Analgesic Effectiveness of Liposomal Bupivacaine versus Plain Local Anesthetics for Abdominal Fascial Plane Blocks: A Systematic Review and Meta-analysis of Randomized Trials.

BACKGROUND: Liposomal bupivacaine is reported to prolong the duration of analgesia when used for abdominal fascial plane blocks compared to plain local anesthetics; however, evidence from randomized trials is mixed. This meta-analysis aims to compare the analgesic effectiveness of liposomal bupivacaine to plain local anesthetics in adults receiving abdominal fascial plane blocks. METHODS: Randomized trials comparing liposomal bupivacaine and plain (nonliposomal) local anesthetics in abdominal fascial plane blocks were sought. The primary outcome was area under the curve rest pain between 24 to 72 h postoperatively. Secondary outcomes included rest pain at individual timepoints (1, 6, 12, 24, 48, and 72 h); analgesic consumption at 0 to 24, 25 to 48, and 49 to 72 h; time to analgesic request; hospital stay duration; and opioid-related side effects. Data were pooled using the Hartung-Knapp-Sidik-Jonkman random effects method. RESULTS: Sixteen trials encompassing 1,287 patients (liposomal bupivacaine, 667; plain local anesthetics, 620) were included. The liposomal bupivacaine group received liposomal bupivacaine mixed with plain bupivacaine in 10 studies, liposomal bupivacaine alone in 5 studies, and both preparations in 1 three-armed study. No difference was observed between the two groups for area under the curve pain scores, with a standardized mean difference (95% CI) of -0.21 cm.h (-0.43 to 0.01; P = 0.058; I2 = 48%). Results were robust to subgroup analysis based on (1) potential conflict of interest and (2) mixing of plain local anesthetics with liposomal bupivacaine. The two groups were not different for any of the day 2 or day 3 secondary outcomes. CONCLUSIONS: This systematic review and meta-analysis suggests similar analgesic effectiveness between liposomal bupivacaine and plain local anesthetics when used for fascial plane block of the abdominal wall. The authors' analysis does not support an evidence-based preference for liposomal bupivacaine compared to plain local anesthetics for abdominal fascial plane blocks.

The analgesic effectiveness of perioperative lidocaine infusions for acute and chronic persistent postsurgical pain in patients undergoing breast cancer surgery: a systematic review and meta-analysis.

BACKGROUND: Breast cancer is the most common cancer among women and tumour resection carries a high prevalence of chronic persistent postsurgical pain (CPSP). Perioperative i.v. lidocaine infusion has been proposed as protective against CPSP; however, evidence of its benefits is conflicting. This review evaluates the effectiveness of perioperative lidocaine infusions for breast cancer surgery. METHODS: Randomised trials comparing perioperative lidocaine infusions with parenteral analgesia in breast cancer surgery patients were sought. The two co-primary outcomes were the odds of CPSP at 3 and 6 months after operation. Secondary outcomes included rest pain at 1, 6, 12, and 24 h; analgesic consumption at 0-24 and 25-48 h; quality of recovery; opioid-related side-effects; and lidocaine infusion side-effects. Hartung-Knapp-Sidik-Jonkman (HKSJ) random effects modelling was used. RESULTS: Thirteen trials (1039 patients; lidocaine: 518, control: 521) were included. Compared with control, perioperative lidocaine infusion did not decrease the odds of developing CPSP at 3 and 6 months. Lidocaine infusion improved postoperative pain at 1 h by a mean difference (95% confidence interval) of -0.65 cm (-0.73 to -0.57 cm) (P<0.0001); however, this difference was not clinically important (1.1 cm threshold). Similarly, lidocaine infusion reduced oral morphine consumption by 7.06 mg (-13.19 to -0.93) (P=0.029) over the first 24 h only; however, this difference was not clinically important (30 mg threshold). The groups were not different for any of the remaining outcomes. CONCLUSIONS: Our results provide moderate-quality evidence that perioperative lidocaine infusion does not reduce CPSP in patients undergoing breast cancer surgery. Routine use of lidocaine infusions for perioperative analgesia and CPSP prevention is not supported in this population. SYSTEMATIC REVIEW PROTOCOL: PROSPERO CRD42023420888.

Analgesic Effectiveness of Motor-sparing Nerve Blocks for Total Knee Arthroplasty: A Network Meta-analysis.

BACKGROUND: The analgesic effectiveness of contemporary motor-sparing nerve blocks used in combination for analgesia in total knee arthroplasty is unclear. This network meta-analysis was conducted to evaluate the analgesic effectiveness of adding single-injection or continuous adductor canal block (ACB) with or without infiltration of the interspace between the popliteal artery and the capsule of the posterior knee (iPACK) to intraoperative local infiltration analgesia (LIA), compared to LIA alone, after total knee arthroplasty. METHODS: Randomized trials examining the addition of single-injection or continuous ACB with or without single-injection block at the iPACK to LIA for total knee arthroplasty were considered. The two primary outcomes were area-under-the-curve pain scores over 24 to 48 h and postoperative function at greater than 24 h. Secondary outcomes included rest pain scores at 0, 6, 12, and 24 h; opioid consumption (from 0 to 24 h and from 25 to 48 h); and incidence of nausea/vomiting. Network meta-analysis was conducted using a frequentist approach. RESULTS: A total of 27 studies (2,317 patients) investigating the addition of (1) single-injection ACB, (2) continuous ACB, (3) single-injection ACB and single-injection block at the iPACK, and (4) continuous ACB and single-injection block at the iPACK to LIA, as compared to LIA alone, were included. For area-under-the-curve 24- to 48-h pain, the addition of continuous ACB with single-injection block at the iPACK displayed the highest P-score probability (89%) of being most effective for pain control. The addition of continuous ACB without single-injection block at the iPACK displayed the highest P-score probability (87%) of being most effective for postoperative function. CONCLUSIONS: The results suggest that continuous ACB, but not single-injection ACB and/or single-injection block at the iPACK, provides statistically superior analgesia when added to LIA for total knee arthroplasty compared to LIA alone. However, the magnitude of these additional analgesic benefits is clinically questionable.

Opioid prescribing and utilization patterns in patients having elective hip and knee arthroplasty: association between prescription patterns and opioid consumption.

PURPOSE: Although guidelines can reduce postoperative opioid prescription, the problem of unused opioids persists. We assessed the pattern of opioid prescription and utilization after total hip arthroplasty (THA) and total knee arthroplasty (TKA). We hypothesized that opioid prescription patterns can influence opioid utilization. METHODS: With institutional ethics approval, patients undergoing THA and TKA were enrolled prospectively. Surveys on opioid use were completed at two, six, and 12 weeks after surgery. Patients' age, sex, American Society of Anesthesiologists' Physical Status score, first 24-hr opioid consumption, quantity of opioid prescribed, and quantity of opioid utilized were analyzed to evaluate their effect on opioid consumption, unused opioid, and patient satisfaction. RESULTS: Patients received prescriptions ranging from 200 morphine milligram equivalents (MME) to 800 MME. Three hundred and thirty THA and 230 TKA patients completed the surveys. Opioid utilization was influenced by the amount of prescribed opioids for both THA and TKA. The percentage of prescribed opioids used (~55% in THA and ~75% in TKA) and the proportion of patients using all prescribed opioids (~22% in THA and ~50% in TKA) were higher after TKA vs THA (P < 0.001 for both). Patients who used opioids for two days or less accounted for most (~50%) of the unused opioid. Patient satisfaction remained high and was not influenced by the amount of prescribed opioid. CONCLUSION: This study showed that larger prescriptions are associated with higher opioid consumption. A wide variation in opioid consumption requires approaches to minimize the initial opioid prescription and to provide additional prescriptions for patients that require higher levels of analgesia.

RéSUMé: OBJECTIF: Bien que les lignes directrices puissent réduire la prescription d'opioïdes postopératoires, le problème des opioïdes inutilisés persiste. Nous avons évalué les schémas de prescription et d'utilisation d'opioïdes après une arthroplastie totale de la hanche (ATH) et une arthroplastie totale du genou (ATG). Nous avons émis l'hypothèse que les schémas de prescription d'opioïdes pouvaient influencer l'utilisation des opioïdes. MéTHODE: Avec l'approbation du comité d'éthique de notre établissement, les patients bénéficiant d'une ATH et une ATG ont été recrutés de manière prospective. Les questionnaires sur la consommation d'opioïdes ont été complétés deux, six et 12 semaines après la chirurgie. L'âge, le sexe et le score de statut physique selon l'American Society of Anesthesiologists des patients, ainsi que la consommation d'opioïdes au cours des premières 24 heures postopératoires, la quantité d'opioïdes prescrits et la quantité d'opioïdes utilisés ont été analysés pour évaluer leur effet sur la consommation d'opioïdes, les opioïdes inutilisés et la satisfaction des patients. RéSULTATS: Les patients ont reçu des ordonnances allant de 200 équivalents de morphine en milligrammes (EMM) à 800 EMM. Trois cent trente patients bénéficiant d'une ATH et 230 patients d'une ATG ont répondu aux questionnaires. L'utilisation des opioïdes a été influencée par la quantité d'opioïdes prescrits pour l'ATH et l'ATG. Le pourcentage d'opioïdes prescrits utilisés (~55 % dans l'ATH et ~75 % dans l'ATG) et la proportion de patients utilisant tous les opioïdes prescrits (~22 % dans l'ATH et ~50 % dans l'ATG) étaient plus élevés après l'ATG vs l'ATH (P < 0,001 pour les deux). Les patients qui ont utilisé des opioïdes pendant deux jours ou moins étaient à l'origine de la plupart (~ 50%) des opioïdes inutilisés. La satisfaction des patients est demeurée élevée et n'a pas été influencée par la quantité d'opioïdes prescrits. CONCLUSION: Cette étude a démontré que les ordonnances plus élevées sont associées à une consommation plus élevée d'opioïdes. Une grande variation dans la consommation d'opioïdes nécessite des approches visant à minimiser la prescription initiale d'opioïdes et à fournir des ordonnances supplémentaires aux patients qui nécessitent des niveaux plus élevés d'analgésie.

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

BACKGROUND: The risk of neurologic symptoms after regional anesthesia in orthopaedic surgery is estimated to approach 3%, with long-term deficits affecting 2 to 4 per 10,000 patients. However, current estimates are derived from large retrospective or observational studies that are subject to important systemic biases. Therefore, to harness the highest quality data and overcome the challenge of small numbers of participants in individual randomized trials, we undertook this systematic review and meta-analysis of contemporary randomized trials. QUESTIONS/PURPOSES: In this systematic review and meta-analysis of randomized trials we asked: (1) What is the aggregate pessimistic and optimistic risk of postoperative neurologic symptoms after regional anesthesia in upper extremity surgery? (2) What block locations have the highest and lowest risk of postoperative neurologic symptoms? (3) What is the timing of occurrence of postoperative neurologic symptoms (in days) after surgery? METHODS: We searched Ovid MEDLINE, Embase, Cochrane Central Register of Controlled Trials and Cochrane Database of Systematic Reviews, Web of Science, Scopus, and PubMed for randomized controlled trials (RCTs) published between 2008 and 2019 that prospectively evaluated postoperative neurologic symptoms after peripheral nerve blocks in operative procedures. Based on the Grading of Recommendations, Assessment, Development, and Evaluation guidance for using the Risk of Bias in Non-Randomized Studies of Interventions tool, most trials registered a global rating of a low-to-intermediate risk of bias. A total of 12,532 participants in 143 trials were analyzed. Data were pooled and interpreted using two approaches to calculate the aggregate risk of postoperative neurologic symptoms: first according to the occurrence of each neurologic symptom, such that all reported symptoms were considered mutually exclusive (pessimistic estimate), and second according to the occurrence of any neurologic symptom for each participant, such that all reported symptoms were considered mutually inclusive (optimistic estimate). RESULTS: At any time postoperatively, the aggregate pessimistic and optimistic risks of postoperative neurologic symptoms were 7% (915 of 12,532 [95% CI 7% to 8%]) and 6% (775 of 12,532 [95% CI 6% to 7%]), respectively. Interscalene block was associated with the highest risk (13% [661 of 5101] [95% CI 12% to 14%]) and axillary block the lowest (3% [88 of 3026] [95% CI 2% to 4%]). Of all symptom occurrences, 73% (724 of 998) were reported between 0 and 7 days, 24% (243 of 998) between 7 and 90 days, and 3% (30 of 998) between 90 and 180 days. Among the 31 occurrences reported at 90 days or beyond, all involved sensory deficits and four involved motor deficits, three of which ultimately resolved. CONCLUSION: When assessed prospectively in randomized trials, the aggregate risk of postoperative neurologic symptoms associated with peripheral nerve block in upper extremity surgery was approximately 7%, which is greater than previous estimates described in large retrospective and observational trials. Most occurrences were reported within the first week and were associated with an interscalene block. Few occurrences were reported after 90 days, and they primarily involved sensory deficits. Although these findings cannot inform causation, they can help inform risk discussions and clinical decisions, as well as bolster our understanding of the evolution of postoperative neurologic symptoms after regional anesthesia in upper extremity surgery. Future prospective trials examining the risks of neurologic symptoms should aim to standardize descriptions of symptoms, timing of evaluation, classification of severity, and diagnostic methods. LEVEL OF EVIDENCE: Level I, therapeutic study.

Postoperative Analgesic Effectiveness of Quadratus Lumborum Block for Cesarean Delivery under Spinal Anesthesia.

BACKGROUND: Spinal morphine is the mainstay of postcesarean analgesia. Quadratus lumborum block has recently been proposed as an adjunct or alternative to spinal morphine. The authors evaluated the analgesic effectiveness of quadratus lumborum block in cesarean delivery with and without spinal morphine. METHODS: Randomized trials evaluating quadratus lumborum block benefits in elective cesarean delivery under spinal anesthesia were sought. Three comparisons were considered: spinal morphine versus spinal morphine and quadratus lumborum block; spinal morphine versus quadratus lumborum block; and no block or spinal morphine versus quadratus lumborum block. The two coprimary outcomes were postoperative (1) 24-h cumulative oral morphine equivalent consumption and (2) pain at 4 to 6 h. Secondary outcomes included area under the curve pain, time to analgesic request, block complications, and opioid-related side effects. RESULTS: Twelve trials (924 patients) were analyzed. The mean differences (95% CIs) in 24-h morphine consumption and pain at 4 to 6 h for spinal morphine versus spinal morphine and quadratus lumborum block comparison were 0 mg (-2 to 1) and -0.1 cm (-0.7 to 0.4), respectively, indicating no benefit. For spinal morphine versus quadratus lumborum block, these differences were 7 mg (-2 to 15) and 0.6 cm (-0.7 to 1.8), respectively, also indicating no benefit. In contrast, for no block or spinal morphine versus quadratus lumborum block, improvements of -18 mg (-28 to -7) and -1.5 cm (-2.4 to -0.6) were observed, respectively, with quadratus lumborum block. Finally, for no block or spinal morphine versus quadratus lumborum block, quadratus lumborum block improved area under the 48-h pain curve by -4.4 cm · h (-5.0 to -3.8), exceeding the clinically important threshold (3.96 cm · h), but no differences were observed in the other comparisons. CONCLUSIONS: Moderate quality evidence suggests that quadratus lumborum block does not enhance analgesic outcomes when combined with or compared with spinal morphine. However, the block improves postcesarean analgesia in the absence of spinal morphine. The clinical utility of this block seems limited to situations in which spinal morphine is not used.

Perineural Liposomal Bupivacaine Is Not Superior to Nonliposomal Bupivacaine for Peripheral Nerve Block Analgesia.

BACKGROUND: Liposomal bupivacaine is purported to extend analgesia of peripheral nerve blocks when administered perineurally. However, evidence of the clinical effectiveness of perineural liposomal bupivacaine is mixed. This meta-analysis seeks to evaluate the effectiveness of perineural liposomal bupivacaine in improving peripheral nerve block analgesia as compared with nonliposomal local anesthetics. METHODS: The authors identified randomized trials evaluating the effectiveness of peripheral nerve block analgesic that compared liposomal bupivacaine with nonliposomal local anesthetics. The primary outcome was the difference in area under the receiver operating characteristics curve (AUC) of the pooled 24- to 72-h rest pain severity scores. Secondary outcomes included postoperative analgesic consumption, time to first analgesic request, incidence of opioid-related side effects, patient satisfaction, length of hospital stay, liposomal bupivacaine side effects, and functional recovery. AUC pain scores were interpreted in light of a minimal clinically important difference of 2.0 cm · h. RESULTS: Nine trials (619 patients) were analyzed. When all trials were pooled, AUC pain scores ± SD at 24 to 72 h were 7.6 ± 4.9 cm · h and 6.6 ± 4.6 cm · h for nonliposomal and liposomal bupivacaine, respectively. As such, perineural liposomal bupivacaine provided a clinically unimportant benefit by improving the AUC (95% CI) of 24- to 72-h pain scores by 1.0 cm · h (0.5 to 1.6; P = 0.003) compared with nonliposomal bupivacaine. Excluding an industry-sponsored trial rendered the difference between the groups nonsignificant (0.7 cm · h [-0.1 to 1.5]; P = 0.100). Secondary outcome analysis did not uncover any additional benefits to liposomal bupivacaine in pain severity at individual timepoints up to 72 h, analgesic consumption, time to first analgesic request, opioid-related side effects, patient satisfaction, length of hospital stay, and functional recovery. No liposomal bupivacaine side effects were reported. CONCLUSIONS: Perineural liposomal bupivacaine provided a statistically significant but clinically unimportant improvement in the AUC of postoperative pain scores compared with plain local anesthetic. Furthermore, this benefit was rendered nonsignificant after excluding an industry-sponsored trial, and liposomal bupivacaine was found to be not different from plain local anesthetics for postoperative pain and all other analgesic and functional outcomes. High-quality evidence does not support the use of perineural liposomal bupivacaine over nonliposomal bupivacaine for peripheral nerve blocks.

Subomohyoid Anterior Suprascapular Block versus Interscalene Block for Arthroscopic Shoulder Surgery: A Multicenter Randomized Trial.

BACKGROUND: Interscalene brachial plexus block, the pain relief standard for shoulder surgery, is an invasive technique associated with important complications. The subomohyoid anterior suprascapular block is a potential alternative, but evidence of its comparative analgesic effect is sparse. The authors tested the hypothesis that anterior suprascapular block is noninferior to interscalene block for improving pain control after shoulder surgery. As a secondary objective, the authors evaluated the success of superior trunk (C5-C6 dermatomes) block with suprascapular block. METHODS: In this multicenter double-blind noninferiority randomized trial, 140 patients undergoing shoulder surgery were randomized to either interscalene or anterior suprascapular block with 15 ml of ropivacaine 0.5% and epinephrine. The primary outcome was area under the curve of postoperative visual analog scale pain scores during the first 24 h postoperatively. The 90% CI for the difference (interscalene-suprascapular) was compared against a -4.4-U noninferiority margin. Secondary outcomes included presence of superior trunk blockade, pain scores at individual time points, opioid consumption, time to first analgesic request, opioid-related side-effects, and quality of recovery. RESULTS: A total of 136 patients were included in the analysis. The mean difference (90% CI) in area under the curve of pain scores for the (interscalene-suprascapular) comparison was -0.3 U (-0.8 to 0.12), exceeding the noninferiority margin of -4.4 U and demonstrating noninferiority of suprascapular block. The risk ratio (95% CI) of combined superior trunk (C5-C6 dermatomes) blockade was 0.98 (0.92 to 1.01), excluding any meaningful difference in superior trunk block success rates between the two groups. When differences in other analgesic outcomes existed, they were not clinically important. CONCLUSIONS: The suprascapular block was noninferior to interscalene block with respect to improvement of postoperative pain control, and also for blockade of the superior trunk. These findings suggest that the suprascapular block consistently blocks the superior trunk and qualify it as an effective interscalene block alternative.

Comparative analgesic efficacy and safety of intermittent local anaesthetic epidural bolus for labour: a systematic review and meta-analysis.

BACKGROUND: Continuous epidural infusion (CEI) is commonly used for labour analgesia, but concerns over potential motor block, second-stage labour complications, and ineffective analgesia in late labour have prompted examining intermittent epidural bolus (IEB) as an alternative. However, evidence comparing these modalities is conflicting. The meta-analysis evaluates the analgesic efficacy of CEI vs IEB. METHODS: Databases were searched for trials comparing CEI to IEB for labour analgesia. The two co-primary outcomes were risk of breakthrough pain and difference in area under the curve (AUC) for pain scores during the first 4 h post-epidural initiation. Local anaesthetic consumption, maternal outcomes (i.e. delivery mode, labour duration, and maternal satisfaction), and side-effects of epidural analgesia were also evaluated. Results were pooled using random-effects modelling. Trial sequential analysis (TSA) was used to evaluate evidence reliability. RESULTS: Twenty-seven studies (3133 patients) were analysed. Compared with CEI, IEB decreased risk of breakthrough pain by 38% (risk ratio [95% confidence interval {CI}] of 0.62 [0.48, 0.81]; P=0.0004; I2=47%; 1164 patients) and reduced AUC of pain during the 4 h interval by 32.9% (mean difference [95% CI] of -16.7 mm h-1 [-18.9, -14.4]; P<0.0001; 1638 patients). Intermittent epidural bolus enhanced maternal satisfaction, shortened labour duration, decreased motor block, and reduced local anaesthetic consumption. The difference between the two groups was not statistically significant for epidural side-effects or mode of delivery. The TSA indicated adequate power for reliable inferences. CONCLUSIONS: Intermittent epidural bolus provides improved labour pain control during the first 4 h after epidural initiation with less breakthrough pain. Moderate- to high-quality evidence of intermittent epidural bolus superiority support its use as a safe and effective continuous epidural infusion alternative for labour analgesia.

Short-term outcomes of combined neuraxial and general anaesthesia versus general anaesthesia alone for elective open abdominal aortic aneurysm repair: retrospective population-based cohort study†.

BACKGROUND: Use of neuraxial anaesthesia for open abdominal aortic aneurysm repair is postulated to reduce mortality and morbidity. This study aimed to determine the 90-day outcomes after elective open abdominal aortic aneurysm repair in patients receiving combined general and neuraxial anaesthesia vs general anaesthesia alone. METHODS: A retrospective population-based cohort study was conducted from 2003 to 2016. All patients ≥40 yr old undergoing open abdominal aortic aneurysm repair were included. The propensity score was used to construct inverse probability of treatment weighted regression models to assess differences in 90-day outcomes. RESULTS: A total of 10 447 elective open abdominal aortic aneurysm repairs were identified; 9003 (86%) patients received combined general and neuraxial anaesthesia and 1444 (14%) received general anaesthesia alone. Combined anaesthesia was associated with significantly lower hazards for all-cause mortality (hazard ratio [HR]=0.47; 95% confidence interval [CI], 0.37-0.61) and major adverse cardiovascular events (HR=0.72; 95% CI, 0.60-0.86). Combined patients were at lower odds for acute kidney injury (odds ratio [OR]=0.66; 95% CI, 0.49-0.89), respiratory failure (OR=0.41; 95% CI, 0.36-0.47), and limb complications (OR=0.30; 95% CI, 0.25-0.37), with higher odds of being discharged home (OR=1.32; 95% CI, 1.15-1.51). Combined anaesthesia was also associated with significant mechanical ventilation and ICU and hospital length of stay benefits. CONCLUSIONS: Combined general and neuraxial anaesthesia in elective open abdominal aortic aneurysm repair is associated with reduced 90-day mortality and morbidity. Neuraxial anaesthesia should be considered as a routine adjunct to general anaesthesia for elective open abdominal aortic aneurysm repair.

AAAPT Diagnostic Criteria for Acute Knee Arthroplasty Pain.

OBJECTIVE: The relationship between preexisting osteoarthritic pain and subsequent post-total knee arthroplasty (TKA) pain is not well defined. This knowledge gap makes diagnosis of post-TKA pain and development of management plans difficult and may impair future investigations on personalized care. Therefore, a set of diagnostic criteria for identification of acute post-TKA pain would inform standardized management and facilitate future research. METHODS: The Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks (ACTTION) public-private partnership with the US Food and Drug Administration (FDA), the American Pain Society (APS), and the American Academy of Pain Medicine (AAPM) formed the ACTTION-APS-AAPM Pain Taxonomy (AAAPT) initiative to address this goal. A multidisciplinary work group of pain experts was invited to conceive diagnostic criteria and dimensions of acute post-TKA pain. RESULTS: The working group used contemporary literature combined with expert opinion to generate a five-dimensional taxonomical structure based upon the AAAPT framework (i.e., core diagnostic criteria, common features, modulating factors, impact/functional consequences, and putative mechanisms) that characterizes acute post-TKA pain. CONCLUSIONS: The diagnostic criteria created are proposed to define the nature of acute pain observed in patients following TKA.

Is Supraclavicular Block as Good as Interscalene Block for Acute Pain Control Following Shoulder Surgery? A Systematic Review and Meta-analysis.

BACKGROUND: Interscalene block (ISB) is the acute pain management technique of choice for shoulder surgery, but its undesirable respiratory side effects have prompted seeking alternatives. Supraclavicular block (SCB) is proposed as an ISB alternative, but evidence of comparative analgesic and respiratory-sparing effects is inconsistent. We compared the analgesic and respiratory effects of SCB and ISB for shoulder surgery. METHODS: Trials comparing ISB to SCB for shoulder surgery were sought. We decided a priori that SCB would be an acceptable alternative if it were noninferior for (1) postoperative 24-hour cumulative oral morphine equivalent consumption (primary outcome, noninferiority margin Δ = -25 mg) and (2) postoperative pain (secondary outcome, noninferiority margin Δ = 4.0 cm·hour); and superior for (3) postblock respiratory dysfunction (primary outcome). Opioid-related side effects and block-related complications were also evaluated. RESULTS: Fifteen studies (1065 patients) were analyzed. In single-injection blocks, SCB was noninferior to ISB for 24-hour morphine consumption (mean difference for SCB-ISB, MD [95% confidence interval {CI}] = -3.11 mg [-9.42 to 3.19], Δ = -25 mg); it was also noninferior for 24-hour pain scores (MD = 0.78 cm·hour [0.07-1.49], Δ = 4.0 cm·hour); and decreased the odds of respiratory dysfunction (odds ratio [OR] [95% CI] = 0.08 [0.01-0.68]). Similarly, in continuous blocks, SCB was noninferior to ISB for 24-hour morphine consumption (MD = 0.46 mg [-6.08 to 5.15], Δ = -25 mg), and decreased the odds of respiratory dysfunction (OR = 0.22 [0.08-0.57]). SCB also decreased odds of minor block-related complications (OR = 0.36 [0.20-0.68] and OR = 0.25 [0.15-0.41] for single-injection and continuous blocks, respectively). Consequently, the null joint-hypothesis was rejected, and SCB can be considered an acceptable alternative to ISB. CONCLUSIONS: For acute pain control following shoulder surgery, high-quality evidence indicates that SCB can be used as an effective ISB alternative. SCB is noninferior for postoperative opioid consumption and acute pain, and it reduces the odds of postblock respiratory dysfunction.

A Population-based Comparative Effectiveness Study of Peripheral Nerve Blocks for Hip Fracture Surgery.

BACKGROUND: Adverse outcomes and resource use rates are high after hip fracture surgery. Peripheral nerve blocks could improve outcomes through enhanced analgesia and decreased opioid related adverse events. We hypothesized that these benefits would translate into decreased resource use (length of stay [primary outcome] and costs), and better clinical outcomes (pneumonia and mortality). METHODS: The authors conducted a retrospective cohort study of hip fracture surgery patients in Ontario, Canada (2011 to 2015) using linked health administrative data. Multilevel regression, instrumental variable, and propensity scores were used to determine the association of nerve blocks with resource use and outcomes. RESULTS: The authors identified 65,271 hip fracture surgery patients; 10,030 (15.4%) received a block. With a block, the median hospital stay was 7 (interquartile range, 4 to 13) days versus 8 (interquartile range, 5 to 14) days without. Following adjustment, nerve blocks were associated with a 0.6-day decrease in length of stay (95% CI, 0.5 to 0.8). This small difference was consistent with instrumental variable (1.1 days; 95% CI, 0.9 to 1.2) and propensity score (0.2 days; 95% CI, 0.2 to 0.3) analyses. Costs were lower with a nerve block (adjusted difference, -$1,421; 95% CI, -$1,579 to -$1,289 [Canadian dollars]), but no difference in mortality (adjusted odds ratio, 0.99; 95% CI, 0.89 to 1.11) or pneumonia (adjusted odds ratio, 1.01; 95% CI, 0.88 to 1.16) was observed. CONCLUSIONS: Receipt of nerve blocks for hip fracture surgery is associated with decreased length of stay and health system costs, although small effect sizes may not reflect clinical significance for length of stay.

Pectoralis-II Myofascial Block and Analgesia in Breast Cancer Surgery: A Systematic Review and Meta-analysis.

BACKGROUND: Thoracic paravertebral block is the preferred regional anesthetic technique for breast cancer surgery, but concerns over its invasiveness and risks have prompted search for alternatives. Pectoralis-II block is a promising analgesic technique and potential alternative to paravertebral block, but evidence of its absolute and relative effectiveness versus systemic analgesia (Control) and paravertebral block, respectively, is conflicting. This meta-analysis evaluates the analgesic effectiveness of Pectoralis-II versus Control and paravertebral block for breast cancer surgery. METHODS: Databases were searched for breast cancer surgery trials comparing Pectoralis-II with Control or paravertebral block. Postoperative oral morphine consumption and difference in area under curve for pooled rest pain scores more than 24 h were designated as coprimary outcomes. Opioid-related side effects, effects on long-term outcomes, such as chronic pain and opioid dependence, were also examined. Results were pooled using random-effects modeling. RESULTS: Fourteen randomized trials (887 patients) were analyzed. Compared with Control, Pectoralis-II provided clinically important reductions in 24-h morphine consumption (at least 30.0 mg), by a weighted mean difference [95% CI] of -30.5 mg [-42.2, -18.8] (P < 0.00001), and in rest pain area under the curve more than 24 h, by -4.7cm · h [-5.1, -4.2] or -1.2cm [-1.3, -1.1] per measurement. Compared with paravertebral block, Pectoralis-II was not statistically worse (not different) for 24-h morphine consumption, and not clinically worse for rest pain area under curve more than 24 h. No differences were observed in opioid-related side effects or any other outcomes. CONCLUSIONS: We found that Pectoralis-II reduces pain intensity and morphine consumption during the first 24 h postoperatively when compared with systemic analgesia alone; and it also offers analgesic benefits noninferior to those of paravertebral block after breast cancer surgery. Evidence supports incorporating Pectoralis-II into multimodal analgesia and also using it as a paravertebral block alternative in this population.

Opioid- and Motor-sparing with Proximal, Mid-, and Distal Locations for Adductor Canal Block in Anterior Cruciate Ligament Reconstruction: A Randomized Clinical Trial.

BACKGROUND: The ideal location for single-injection adductor canal block that maximizes analgesia while minimizing quadriceps weakness after painful knee surgery is unclear. This triple-blind trial compares ultrasound-guided adductor canal block injection locations with the femoral artery positioned medial (proximal adductor canal), inferior (mid-adductor canal), and lateral (distal adductor canal) to the sartorius muscle to determine the location that optimizes postoperative analgesia and motor function. The hypothesis was that distal adductor block has (1) a superior opioid-sparing effect and (2) preserved quadriceps strength, compared with proximal and mid-locations for anterior cruciate ligament reconstruction. METHODS: For the study, 108 patients were randomized to proximal, mid-, or distal adductor canal injection locations for adductor canal block. Cumulative 24-h oral morphine equivalent consumption and percentage quadriceps strength decrease (maximum voluntary isometric contraction) at 30 min postinjection were coprimary outcomes. The time to first analgesic request, pain scores, postoperative nausea/vomiting at least once within the first 24 h, and block-related complications at 2 weeks were also evaluated. RESULTS: All patients completed the study. Contrary to the hypothesis, proximal adductor canal block decreased 24-h morphine consumption to a mean ± SD of 34.3 ± 19.1 mg, (P < 0.0001) compared to 64.0 ± 33.6 and 65.7 ± 22.9 mg for the mid- and distal locations, respectively, with differences [95% CI] of 29.7 mg [17.2, 42.2] and 31.4 mg [21.5, 41.3], respectively, mostly in the postanesthesia care unit. Quadriceps strength was similar, with 16.7%:13.4%:15.3% decreases for proximal:mid:distal adductor canal blocks. The nausea/vomiting risk was also lower with proximal adductor canal block (10 of 34, 29.4%) compared to distal location (23 of 36, 63.9%; P = 0.005). The time to first analgesic request was longer, and postoperative pain was improved up to 6 h for proximal adductor canal block, compared to mid- and distal locations. CONCLUSIONS: A proximal adductor canal injection location decreases opioid consumption and opioid-related side effects without compromising quadriceps strength compared to mid- and distal locations for adductor canal block in patients undergoing anterior cruciate ligament reconstruction.

Evidence Basis for Regional Anesthesia in Ambulatory Anterior Cruciate Ligament Reconstruction: Part I-Femoral Nerve Block.

The optimal management of pain after ambulatory anterior cruciate ligament reconstruction (ACLR) is unclear. Femoral nerve block (FNB) is purported to enhance postoperative analgesia, but its effectiveness in the setting of modern multimodal analgesia is unclear. This systematic review examines the effect of adding FNB to multimodal analgesia on analgesic outcomes after ACLR, whether or not the analgesic regimen used included local instillation analgesia (LIA). We retrieved randomized controlled trials evaluating the effects of adding FNB to multimodal analgesia on analgesic outcomes after ACLR, compared to multimodal analgesia alone (control). We designated postoperative opioid consumption at 24 hours as our primary outcome. Secondary outcomes included postoperative opioid consumption at 24-48 hours, rest, and dynamic pain severity between 0 and 48 hours, time to analgesic request, postanesthesia care unit and hospital stay durations, patient satisfaction, postoperative nausea and vomiting, functional outcomes, and long-term (>1 month) quadriceps strength. Eight randomized controlled trials (716 patients) were identified. Five trials compared FNB administration to control, and another 3 compared the combination of FNB and LIA to LIA alone. Compared to control, adding FNB resulted in modest reductions in 24-hour opioid consumption in 2 of 3 trials, and improvements in rest pain at 1 hour in 1 trial and up to 24 hours in another. In contrast, the combination of FNB and LIA, compared to LIA alone, did not reduce opioid consumption in any of the trials, but it did improve pain scores at 20 minutes only in 1 trial. The effect of FNB on long-term quadriceps strength or function after ACLR was not evaluated in the reviewed trials. Contemporary evidence suggests that the benefits of adding FNB to multimodal analgesia for ACLR are modest and conflicting, but there is no incremental analgesic benefit if the multimodal analgesic regimen included LIA. Our findings do not support the routine use of FNB for analgesia in patients having ACLR.

Pain Management for Ambulatory Arthroscopic Anterior Cruciate Ligament Reconstruction: Evidence-Based Recommendations From the Society for Ambulatory Anesthesia.

Ambulatory arthroscopic anterior cruciate ligament reconstruction is associated with moderate pain, even when nonopioid oral analgesics such as acetaminophen and nonsteroidal anti-inflammatory drugs are used. Regional analgesia can supplement nonopioid oral analgesics and reduce postoperative opioid requirements, but the choice of regional analgesia technique for anterior cruciate ligament reconstruction remains controversial. Femoral nerve block, adductor canal block, and local instillation analgesia have all been proposed and are supported by some evidence from randomized controlled trials. Consequently, regional analgesia practice in patients undergoing anterior cruciate ligament reconstruction remains mixed. Published systematic reviews were used to identify the regional analgesia modality that would provide a balance between analgesic efficacy and associated potential risks in the setting of nonopioid multimodal analgesic strategies. Based on the evidence available, local instillation analgesia provides the best balance of analgesic efficacy and associated risks (strong recommendation, moderate level of evidence) when used as a component of multimodal analgesic technique in the first 24 hours after outpatient arthroscopic anterior cruciate ligament reconstruction. In the absence of local instillation analgesia, clinicians might use adductor canal block or femoral nerve block (weak recommendation, weak level of evidence). These recommendations have been endorsed by the Society of Ambulatory Anesthesia and approved by its board of directors.

Evidence Basis for Regional Anesthesia in Ambulatory Anterior Cruciate Ligament Reconstruction: Part III: Local Instillation Analgesia-A Systematic Review and Meta-analysis.

BACKGROUND: Local infiltration analgesia offers effective postoperative analgesia after knee arthroplasty, but the role of its counterpart, local instillation analgesia (LIA), in anterior cruciate ligament reconstruction (ACLR) is unclear. This systematic review and meta-analysis evaluates the analgesic benefits of LIA for outpatient ACLR. METHODS: We sought randomized controlled trials investigating the analgesic effects of LIA versus control in adults having outpatient ACLR and receiving multimodal analgesia (excluding nerve blocks, which are examined in parts I and II of this project). Cumulative postoperative analgesic consumption at 24 hours was designated as a primary outcome. Analgesic consumption during postanesthesia care unit stay, proportion of patients requiring analgesic supplementation, time-to-first analgesic request, rest pain scores during the first 48 hours, hospital length of stay, and incidence of opioid-related side effects were analyzed as secondary outcomes and pooled using random effects modeling. RESULTS: Eleven randomized controlled trials (515 patients) were included. Analgesic consumption was selected as the primary outcome in 4 trials (36%). Compared to control, LIA reduced the 24-hour morphine consumption by a weighted mean difference (95% confidence interval) of -18.0 mg (-33.4 to -2.6) (P = .02). LIA reduced postanesthesia care unit morphine consumption by -55.9 mg (-88.4 to -23.4) (P < .05) and decreased the odds (odds ratio [95% confidence interval]) of analgesic supplementation during the first 24 hours by 0.4 (0.2-0.8) (P = .004). LIA also improved pain scores during the 0-24-hour interval, most notably at 4 hours (-1.6 [-2.2 to -1.0) (P < .00001). CONCLUSIONS: Administering LIA for outpatient ACLR improves postoperative analgesia by decreasing opioid consumption and improving pain control up to 24 hours, with minimal complications. These findings encourage integrating LIA into the care standard for ACLR. Questions regarding the ideal LIA components, location, and role in the setting of hamstring grafts require further research.

Dexamethasone Is Superior to Dexmedetomidine as a Perineural Adjunct for Supraclavicular Brachial Plexus Block: Systematic Review and Indirect Meta-analysis.

BACKGROUND: Both dexamethasone and dexmedetomidine are effective peripheral nerve block (PNB) perineural adjuncts that prolong block duration. However, each is associated with side effects. With paucity of head-to-head comparisons of these adjuncts, the question of the best adjunct to mix with local anesthetics (LA) for PNB is unanswered. This meta-analysis aims to inform current practice and future research by identifying the superior adjunct by comparing dexamethasone and dexmedetomidine. METHODS: Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, trials comparing the combination of perineural dexamethasone or dexmedetomidine with LA to LA alone for PNB were sought. The Cochrane Risk of Bias Tool was used to assess the methodological quality of trials, and indirect or network meta-analyses using random-effects modeling were planned. We designated duration of analgesia as a primary outcome. Secondary outcomes included sensory and motor block durations, sensory and motor block onset times, and the risks of hypotension, sedation, and neurological symptoms. RESULTS: Fifty trials were identified, including only 1 direct comparison, precluding a network meta-analysis. Indirect meta-analysis of 49 trials (3019 patients) was performed. Compared to dexmedetomidine, dexamethasone prolonged the duration of analgesia by a mean difference (95% confidence interval [CI]) of 148 minutes (37-259 minutes) (P = .003), without prolonging sensory/motor blockade. Dexmedetomidine increased rates of hypotension (risk ratio [95% CI], 6.3 [1.5-27.5]; P = .01) and sedation (risk ratio [95% CI], 15.8 [3.9-64.6]; P = .0001). Overall risk of bias was moderate, and publication bias was noted, resulting in downgrading evidence strength. CONCLUSIONS: There is low-quality evidence that both adjuncts similarly prolong sensory/motor blockade. However, dexamethasone may be a superior adjunct; it improves the duration of analgesia by a statistically significant increase, albeit clinically modest, equivalent to 2.5 hours more than dexmedetomidine, without the risks of hypotension or sedation. Future direct comparisons are encouraged.

Evidence Basis for Regional Anesthesia in Ambulatory Arthroscopic Knee Surgery and Anterior Cruciate Ligament Reconstruction: Part II: Adductor Canal Nerve Block-A Systematic Review and Meta-analysis.

BACKGROUND: Adductor canal block (ACB) has emerged as an effective analgesic regional technique for major knee surgeries in the last decade. Its motor-sparing properties make it particularly attractive for ambulatory knee surgery, but evidence supporting its use in ambulatory arthroscopic knee surgery is conflicting. This systematic review and meta-analysis evaluates the analgesic effects of ACB for ambulatory arthroscopic knee surgeries. METHODS: We conducted a comprehensive search of electronic databases for randomized controlled trials examining the analgesic effects of ACB compared to control or any other analgesic modality. Both minor arthroscopic and anterior cruciate ligament reconstruction (ACLR) surgeries were considered. Rest and dynamic pain scores, opioid consumption, opioid-related adverse effects, time to first analgesic request, patient satisfaction, quadriceps strength, and block-related complications were evaluated. Data were pooled using random-effects modeling. RESULTS: Our search yielded 10 randomized controlled trials comparing ACB with placebo or femoral nerve block (FNB); these were subgrouped according to the type of knee surgery. For minor knee arthroscopic surgery, ACB provided reduced postoperative resting pain scores by a mean difference (95% confidence interval) of -1.46 cm (-2.03 to -0.90) (P < .00001), -0.51 cm (-0.92 to -0.10) (P = .02), and -0.48 cm (-0.93 to -0.04) (P = .03) at 0, 6, and 8 hours, respectively, compared to control. Dynamic pain scores were reduced by a mean difference (95% confidence interval) of -1.50 cm (-2.10 to -0.90) (P < .00001), -0.50 cm (-0.95 to -0.04) (P = .03), and -0.59 cm (-1.12 to -0.05) (P = .03) at 0, 6, and 8 hours, respectively, compared to control. ACB also reduced the cumulative 24-hour oral morphine equivalent consumption by -7.41 mg (-14.75 to -0.08) (P = .05) compared to control. For ACLR surgery, ACB did not provide any analgesic benefits and did not improve any of the examined outcomes, compared to control. ACB was also not different from FNB for these outcomes. CONCLUSIONS: After minor ambulatory arthroscopic knee surgery, ACB provides modest analgesic benefits, including improved relief for rest pain, and reduced opioid consumption for up to 8 and 24 hours, respectively. The analgesic benefits of ACB are not different from placebo or FNB after ambulatory ACLR, suggesting a limited role of both blocks in this procedure. Paucity of trials dictates cautious interpretation of these findings. Future studies are needed to determine the role of ACB in the setting of local anesthetic instillation and/or graft donor-site analgesia.