The analgesic efficacy of transversus abdominis plane block vs. wound infiltration after inguinal and infra-umbilical hernia repairs: A systematic review and meta-analysis with trial sequential analysis.

BACKGROUND: Both transversus abdominis plane (TAP) block and wound infiltration with local anaesthetic have been used to relieve pain after inguinal or infra-umbilical hernia repair. OBJECTIVES: To determine whether TAP block or local anaesthetic infiltration is the best analgesic option after inguinal or infra-umbilical hernia repair. DESIGN: Systematic review and meta-analysis with trial sequential analysis. DATA SOURCES: MEDLINE, Embase, Cochrane Central Register of Controlled Clinical Trials, Web of Science, up to June, 2020. ELIGIBILITY CRITERIA: We retrieved randomised controlled trials comparing TAP block with wound infiltration after inguinal or infra-umbilical hernia repair. Primary outcome was rest pain score (analogue scale 0 to 10) at 2 postoperative hours. Secondary pain-related outcomes included rest pain score at 12 and 24 h, and intravenous morphine consumption at 2, 12 and 24 h. Other secondary outcomes sought were block-related complications such as rates of postoperative infection, haematoma, visceral injury and systemic toxicity of local anaesthetic. RESULTS: Seven trials including 420 patients were identified. There was a significant difference in rest pain score at 2 postoperative hours in favour of TAP block compared with wound infiltration, with a mean (95% confidence interval) difference of -0.8 (-1.3 to -0.2); I2  = 85%; P   =  0.01. Most secondary pain-related outcomes were also significantly improved following TAP block. No complication was reported. The overall quality of evidence was moderate. CONCLUSION: There is moderate level evidence that TAP block provides superior analgesia compared with wound infiltration following inguinal or infra-umbilical hernia repair. TRIAL REGISTRY NUMBER: PROSPERO CRD42020208053.

Transversus abdominis plane block versus local anaesthetic wound infiltration for analgesia after caesarean section: A systematic review and meta-analysis with trial sequential analysis.

BACKGROUND: Transversus abdominis plane (TAP) block and local anaesthetic wound infiltration are used to relieve pain after caesarean section. OBJECTIVES: To determine whether TAP block or local anaesthetic wound infiltration is the better analgesic option after caesarean section. DESIGN: Systematic review and meta-analysis with trial sequential analysis. DATA SOURCES: MEDLINE, Embase, Cochrane Central Register of Controlled Clinical Trials, Web of Science up to June 2020. ELIGIBILITY CRITERIA: We retrieved randomised controlled trials comparing TAP block with wound infiltration after caesarean section. Primary outcome was pain score during rest (analogue scale, 0 to 10) at 2 h postoperatively, analysed according to the TAP block technique (ultrasound-guided/landmark-guided), anaesthetic strategy (spinal/general), intrathecal fentanyl (yes/no) and multimodal analgesia (yes/no). Secondary pain-related outcomes included pain scores during rest at 12 and 24 h, and total intravenous morphine consumption at 2, 12 and 24 h. We sought rates of block complications, including postoperative infection, haematoma, visceral injury and local anaesthetic systemic toxicity. RESULTS: Seven trials, totalling 475 patients, were identified. There was no difference in pain score during rest at 2 h between groups. Subgroup analyses revealed no differences related to TAP block technique (P = 0.64), anaesthetic strategy (P = 0.53), administration of intrathecal fentanyl (P = 0.59) or presence of multimodal analgesia (P = 0.57). Pain score during rest at 12 h and intravenous morphine consumption at 2 and 12 h were identical in both groups. Data were insufficient to compare block complications. Overall quality of evidence was moderate. CONCLUSION: There is moderate level evidence that TAP block and wound infiltration provide similar postoperative analgesia after caesarean section. TRIAL REGISTRY NUMBER: PROSPERO CRD42020208046.

Factors associated with success and failure of patient-controlled oral analgesia after total hip and knee arthroplasty: a historical comparative cohort study.

PURPOSE: Patient-controlled oral analgesia (PCOA) is a novel method of oral opioid administration using set doses of short-acting oral opioids self-administered by patients with a "lockout" period as part of a multimodal regimen. Failure of PCOA can result in severe postoperative pain necessitating use of intravenous patient-controlled analgesia (IV-PCA) with its potential complications. This study evaluated factors related to success or failure of PCOA following total hip arthroplasty (THA) and total knee arthroplasty (TKA). METHODS: We conducted a retrospective cohort study of all adults who underwent THA and TKA at our institution by extracting data from the proprietary database of our acute pain service. Patient, anesthetic, and surgical variables associated with PCOA failure defined as inadequate analgesia requiring conversion to IV-PCA within 24 hr following THA and TKA were evaluated. Univariable and multivariable logistic regression analyses were performed to identify predictors of PCOA failure. RESULTS: Of the 926 patients who underwent THA or TKA (n = 411 and 515, respectively), 147 (15.9%) patients (67 THA and 80 TKA patients) had PCOA failure with moderate-to-severe pain. Multivariable regression analysis showed that PCOA failure occurred in those with younger age (adjusted odds ratio [aOR] per year of age, 0.97; 99% CI, 0.95 to 0.99; P < 0.001), preoperative chronic use of controlled-release opioids (aOR, 3.45; 99% CI, 1.60 to 7.35; P < 0.001), and with the use of general anesthesia vs spinal anesthesia (aOR, 2.86; 99% CI, 1.20 to 6.84; P = 0.002). CONCLUSION: The use of PCOA provides adequate analgesia to a majority of patients undergoing THA and TKA. Factors predictive for PCOA failure should be considered when choosing the primary breakthrough analgesic modality following THA/TKA.

RéSUMé: OBJECTIF: L'analgésie orale contrôlée par le patient (AOCP) est une méthode novatrice d'administration d'opioïdes oraux qui utilise des doses pré-établies d'opioïdes oraux à courte action auto-administrées par les patients avec un intervalle minimal entre les doses dans le cadre d'un régime multimodal. Le non-fonctionnement d'une AOCP peut entraîner une douleur postopératoire grave nécessitant le recours à une analgésie intraveineuse contrôlée par le patient (ACP-IV), ce qui s'accompagne de complications potentielles. Cette étude a évalué les facteurs liés à la réussite ou à l'échec de l'AOCP à la suite d'une arthroplastie totale de la hanche (ATH) ou du genou (ATG). MéTHODE: Nous avons réalisé une étude de cohorte rétrospective de tous les adultes ayant subi une ATH ou une ATG dans notre établissement en extrayant les données de la base de données de notre service de douleur aiguë. Les variables liées au patient, à l'anesthésie, et à la chirurgie et associées à un échec de l'AOCP, défini comme une analgésie inadéquate exigeant la conversion en ACP-IV dans les 24 heures suivant l'ATH ou l'ATG, ont été évaluées. Des analyses de régression logistique univariée et multivariée ont été effectuées pour identifier les prédicteurs d'un échec de l'AOCP. RéSULTATS: Sur les 926 patients ayant subi une ATH ou une ATG (n = 411 et 515, respectivement), l'AOCP n'a pas fonctionné chez 147 (15,9 %) patients (67 patients d'ATH et 80 d'ATG), entraînant une douleur modérée à grave. L'analyse de régression multivariée a montré que les échecs de l'AOCP sont survenus chez les personnes plus jeunes (rapport de cotes ajusté [RCA] par année d'âge, 0,97; IC 99 %, 0,95 à 0,99; P < 0,001), lors d'une utilisation préopératoire chronique d'opioïdes à libération contrôlée (RCA, 3,45; IC 99 %, 1,60 à 7,35; P < 0,001), et lors d'une anesthésie générale vs une rachianesthésie (RCA, 2,86; IC 99 %, 1,20 à 6,84; P = 0,002). CONCLUSION: L'utilisation de l'AOCP procure une analgésie adéquate à la majorité des patients subissant une ATH ou une ATG. Les facteurs prédictifs d'un échec de l'AOCP devraient être pris en considération lors du choix de la principale modalité analgésique après une ATH/ATG.

Low- versus high-dose intraoperative opioids: A systematic review with meta-analyses and trial sequential analyses.

BACKGROUND: Opioid-induced hyperalgesia is a state of nociceptive sensitisation secondary to opioid administration. The objective of this meta-analysis was to test the hypothesis that high-dose intraoperative opioids contribute to increased post-operative pain and hyperalgesia when compared with a low-dose regimen in patients under general anaesthesia. METHODS: We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement guidelines and rated the certainty of evidence with the Grading of Recommendations, Assessment, Development and Evaluation system. Only trials investigating pain outcomes and comparing two different dosages of the same intraoperative opioid in patients under general anaesthesia were included. The primary outcome was pain score (analogue scale, 0-10) at 24 post-operative hours. Secondary outcomes included pain score and cumulative intravenous morphine equivalents (mg) consumed at 2 post-operative hours, together with mechanical pain threshold (g·mm-2 ). RESULTS: Twenty-seven randomised controlled trials, including 1630 patients, were identified. Pain score at rest at 24 post-operative hours was increased in the high-dose group (mean difference [95% CI]: -0.2 [-0.4, -0.1]; trial sequential analysis-adjusted CI: -0.4, -0.02; low certainty of evidence). Similarly, at 2 post-operative hours, both pain score (mean difference [95% CI]: -0.4 [-0.6, -0.2]; low certainty of evidence) and cumulative intravenous morphine equivalents consumed (mean difference [95% CI]: -1.6 mg [-2.6, -0.7]; low certainty of evidence) were significantly higher in the high-dose group. Finally, the threshold for mechanical pain was significantly lower in the high-dose group (mean difference to pressure [95% CI]: 3.8 g·mm-2 [1.8, 5.8]; low certainty of evidence). CONCLUSIONS: There is low certainty of evidence that high-dose intraoperative opioid administration increases pain scores in the post-operative period, when compared with a low-dose regimen.

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

BACKGROUND: Innervation of the clavicle is complex and debated, with scarce data on the analgesic and clinical impact of regional anaesthesia after surgical repair of clavicle fracture. METHODS: In order to assess the analgesic efficiency of an interscalene brachial plexus block (ISB) for surgical repair of clavicle fracture, 50 consecutive patients scheduled for surgical fixation of middle/lateral clavicle fracture under general anaesthesia with ISB were prospectively enrolled. This cohort was compared to a historical control of 76 retrospective patients without regional block. The primary outcome was total intravenous morphine equivalent consumption at 2 postoperative hours. To assess the ISB impact, both an overall cohort analysis and a case-matched analysis with each ISB-treated patient matched to a Non-ISB-treated patient was performed. Matching employed a 1-to-1, nearest-neighbour approach using the Mahalanobis metric. RESULTS: In the overall cohort, patients with ISB had significantly lower i.v. morphine equivalent consumption at 2 postoperative hours (0.7 mg (95% CI 0.1 to 1.2) versus controls 8.8 mg (95% CI 7.1 to 10.4); P <  0.0001). These results persisted after case-matching the cohorts (mean difference for the primary outcome: 8.3 mg (95% CI 6.5 to 10.0); P <  0.001). CONCLUSIONS: ISB provides effective analgesia after surgical fixation of middle and lateral clavicle fracture. These results should help physicians in establishing an analgesic strategy for this type of surgery. Further research is needed to identify the optimal regional technique for medial third clavicle fractures and the clinically relevant contributions of the cervical and brachial plexus. TRIAL REGISTRATION: Clinicaltrials.gov - NCT02565342, October 1st 2015.

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

BACKGROUND: Both the adductor canal block (ACB) and local infiltration analgesia (LIA) are effective analgesic techniques after anterior cruciate ligament (ACL) reconstruction, but they have never been compared head-to-head. This randomised controlled triple-blinded trial tested the hypothesis that ACB provides superior analgesia to LIA after ACL reconstruction, with additional focus on postoperative functional outcomes. METHODS: Of 104 enrolled ACL reconstruction patients receiving general anaesthesia, 52 were randomly allocated to either ACB under ultrasound guidance or LIA. For each intervention, ropivacaine 0.5%, 20 ml was injected. Postoperative pain treatment followed a predefined protocol with i.v. patient-controlled morphine, paracetamol, and ibuprofen. The primary outcome was cumulative i.v. morphine consumption at 24 h after operation. Secondary pain-related outcomes included resting and dynamic pain scores (numeric rating scale out of 10) measured 2, 24, and 48 h after operation and cumulative i.v. morphine consumption 2 and 48 h after operation. Early function-related outcomes evaluated were quadriceps strength, walking distance, and range of motion, all measured 24 and 48 h after operation. Late function-related outcomes were concentric quadriceps strength, single-hop test, triple-hop test, cross-over test, and Y balance test, measured at 4 and 8 postoperative months. RESULTS: Cumulative i.v. morphine consumption at 24 h was similar between groups (ACB group: 17.1 mg [95% confidence interval, CI: 13.1, 21.2]; LIA group: 17.7 mg [95% CI: 13.2, 22.6], P=0.84). Similarly, no differences between groups were seen in the secondary pain- or function-related outcomes. CONCLUSIONS: ACB and LIA result in equivalent postoperative opioid consumption with similar impact on postoperative pain scores and functional outcomes. CLINICAL TRIAL REGISTRATION: NCT02524652.

Fascia iliaca block in the emergency department for hip fracture: a randomized, controlled, double-blind trial.

BACKGROUND: Hip fracture causes moderate to severe pain and while fascia iliaca block has been reported to provide analgesic benefit, most previous trials were unblinded, with subsequent high risks of performance, selection and detection biases. In this randomized, control double-blind trial, we tested the hypothesis that a fascia iliaca block provides effective analgesia for patients suffering from hip fracture. METHODS: Thirty ASA I-III hip fracture patients over 70 years old, who received prehospital morphine, were randomized to receive either a fascia iliaca block using 30 ml of bupivacaine 0.5% with epinephrine 1:200,000 or a sham injection with normal saline. The fascia iliaca block was administered by emergency medicine physicians trained to perform an anatomic landmark-based technique. The primary outcome was the comparison between groups of the longitudinal pain score profiles at rest over the first 45 min following the procedure (numeric rating scale, 0-10). Secondary outcomes included the longitudinal pain score profiles on movement and the comparison over 4 h, 8 h, 12 h, and 24 h after the procedure, along with cumulative intravenous morphine consumption at 24 h. RESULTS: At baseline, the fascia iliaca group had a lower mean pain score than the sham injection group, both at rest (difference = - 0.9, 95%CI [- 2.4, 0.5]) and on movement (difference = - 0.9, 95%CI [- 2.7; 0.9]). These differences remained 45 min after the procedure and the two longitudinal pain score profiles were parallel both for patients at rest and on movement (test of parallelism for patients at rest p = 0.53 and on movement p = 0.45). The same parallel change in pain scores over time was observed over 24 h of follow-up (test of parallelism for patients at rest p = 0.82 and on movement p = 0.12). These results were confirmed after adjustment for gender, ASA score, and cumulative sums of intravenous morphine received pre-procedure and during-follow-up. In addition, there was no difference between the two groups in total cumulative intravenous morphine consumption at 24 h. CONCLUSION: Fascia iliaca block following anatomic landmarks may not provide supplementary analgesia for patients suffering from hip fracture, when low pain scores are reported after prehospital morphine. Additional larger trials will help reach definitive conclusion. TRIAL REGISTRATION NUMBER: Clinicaltrials.gov - NCT02433548 . The study was registered retrospectively.

Practice advisory on the bleeding risks for peripheral nerve and interfascial plane blockade: evidence review and expert consensus.

The risk of bleeding complications during regional anesthesia procedures is a significant patient safety consideration. Nevertheless, existing literature provides limited guidance on the stratification of bleeding risk for peripheral nerve and newly described interfascial plane blocks. Our objective was to produce an evidence-based consensus advisory that classifies bleeding risks in patients undergoing regional peripheral nerve and interfascial plane block procedures. This advisory is intended to facilitate clinical decision-making in conjunction with national or local guidelines and to guide consideration for appropriate alterations to anticoagulation regimens before specific regional anesthesia procedures. In pursuit of this goal, the Regional Anesthesia and Acute Pain Section of the Canadian Anesthesiologists Society (CAS) assembled a panel of seven Canadian experts to classify the risk of bleeding complications associated with regional peripheral nerve and interfascial plane blocks. At the 75th annual meeting of the CAS in June 2018, the panel's expert opinion was finalized and the published literature was quantified within an organized framework. All common peripheral nerve and interfascial plane blocks were categorized into "low risk", "intermediate risk", and "high risk" based on the literature evidence, bleeding risk scores, and consensus opinion (in that order of priority). Clinical data is often limited, so readers of this consensus report should be reminded that these recommendations are mostly based on expert consensus. Hence, this advisory should not to be defined as a standard of care but rather serve as a resource for clinicians assessing the risk and benefits of regional anesthesia in management of their patients.

Measuring the frequency and variation of unnecessary care across Canada.

BACKGROUND: Through the Choosing Wisely Canada (CWC) campaign, national medical specialty societies have released hundreds of recommendations against health care services that are unnecessary, i.e. present little to no benefit or cause avoidable harm. Despite growing interest in unnecessary care both within Canada and internationally, prior research has typically avoided taking a national or even multi-jurisdictional approach in measuring the extent of the issue. This study estimates use of three unnecessary services identified by CWC recommendations across multiple Canadian jurisdictions. METHODS: Two retrospective cohort studies were conducted using administrative health care data collected between fiscal years 2011/12 and 2012/13 to respectively quantify use of 1) diagnostic imaging (spinal X-ray, CT or MRI) among Albertan patients following a visit for lower back pain and 2) cardiac tests (electrocardiogram, chest X-ray, stress test, or transthoracic echocardiogram) prior to low-risk surgical procedures in Alberta, Saskatchewan, and Ontario. A cross-sectional study of the 2012 Canadian Community Health Survey was also conducted to estimate 3) the proportion of females aged 40-49 that reported having a routine mammogram in the past two years. RESULTS: Use of unnecessary care was relatively frequent across all three services and jurisdiction measured: 30.7% of Albertan patients had diagnostic imaging within six months of their initial visit for lower back pain; a cardiac test preceded 17.9 to 35.5% of low-risk surgical procedures across Alberta, Saskatchewan, and Ontario; and 22.2% of Canadian women aged 40-49 at average-risk for breast cancer reported having a routine screening mammogram in the past two years. CONCLUSIONS: The use of potentially unnecessary care appears to be common in Canada. This investigation provides methodology to facilitate future measurement efforts that may incorporate additional jurisdictions and/or unnecessary services.

Optimal Dose of Perineural Dexamethasone to Prolong Analgesia After Brachial Plexus Blockade: A Systematic Review and Meta-analysis.

BACKGROUND: Perineural dexamethasone has gained popularity in regional anesthesia to prolong analgesia duration. However, uncertainty remains regarding the optimal perineural dose. Clarification of this characteristic is of significant importance as the administration of dexamethasone may lead to dose-dependent complications. The objective of this meta-analysis was to define the optimal perineural dexamethasone dose to prolong analgesia after brachial plexus blockade for adult patients undergoing upper limb surgery. METHODS: We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement guidelines and searched databases including MEDLINE, PubMed, and EMBASE until January 2017, without language restriction. Only trials comparing perineural dexamethasone and local anesthetics with local anesthetics alone for brachial plexus blocks were included in the present meta-analysis. The Cochrane Collaboration's Risk of Bias Tool was used to assess the methodological quality of each trial and meta-analyses were performed following a random effects model. The primary outcome was duration of analgesia for each type of local anesthetic (short-/intermediate-acting and long-acting local anesthetics). A meta-regression followed by a subgroup analysis were performed to assess the impact of different perineural dexamethasone doses on duration of analgesia; for the latter analysis, trials were grouped in low (1-4 mg) and moderate (5-10 mg) dexamethasone doses. Secondary outcomes included the rate of neurologic complication and resting pain scores and morphine consumption within the first 24 hours. RESULTS: Thirty-three controlled trials, including 2138 patients, were identified. The meta-regression revealed a ceiling effect with a perineural dexamethasone dose of 4 mg when combined with short-/intermediate-acting (8 trials; 366 participants) or long-acting local anesthetics (23 trials; 1869 participants). This finding was confirmed by subgroup analyses comparing low and moderate dexamethasone doses. With short-/intermediate-acting local anesthetics, the mean difference (95% confidence interval) of analgesia duration with low and moderate doses was 277 (234-322) minutes and 229 (161-297) minutes, respectively. With long-acting local anesthetics, the mean differences with low and moderate doses were 505 (342-669) minutes and 509 (443-575) minutes. Perineural dexamethasone did not increase the rate of neurologic complications (risk ratio [95% confidence interval], 1.40 [0.54-3.63]). The Grades of Recommendation, Assessment, Development, and Evaluation quality of evidence for the primary and secondary outcomes were very low, due mainly to limitations, inconsistency, indirectness, and publication bias. CONCLUSIONS: There is currently very low quality evidence that 4 mg of perineural dexamethasone represents a ceiling dose that prolongs analgesia duration by a mean period of 6 and 8 hours when combined with short-/intermediate- or long-acting local anesthetics, respectively. Additional data are needed to explore the threshold for this effect, particularly with doses below 4 mg. The risk of neurologic complications is probably not increased (very low evidence).

Preoperative Laboratory Investigations: Rates and Variability Prior to Low-risk Surgical Procedures.

BACKGROUND: Increasing attention has been focused on low-value healthcare services. Through Choosing Wisely campaigns, routine laboratory testing before low-risk surgery has been discouraged in the absence of clinical indications. The authors investigated rates, determinants, and institutional variation in laboratory testing before low-risk procedures. METHODS: Patients who underwent ophthalmologic surgeries or predefined low-risk surgeries in Ontario, Canada, between April 1, 2008, and March 31, 2013, were identified from population-based administrative databases. Preoperative blood work was defined as a complete blood count, prothrombin time, partial thromboplastin, or basic metabolic panel within 60 days before an index procedure. Adjusted associations between patient and institutional factors and preoperative testing were assessed with hierarchical multivariable logistic regression. Institutional variation was characterized using the median odds ratio. RESULTS: The cohort included 906,902 patients who underwent 1,330,466 procedures (57.1% ophthalmologic and 42.9% low-risk surgery) at 119 institutions. Preoperative blood work preceded 400,058 (30.1%) procedures. The unadjusted institutional rate of preoperative blood work varied widely (0.0 to 98.1%). In regression modeling, significant predictors of preoperative testing included atrial fibrillation (adjusted odds ratio [AOR], 2.58; 95% CI, 2.51 to 2.66), preoperative medical consultation (AOR, 1.68; 95% CI, 1.65 to 1.71), previous mitral valve replacement (AOR, 2.33; 95% CI, 2.10 to 2.58), and liver disease (AOR, 1.69; 95% CI, 1.55 to 1.84). The median odds ratio for interinstitutional variation was 2.43. CONCLUSIONS: Results of this study suggest that testing is associated with a range of clinical covariates. However, an association was similarly identified with preoperative consultation, and significant variation between institutions exists across the jurisdiction.

Preoperative testing before low-risk surgical procedures.

BACKGROUND: There is concern about increasing utilization of low-value health care services, including preoperative testing for low-risk surgical procedures. We investigated temporal trends, explanatory factors, and institutional and regional variation in the utilization of testing before low-risk procedures. METHODS: For this retrospective cohort study, we accessed linked population-based administrative databases from Ontario, Canada. A cohort of 1 546 223 patients 18 years or older underwent a total of 2 224 070 low-risk procedures, including endoscopy and ophthalmologic surgery, from Apr. 1, 2008, to Mar. 31, 2013, at 137 institutions in 14 health regions. We used hierarchical logistic regression models to assess patient- and institution-level factors associated with electrocardiography (ECG), transthoracic echocardiography, cardiac stress test or chest radiography within 60 days before the procedure. RESULTS: Endoscopy, ophthalmologic surgery and other low-risk procedures accounted for 40.1%, 34.2% and 25.7% of procedures, respectively. ECG and chest radiography were conducted before 31.0% (95% confidence interval [CI] 30.9%-31.1%) and 10.8% (95% CI 10.8%-10.8%) of procedures, respectively, whereas the rates of preoperative echocardiography and stress testing were 2.9% (95% CI 2.9%-2.9%) and 2.1% (95% CI 2.1%-2.1%), respectively. Significant variation was present across institutions, with the frequency of preoperative ECG ranging from 3.4% to 88.8%. Receipt of preoperative ECG and radiography were associated with older age (among patients 66-75 years of age, for ECG, adjusted odds ratio [OR] 18.3, 95% CI 17.6-19.0; for radiography, adjusted OR 2.9, 95% CI 2.8-3.0), preoperative anesthesia consultation (for ECG, adjusted OR 8.7, 95% CI 8.5-8.8; for radiography, adjusted OR 2.2, 95% CI 2.1-2.2) and preoperative medical consultation (for ECG, adjusted OR 6.8, 95% CI 6.7-6.9; for radiography, adjusted OR 3.6, 95% CI 3.5-3.6). The median ORs for receipt of preoperative ECG and radiography were 2.3 and 1.6, respectively. INTERPRETATION: Despite guideline recommendations to limit testing before low-risk surgical procedures, preoperative ECG and chest radiography were performed frequently. Significant variation across institutions remained after adjustment for patient- and institution-level factors.

The Analgesic Efficacy of Ultrasound-Guided Transversus Abdominis Plane Block in Adult Patients: A Meta-Analysis.

BACKGROUND: Previous meta-analyses of the transversus abdominis plane (TAP) block have examined a maximum of 12 articles, including fewer than 650 participants, and have not examined the effect of ultrasound-guided techniques specifically. Recently, many trials that use ultrasound approaches to TAP block have been published, which report conflicting analgesic results. This meta-analysis aims to evaluate the analgesic efficacy of ultrasound-guided TAP blocks exclusively for all types of abdominal surgeries in adult patients. METHODS: This meta-analysis was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement guidelines. The primary outcome was cumulative IV morphine consumption at 6 hours postoperatively, analyzed according to the type of surgery, the type of surgical anesthesia, the timing of injection, the block approach adopted, and the presence of postoperative multimodal analgesia. Secondary outcomes included IV morphine consumption at 24 hours postoperatively; pain scores at rest and on movement at 6 and 24 hours postoperatively; and postoperative nausea and vomiting, pruritus, and rates of complications. RESULTS: Thirty-one controlled trials including 1611 adult participants were identified. Independent of the type of surgery (abdominal laparotomy, abdominal laparoscopy, and cesarean delivery) but not independent of the type of surgical anesthesia (general anesthesia, spinal anesthesia with or without intrathecal long-acting opioid), ultrasound-guided TAP block reduced IV morphine consumption at 6 hours postoperatively by a mean difference of 6 mg (95% confidence interval [CI], -7 to -4 mg; I2 = 94%; P < 0.00001). The magnitude of the reduction in morphine consumption at 6 hours postoperatively was not influenced by the timing of injection (I2 = 0%; P = 0.72), the block approach adopted (I2 = 0%; P = 0.72), or the presence of postoperative multimodal analgesia (I2 = 73%; P = 0.05). This difference persisted at 24 hours postoperatively (mean difference, -11 mg; 95% CI, -14 to -8 mg; I2 = 99%; P < 0.00001). Pain scores at rest and on movement were reduced at 6 hours postoperatively (mean difference at rest, -10; 95% CI, -15 to -5; I2 = 92%; P = 0.0002; mean difference on movement, -9; 95% CI, -14 to -5; I2 = 58%; P < 0.00001). There were neither differences in the incidence of postoperative nausea and vomiting (I2 = 1%; P = 0.59) nor in the pruritus (I2 = 12%; P = 0.58) Two minor complications (1 bruise and 1 anaphylactoid reaction) were reported in 1028 patients. CONCLUSIONS: Ultrasound-guided TAP block provides marginal postoperative analgesic efficacy after abdominal laparotomy or laparoscopy and cesarean delivery. However, it does not provide additional analgesic effect in patients who also received spinal anesthesia containing a long-acting opioid. The minimal analgesic efficacy is independent of the timing of injection, the approach adopted, or the presence of postoperative multimodal analgesia. Because of heterogeneity of the results, these findings should be interpreted with caution.

Gabapentin reduces preoperative anxiety and pain catastrophizing in highly anxious patients prior to major surgery: a blinded randomized placebo-controlled trial.

INTRODUCTION: Gabapentin is increasingly being used for the treatment of postoperative pain and a variety of psychiatric diseases, including chronic anxiety disorders. Trials have reported mixed results when gabapentin has been administered for the treatment of preoperative anxiety. We tested the hypothesis that gabapentin 1,200 mg vs placebo would reduce preoperative anxiety in patients who exhibit moderate to high preoperative anxiety. METHODS: A blinded randomized controlled trial was conducted from September 2009 to June 2011 at the Toronto General Hospital. Following ethics approval and informed consent, 50 female patients with a 0-10 numeric rating scale (NRS) anxiety score of greater than or equal to 5/10 consented to receive either gabapentin 1,200 mg (n = 25) or placebo (n = 25) prior to surgery. Randomization was computer generated, and the Investigational Pharmacy was responsible for the blinding and dispensing of medication. All patients and care providers, including physicians, nurses, and study personnel, were blinded to group allocation. Before administering the study medication, baseline anxiety levels were measured using a NRS, the Spielberger State-Trait Anxiety Inventories, the Pain Catastrophizing Scale, and the Pain Anxiety Symptoms Scale-20. Baseline pain intensity (0-10 NRS) and level of sedation (0-10 NRS and Richmond Agitation-Sedation Scale [RASS]) were also measured. Two hours after the administration of gabapentin or placebo (prior to surgery), patients again rated their anxiety, pain, and sedation levels using the same measurement tools as at baseline. The main outcome was a reduction in preoperative anxiety. RESULTS: Forty-four patients (22 treated with gabapentin 1,200 mg and 22 treated with placebo) were included in the analysis of the primary outcome. Analysis of covariance in which pre-drug NRS anxiety scores were used as the covariate showed that post-drug preoperative NRS anxiety (Effect size, 1.44; confidence interval [CI] 0.19 to 2.70) and pain catastrophizing (Effect size, 0.43; CI 0.12 to 0.74) scores were significantly lower in the gabapentin group than in the placebo control group, respectively. Post-drug sedation (Effect size, -3.02; CI -4.28 to -1.77) and RASS (Effect size, 0.41; CI 0.12 to 0.71) scores were significantly higher in the gabapentin group than in the placebo group, respectively. CONCLUSIONS: Administration of gabapentin 1,200 mg prior to surgery reduces preoperative NRS anxiety scores and pain catastrophizing scores and increases sedation prior to entering the operating room. These results suggest that gabapentin 1,200 mg may be a treatment option for patients who exhibit high levels of preoperative anxiety and pain catastrophizing; however, the sedative properties of the medication and the possibility of delayed postoperative discharge in the elective ambulatory population need to be considered.

Validity of non-contact methods for diagnosis of Obstructive Sleep Apnea: a systematic review and meta-analysis.

STUDY OBJECTIVE: Obstructive Sleep Apnea (OSA) is associated with increased perioperative cardiac, respiratory and neurological complications. Pre-operative OSA risk assessment is currently done through screening questionnaires with high sensitivity but poor specificity. The objective of this study was to evaluate the validity and diagnostic accuracy of portable, non-contact devices in the diagnosis of OSA as compared with polysomnography. DESIGN: This study is a systematic review of English observational cohort studies with meta-analysis and risk of bias assessment. SETTING: Pre-operative, including in the hospital and clinic setting. PATIENTS: Adult patients undergoing sleep apnea assessment using polysomnography and an experimental non-contact tool. INTERVENTIONS: A novel non-contact device, which does not utilize any monitor that makes direct contact with the patient's body, in conjunction with polysomnography. MEASUREMENTS: Primary outcomes included pooled sensitivity and specificity of the experimental device in the diagnosis of obstructive sleep apnea, in comparison to gold-standard polysomnography. RESULTS: Twenty-eight of 4929 screened studies were included in the meta-analysis. A total of 2653 patients were included with the majority being patients referred to a sleep clinic (88.8%). Average age was 49.7(SD±6.1) years, female sex (31%), average body mass index of 29.5(SD±3.2) kg/m2, average apnea-hypopnea index (AHI) of 24.7(SD±5.6) events/h, and pooled OSA prevalence of 72%. Non-contact technology used was mainly video, sound, or bio-motion analysis. Pooled sensitivity and specificity of non-contact methods in moderate to severe OSA diagnosis (AHI > 15) was 0.871 (95% CI 0.841,0.896, I2 0%) and 0.8 (95% CI 0.719,0.862), respectively (AUC 0.902). Risk of bias assessment showed an overall low risk of bias across all domains except for applicability concerns (none were conducted in the perioperative setting). CONCLUSION: Available data indicate contactless methods have high pooled sensitivity and specificity for OSA diagnosis with moderate to high level of evidence. Future research is needed to evaluate these tools in the perioperative setting.

Impact of an extrafascial versus intrafascial injection for supraclavicular brachial plexus block on respiratory function: a randomized, controlled, double-blind trial.

INTRODUCTION: Hemidiaphragmatic paresis after ultrasound-guided supraclavicular brachial plexus block is reported to occur in up to 67% of patients. We tested the hypothesis that an injection outside the brachial plexus sheath reduces the incidence of hemidiaphragmatic paresis compared with an intrafascial injection while providing similar analgesia. METHODS: Fifty American Society of Anesthesiologists I-III patients scheduled for elective upper limb surgery received a supraclavicular brachial plexus block using 30 mL of 1:1 mixture of mepivacaine 1% and ropivacaine 0.5%. The block procedures were randomized to position the needle tip either within the brachial plexus after piercing the sheath (intrafascial injection) or outside the brachial plexus sheath (extrafascial injection). The primary outcome was the incidence of hemidiaphragmatic paresis 30 min after the injection, measured by M-mode ultrasonography. Additional outcomes included time to surgery readiness, and resting and dynamic pain scores at 24 hours postoperatively (Numeric Rating Scale, 0-10). RESULTS: The incidence of hemidiaphragmatic paresis 30 min after the injection was 9% (95% CI 1% to 29%) and 0% (95% CI 0% to 15%) in the intrafascial and extrafascial groups respectively (p=0.14). Extrafascial injection was associated with a longer time to surgery readiness (intrafascial: 18 min (95% CI: 16 to 21 min); extrafascial: 37 min (95% CI: 31 to 42 min); p<0.001). At 24 hours, resting and dynamic pain scores were similar between groups. DISCUSSION: Ultrasound-guided supraclavicular brachial plexus block with an extrafascial injection does not reduce the incidence of hemidiaphragmatic paresis although it provides similar analgesia, when compared with an intrafascial injection. The longer time to surgery readiness is less compatible with contemporary operating theater efficiency requirements. TRIAL REGISTRATION NUMBER: NCT03957772.