previous history of delirium, higher education, the number of daily medications, and longer surgical duration were associated with POD discussion. On average, anesthesiologists rated the importance of POD at 8/10, and 42% ranked "patient risk factors" as the top reason prompting discussion.

CONCLUSION

The combined evaluation of patients' and anesthesiologists' perspectives provides valuable information on preoperative POD screening and risk assessment, and highlights areas for improvement in the current practice. Most factors we identified to be associated with higher odds of POD discussion are recognized risk factors of POD.

Methodological and reporting quality assessment of network meta-analyses in anesthesiology: a systematic review and meta-epidemiological study

PURPOSE

The scientific rigour of the conduct and reporting of anesthesiology network meta-analyses (NMAs) is unknown. This systematic review and meta-epidemiological study assessed the methodological and reporting quality of NMAs in anesthesiology.

METHODS

We searched four databases, including MEDLINE, PubMed, Embase, and the Cochrane Systematic Reviews Database, for anesthesiology NMAs published from inception to October 2020. We assessed the compliance of NMAs against A Measurement Tool to Assess Systematic Reviews (AMSTAR-2), Preferred Reporting Items for Systematic Reviews and Meta-Analyses Statement for Network Meta-Analyses (PRISMA-NMA), and PRISMA checklists. We measured the compliance across various items in AMSTAR-2 and PRISMA checklists and provided recommendations to improve quality.

RESULTS

Using the AMSTAR-2 rating method, 84% (52/62) of NMAs were rated "critically low." Quantitatively, the median [interquartile range] AMSTAR-2 score was 55 [44-69]%, while the PRISMA score was 70 [61-81]%. Methodological and reporting scores showed a strong correlation (R = 0.78). Anesthesiology NMAs had a higher AMSTAR-2 score and PRISMA score if they were published in higher impact factor journals (P = 0.006 and P = 0.01, respectively) or followed PRISMA-NMA reporting guidelines (P = 0.001 and P = 0.002, respectively). Network meta-analyses from China had lower scores (P < 0.001 and P < 0.001, respectively). Neither score improved over time (P = 0.69 and P = 0.67, respectively).

CONCLUSION

The current study highlights numerous methodological and reporting deficiencies in anesthesiology NMAs. Although the AMSTAR tool has been used to assess the methodological quality of NMAs, dedicated tools for conducting and assessing the methodological quality of NMAs are urgently required.

STUDY REGISTRATION

PROSPERO (CRD42021227997); first submitted 23 January 2021.

Evidence-based clinical practice guidelines on postdural puncture headache: a consensus report from a multisociety international working group

INTRODUCTION

Postdural puncture headache (PDPH) can follow unintentional dural puncture during epidural techniques or intentional dural puncture during neuraxial procedures such as a lumbar puncture or spinal anesthesia. Evidence-based guidance on the prevention, diagnosis or management of this condition is, however, currently lacking. This multisociety guidance aims to fill this void and provide practitioners with comprehensive information and patient-centric recommendations to prevent, diagnose and manage patients with PDPH.

METHODS

Based on input from committee members and stakeholders, the committee cochairs developed 10 review questions deemed important for the prevention, diagnosis and management of PDPH. A literature search for each question was performed in MEDLINE (Ovid) on 2 March 2022. The results from each search were imported into separate Covidence projects for deduplication and screening, followed by data extraction. Additional relevant clinical trials, systematic reviews and research studies published through March 2022 were also considered for the development of guidelines and shared with contributors. Each group submitted a structured narrative review along with recommendations graded according to the US Preventative Services Task Force grading of evidence. The interim draft was shared electronically, with each collaborator requested to vote anonymously on each recommendation using two rounds of a modified Delphi approach.

RESULTS

Based on contemporary evidence and consensus, the multidisciplinary panel generated 50 recommendations to provide guidance regarding risk factors, prevention, diagnosis and management of PDPH, along with their strength and certainty of evidence. After two rounds of voting, we achieved a high level of consensus for all statements and recommendations. Several recommendations had moderate-to-low certainty of evidence.

CONCLUSIONS

These clinical practice guidelines for PDPH provide a framework to improve identification, evaluation and delivery of evidence-based care by physicians performing neuraxial procedures to improve the quality of care and align with patients' interests. Uncertainty remains regarding best practice for the majority of management approaches for PDPH due to the paucity of evidence. Additionally, opportunities for future research are identified.

Consensus Practice Guidelines on Postdural Puncture Headache From a Multisociety, International Working Group: A Summary Report

Importance

Postdural puncture headache (PDPH) can follow unintentional dural puncture during epidural techniques or intentional dural puncture during neuraxial procedures, such as a lumbar puncture or spinal anesthesia. Evidence-based guidance on the prevention, diagnosis, and management of this condition is, however, currently lacking.

Objective

To fill the practice guidelines void and provide comprehensive information and patient-centric recommendations for preventing, diagnosing, and managing PDPH.

Evidence Review

With input from committee members and stakeholders of 6 participating professional societies, 10 review questions that were deemed important for the prevention, diagnosis, and management of PDPH were developed. A literature search for each question was performed in MEDLINE on March 2, 2022. Additional relevant clinical trials, systematic reviews, and research studies published through March 2022 were also considered for practice guideline development and shared with collaborator groups. Each group submitted a structured narrative review along with recommendations that were rated according to the US Preventive Services Task Force grading of evidence. Collaborators were asked to vote anonymously on each recommendation using 2 rounds of a modified Delphi approach.

Findings

After 2 rounds of electronic voting by a 21-member multidisciplinary collaborator team, 47 recommendations were generated to provide guidance on the risk factors for and the prevention, diagnosis, and management of PDPH, along with ratings for the strength and certainty of evidence. A 90% to 100% consensus was obtained for almost all recommendations. Several recommendations were rated as having moderate to low certainty. Opportunities for future research were identified.

Conclusions and Relevance

Results of this consensus statement suggest that current approaches to the treatment and management of PDPH are not uniform due to the paucity of evidence. The practice guidelines, however, provide a framework for individual clinicians to assess PDPH risk, confirm the diagnosis, and adopt a systematic approach to its management.

Quality of recovery after pericapsular nerve group (PENG) block for primary total hip arthroplasty under spinal anaesthesia: a randomised controlled observer-blinded trial

BACKGROUND

The pericapsular nerve group (PENG) block is a novel regional anaesthesia technique that has been proposed as an effective motor-sparing block for total hip arthroplasty. Recent randomised studies show conflicting results regarding the analgesic efficacy of the PENG block for total hip arthroplasty.

METHODS

We conducted a randomised controlled observer-blinded single-centre superiority trial comparing the efficacy of the PENG block with no block for patients undergoing primary total hip arthroplasty under spinal anaesthesia. All subjects received multimodal analgesia consisting of paracetamol and celecoxib. The primary outcome was quality of recovery (QoR) at 24 h as measured by the QoR-15 questionnaire.

RESULTS

A total of 112 participants (56 in each group) were included in the analysis. The median (inter-quartile range [IQR]) 24-h QoR-15 scores were higher in subjects who received a PENG block (132 [116-138]) compared with subjects who did not (103 [97-112]) with a median difference of 26 (95% confidence interval, 18-31; P<0.001). Similarly, QoR-15 at 48 h was higher in the PENG group, and opioid use at 24 and 48 h postoperatively was significantly lower in the PENG group. However, we did not find significant differences in pain score, distance to ambulation, or anti-emetic use at any time point. We did not observe any PENG block-related complications.

CONCLUSION

Adding a PENG block to a multimodal analgesia regimen that includes paracetamol and celecoxib improves the quality of recovery and reduces opioid requirements for patients undergoing primary total hip arthroplasty under spinal anaesthesia.

CLINICAL TRIAL REGISTRATION

NCT04591353.

Epidemiological, methodological, and statistical characteristics of network meta-analysis in anaesthesia: a systematic review

BACKGROUND

Network meta-analyses (NMAs) combine direct and indirect estimates to provide mixed (or network) estimates of effect sizes. The scientific rigour of the conduct and reporting of anaesthesia NMAs is unknown. This review assessed the epidemiological, methodological, and statistical characteristics of anaesthesia NMAs.

METHODS

We searched four databases for anaesthesia NMAs and developed a 64-item checklist to evaluate NMAs. For 29 binary items, we defined compliance as 'the ratio of NMAs that was awarded a 'yes' for that item, divided by the total number of NMAs. The compliance of such binary items was reclassified as very low (≤25%), low (26-50%), fair (51-75%), and high (>75%). We amalgamated findings from 29 key items to provide specific recommendations (post hoc). We compared the compliance of NMAs in anaesthesia across 26 items, with that of cancer NMAs and Cochrane NMAs, and analysed improvement over time (post hoc).

RESULTS

Among 62 included NMAs, compliance was low (26-50%) for protocol registration, use of PRISMA-NMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses for NMA), publication bias assessment, evidence appraisal, reporting of Bayesian methodology and consistency evaluation. Compliance was very low (≤25%) for bias assessment, biostatistician involvement, search specialist, and use of predefined important differences.

CONCLUSIONS

Anaesthesia NMAs need improvement in their conduct and reporting. Anaesthesia journals should mandate the registration of protocols and reporting of NMAs using PRISMA-NMA. Authors should carefully assess publication bias, and use updated bias assessment tools, and evidence appraisal methods designed for NMAs.

SYSTEMATIC REVIEW PROTOCOL

PROSPERO CRD42021227608.

Cost comparison between spinal versus general anesthesia for hip and knee arthroplasty: an incremental cost study

PURPOSE

Wait list times for total joint arthroplasties have been growing, particularly in the aftermath of the COVID-19 pandemic. Increasing operating room (OR) efficiency by reducing OR time and associated costs while maintaining quality allows the greatest number of patients to receive care.

METHODS

We used propensity score matching to compare parallel processing with spinal anesthesia in a block room vs general anesthesia in a retrospective cohort of adult patients undergoing primary total hip arthroplasty (THA) and total knee arthroplasty (TKA). We compared perioperative costs, hospital costs, OR time intervals, and complications between the groups with nonparametric tests using an intention-to-treat approach.

RESULTS

After matching, we included 636 patients (315 TKA; 321 THA). Median [interquartile range (IQR)] perioperative costs were CAD 7,417 [6,521-8,109], and hospital costs were CAD 10,293 [9,344-11,304]. Perioperative costs were not significantly different between groups (pseudo-median difference [MD], CAD -47 (95% confidence interval [CI], -214 to -130; P = 0.60); nor were total hospital costs (MD, CAD -78; 95% CI, -340 to 178; P = 0.57). Anesthesia-controlled time and total intraoperative time were significantly shorter for spinal anesthesia (MD, 14.6 min; 95% CI, 13.4 to 15.9; P < 0.001; MD, 15.9; 95% CI, 11.0 to 20.9; P < 0.001, respectively). There were no significant differences in complications.

CONCLUSION

Spinal anesthesia in the context of a dedicated block room reduced both anesthesia-controlled time and total OR time. This did not translate into a reduction in incremental cost in the spinal anesthesia group.

Efficacy of regional anesthesia techniques for postoperative analgesia in patients undergoing major oncologic breast surgeries: a systematic review and network meta-analysis of randomized controlled trials

BACKGROUND

The optimal regional technique to control pain after breast cancer surgery remains unclear. We sought to synthesize available data from randomized controlled trials comparing pain-related outcomes following various regional techniques for major oncologic breast surgery.

METHODS

In a systematic review and network meta-analysis, we searched trials in PubMed, Embase Scopus, Medline, Cochrane Central and Google Scholar, from inception to 31 July 2020, for commonly used regional techniques. The primary outcome was the 24-hr resting pain score measured on a numerical rating score of 0-10. We used surface under the cumulative ranking curve (SUCRA) to establish the probability of an intervention ranking highest. The analysis was performed using the Bayesian random effects model, and effect sizes are reported as 95% credible interval (Crl). We conducted cluster-rank analysis by combining 24-hr pain ranking with 24-hr opioid use or incidence of postoperative nausea and vomiting.

RESULTS

Seventy-nine randomized controlled trials containing 11 different interventions in 5,686 patients were included. The SUCRA values of the interventions for 24-hr resting pain score were continuous paravertebral block (0.83), serratus anterior plane block (0.76), continuous wound infusion (0.76), single-level paravertebral block (0.68), erector spinae plane block (0.59), modified pectoral block (0.49), intercostal block (0.45), multilevel paravertebral block (0.41), wound infiltration (0.33), no intervention (0.12), and placebo (0.08). When compared with placebo, the continuous paravertebral block (mean difference, 1.26; 95% Crl, 0.43 to 2.12) and serratus anterior plane block (mean difference, 1.12; 95% Crl, 0.32 to 1.9) had the highest estimated probability of decreasing 24-hr resting pain scores. Cluster ranking analysis combining 24-hr resting pain scores and opioid use showed that most regional analgesia techniques were more effective than no intervention or placebo. Nevertheless, wound infiltration and continuous wound infusion may be the least effective active interventions for reducing postoperative nausea and vomiting.

CONCLUSION

Continuous paravertebral block and serratus anterior plane block had a high probability of reducing pain at 24 hr after major oncologic breast surgery. The certainty of evidence was moderate to very low. Future studies should compare different regional anesthesia techniques, including surgeon-administered techniques such as wound infiltration or catheters. Trials comparing active intervention with placebo are unlikely to change clinical practice.

STUDY REGISTRATION

PROSPERO (CRD42020198244); registered 19 October 2020.

The practice of regional anesthesia during the COVID-19 pandemic: an international survey of members of three regional anesthesia societies

Purpose

To determine the preferences and attitudes of members of regional anesthesia societies during the COVID-19 pandemic.

Methods

We distributed an electronic survey to members of the American Society of Regional Anesthesia and Pain Medicine, Regional Anaesthesia-UK, and the European Society of Regional Anaesthesia & Pain Therapy. A questionnaire consisting of 19 questions was developed by a panel of experienced regional anesthesiologists and distributed by email to the participants. The survey covered the following domains: participant information, practice settings, preference for the type of anesthetic technique, the use of personal protective equipment, and oxygen therapy.

Results

The survey was completed by 729 participants from 73 different countries, with a response rate of 20.1% (729/3,630) for the number of emails opened and 8.5% (729/8,572) for the number of emails sent. Most respondents (87.7%) identified as anesthesia staff (faculty or consultant) and practiced obstetric and non-obstetric anesthesia (55.3%). The practice of regional anesthesia either expanded or remained the same, with only 2% of respondents decreasing their use compared with the pre-pandemic period. The top reasons for an increase in the use of regional anesthesia was to reduce the need for an aerosol-generating medical procedure and to reduce the risk of possible complications to patients. The most common reason for decreased use of regional anesthesia was the risk of urgent conversion to general anesthesia. Approximately 70% of the responders used airborne precautions when providing care to a patient under regional anesthesia. The most common oxygen delivery method was nasal prongs (cannula) with a surgical mask layered over it (61%).

Conclusions

Given the perceived benefits of regional over general anesthesia, approximately half of the members of three regional anesthesia societies seem to have expanded their use of regional anesthesia techniques during the initial surge of the COVID-19 pandemic.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12630-021-02150-8.

Standardizing nomenclature in regional anesthesia: an ASRA-ESRA Delphi consensus study of abdominal wall, paraspinal, and chest wall blocks

BACKGROUND

There is heterogeneity in the names and anatomical descriptions of regional anesthetic techniques. This may have adverse consequences on education, research, and implementation into clinical practice. We aimed to produce standardized nomenclature for abdominal wall, paraspinal, and chest wall regional anesthetic techniques.

METHODS

We conducted an international consensus study involving experts using a three-round Delphi method to produce a list of names and corresponding descriptions of anatomical targets. After long-list formulation by a Steering Committee, the first and second rounds involved anonymous electronic voting and commenting, with the third round involving a virtual round table discussion aiming to achieve consensus on items that had yet to achieve it. Novel names were presented where required for anatomical clarity and harmonization. Strong consensus was defined as ≥75% agreement and weak consensus as 50% to 74% agreement.

RESULTS

Sixty expert Collaborators participated in this study. After three rounds and clarification, harmonization, and introduction of novel nomenclature, strong consensus was achieved for the names of 16 block names and weak consensus for four names. For anatomical descriptions, strong consensus was achieved for 19 blocks and weak consensus was achieved for one approach. Several areas requiring further research were identified.

CONCLUSIONS

Harmonization and standardization of nomenclature may improve education, research, and ultimately patient care. We present the first international consensus on nomenclature and anatomical descriptions of blocks of the abdominal wall, chest wall, and paraspinal blocks. We recommend using the consensus results in academic and clinical practice.

Intraoperative Nociception Monitoring

Nociception refers to the process of encoding and processing noxious stimuli. Its monitoring can have potential benefits. Under anesthesia, nociceptive signals are continuously generated to cause involuntary effects on the autonomic nervous system, reflex movement, and stress response. Most available systems depend on the identification and measurement of these indirect effects to indicate nociception-antinociception balance. Despite advances in monitoring technology and availability, their limitations presently override their benefits. Hence, their utility and applicability in present-day anesthesia care is uncertain. Future technologies might allow automated closed-loop multimodal anesthesia systems, which includes the components of hypnosis and analgesic balance for a patient.

Ultrasound Imaging of the Spine for Central Neuraxial Blockade: a Technical Description and Evidence Update

Purpose of Review

This article describes the anatomy of the spine, relevant ultrasonographic views, and the techniques used to perform the neuraxial blocks using ultrasound imaging. Finally, we review the available evidence for the use of ultrasound imaging to perform neuraxial blocks.

Recent Findings

Central neuraxial blockade using traditional landmark palpation is a reliable technique to provide surgical anesthesia and postoperative analgesia. However, factors like obesity, spinal deformity, and previous spine surgery can make the procedure challenging. The use of ultrasound imaging has been shown to assist in these scenarios.

Summary

Preprocedural imaging minimizes the technical difficulty of spinal and epidural placement with fewer needle passes and skin punctures. It helps to accurately identify the midline, vertebral level, interlaminar space, and can predict the depth to the epidural and intrathecal spaces. By providing information about the best angle and direction of approach, in addition to the depth, ultrasound imaging allows planning an ideal trajectory for a successful block. These benefits are most noticeable when expert operators carry out the ultrasound examination and for patients with predicted difficult spinal anatomy. Recent evidence suggests that pre-procedural neuraxial ultrasound imaging may reduce complications such as vascular puncture, headache, and backache. Neuraxial ultrasound imaging should be in the skill set of every anesthesiologist who routinely performs lumbar or thoracic neuraxial blockade. We recommend using preprocedural neuraxial imaging routinely to acquire and maintain the imaging skills to enable success for challenging neuraxial procedures.

Factors associated with rebound pain after peripheral nerve block for ambulatory surgery

BACKGROUND

Rebound pain is a common, yet under-recognised acute increase in pain severity after a peripheral nerve block (PNB) has receded, typically manifesting within 24 h after the block was performed. This retrospective cohort study investigated the incidence and factors associated with rebound pain in patients who received a PNB for ambulatory surgery.

METHODS

Ambulatory surgery patients who received a preoperative PNB between March 2017 and February 2019 were included. Rebound pain was defined as the transition from well-controlled pain (numerical rating scale [NRS] ≤3) while the block is working to severe pain (NRS ≥7) within 24 h of block performance. Patient, surgical, and anaesthetic factors were analysed for association with rebound pain by univariate, multivariable, and machine learning methods.

RESULTS

Four hundred and eighty-two (49.6%) of 972 included patients experienced rebound pain as per the definition. Multivariable analysis showed that the factors independently associated with rebound pain were younger age (odds ratio [OR] 0.98; 95% confidence interval [CI] 0.97-0.99), female gender (OR 1.52 [1.15-2.02]), surgery involving bone (OR 1.82 [1.38-2.40]), and absence of perioperative i.v. dexamethasone (OR 1.78 [1.12-2.83]). Despite a high incidence of rebound pain, there were high rates of patient satisfaction (83.2%) and return to daily activities (96.5%).

CONCLUSIONS

Rebound pain occurred in half of the patients and showed independent associations with age, female gender, bone surgery, and absence of intraoperative use of i.v. dexamethasone. Until further research is available, clinicians should continue to use preventative strategies, especially for patients at higher risk of experiencing rebound pain.

Continuous peripheral nerve blocks compared to thoracic epidurals or multimodal analgesia for midline laparotomy: a systematic review and meta-analysis

BACKGROUND

Continuous peripheral nerve blocks (CPNBs) have been investigated to control pain for abdominal surgery via midline laparotomy while avoiding the adverse events of opioid or epidural analgesia. The review compiles the evidence comparing CPNBs to multimodal and epidural analgesia.

METHODS

We conducted a systematic review using broad search terms in MEDLINE, EMBASE, Cochrane. Primary outcomes were pain scores and cumulative opioid consumption at 48 hours. Secondary outcomes were length of stay and postoperative nausea and vomiting (PONV). We rated the quality of the evidence using Cochrane and GRADE recommendations. The results were synthesized by meta-analysis using Revman.

RESULTS

Our final selection included 26 studies (1,646 patients). There was no statistically significant difference in pain control comparing CPNBs to either multimodal or epidural analgesia (low quality evidence). Less opioids were consumed when receiving epidural analgesia than CPNBs (mean difference [MD]: -16.13, 95% CI [-32.36, 0.10]), low quality evidence) and less when receiving CPNBs than multimodal analgesia (MD: -31.52, 95% CI [-42.81, -20.22], low quality evidence). The length of hospital stay was shorter when receiving epidural analgesia than CPNBs (MD: -0.78 days, 95% CI [-1.29, -0.27], low quality evidence) and shorter when receiving CPNBs than multimodal analgesia (MD: -1.41 days, 95% CI [-2.45, -0.36], low quality evidence). There was no statistically significant difference in PONV comparing CPNBs to multimodal (high quality evidence) or epidural analgesia (moderate quality evidence).

CONCLUSIONS

CPNBs should be considered a viable alternative to epidural analgesia when contraindications to epidural placement exist for patients undergoing midline laparotomies.

Wrong-site nerve blocks: evidence-review and prevention strategies

PURPOSE OF REVIEW

There has been increasing attention to wrong site medical procedures over the last 20 years. This review aims to provide a summary of the current understanding and recommendations for the prevention of wrong-site nerve blocks (WSNB).

RECENT FINDINGS

Various procedural, patient, practitioner, and organizational factors have been associated with the risk of WSNB. Recent findings have suggested that the use of a checklist is likely to reduce the incidence of WSNB. However, despite the widespread use of preprocedural checklists, WSNB continue to occur at significant frequency. This may be due to the inability of practitioners and teams to implement checklists correctly or the cognitive errors that prevent checklists from being executed as designed.

SUMMARY

Though the evidence is limited, it is recommended that a combination of multiple strategies should be employed to prevent WSNB. These include the use of preprocedural markings, well constructed checklists, time-out/stop-moments, and cognitive/physical aids. Effective implementation requires team education and engagement that empowers all team members to speak up as part of a culture of safety.

Neuraxial anaesthesia and peripheral nerve blocks during the COVID-19 pandemic: a literature review and practice recommendations

Coronavirus disease 2019 (COVID‐19) has had a significant impact on global healthcare services. In an attempt to limit the spread of infection and to preserve healthcare resources, one commonly used strategy has been to postpone elective surgery, whilst maintaining the provision of anaesthetic care for urgent and emergency surgery. General anaesthesia with airway intervention leads to aerosol generation, which increases the risk of COVID‐19 contamination in operating rooms and significantly exposes the healthcare teams to COVID‐19 infection during both tracheal intubation and extubation. Therefore, the provision of regional anaesthesia may be key during this pandemic, as it may reduce the need for general anaesthesia and the associated risk from aerosol‐generating procedures. However, guidelines on the safe performance of regional anaesthesia in light of the COVID‐19 pandemic are limited. The goal of this review is to provide up‐to‐date, evidence‐based recommendations or expert opinion when evidence is limited, for performing regional anaesthesia procedures in patients with suspected or confirmed COVID‐19 infection. These recommendations focus on seven specific domains including: planning of resources and staffing; modifying the clinical environment; preparing equipment, supplies and drugs; selecting appropriate personal protective equipment; providing adequate oxygen therapy; assessing for and safely performing regional anaesthesia procedures; and monitoring during the conduct of anaesthesia and post‐anaesthetic care. Implicit in these recommendations is preserving patient safety whilst protecting healthcare providers from possible exposure.

Effect of combining peri-hamstring injection or anterior obturator nerve block on the analgesic efficacy of adductor canal block for anterior cruciate ligament reconstruction: a randomised controlled trial

BACKGROUND

Pain after anterior cruciate ligament reconstruction (ACLR) with autologous hamstring graft can be attributed to both arthroscopic surgery and the graft donor site. This study investigated whether donor site pain control was superior with the addition of either peri-hamstring injection or anterior division obturator nerve block in comparison with adductor canal block (ACB) alone.

METHODS

Patients scheduled to undergo knee arthroscopy with ACLR using a graft from the ipsilateral hamstring were randomised to one of three groups. All patients received ACB and multimodal analgesia. Subjects in Group H received peri-hamstring local anaesthetic injection while subjects in Group O received an anterior division of the obturator nerve block, and subjects in Group C served as a control group (ACB alone).

RESULTS

In 105 subjects undergoing ACLR, there was no significant difference between groups H, O, and C for the primary outcome of pain on movement as assessed by numerical rating scale (NRS) on knee flexion at 2 h after operation (P=0.11). There was no difference in NRS at any time point in the first 48 h after operation, nor was there a difference in oxycodone consumption between the three groups at 24 h (P=0.2). Worst knee pain was initially at the graft donor site in all three groups, which transitioned to anterior knee pain after 12 h.

CONCLUSIONS

The addition of ultrasound-guided peri-hamstring injection or anterior division of obturator nerve block to ACB did not result in a significant reduction in pain or opioid consumption after ACLR with ipsilateral hamstring graft.

CLINICAL TRIAL REGISTRATION

NCT01868282.

Association of obesity with failure of ultrasound-guided axillary brachial plexus block: a two-centre, prospective, observational, cohort study

The objective of this study was to evaluate whether the failure rate of ultrasound-guided axillary brachial plexus block is similar in obese patients compared with non-obese patients when performed as the primary anaesthetic technique. We recruited 105 obese (body mass index ≥ 30 kg.m-2 ) and 144 non-obese patients to this prospective, observational, cohort study conducted at two Canadian centres. A perineural technique of axillary brachial plexus block was performed using 30 ml ropivacaine 0.5% under real-time ultrasound guidance. Sensory and motor block assessment was carried out every 5 min until 30 min after block completion in all four terminal nerve distributions (radial, median, ulnar and musculocutaneous nerve). A composite score consisting of three sensory points and three motor points was used for assessment in each nerve distribution. A failed block was defined as a score of less than 14 points out of a possible 16 points, or a sensory block score less than 7 out of 8 points 30 min after block completion. Thirty minutes after block completion, obese patients had a higher failure rate of 33.7% (34/101) compared with 17.8% (24/135) for non-obese patients, with a failure rate difference (95%CI) of 15.9% (6.4-27.1%) between the groups. The median (IQR [range]) time to achieve a successful block in obese patients was 25 (20-30 [5-30]) min, compared with non-obese patients at 20 (15-30 [5-30]) min (p = 0.003). Despite a higher sensory-motor failure rate as per the composite score, the axillary brachial plexus block provided adequate surgical anaesthesia as indicated by a low need for conversion to general anaesthetic in obese (8.6%) and non-obese patients (7.0%; p = 0.656). This study showed that despite ultrasound guidance, obese patients had a slower onset time and higher axillary brachial plexus block failure rate at 30 min compared with non-obese patients.

Bilateral Thoracic Paravertebral Blocks Compared to Thoracic Epidural Analgesia After Midline Laparotomy: A Pragmatic Noninferiority Clinical Trial

BACKGROUND

Bilateral paravertebral block (PVB) is a suitable alternative to thoracic epidural analgesia (TEA) for abdominal surgeries. This randomized clinical trial aims to determine if PVB is noninferior to TEA in terms of analgesia after midline laparotomy.

METHODS

Seventy American Society of Anesthesiologists (ASA) class I-III patients undergoing a laparotomy through a midline incision were randomized to receive either TEA (TEA group) or continuous bilateral PVB (PVB group) as a part of a multimodal analgesia regimen in an open-label design. Noninferiority was to be concluded if the mean between-group difference in pain on movement at the 24 postoperative hours was within a margin of 2 points on a 0-10 numerical rating scale (NRS). Pain score at rest and on movement, analgesic consumption, hemodynamics, and adverse events during the first 72 postoperative hours were the secondary outcome measures assessed for superiority. Postblock and steady-state plasma concentrations of ropivacaine and pattern of dye spread were also recorded in the PVB group.

RESULTS

The primary outcome of pain scores on movement at 24 postoperative hours was noninferior in PVB group in comparison to TEA group (mean difference [95% confidence interval {CI}], 0.43 [-0.72-1.58]). The pain scores at rest and on movement at other time points of assessment were within clinically acceptable limits in both groups with no significant differences between the groups over time. Arterial plasma ropivacaine levels were within safe limits, while steady-state venous level was higher than an acceptable threshold in 9 of 34 cases.

CONCLUSIONS

As a component of multimodal analgesia, bilateral PVB provides noninferior analgesia compared to TEA for midline laparotomy.

Effect of Beam Steering on Echogenic and Nonechogenic Needle Visibility at 40°, 50°, and 60° Needle Insertion Angles

Currently, there is little understanding of the role of echogenic needles and beam steering at moderate angles of needle insertion. The ultrasound images of the echogenic and nonechogenic needles inserted into pork at 40°, 50°, and 60° were scored by anesthesiologists on a scale of 0-10. The effect of different levels of beam steer was also explored. At 40°, steep beam steering improves visualization of both nonechogenic and echogenic needles to an equal, satisfactory level. At 50° and 60°, visualization of nonechogenic needles is poor, whereas visibility of an echogenic needle was adequate and may be improved with steep beam steering.

Intrathecal hyperbaric versus isobaric bupivacaine for adult non-caesarean-section surgery: systematic review protocol

INTRODUCTION

Bupivacaine is the most commonly used local anaesthetic for spinal anaesthesia (SA). There are two forms of commercially available bupivacaine; isobaric bupivacaine (IB): a formulation with a specific gravity or density equal to cerebrospinal fluid, and hyperbaric bupivacaine (HB): a formulation with density heavier than cerebrospinal fluid. The difference in densities of the two available preparations is believed to affect the diffusion pattern that determines the effectiveness, spread and side-effect profile of bupivacaine. This systematic review will summarise the best available evidence regarding the effectiveness and safety on the use of HB compared with IB, when used to provide SA for surgery. Primarily, we will analyse the need for conversion to general anaesthesia. As secondary outcomes, we will compare the incidence of hypotension, incidence of nausea/vomiting, the onset time and duration of anaesthesia.

METHODS AND ANALYSIS

We will search key electronic databases using search strategy (1) injections, spinal OR intrathecal OR subarachnoid; (2) bupivacaine OR levobupivacaine; (3) hypobaric OR isobaric OR plain; (4) baricity. We will search MEDLINE, EMBASE and Cochrane databases, from their inception for randomised controlled trials, with no restrictions on language. Caesarean section surgery will be excluded. 2 reviewers will independently extract the data using a standardised form. Extracted items will include study characteristics, risk of bias domains, as per modified Cochrane risk of bias, participant disposition and study outcomes. We will conduct a meta-analysis for variables that can be compared across the studies. We will evaluate clinical heterogeneity by qualitatively appraising differences in study characteristics in participants, interventions and the outcomes assessed. We will report our findings as relative risks (dichotomous), and weighted mean differences (continuous) for individual outcomes, along with their 95% CIs.

ETHICS AND DISSEMINATION

We plan to submit, and will publish, our findings in a peer-reviewed scientific journal, and present our results at national and international meetings.

TRIAL REGISTRATION NUMBER

CRD42015017672.