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Background: Front-of-neck airway rescue in a cannot intubate, cannot oxygenate (CICO) scenario with impalpable anatomy is particularly challenging. Several techniques have been described based on a midline vertical neck incision with subsequent finger dissection, followed by either a cannula or scalpel puncture of the now palpated airway. We explored whether the speed of rescue oxygenation differs between these techniques., Methods: In a high-fidelity simulation of a CICO scenario in anaesthetised Merino sheep with impalpable front-of-neck anatomy, 35 consecutive eligible participants undergoing airway training performed scalpel-finger-cannula and scalpel-finger-bougie in a random order. The primary outcome was time from airway palpation to first oxygen delivery. Data, were analysed with Cox proportional hazards., Results: Scalpel-finger-cannula was associated with shorter time to first oxygen delivery on univariate (hazard ratio [HR]=11.37; 95% confidence interval [CI], 5.14-25.13; P<0.001) and multivariate (HR=8.87; 95% CI, 4.31-18.18; P<0.001) analyses. In the multivariable model, consultant grade was also associated with quicker first oxygen delivery compared with registrar grade (HR=3.28; 95% CI, 1.36-7.95; P=0.008). With scalpel-finger-cannula, successful oxygen delivery within 3 min of CICO declaration and ≤2 attempts was more frequent; 97% vs 63%, P<0.001. In analyses of successful cases only, scalpel-finger-cannula resulted in earlier improvement in arterial oxygen saturations (-25 s; 95% CI, -35 to -15; P<0.001), but a longer time to first capnography reading (+89 s; 95% CI, 69 to 110; P<0.001). No major complications occurred in either arm., Conclusions: The scalpel-finger-cannula technique was associated with superior oxygen delivery performance during a simulated CICO scenario in sheep with impalpable front-of-neck anatomy., (Copyright © 2020 British Journal of Anaesthesia. All rights reserved.)

Background: Train-of-four twitch monitoring can be performed using palpation of thumb movement, or by the use of a more objective quantitative monitor, such as mechanomyography, acceleromyography, or electromyography. The relative performance of palpation and quantitative monitoring for determination of the train-of-four ratio has been studied extensively, but the relative performance of palpation and quantitative monitors for counting train-of-four twitch responses has not been completely described., Methods: We compared train-of-four counts by palpation to mechanomyography, acceleromyography (Stimpod™), and electromyography (TwitchView Monitor™) in anaesthetised patients using 1691 pairs of measurements obtained from 46 subjects., Results: There was substantial agreement between palpation and electromyography (kappa = 0.80), mechanomyography (kappa = 0.67), or acceleromyography (kappa = 0.63). Electromyography with TwitchView and mechanomyography most closely resembled palpation, whereas acceleromyography with StimPod often underestimated train-of-four count. With palpation as the comparator, acceleromyography was more likely to measure a lower train-of-four count, with 36% of counts less than palpation, and 3% more than palpation. For mechanomyography, 31% of train-of-four counts were greater than palpation, and 9% were less. For electromyography, 15% of train-of-four counts were greater than palpation, and 12% were less. The agreement between acceleromyography and electromyography was fair (kappa = 0.38). For acceleromyography, 39% of train-of-four counts were less than electromyography, and 5% were more., Conclusions: Acceleromyography with the StimPod frequently underestimated train-of-four count in comparison with electromyography with TwitchView., (Copyright © 2020 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Caudal epidural blockade in children is one of the most widely administered techniques of regional anaesthesia. Recent clinical studies have answered major pharmacodynamic and pharmacokinetic questions, thus providing the scientific background for safe and effective blocks in daily clinical practice and demonstrating that patient selection can be expanded to range from extreme preterm births up to 50 kg of body weight. This narrative review discusses the main findings in the current literature with regard to patient selection (sub-umbilical vs mid-abdominal indications, contraindications, low-risk patients with spinal anomalies); anatomical considerations (access problems, age and body positioning, palpation for needle insertion); technical considerations (verification of needle position by ultrasound vs landmarks vs 'whoosh' or 'swoosh' testing); training and equipment requirements (learning curve, needle types, risk of tissue spreading); complications and safety (paediatric regional anaesthesia, caudal blocks); local anaesthetics (bupivacaine vs ropivacaine, risk of toxicity in children, management of toxic events); adjuvant drugs (clonidine, dexmedetomidine, opioids, ketamine); volume dosing (dermatomal reach, cranial rebound); caudally accessed lumbar or thoracic anaesthesia (contamination risk, verifying catheter placement); and postoperative pain. Caudal blocks are an efficient way to offer perioperative analgesia for painful sub-umbilical interventions. Performed on sedated children, they enable not only early ambulation, but also periprocedural haemodynamic stability and spontaneous breathing in patient groups at maximum risk of a difficult airway. These are important advantages over general anaesthesia, notably in preterm babies and in children with cardiopulmonary co-morbidities. Compared with other techniques of regional anaesthesia, a case for caudal blocks can still be made., (Copyright © 2019 British Journal of Anaesthesia. Published by Elsevier Ltd. All rights reserved.)

Background: Peripheral vein cannulation is a routine and straightforward invasive procedure, although i.v. access can be difficult to obtain. To increase the success rate of inserting an i.v. catheter, many devices have been proposed, including ultrasonography. The objective of this study was to compare ultrasound guidance with the traditional approach of palpation and direct visualisation for peripehral vein cannulation. The primary outcome was successful peripheral i.v. cannulation., Methods: Database search was performed on PubMed, Clinical Key, CINAHL, Cochrane Library of Clinical Trials, and Trip Database (from January 2000 to December 2017). Random-effect meta-analysis was performed to determine the pooled odds ratio for success in peripheral i.v. cannulation., Results: After database review and eligibility screening, eight studies were included in the final analysis, with a total of 1660 patients. The success rate in the ultrasound group was 81% (n=855), and was 70% (n=805) in the control group, resulting in a pooled odds ratio for success upon ultrasound-guided peripheral i.v. cannulation of 2.49 (95% confidence interval 1.37-4.52, P=0.003). Furthermore, the ultrasound-guided technique reduced the number of punctures and time needed to achieve i.v. access, and increased the level of patient satisfaction, although it did not result in a decreased number of complications., Conclusions: Ultrasound guidance increases the success rate of peripheral i.v. cannulation, especially in patients with known or predicted difficult i.v. access., (Copyright © 2018 British Journal of Anaesthesia. Published by Elsevier Ltd. All rights reserved.)

Inability to identify the cricothyroid membrane by inspection and palpation contributes substantially to the high failure rate of cricothyrotomy. This narrative review summarizes the current evidence for application of airway ultrasonography for identification of the cricothyroid membrane compared with the clinical techniques. We identified the best-documented techniques for bedside use, their success rates, and the necessary training for airway-ultrasound-naïve clinicians. After a short but structured training, the cricothyroid membrane can be identified using ultrasound in difficult patients by previously airway-ultrasound naïve anaesthetists with double the success rate of palpation. Based on the literature, we recommend identifying the cricothyroid membrane before induction of anaesthesia in all patients. Although inspection and palpation may suffice in most patients, the remaining patients will need ultrasonographic identification; a service that we should aim at making available in all locations where anaesthesia is undertaken and where patients with difficult airways could be encountered., (© The Author 2016. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Cricoid pressure (CP) is commonly applied during rapid sequence intubation and may be protective during induction of anaesthesia; however, CP application by untrained practitioners may not be performed optimally. The objective of this systematic review was to synthesize the evidence regarding effectiveness of technology-enhanced simulation training to improve efficacy of CP application. Electronic databases from inception through May 11, 2011 were searched. Eligible studies evaluated CP simulation training. Independent reviewers working in duplicate extracted study characteristics, validity, and outcomes data. Pooled effect size (ES) with 95% confidence intervals (CIs) were estimated from each study that compared technology-enhanced simulation with no intervention or with other methods of CP training using random-effects model. Twelve studies (772 trainees) evaluated CP training as an outcome. Nine studies reported information on baseline skill, with 23% of providers being able to achieve the target CP before training. In a meta-analysis of 10 studies (570 trainees), CP training resulted in a large favourable impact on skills among trainees compared with no intervention (pooled ES 1.18; 95% CI 0.85-1.51; P<0.0001). Four studies found evidence of skills retention for CP application after training, but for a limited time (<4 weeks). Comparative effectiveness research shows beneficial effects to force feedback training over training without feedback. Simulation training significantly improves the efficacy of CP application. Future studies might evaluate the clinical impact of training on CP application during rapid sequence intubation, and the comparative effectiveness of different training approaches.

Background: The most common misplacement during subclavian vein (SCV) catheterization is into the ipsilateral internal jugular vein (IJV). Chest radiography is the gold standard for the confirmation of correct placement. However, it is time-consuming and has the disadvantage of radiation exposure. We assessed the sensitivity and specificity of our previously reported 'flush test' for confirming correct central line placement., Methods: All neurosurgical patients who underwent successful SCV catheterization on the right side by an infraclavicular approach were enrolled in this study. The flush test was performed by injecting 10 ml of normal saline in the distal port of catheter, while anterior angle of ipsilateral neck was palpated by an independent observer. A thrill of fluid elicited on the palm of hand (positive test) was suggestive of misplaced catheter into ipsilateral IJV. This was confirmed with chest fluoroscopy., Results: SCV catheterization was performed in 570 patients. The flush test was positive in 19 patients (3.3%) and negative in 551 patients (96.7%). There were 26 (4.6%) misplacements as detected by chest radiography; 19 entered the IJV (3.3%) and seven the contralateral SCV (1.2%). In all patients who had a misplaced catheter into the ipsilateral IJV, the flush test results were positive, whereas the results were negative in patients who had normally placed catheter or misplaced catheter elsewhere. It was found that the test had 100% sensitivity and specificity to detect misplacement of SCV catheter into the ipsilateral IJV., Conclusions: Saline flush test is a simple and sensitive bedside test that successfully detects misplaced SCV catheters into ipsilateral IJV.