Flexible bronchoscopic intubation through a supraglottic airway device: An evaluation of consultant anaesthetist performance.

BACKGROUND: Few clinical studies investigate technical skill performance in experienced clinicians. METHODS: We undertook a prospective observational study evaluating procedural skill competence in consultant anaesthetists who performed flexible bronchoscopic intubation (FBI) under continuous ventilation through a second-generation supraglottic airway device (SAD). Airway management was recorded on video and performance evaluated independently by three external assessors. We included 100 adult patients undergoing airway management by 25 anaesthetist specialists, each performing four intubations. We used an Objective Structured Assessment of Technical Skills-inspired global rating scale as primary outcome. Further, we assessed the overall pass rate (proportion of cases where the average of assessors' evaluation for every domain scored ≥3); the progression in the global rating scale score; time to intubation; self-reported procedural confidence; and pass rate from the first to the fourth airway procedure. RESULTS: Overall median global rating scale score was 29.7 (interquartile range 26.0-32.7 [range 16.7-37.7]. At least one global rating scale domain was deemed 'not competent' (one or more domains in the evaluation was scored <3) in 30% of cases of airway management, thus the pass rate was 70% (95% CI 60%-78%). After adjusting for multiple testing, we found a statistically significant difference between the first and fourth case of airway management regarding time to intubation (p = .006), but no difference in global rating scale score (p = .018); self-reported confidence before the procedure (p = .014); or pass rate (p = .109). CONCLUSION: Consultant anaesthetists had a median global rating scale score of 29.7 when using a SAD as conduit for FBI. However, despite reporting high procedural confidence, at least one global rating scale domain was deemed 'not competent' in 30% of cases, which indicates a clear potential for improvement of skill competence among professionals.

Mixing short- and long-acting local anaesthetics in peripheral nerve blocks: Protocol for a systematic review and meta-analysis.

INTRODUCTION: This protocol describes a systematic review and meta-analysis to evaluate the clinical effects of mixing short- and long-acting local anaesthetics in peripheral nerve blocks. Clinicians often combine short- and long-acting local anaesthetics to achieve a briefer onset time. However, this may come with a prize, namely a shorter total duration of the block, which is of clinical importance. OBJECTIVE: This systematic review aims to strengthen the knowledge of the clinical effects associated with this practice. The primary outcome is the duration of block analgesia. Secondary outcomes are block onset time, sensory and motor block duration. Exploratory outcomes are postoperative pain scores, cumulative 24-h opioid consumption and the prevalence of serious adverse events. METHODS: We will conduct a meta-analysis of the extracted data, and the risk of bias for each study will be evaluated. We will perform a Trial Sequential Analysis, subgroup, and sensitivity analyses and assess the overall risk of publication bias. Finally, we will evaluate the review using the GRADE principles.

Peripheral nerve blocks for closed reduction of distal radius fractures-A protocol for a systematic review.

BACKGROUND: Current methods of anaesthesia used for closed reduction of distal radial fractures may be insufficient for pain relief and muscle relaxation, potentially compromising reduction quality and patient satisfaction. Peripheral nerve blocks have already been implemented for surgery of wrist fractures and may provide optimal conditions for closed reduction due to complete motor and sensory blockade of the involved nerves. However, existing literature on peripheral nerve blocks for closed reduction is sparse, and no updated systematic review or meta-analysis exists. AIMS: This protocol is developed according to the PRISMA-P statement. The systematic review and meta-analysis aim to consolidate the literature regarding the effect and harm of peripheral nerve blocks compared with other anaesthesia modalities for closed reduction of distal radius fractures in adults. METHODS: The two primary outcomes are the proportion of participants needing surgery after closed reduction and pain during closed reduction. We will only include randomised clinical trials. Two review authors will each independently screen literature, extract data, and assess risk of bias with Risk of Bias 2 Tool. Meta-analysis will be carried out with Rstudio. We will also perform a Trial Sequential Analysis. The certainty of evidence will be judged using GRADE guidelines. DISCUSSION: We will use up-to-date methodology when conducting the systematic review outlined in this protocol. The results may guide clinicians in their decision-making regarding the use of anaesthesia for closed reduction of distal radius fractures in adults.

Intra-operative blood transfusion in elderly patients on antithrombotic therapy.

BACKGROUND: Many elderly patients are receiving antithrombotics, which may increase intra-operative blood loss. We aimed to assess whether chronic antithrombotic therapy was associated with intra-operative transfusion of packed red blood cells in patients at least 80 years of age undergoing elective procedures. METHODS: We performed a secondary analysis of the prospective, observational European multicentre study entitled POSE (peri-interventional outcome study in the elderly) including 9497 surgical patients aged 80 years and older in 177 centres from October 2017 to December 2018. In this secondary analysis we included POSE patients who underwent elective procedures and with available data on chronic antithrombotic therapy. The primary outcome was intra-operative transfusion of packed red blood cells and results were analysed using multiple logistic regression model. We adjusted for the following predetermined explanatory variables: Age, sex, body mass index, American Society of Anaesthesiologists Physical Status Classification System, baseline haemoglobin concentration, disseminated cancer, and type and severity of surgery. RESULTS: A total of 7174 patients were included of whom 4073 (56.8%) were on antithrombotic therapy. Among patients on antithrombotic therapy 191 (4.7%) received intra-operative blood transfusion compared with 98 (3.2%) of patients not on chronic antithrombotic therapy (crude odds ratio: 1.51, 95% CI 1.18-1.94). Following multiple logistic regression analysis, the adjusted odds ratio was 0.98; 0.73-1.32. We found that chronic antithrombotic therapy was associated with intra-operative transfusion of packed red blood cells in elderly patients undergoing elective procedures in an unadjusted analysis, but not in a multivariate adjusted model.

Pain treatment after total hip arthroplasty: Detailed statistical analysis plan for the RECIPE randomised clinical trial.

BACKGROUND: The RECIPE trial systematically investigates the effects of different combinations of paracetamol, ibuprofen and dexamethasone for pain treatment after total hip arthroplasty. To preserve transparency, minimise risk of bias and to prevent data-driven analysis, we present this detailed statistical analysis plan. METHODS: The RECIPE trial is a randomised, blinded, parallel four-group multicenter clinical trial for patients undergoing planned primary total hip arthroplasty. Interventions are initiated preoperatively and continued for 24 h postoperatively. Primary outcome is total opioid consumption 0-24 h after end of surgery. Primary analysis will be performed in the modified intention to treat population of all patients undergoing total hip arthroplasty, and all analyses will be stratified for site. We will perform pairwise comparisons between each of the four groups. The primary outcome will be analysed using the van Elteren test and we will present Hodges-Lehmann median differences and confidence intervals. Binary outcomes will be analysed using logistic regression. To preserve a family-wise error rate of <0.05, we will use a Bonferroni-adjusted alfa of 0.05/6 = 0.0083 for all six pairwise comparisons between groups when analysing the primary outcome. We will systematically assess the underlying statistical assumptions for each analysis. Data will be analysed by two blinded independent statisticians, and we will write abstracts covering all possible combinations of conclusions, before breaking the blind. DISCUSSION: The RECIPE trial will provide important information on benefit and harm of combinations of the most frequently used non-opioid analgesics for pain after primary hip arthroplasty.

Single injection combined suprascapular and axillary nerve block: A randomised controlled non-inferiority trial in healthy volunteers.

BACKGROUND: A shoulder block without lung affection is desirable. In this study, we compared a low versus a high volume of a modified supraclavicular brachial plexus block. We hypothesised that a low volume of local anaesthetic would provide non-inferior block success rate with better preserved lung function. METHODS: Healthy volunteers were randomised to receive ultrasound guided 5 or 20 ml ropivacaine 0.5% at the departure of the suprascapular nerve from the brachial plexus. Primary outcome was successful shoulder block-defined as cutaneous sensory affection of the axillary nerve and motor affection of the suprascapular nerve (>50% reduction in external rotation force measured with dynamometry). We used a non-inferiority margin of 20%. Secondary outcome was change in lung function measured with spirometry. RESULTS: Thirteen of 16 (81.3%; 95% confidence interval [CI] 57.0% to 93.4%) in the 5 ml group and 15 of 16 (93.8%; 95% CI 71.7% to 98.9%) in the 20 ml group had successful shoulder block (p = .6). The ratio of the event rates of the 20 ml (standard) and 5 ml (intervention) groups was (15/16)/(13/16) = 0.937/0.813 = 1.15 (95% CI 0.88 to 1.51). All mean reductions in lung function parameters were non-significantly lower in the 5 ml group compared with the 20 ml group. CONCLUSION: For our primary outcome, the 95% CI of the difference of event ratio included the non-inferiority margin. We are therefore unable to conclude that 5 ml LA is non-inferior to 20 ml LA with respect to block success rate.

Low volume proximal suprascapular nerve block after arthroscopic shoulder surgery - A randomised, controlled trial.

BACKGROUND: A proximal suprascapular nerve block has been suggested as an alternative to an interscalene brachial plexus block after arthroscopic shoulder surgery. The aim of this randomised controlled trial was to compare the analgesic and opioid-sparing effect of a low volume proximal suprascapular nerve block with placebo in patients with moderate-to-severe pain after arthroscopic shoulder surgery. METHODS: Patients with a VAS score equal to or above 50 during the first postoperative hour after planned arthroscopic shoulder surgery were included in the study. They were randomised to an ultrasound-guided proximal suprascapular nerve block with either 5 ml ropivacaine 7.5 mg/ml or 5 ml isotonic NaCl. Primary outcome was change in VAS score at rest from baseline to 30 min after the block procedure (T30). Secondary outcomes included total morphine consumption from 0-6 h after block procedure. RESULTS: There was a significant difference in mean VAS reductions at T30 between the two groups favouring the ropivacaine group (-50.2 vs -26.8, p < .001). Total intravenous morphine consumption from 0-6 h after block procedure was significantly lower in the ropivacaine group compared to the placebo group (8.5 mg vs 18.5 mg, p < .01). CONCLUSION: In this study, a proximal suprascapular nerve block with only 5 ml ropivacaine resulted in a substantial pain reduction and opioid-sparing effect in patients with VAS of 50 or more after arthroscopic shoulder surgery.

AuraGain™ versus i-gel™ for bronchoscopic intubation under continuous oxygenation: A randomised controlled trial.

INTRODUCTION: After failed mask ventilation and tracheal intubation, guidelines issued by the Difficult Airway Society recommend placing a second generation supraglottic airway device to secure oxygenation. Ultimately, a secure airway can be obtained by tracheal intubation through the supraglottic airway device using a bronchoscope. In this randomised trial, we compared the AuraGain™ with the i-gel™ as conduit for bronchoscopic intubation under continuous oxygenation performed by a group of anaesthesiologists with variable experience in a general population of patients. METHOD: We randomised one hundred patients who were equally allocated to flexible bronchoscopic intubation through the i-gel™ or the AuraGain™. In a random order, 25 anaesthesiologists each performed four intubations, two using the i-gel™ and two using the AuraGain™. Our primary outcome was 'total time for airway management'; i.e. total time from manually reaching the SAD to successful FBI confirmed at the end of the first inspiratory downstroke on the capnography curve. RESULTS: In total, 87% (95% CI, 79%-92%) of the patients were successfully intubated through the allocated supraglottic airway device. There was no difference in total time for airway management between the i-gel™ and the AuraGain™ (199 vs. 227 s, p = .076). However, there was a difference in time for placement of the i-gel™, compared to the AuraGain™, (37 vs. 54 s, p < .001). There were nine failed intubations in the AuraGain™ group compared to four in the i-gel™ group (p = .147). CONCLUSION: We found no difference in total time for airway management between using the i-gel™ and using the AuraGain™.

A new tool to assess Clinical Diversity In Meta-analyses (CDIM) of interventions.

OBJECTIVE: To develop and validate Clinical Diversity In Meta-analyses (CDIM), a new tool for assessing clinical diversity between trials in meta-analyses of interventions. STUDY DESIGN AND SETTING: The development of CDIM was based on consensus work informed by empirical literature and expertise. We drafted the CDIM tool, refined it, and validated CDIM for interrater scale reliability and agreement in three groups. RESULTS: CDIM measures clinical diversity on a scale that includes four domains with 11 items overall: setting (time of conduct/country development status/units type); population (age, sex, patient inclusion criteria/baseline disease severity, comorbidities); interventions (intervention intensity/strength/duration of intervention, timing, control intervention, cointerventions); and outcome (definition of outcome, timing of outcome assessment). The CDIM is completed in two steps: first two authors independently assess clinical diversity in the four domains. Second, after agreeing upon scores of individual items a consensus score is achieved. Interrater scale reliability and agreement ranged from moderate to almost perfect depending on the type of raters. CONCLUSION: CDIM is the first tool developed for assessing clinical diversity in meta-analyses of interventions. We found CDIM to be a reliable tool for assessing clinical diversity among trials in meta-analysis.

Volume of ropivacaine 0.2% and sciatic nerve block duration: A randomized, blinded trial in healthy volunteers.

BACKGROUND: Sciatic nerve blocks are used for many orthopaedic procedures on the knee, lower leg, foot and ankle. However, as nerve block durations vary considerably, the timing of supplemental analgesia is challenging. Therefore, knowledge on the effect of local anaesthetic (LA) dose on block duration is important to outweigh the benefits of increasing LA dose against the risk of LA systemic toxicity. In this randomized, double-blind trial, we aimed to explore the relationship between the volume of ropivacaine 0.2% and sciatic nerve block duration. We hypothesized that increasing LA volume would prolong block duration. METHODS: We randomized 60 healthy volunteers to receive one of five volumes of ropivacaine 0.2%: 5, 10, 15, 20, or 30 mL. We used an ultrasound-guided, catheter-based technique targeting the sciatic nerve in the infragluteal region. The primary outcome was sensory block duration defined as the time of insensitivity to a cold stimulus. Intergroup differences were tested using one-way ANOVA. RESULTS: Mean (SD) sensory block durations for the tibial nerve (TN) with increasing volume were: 9.3 hours (1.7), 10.4 hours (1.6), 9.7 hours (2.9), 10.7 hours (2.8) and 9.9 hours (2.6). Mean (SD) sensory block durations for the common peroneal nerve (CPN) were: 10.6 hours (2.7), 11.9 hours (1.5), 11.0 hours (3.3), 13.2 hours (3.7), and 13.5 hours (6.1). There were no intergroup differences (P = .67 [TN]; P = .25 [CPN]). CONCLUSION: We found no effect of increasing the volume of ropivacaine 0.2% from 5 to 30 mL on sensory sciatic nerve block duration.

Intra- and inter-Individual variability in nerve block duration: A randomized cross-over trial in the common peroneal nerve of healthy volunteers.

BACKGROUND: The reported variation in nerve block duration is considerable. To individualize nerve block therapy, knowledge of the intra- vs inter-individual variability is essential. We investigated the relative contribution of these 2 parameters to the overall nerve block duration variability. METHODS: With ethics committee approval, we conducted a randomized cross-over trial where 20 healthy volunteers received 8 common peroneal nerve blockades with lidocaine 0.5% on 4 consecutive days. Allocations were 5 mL to either the right or left side and 10 mL to the opposite side on day 1 and 2 and vice versa on day 3 and 4. With fixed needle entry and nerve target, we repeated local anaesthetic deposition for each blockade. The primary outcome was variation in duration of sensory nerve block defined as insensitivity to a cold stimulus. Data were analysed using linear mixed model regression. RESULTS: The mean sensory block duration of 380 (95% CI = [342; 418]) minutes on day one was 55 [33; 77] minutes longer than on day two (P < .001), but there were no differences in mean duration between days 2, 3 and 4. The ratios with 2.5; 97.5 percentiles between inter- and intra-individual variation were 2.4 [0.8; 5.2] for the 5 mL blockades and 3.0 [0.9; 6.7] for the 10 mL blockades. The probabilities of inter- to intra-individual variation-ratios >1 were 96% and 97%. CONCLUSION: The intra-individual variability is a substantially minor contributor to the overall variability in sensory nerve block duration compared with the inter-individual variability.

Adductor canal block with a suture-method catheter - A parallel or perpendicular approach?

BACKGROUND: We performed a randomised blinded pilot study in 16 healthy volunteers to assess whether placing a suture-method catheter in the adductor canal is feasible with two different insertion techniques. METHODS: Each volunteer had a suture-method catheter placed approximately halfway between the superior anterior iliac spine and base of the patella in both legs. Catheters were placed using a parallel technique in one leg and a perpendicular technique in the other leg, according to randomisation. 15 mL lidocaine 1% was injected in each catheter. Successful placement was defined as loss of cold sensation in the saphenous area 30 min after injection. Volunteers were sent home and returned the following day and another dose of lidocaine (15 mL, 1%) was injected through the catheters. Catheter displacement distance was assessed by ultrasound and cold sensation was assessed. In case of preserved cold sensation, we attempted to reposition the catheter with a subsequent injection of lidocaine and reassessment of cold sensation. RESULTS: All primary placements were successful using the perpendicular approach (100%; 95% CI 81%-100%) whereas one placement failed using the parallel approach (94%; 95% CI 72%-99%). Three catheters placed using the perpendicular approach were displaced on day 2, compared to one catheter placed with the parallel approach. Displacement distance was highly variable. All catheters, except one, could be repositioned. Three volunteers reported transient sensory deficits lasting approximately 6-8 weeks. CONCLUSION: The suture-method catheter can be placed in the adductor canal with high success rates for initial placement with both techniques.

Effects of strength training to patients undergoing dialysis: a systematic review.

INTRODUCTION: Chronic kidney disease is associated with several negative factors that may counteract the potential effects of strength training. The purpose of this systematic review was to explore the effects of strength training on muscle mass, muscle strength, physical function and quality of life in patients undergoing dialysis. METHODS: A literature search was conducted in The Cochrane Library, MEDLINE, Embase, CINAHL and PEDro. Eight randomised, controlled trials of patients undergoing haemodialysis (n = 290) were included. RESULTS: There were inconsistencies in the results on the effects of strength training on muscle mass. Muscle strength was improved in six of eight tests. Objectively tested physical function remained unchanged. Pooled data for self-rated physical health and physical function from Short Form 36 were improved with strength training (mean (95% confidence interval) 10.05 (2.95-17.14), p = 0.006, and 9.38 (0.79-17.97), p = 0.03, respectively). CONCLUSIONS: The results suggest that it may be difficult to increase muscle mass with strength training in patients who are undergoing haemodialysis. Muscle growth may be impaired as a result of several catabolic conditions. Strength training was associated with important clinical outcomes including increased muscle strength and improved self-rated physical health and function.

Local Anesthetic Injection Speed and Common Peroneal Nerve Block Duration: A Randomized Controlled Trial in Healthy Volunteers.

BACKGROUND AND OBJECTIVES: The speed of local anesthetic (LA) injections in peripheral regional anesthesia ranges from slow continuous infusions (3-12 mL/h) to rapid manual injections (>7500 mL/h). Optimizing injection speed could augment the spread of LA toward the targeted nerves and influence nerve block characteristics. The objective of this study was to investigate whether injection speed of a single dose of LA affects peripheral nerve block duration. METHODS: After approval from the Danish Regional Scientific Ethics Committee, we enrolled 60 healthy adult volunteers. We used an ultrasound-guided catheter-based technique to perform a common peroneal nerve block. Participants were randomized to receive 4.0 mL of ropivacaine 0.2% with 1 of 5 injection speeds: 12, 60, 300, 600, or 1800 mL/h. Investigators and participants were blinded to group assignment and intervention. Primary outcome was duration of sensory nerve block defined by insensitivity toward cold. Secondary outcomes were duration of motor nerve block, time to onset of sensory nerve block, and grades of sensory and motor nerve block.Intergroup differences were tested by one-way analysis of variance. RESULTS: We found no differences in sensory block duration between the 5 groups. Durations were median [range]: 11 [6-14], 12 [9-14], 10.5 [2-15], 11 [8-17], and 12 [9-18] hours, respectively (P = 0.294). In addition, we found no differences in secondary outcomes. CONCLUSIONS: Injection speed of LA in the range of 12 to 1800 mL/h did not affect common peroneal nerve block duration. CLINICAL TRIAL REGISTRATION: This study was registered at ClinicalTrials.gov, identifier NCT02801799.

"Eyeball test" of thermographic patterns for predicting a successful lateral infraclavicular block.

PURPOSE: Increased distal skin temperature can be used to predict the success of lateral infraclavicular (LIC) block. We hypothesized that an "eyeball test" of specific infrared thermographic patterns after LIC block could be used to determine block success. METHODS: In this observational study, five observers trained in four distinct thermographic patterns independently evaluated thermographic images of the hands of 40 patients at baseline and at one-minute intervals for 30 min after a LIC block. Sensitivity, specificity, and predictive values of a positive and a negative test were estimated to evaluate the validity of specific thermographic patterns for predicting a successful block. Sensory and motor block of the musculocutaneous, radial, ulnar, and median nerves defined block success. Fleiss' kappa statistics of multiple interobserver agreements were used to evaluate reliability. RESULTS: As a diagnostic test, the defined specific thermographic patterns of the hand predicted a successful block with increasing accuracy over the 30-min observation period. Block success was predicted with a sensitivity of 92.4% (95% confidence interval [CI], 86.8 to 96.2) and with a specificity of 84.0% (95% CI, 70.3 to 92.4) at min 30. The Fleiss' kappa for the five observers was 0.87 (95% CI, 0.77 to 0.96). CONCLUSION: We conclude that visual evaluation by an eyeball test of specific thermographic patterns of the blocked hands may be useful as a valid and reliable diagnostic test for predicting a successful LIC block.

Avoidance versus use of neuromuscular blocking agents for improving conditions during tracheal intubation or direct laryngoscopy in adults and adolescents.

BACKGROUND: Tracheal intubation during induction of general anaesthesia is a vital procedure performed to secure a patient's airway. Several studies have identified difficult tracheal intubation (DTI) or failed tracheal intubation as one of the major contributors to anaesthesia-related mortality and morbidity. Use of neuromuscular blocking agents (NMBA) to facilitate tracheal intubation is a widely accepted practice. However, because of adverse effects, NMBA may be undesirable. Cohort studies have indicated that avoiding NMBA is an independent risk factor for difficult and failed tracheal intubation. However, no systematic review of randomized trials has evaluated conditions for tracheal intubation, possible adverse effects, and postoperative discomfort. OBJECTIVES: To evaluate the effects of avoiding neuromuscular blocking agents (NMBA) versus using NMBA on difficult tracheal intubation (DTI) for adults and adolescents allocated to tracheal intubation with direct laryngoscopy. To look at various outcomes, conduct subgroup and sensitivity analyses, examine the role of bias, and apply trial sequential analysis (TSA) to examine the level of available evidence for this intervention. SEARCH METHODS: We searched CENTRAL, MEDLINE, Embase, BIOSIS, International Web of Science, LILACS, advanced Google, CINAHL, and the following trial registries: Current Controlled Trials; ClinicalTrials.gov; and www.centerwatch.com, up to January 2017. We checked the reference lists of included trials and reviews to look for unidentified trials. SELECTION CRITERIA: We included randomized controlled trials (RCTs) that compared the effects of avoiding versus using NMBA in participants 14 years of age or older. DATA COLLECTION AND ANALYSIS: Two review authors extracted data independently. We conducted random-effects and fixed-effect meta-analyses and calculated risk ratios (RRs) and their 95% confidence intervals (CIs). We used published data and data obtained by contacting trial authors. To minimize the risk of systematic error, we assessed the risk of bias of included trials. To reduce the risk of random errors caused by sparse data and repetitive updating of cumulative meta-analyses, we applied TSA. MAIN RESULTS: We identified 34 RCTs with 3565 participants that met our inclusion criteria. All trials reported on conditions for tracheal intubation; seven trials with 846 participants described 'events of upper airway discomfort or injury', and 13 trials with 1308 participants reported on direct laryngoscopy. All trials used a parallel design. We identified 18 dose-finding studies that included more interventions or control groups or both. All trials except three included only American Society of Anesthesiologists (ASA) class I and II participants, 25 trials excluded participants with anticipated DTI, and obesity or overweight was an excluding factor in 13 studies. Eighteen trials used suxamethonium, and 18 trials used non-depolarizing NMBA.Trials with an overall low risk of bias reported significantly increased risk of DTI with no use of NMBA (random-effects model) (RR 13.27, 95% CI 8.19 to 21.49; P < 0.00001; 508 participants; four trials; number needed to treat for an additional harmful outcome (NNTH) = 1.9, I2 = 0%, D2 = 0%, GRADE = moderate). The TSA-adjusted CI for the RR was 1.85 to 95.04. Inclusion of all trials resulted in confirmation of results and of significantly increased risk of DTI when an NMBA was avoided (random-effects model) (RR 5.00, 95% CI 3.49 to 7.15; P < 0.00001; 3565 participants; 34 trials; NNTH = 6.3, I2 = 70%, D2 = 82%, GRADE = low). Again the cumulative z-curve crossed the TSA monitoring boundary, demonstrating harmful effects of avoiding NMBA on the proportion of DTI with minimal risk of random error. We categorized only one trial reporting on upper airway discomfort or injury as having overall low risk of bias. Inclusion of all trials revealed significant risk of upper airway discomfort or injury when an NMBA was avoided (random-effects model) (RR 1.37, 95% CI 1.09 to 1.74; P = 0.008; 846 participants; seven trials; NNTH = 9.1, I2 = 13%, GRADE = moderate). The TSA-adjusted CI for the RR was 1.00 to 1.85. None of these trials reported mortality. In terms of our secondary outcome 'difficult laryngoscopy', we categorized only one trial as having overall low risk of bias. All trials avoiding NMBA were significantly associated with difficult laryngoscopy (random-effects model) (RR 2.54, 95% CI 1.53 to 4.21; P = 0.0003; 1308 participants; 13 trials; NNTH = 25.6, I2 = 0%, D2= 0%, GRADE = low); however, TSA showed that only 6% of the information size required to detect or reject a 20% relative risk reduction (RRR) was accrued, and the trial sequential monitoring boundary was not crossed. AUTHORS' CONCLUSIONS: This review supports that use of an NMBA may create the best conditions for tracheal intubation and may reduce the risk of upper airway discomfort or injury following tracheal intubation. Study results were characterized by indirectness, heterogeneity, and high or uncertain risk of bias concerning our primary outcome describing difficult tracheal intubation. Therefore, we categorized the GRADE classification of quality of evidence as moderate to low. In light of defined outcomes of individual included trials, our primary outcomes may not reflect a situation that many clinicians consider to be an actual difficult tracheal intubation by which the patient's life or health may be threatened.

Lack of national consensus in preoperative airway assessment.

INTRODUCTION: Difficult airway management is associated with an increased risk of morbidity and mortality. Several preoperative risk factors associated with airway management difficulties have been proposed; however, no clear guideline for airway assessments exists. We therefore hypothesised that Danish airway assessment was lacking uniformity. We aimed to examine whether multivariable risk assessment tools and predictors for difficult intubation and mask ventilation were used systematically. METHODS: Heads of anaesthesia departments were sent a six-question survey at the beginning of 2012. We asked if systematic risk assessment tools, particularly the Simplified Airway Risk Index (SARI), and predictors for difficult intubation and mask ventilation were used. Additionally, we asked if any risk factors were pre-printed on the anaesthesia record. RESULTS: In all, 29 of 31 (94%) departments responded. The SARI was implemented in 8 of 29 (28%, 95% confidence interval (CI): 15-46%) departments with major regional differences. There was no significant association between using the SARI and a reduced number of unanticipated difficult intubation (p = 0.06). Mallampati classification (95.2%, 95% CI: 77.3-99.2%), history of airway management difficulties (85.7%, 95% CI: 65.4-95.0%), ability to prognath (81.0%, 95% CI: 60.0-92.3%) and neck mobility (81.0%, 95% CI: 60.0-92.3%) were the main predictors registered. CONCLUSION: We found considerable inter-departmental variance in the standards employed for airway assessment and no uniform pattern in the registration of risk factors for airway management difficulties. Better prediction of difficult intubation could not be detected in departments that used the SARI. FUNDING: none. TRIAL REGISTRATION: not relevant.

Risk Factors for and Prediction of a Difficult Neuraxial Block: A Cohort Study of 73,579 Patients from the Danish Anaesthesia Database.

BACKGROUND: A difficult neuraxial block (DNB) may be associated with complications. The aims of this study were to estimate the prevalence of DNB, assess patient-related and organizational factors associated with DNB, and evaluate the diagnostic accuracy of an accumulated risk score for predicting DNB. METHODS: A consecutive cohort of 73,579 patients was retrieved. A predefined DNB score and information on patient-related and organizational factors were included in the analyses. Logistic regression analysis was performed. We evaluated the diagnostic accuracy of an accumulated weighted point score of the patient-related risk factors of DNB. RESULTS: The prevalence of DNB and abandoned neuraxial block was 3.9 (95% confidence interval [95% CI], 3.7-4.0) and 0.2 (95% CI, 0.16-0.22), respectively. Body mass index of 35 or higher and previous DNB were associated with DNB, with 3.23 (95% CI, 2.87-3.65) and 2.00 (95% CI, 1.33-3.00), respectively. However, the remaining patient-related covariates were associated with DNB with substantial lower odds ratios. The diagnostic accuracy of an accumulated sum score demonstrated an area under the curve of 0.62 (95% CI, 0.61-0.64), a positive predictive value of 5%, and a positive likelihood ratio of 1.4. CONCLUSIONS: Despite of strong statistical association between DNB and the tested risk factors, the low odds ratios and estimates of the diagnostic test indicate that the clinical impact using an accumulated risk sum score is limited.