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.

RéSUMé: OBJECTIF: Bien qu'un bloc interscalénique à injection unique fournisse une analgésie postopératoire précoce efficace après une chirurgie de l'épaule, les patient·es peuvent ressentir une « douleur de rebond ¼ lorsque le bloc se résorbe. Notre objectif était de déterminer si l'hydromorphone orale (2 mg) administrée six heures après une injection unique de bloc interscalénique pour une chirurgie arthroscopique de l'épaule entraînait une réduction cliniquement significative de la gravité de la douleur de rebond. MéTHODE: Après l'approbation des comités d'éthique de la recherche, nous avons mené une étude de supériorité dans deux centres, en groupes parallèles, à double insu, randomisée et contrôlée par placebo. Les patient·es ont reçu un bloc interscalénique préopératoire, une anesthésie générale et de l'hydromorphone ou un placebo six heures après le bloc. Le critère d'évaluation principal était le pire score de douleur au cours des premières 24 heures postopératoires, mesuré sur une échelle d'évaluation numérique de 11 points (0 à 10). RéSULTATS: Au total, 73 personnes ont participé à l'étude et ont été aléatoirement assignées au groupe hydromorphone ou au groupe placebo. Il n'y avait pas de différence statistiquement significative dans le score moyen (écart type) de la pire douleur dans les 24 heures entre les groupes hydromorphone et placebo (6,5 [2,4] vs 5,9 [2,3]; différence moyenne, 0,6; intervalle de confiance à 95 %, −0,5 à 1,8). De même, nous n'avons trouvé aucune différence significative dans la trajectoire de la douleur, la consommation d'opioïdes ou l'incidence de nausées et vomissements entre les groupes. Le temps moyen jusqu'à la pire douleur était de 14,6 heures, et le temps moyen jusqu'à la première analgésie de secours était de 11,3 heures après le bloc interscalénique. CONCLUSION: L'hydromorphone 2 mg administrée six heures après le bloc interscalénique n'a pas réduit la gravité de la douleur de rebond postopératoire par rapport au placebo chez les patient·es bénéficiant d'une chirurgie arthroscopique de l'épaule. ENREGISTREMENT DE L'éTUDE: ClinicalTrials.gov (NCT02939209); enregistrée le 19 octobre 2016.

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.

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.

RéSUMé: OBJECTIF: La rigueur scientifique de la conduite et de la communication des méta-analyses en réseau (MAR) en anesthésiologie est inconnue. Cette revue systématique et étude méta-épidémiologique a évalué la qualité méthodologique et de communication des MAR en anesthésiologie. MéTHODE: Nous avons mené des recherches dans quatre bases de données, soit MEDLINE, PubMed, Embase et la base de données des revues systématiques Cochrane, pour trouver des MAR en anesthésiologie publiées depuis la création de ces bases de données jusqu'en octobre 2020. Nous avons évalué la conformité des MAR par rapport à trois outils, soit : AMSTAR-2 (outil de mesure pour évaluer les revues systématiques), PRISMA-NMA et les listes de contrôle PRISMA. Nous avons mesuré la conformité de divers éléments des listes de contrôle AMSTAR-2 et PRISMA et formulé des recommandations pour améliorer la qualité. RéSULTATS: En utilisant la méthode de notation AMSTAR-2, 84 % (52/62) des MAR ont reçu la cote « extrêmement faible ¼. Quantitativement, le score médian [écart interquartile] sur l'AMSTAR-2 était de 55 [44-69] %, tandis que le score PRISMA était de 70 [61-81] %. Les scores méthodologiques et de communication ont montré une forte corrélation (R = 0,78). Les MAR en anesthésiologie avaient un score AMSTAR-2 et un score PRISMA plus élevés si elles étaient publiées dans des revues à facteur d'impact plus élevé (P = 0,006 et P = 0,01, respectivement) ou avaient suivi les lignes directrices de PRISMA-NMA en matière de communication des résultats (P = 0,001 et P = 0,002, respectivement). Les méta-analyses en réseau provenant de Chine avaient des scores plus faibles (P < 0,001 et P < 0,001, respectivement). Aucun des deux scores ne s'est amélioré au fil du temps (P = 0,69 et P = 0,67, respectivement). CONCLUSION: La présente étude met en évidence de nombreuses lacunes méthodologiques et de communication dans les MAR en anesthésiologie. Bien que l'outil AMSTAR ait été utilisé pour évaluer la qualité méthodologique des MAR, il est urgent de disposer d'outils spécialisés pour mener des MAR et en évaluer la qualité méthodologique. ENREGISTREMENT DE L'éTUDE: PROSPERO (CRD42021227997); soumis pour la première fois le 23 janvier 2021.

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.

Quadratus lumborum block for postoperative analgesia: a systematic review and meta-analysis.

PURPOSE: The goal of the present systematic review is to determine the efficacy of the quadratus lumborum block (QLB) in providing postoperative analgesia for abdominal wall and hip surgeries when compared with placebo or other analgesic techniques. METHODS: Electronic databases (Medline, Embase, Cochrane Central, and Scopus) were searched for keywords and controlled vocabulary terms related to QLB from their inception to November 2019. The included studies compared ultrasound-guided single-injection QLB to placebo and other analgesic techniques in adult patients. RESULTS: Forty-two randomized-controlled trials provided the data for this systematic review. Eight studies were assessed as high risk of bias in at least one domain. The included studies had significant heterogeneity with regard to the type of surgery, comparator groups, and outcomes measured; therefore, a limited quantitative analysis was undertaken for the comparison of QLB vs no block or placebo in patients undergoing Cesarean delivery only. For Cesarean delivery, the QLB reduced the opioid use by 24.1 (95% confidence interval, 17.3 to 30.9) mg oral morphine equivalents in the first postoperative 24 hr compared with no block or placebo with no difference in pain scores at rest. For other surgical procedures, the pain scores and opioid use were lower in the QLB group when compared with placebo or no regional anesthesia technique. When compared with other regional anesthetic techniques, the analgesic benefit of QLB was marginal. CONCLUSION: Quadratus lumborum block provided analgesic benefits compared with placebo for use in the abdominal wall and hip surgery, with only marginal benefits compared with other regional analgesic techniques. The identified studies used different variants of QLB in many different surgery types. These findings and conclusions, therefore, should be considered preliminary. TRIAL REGISTRATION: PROSPERO (CRD42018095965); registered 6 June 2018.

RéSUMé: OBJECTIF: L'objectif de cette revue systématique était de déterminer l'efficacité d'un bloc du muscle du carré des lombes pour l'analgésie postopératoire après une chirurgie impliquant la paroi abdominale ou les hanches, comparativement à un placebo ou à d'autres techniques analgésiques. MéTHODE: Nous avons réalisé des recherches dans les bases de données électroniques (Medline, Embase, Cochrane Central, et Scopus) pour trouver les mots-clés et les termes de vocabulaire contrôlé liés au bloc du carré des lombes depuis la création des bases de données jusqu'au mois de novembre 2019. Les études incluses comparaient une injection échoguidée unique pour réaliser un bloc du carré des lombes à un placebo et à d'autres techniques analgésiques chez des patients adultes. RéSULTATS: Quarante-deux études randomisées contrôlées ont fourni des données pour cette revue systématique. Huit études démontraient un risque élevé de biais dans au moins un domaine. Les études incluses présentaient une hétérogénéité importante en matière de type de chirurgie, de groupes comparés, et de résultats mesurés; une analyse quantitative limitée a par conséquent été entreprise pour comparer l'utilisation d'un bloc du muscle carré des lombes vs aucun bloc ou un placebo chez des patientes subissant un accouchement par césarienne. Lors d'un accouchement par césarienne, le bloc du carré des lombes a réduit la consommation d'opioïdes de 24,1 (intervalle de confiance 95 %, 17,3 à 30,9) mg en équivalent de morphine orale au cours des premières 24 h postopératoires par rapport à un accouchement par césarienne sans bloc ou avec placebo, et aucune différence n'a été observée dans les scores de douleur au repos. En ce qui a trait aux autres interventions chirurgicales, les scores de douleur et la consommation d'opioïdes étaient plus bas dans le groupe bloc du carré des lombes par rapport aux groupes placebo / aucune technique d'anesthésie régionale. Comparativement à d'autres techniques d'anesthésie régionale, les bienfaits analgésiques d'un bloc du carré des lombes étaient marginaux. CONCLUSION: Le bloc du carré des lombes a procuré des bienfaits analgésiques par rapport à un placebo lorsqu'il était utilisé en cas de chirurgie impliquant la paroi abdominale ou la hanche, mais ses bienfaits étaient marginaux comparativement aux autres techniques d'analgésie régionale. Les études identifiées utilisaient différentes variantes du bloc du carré des lombes dans de nombreux types différents de chirurgie. Il convient donc de considérer comme préliminaires ces observations et conclusions. ENREGISTREMENT DE L'éTUDE: PROSPERO (CRD42018095965); enregistrée le 6 juin 2018.

Efficacy of Intrathecal Fentanyl for Cesarean Delivery: A Systematic Review and Meta-analysis of Randomized Controlled Trials With Trial Sequential Analysis.

BACKGROUND: Fentanyl and morphine are the 2 most commonly added opioids to bupivacaine for spinal anesthesia during cesarean delivery. Numerous clinical trials have assessed efficacy and safety of different doses of fentanyl added to intrathecal bupivacaine for spinal anesthesia, yet its benefit, harm, and optimal dose remain unclear. This study aimed to systematically review the evidence of the efficacy of fentanyl when added to intrathecal bupivacaine alone and when added to bupivacaine with morphine for spinal anesthesia during cesarean delivery. METHODS: Key electronic databases (PubMed, Embase, and Cochrane Library) were searched for randomized controlled trials in the cesarean delivery population. The primary outcome was the failure rate of spinal anesthesia, as assessed by the need for either conversion to general anesthesia or intraoperative analgesic supplementation. Two reviewers independently extracted the data using a standardized electronic form. Results are expressed as relative risks or mean differences with 95% CIs. RESULTS: Seventeen randomized controlled clinical trials (most judged as low or unclear risk of bias) with 1064 participants provided data for the meta-analysis. Fentanyl added to intrathecal bupivacaine alone reduced the need for intraoperative supplemental analgesia (relative risk, 0.18; 95% CI, 0.11-0.27; number needed to treat, 4) and the incidence of nausea/vomiting (relative risk, 0.41; 95% CI, 0.24-0.70; number needed to treat, 6.5), with longer time to first postoperative analgesia request (mean difference, 91 minutes; 95% CI, 69-113). No difference was observed regarding the need for conversion to general anesthesia (relative risk, 0.67; 95% CI, 0.12-3.57), the incidence of hypotension, the onset of sensory block, or the duration of motor block. However, the addition of intrathecal fentanyl was associated with higher incidence of intraoperative pruritus (relative risk, 5.89; 95% CI, 2.07-16.79; number needed to harm, 13.5). The inclusion of fentanyl to intrathecal bupivacaine-morphine compared to intrathecal bupivacaine-morphine alone conferred a similar benefit, with a significantly reduced need for intraoperative supplemental analgesia (relative risk, 0.16; 95% CI, 0.03-0.95; number needed to treat, 9). Analysis using a funnel plot indicated a possibility of publication bias in included studies. CONCLUSIONS: Current evidence suggests a benefit of using fentanyl as both an additive to intrathecal bupivacaine alone and to intrathecal bupivacaine combined with morphine for cesarean delivery under spinal anesthesia. The possibility of publication bias, small sample size, and high risk of bias in some of the included studies warrant treating the results with caution.

Incidence of sub-perineural injection using a targeted intracluster supraclavicular ultrasound-guided approach in cadavers.

BACKGROUND: Multi-injection targeted intracluster injection ultrasound-guided supraclavicular brachial plexus block has been advocated to provide a faster onset of anaesthesia compared with a double injection technique. By placing the needle within clusters of hypoechoic structures, corresponding to neural tissue, this technique may increase needle trauma and the incidence of nerve injury. This study assessed the rate of sub-perineural needle placement with a single intracluster brachial plexus injection in the supraclavicular fossa of human cadavers. METHODS: A single ultrasound-guided intracluster brachial plexus injection was performed bilaterally at the supraclavicular fossa on 21 lightly embalmed clinical grade cadavers. Using an in-plane technique, an echogenic needle was positioned to target the middle or lower trunk 'cluster', where 0.2 ml black India ink was injected. An effort was taken to avoid the hypoechoic structures with the needle tip. Tissue samples were assessed histologically by two experienced reviewers. RESULTS: All 42 injections were sonographically assessed to be within the 'main cluster'. Ink was extra-epineural in 13/41 (32%), sub-epineural but outside perineurium in 18/41 (44%), and sub-perineural in 10/41 sections (24%; 95% confidence interval, 13-41%). The histology from one injection was uninterpretable. Of the 10 sub-perineural deposits, the ink was intrafascicular in nine sections. CONCLUSIONS: We observed a high rate of sub-perineural injection with a single intracluster injection. Thus the targeted intracluster injection supraclavicular block cannot be recommended until further evidence is available regarding the safety of this technique.

Hyperbaric Versus Isobaric Bupivacaine for Spinal Anesthesia: Systematic Review and Meta-analysis for Adult Patients Undergoing Noncesarean Delivery Surgery.

BACKGROUND: It is widely believed that the choice between isobaric bupivacaine and hyperbaric bupivacaine formulations alters the block characteristics for the conduct of surgery under spinal anesthesia. The aim of this study was to systematically review the comparative evidence regarding the effectiveness and safety of the 2 formulations when used for spinal anesthesia for adult noncesarean delivery surgery. METHODS: Key electronic databases were searched for randomized controlled trials, excluding cesarean delivery surgeries under spinal anesthesia, without any language or date restrictions. The primary outcome measure for this review was the failure of spinal anesthesia. Two independent reviewers selected the studies and extracted the data. Results were expressed as relative risk (RR) or mean differences (MDs) with 95% confidence intervals (CIs). RESULTS: Seven hundred fifty-one studies were identified between 1946 and 2016. After screening, there were 16 randomized controlled clinical trials, including 724 participants, that provided data for the meta-analysis. The methodological reporting of most studies was poor, and appropriate judgment of their individual risk of bias elements was not possible. There was no difference between the 2 drugs regarding the need for conversion to general anesthesia (RR, 0.60; 95% CI, 0.08-4.41; P = .62; I = 0%), incidence of hypotension (RR, 1.15; 95% CI, 0.69-1.92; P = .58; I = 0%), nausea/vomiting (RR, 0.29; 95% CI, 0.06-1.32; P = .11; I = 7%), or onset of sensory block (MD = 1.7 minutes; 95% CI, -3.5 to 0.1; P = .07; I = 0%). The onset of motor block (MD = 4.6 minutes; 95% CI, 7.5-1.7; P = .002; I = 78%) was significantly faster with hyperbaric bupivacaine. Conversely, the duration of motor (MD = 45.2 minutes; 95% CI, 66.3-24.2; P < .001; I = 87%) and sensory (MD = 29.4 minutes; 95% CI, 15.5-43.3; P < .001; I = 73%) block was longer with isobaric bupivacaine. CONCLUSIONS: Both hyperbaric bupivacaine and isobaric bupivacaine provided effective anesthesia with no difference in the failure rate or adverse effects. The hyperbaric formulation allows for a relatively rapid motor block onset, with shorter duration of motor and sensory block. The isobaric formulation has a slower onset and provides a longer duration of both sensory and motor block. Nevertheless, the small sample size and high heterogeneity involving these outcomes suggest that all the results should be treated with caution.