The effect of simulation-based training on initial performance of ultrasound-guided axillary brachial plexus blockade in a clinical setting - a pilot study.

BACKGROUND: In preparing novice anesthesiologists to perform their first ultrasound-guided axillary brachial plexus blockade, we hypothesized that virtual reality simulation-based training offers an additional learning benefit over standard training. We carried out pilot testing of this hypothesis using a prospective, single blind, randomized controlled trial. METHODS: We planned to recruit 20 anesthesiologists who had no experience of performing ultrasound-guided regional anesthesia. Initial standardized training, reflecting current best available practice was provided to all participating trainees. Trainees were randomized into one of two groups; (i) to undertake additional simulation-based training or (ii) no further training. On completion of their assigned training, trainees attempted their first ultrasound-guided axillary brachial plexus blockade. Two experts, blinded to the trainees' group allocation, assessed the performance of trainees using validated tools. RESULTS: This study was discontinued following a planned interim analysis, having recruited 10 trainees. This occurred because it became clear that the functionality of the available simulator was insufficient to meet our training requirements. There were no statistically significant difference in clinical performance, as assessed using the sum of a Global Rating Score and a checklist score, between simulation-based training [mean 32.9 (standard deviation 11.1)] and control trainees [31.5 (4.2)] (p = 0.885). CONCLUSIONS: We have described a methodology for assessing the effectiveness of a simulator, during its development, by means of a randomized controlled trial. We believe that the learning acquired will be useful if performing future trials on learning efficacy associated with simulation based training in procedural skills. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT01965314. Registered October 17th 2013.

Chest Wall Regional Anesthesia for Modified Radical Mastectomy and Axillary Lymph Node Dissection: A Case Report.

Restrictive chest wall disorders impair cardiopulmonary physiology and pose anesthesia-related safety challenges. Regional anesthesia, as the primary anesthetic modality, may mitigate general anesthesia-related risks in such patients presenting for breast cancer surgery. We describe the use of chest wall fascial plane blocks as the primary anesthetic, combined with high-flow humidified nasal oxygen and low-dose propofol sedation, in a patient with complex comorbidities presenting for modified radical mastectomy and axillary lymph node dissection.

Standardizing nomenclature in regional anesthesia: an ASRA-ESRA Delphi consensus study of abdominal wall, paraspinal, and chest wall blocks.

BACKGROUND: There is heterogeneity in the names and anatomical descriptions of regional anesthetic techniques. This may have adverse consequences on education, research, and implementation into clinical practice. We aimed to produce standardized nomenclature for abdominal wall, paraspinal, and chest wall regional anesthetic techniques. METHODS: We conducted an international consensus study involving experts using a three-round Delphi method to produce a list of names and corresponding descriptions of anatomical targets. After long-list formulation by a Steering Committee, the first and second rounds involved anonymous electronic voting and commenting, with the third round involving a virtual round table discussion aiming to achieve consensus on items that had yet to achieve it. Novel names were presented where required for anatomical clarity and harmonization. Strong consensus was defined as ≥75% agreement and weak consensus as 50% to 74% agreement. RESULTS: Sixty expert Collaborators participated in this study. After three rounds and clarification, harmonization, and introduction of novel nomenclature, strong consensus was achieved for the names of 16 block names and weak consensus for four names. For anatomical descriptions, strong consensus was achieved for 19 blocks and weak consensus was achieved for one approach. Several areas requiring further research were identified. CONCLUSIONS: Harmonization and standardization of nomenclature may improve education, research, and ultimately patient care. We present the first international consensus on nomenclature and anatomical descriptions of blocks of the abdominal wall, chest wall, and paraspinal blocks. We recommend using the consensus results in academic and clinical practice.

An estimation of the minimum effective anesthetic volume of 2% lidocaine in ultrasound-guided axillary brachial plexus block.

BACKGROUND: Ultrasound guidance facilitates precise needle and injectate placement, increasing axillary block success rates, reducing onset times, and permitting local anesthetic dose reduction. The minimum effective volume of local anesthetic in ultrasound-guided axillary brachial plexus block is unknown. The authors performed a study to estimate the minimum effective anesthetic volume of 2% lidocaine with 1:200,000 epinephrine (2% LidoEpi) in ultrasound-guided axillary brachial plexus block. METHODS: After ethical approval and informed consent, patients undergoing hand surgery of less than 90 min duration were recruited. A step-up/step-down study model was used with nonprobability sequential dosing based on the outcome of the previous patient. The starting dose of 2% LidoEpi was 4 ml per nerve. Block failure resulted in a dose increase of 0.5 ml; block success in a reduction of 0.5 ml.A blinded assistant assessed sensory and motor blockade at 5-min intervals up to 30 min. Block performance time and duration were measured. Two predetermined stopping points were used; a minimum of five consecutive block success/failures and five consecutive successful blocks at 1 ml per nerve. RESULTS: The study was terminated when five consecutive patients had successful blocks using 1 ml of 2% LidoEpi per nerve (overall group n = 11). All five patients had surgical anesthesia within 10 min. The mean (SD) block performance time was 445 (100) s, and block duration was 190 min (range 120-310 min). All surgical procedures were performed under regional anesthesia with anxiolytic sedation provided in 3 of 11 cases. CONCLUSION: Successful ultrasound-guided axillary brachial plexus block may be performed with 1 ml per nerve of 2% LidoEpi.

Ultrasound-guided axillary brachial plexus block with 20 milliliters local anesthetic mixture versus general anesthesia for upper limb trauma surgery: an observer-blinded, prospective, randomized, controlled trial.

OBJECTIVE: We performed a randomized, controlled trial comparing low-dose ultrasound-guided axillary block with general anesthesia evaluating anesthetic and perioperative analgesic outcomes. METHODS: Patients were randomized to either ultrasound-guided axillary block or general anesthesia. Ultrasound-guided axillary block was performed using a needle-out-of-plane approach. Up to 5 mL of local anesthetic injectate (equal parts 2% lidocaine with 1:200,000 epinephrine and 0.5% bupivacaine with 7.5 mg/mL clonidine) was injected after identifying the median, ulnar, radial, and musculocutaneous nerves. A maximum of 20 mL local anesthetic injectate was used. General anesthesia was standardized to include induction with fentanyl and propofol, maintenance with sevoflurane in an oxygen/nitrous oxide mixture. Pain scores were measured in the recovery room and at 2, 6, 24, 48 h, and 7 days. Ability to bypass the recovery room and time to achieve hospital discharge criteria were also assessed. RESULTS: All ultrasound-guided axillary block patients achieved satisfactory anesthesia. The ultrasound-guided axillary block group had lower visual analog scale pain scores in the recovery room (0.3 [1.3] vs 55.8 [36.5], P < 0.001), and visual rating scale pain scores at 2 h (0.3 [1.3] vs 45 [29.6], P < 0.001), and at 6 h (1.1 [2.7] vs 4 [2.8], P < 0.01). All ultrasound-guided axillary block patients bypassed the recovery room and attained earlier hospital discharge criteria (30 min vs 120 min 30/240 P < 0.0001 median [range]). CONCLUSIONS: Ultrasound-guided axillary brachial plexus block with 20 mL local anesthetic mixture provided satisfactory anesthesia and superior analgesia after upper limb trauma surgery when compared with general anesthesia.

Novel nerve imaging and regional anesthesia, bio-impedance and the future.

Ultrasound technology has transformed the practice of regional anaesthesia. Anaesthesiologists routinely use real-time images to guide needle and local anaesthetic placement adjacent to nerves. It is widely accepted that the era of ultrasonography has improved peripheral nerve block success rates and lessened the dose of local anaesthetic required to achieve success. Contemporary reports of harm in relation to nerve injury or local anaesthetic systemic toxicity are reassuring. The safety and efficacy of regional anaesthesia have thus been enhanced. Ultrasound guidance is, however, not a panacea. Ultrasound guidance requires the development of complex psychomotor skills. Harm may still occur where the needle or local anaesthetic is misplaced, resulting in nerve injury, vascular injury or local anaesthetic systemic toxicity. Advances in both imaging and needle technology may further enhance the safety and efficacy of ultrasound-guided regional anaesthesia. This review will focus on peer review literature to characterise the clinical challenges and explore the potential solutions.

Regional anesthesia techniques for ambulatory orthopedic surgery.

PURPOSE OF REVIEW: The purpose of this review is to present advances in the use of regional anesthetic techniques in ambulatory orthopedic surgery. New findings regarding the use of both neuraxial anesthesia and peripheral nerve block are discussed. RECENT FINDINGS: Neuraxial anesthesia: The use of short-acting local anesthetic agents such as mepivacaine, 2-chloroprocaine, and articaine permits rapid onset intrathecal anesthesia with early recovery profiles. Advantages and limitations of these agents are discussed.Peripheral nerve block: Peripheral nerve blocks in limb surgery have the potential to transform this patient cohort into a truly ambulatory, self-caring group. Recent trends and evidence regarding the benefits of regional anesthesia techniques are presented.Continuous perineural catheters permit extension of improved perioperative analgesia into the ambulatory home setting. The role and reported safety of continuous catheters are discussed. SUMMARY: In summary, shorter acting, neuraxial, local anesthetic agents, specific to the expected duration of surgery, may provide superior recovery profiles in the ambulatory setting. A trend towards more peripheral and selective nerve blocks exists. The infrapatellar block is a promising technique to provide analgesia following knee arthroscopy. Improved analgesia seen in the perioperative period can be safely and effectively extended to the postoperative period with the use of perineural catheters.

The Use of Thromboelastography to Measure the Influence Inclusion of a Local Anesthetic Agent has on the Mechanical and Kinetic Properties of Fibrin.

CONTEXT: Delivery of slow-release local anesthesia has considerable potential for postoperative analgesia. Fibrin gel has shown huge potential for drug delivery, but has not been fully investigated for the delivery of local anesthetics nor has whether incorporation of anesthetic drugs into fibrin alters its mechanical properties. AIMS: This study aimed to evaluate the effects of bupivacaine inclusion on the mechanical and kinetic properties of fibrin as measured by thromboelastography (TEG). MATERIALS AND METHODS: Serial dilutions of fibrinogen with thrombin were tested with TEG to identify the optimal concentrations to give reproducible results. Following this, fibrinogen samples diluted with bupivacaine 0.5% in place of normal saline (also 1:20 dilution) were added to thrombin to assess what influence this had on clot strength and kinetics as measured by TEG values (with R, K, and α angle relating to clot kinetics and MA and G (or shear elastic modulus strength) relating to clot strength). RESULTS: The mean values yielded for R were higher and lower for α angle, suggesting that the inclusion of bupivacaine produced a fibrin clot at a slower rate. The values for MA and G were both lower when bupivacaine was included, suggesting inclusion of the local anaesthetic also resulted in a fibrin clot of inferior strength. These results were not statistically significant. CONCLUSION: Although TEG failed to consistently measure these properties, the results suggest that inclusion of local anesthetic affects the clotting process of fibrin, potentially interfering with its ability to function as a sealant, adhesive, or hemostat.

An examination of the effect of open versus paywalled access publication on the disseminative impact and citation count of publications in intensive care medicine and anesthesia.

PURPOSE: We aimed to assess the impact of open access (OA) versus paywalled access (PA) publication on Altmetric Attention Scores (AAS) and whether AAS correlates with future citation count access in the context of intensive care medicine (ICM) and anesthesia. METHODS: 1854 and 2935 publications, in the year 2015, were identified in ICM and anesthesia respectively, using a Pubmed search. The mean AAS was measured for each article. RESULTS: More ICM articles were OA, compared to of anesthesia articles (38.9% v 35.0% p = 0.02). The mean AAS for OA ICM publications was significantly higher than that of PA ICM publications (17.34 vs 8.45, p < 0.01), however, this was not observed when examined in a fixed follow up time frame. AAS appear to correlate with future citation counts. CONCLUSIONS: ICM publications that are available as OA in the medium term result in higher AAS when compared to PA publications, this phenomenon was not observed in anesthesia. AAS correlate with future citation counts, however, a larger study is required to confirm this.

Deliberate practice using validated metrics improves skill acquisition in performance of ultrasound-guided peripheral nerve block in a simulated setting.

STUDY OBJECTIVES: The aim of this study was to compare the effects of deliberate vs. self-guided practices (both using validated metrics) on the acquisition of needling skills by novice learners. DESIGN: Randomized Controlled Study. SETTING: Simulation lab, Department of Anesthesia, St.Vincent's Hospital, Dublin. SUBJECTS: Eighteen medical students. INTERVENTIONS: Students were assigned to either (i) deliberate practice (n = 10) or (ii) self-guided practice (n = 8) groups. After completion of a 'learning phase', subjects attempted to perform a predefined task, which entailed advancing a needle towards a target on a phantom gel under ultrasound guidance. Subsequently, all subjects practiced this task using predefined metrics. Only subjects in the deliberate practice group had an expert anesthesiologist during practice. Immediately after completing 'practice phase', all subjects attempted to perform the same task, and, on the following day, made two further attempts in succession. Two trained consultant anesthesiologists assessed a video of each performance independently using the pre-defined metrics. MEASUREMENTS: Number of procedural steps completed and number of errors made. MAIN RESULTS: Compared with novices who self-guided their practice using metrics, those who undertook expert-supervised deliberate practice using metrics completed more steps (performance metrics) immediately after practice (median [range], 14.5 [12-15] vs. 3 [1-10], p < 0.0001) and 24 h later (15 [12-15] vs. 4.5 [1-11], p < 0.0001 and 15 [11-15] vs. 4 [2-14], p < 0.0001). They also made fewer errors immediately after practice (median [range], 0 [0-0] vs. 5 [3-8], p < 0.0001) and 24 h later, (0 [0-3] vs. 6.5 [3-8], p < 0.0001 and 0 [0-3] vs. 4 [2-7], p < 0.0001). CONCLUSION: Combining deliberate practice with metrics improved acquisition of needling skills.

Transversus abdominis plane block: a cadaveric and radiological evaluation.

BACKGROUND AND OBJECTIVES: The abdominal wall is a significant source of pain after abdominal surgery. Anterior abdominal wall analgesia may assist in improving postoperative analgesia. We have recently described a novel approach to block the abdominal wall neural afferents via the bilateral lumbar triangles of Petit, which we have termed a transversus abdominis plane block. The clinical efficacy of the transversus abdominis plane block has recently been demonstrated in a randomized controlled clinical trial of adults undergoing abdominal surgery. METHODS: After institutional review board approval, anatomic studies were conducted to determine the deposition and spread of methylene blue injected into the transversus abdominis plane via the triangles of Petit. Computerized tomographic and magnetic resonance imaging studies were then conducted in volunteers to ascertain the deposition and time course of spread of solution within the transversus abdominis fascial plane in vivo. RESULTS: Cadaveric studies demonstrated that the injection of methylene blue via the triangle of Petit using the "double pop" technique results in reliable deposition into the transversus abdominis plane. In volunteers, the injection of local anesthetic and contrast produced a reliable sensory block, and demonstrated deposition throughout the transversus abdominis plane. The sensory block produced by lidocaine 0.5% extended from T7 to L1, and receded over 4 to 6 hours, and this finding was supported by magnetic resonance imaging studies that showed a gradual reduction in contrast in the transversus abdominis plane over time. CONCLUSIONS: These findings define the anatomic characteristics of the transversus abdominis plane block, and underline the clinical potential of this novel block.

An evaluation of operating room throughput in a stand-alone soft-tissue trauma operating theatre.

BACKGROUND: Operating room time is a limited, expensive commodity in acute hospitals. Strategies aimed at reduction of non-operative time improve operating room throughput and capacity. We conducted a prospective study to evaluate and augment operating room throughput and capacity using context-specific work practice changes. METHODS: Following institutional and ethical approval, an interdisciplinary group designed and introduced a series of work practice changes specific to a stand-alone soft tissue trauma theatre, comprising modifications to patient processing, staff behaviours and additional anaesthesiologist hours. Time intervals relating to each patient were measured during a 16 week period before and after implementing work practice changes. The primary outcome measure was non-operative time, with daily caseload and cancellations amongst secondary outcome measures. RESULTS: 251 procedures were included over 58 working days (8 to 17 Monday to Friday). Non-operative time [55.6 (31.1) vs 52.3 (9.8) minutes, p = 0.48], daily caseload [4 [1-9] vs 4 [2-7], p = 0.56], and the number of daily cancellations [3 [0-11] vs 5 [0-8], p = 0.38], did not differ between baseline and study phases. Regional anaesthesia for upper limb surgery increased during the study phase [26/59 (44.0%) vs 10/63 (15.9%), p = 0.014] with resultant decrease in mean duration of recovery room stay [20.7 (17.7) vs 30 (20.5) minutes, p = 0.0001] and increased recovery room bypass [26/116 (22.4%) vs 6/135 (4.4%), p = 0.0002]. Avoidable delays accounted for 124.8 (72.2) minutes of theatre time lost each day. CONCLUSION: In conclusion, additional attending anaesthesiologist hours combined with work practice changes did not impact on measures of theatre throughput and capacity. The study identified important variables that contribute to avoidable delays, and points the way for future research.

Development of performance and error metrics for ultrasound-guided axillary brachial plexus block.

PURPOSE: Change in the landscape of medical education coupled with a paradigm shift toward outcome-based training mandates the trainee to demonstrate specific predefined performance benchmarks in order to progress through training. A valid and reliable assessment tool is a prerequisite for this process. The objective of this study was to characterize ultrasound-guided axillary brachial plexus block to develop performance and error metrics and to verify face and content validity using a modified Delphi method. METHODS: A metric group (MG) was established, which comprised three expert regional anesthesiologists, an experimental psychologist and a trained facilitator. The MG deconstructed ultrasound-guided axillary brachial plexus block to identify and define performance and error metrics. Experts reviewed five video recordings of the procedure performed by anesthesiologists with different levels of expertise to aid task deconstruction. Subsequently, the MG subjected the metrics to "stress testing", a process to ascertain the extent to which the performance and error metrics could be scored objectively, either occurring or not occurring with a high degree of reliability. Ten experienced regional anesthesiologists used a modified Delphi method to reach consensus on the metrics. RESULTS: Fifty-four performance metrics, organized in six procedural phases and characterizing ultrasound-guided axillary brachial plexus block and 32 error metrics (nine categorized as critical) were identified and defined. Based on the Delphi panel consensus, one performance metric was modified, six deleted and three added. CONCLUSION: In this study, we characterized ultrasound-guided axillary brachial plexus block to develop performance and error metrics as a prerequisite for outcome-based training and assessment. Delphi consensus verified face and content validity.

Novel methods of local anesthetic delivery in the perioperative and postoperative setting-potential for fibrin hydrogel delivery.

The benefits of high-quality postoperative analgesia are well documented and include earlier mobilization, fewer respiratory and cardiovascular complications, and shorter hospital stay. Local anesthesia-based acute pain regimens are at worst equal to and at best superior to opiate-based regimens from the perspective of analgesia. A multimodal approach limiting opioids by combining with local anesthetics has additional beneficial effect on outcomes such as nausea and vomiting, pruritus, gastrointestinal function, respiratory complications, and neutrophil function. Wound catheters providing continuous infiltration of local anesthetics offer a rational approach to effective perioperative analgesia, but their use is limited by a short duration of action. There is an identified need for further methods to optimize longer-acting delivery of these agents. This article reviews current and evolving longer-acting techniques and their limitations with particular focus on the potential advantages of a fibrin hydrogel-based system.

Long versus short axis ultrasound guided approach for internal jugular vein cannulation: a prospective randomised controlled trial.

AIM: The aim of this study was to compare the short and long axis approaches to ultrasound guided right internal jugular vein cannulation with respect to indicators of success. METHODS: Patients undergoing cardiac surgery requiring central venous cannulation (99 patients) were randomised to undergo either long or short axis ultrasound guided cannulation of the right internal jugular vein by a skilled anaesthetist. First pass success, number of needle passes, procedural taken and complications were documented for each procedure. RESULTS: The right internal jugular vein was successfully cannulated in all 99 patients. The first pass success rate was significantly higher in the short axis 98% group compared to the long axis group 78% [48:1 (98%) versus 39:11 (78%) p <0.006]. Procedural time was comparable in both the groups [39.6 (18.4) versus 46.9 (42.4)]. Fewer needle redirections were required in the short axis group [1.02 (0.02) versus 1.24 (0.56) p <0.004]. Carotid artery puncture only occurred in the long axis group. CONCLUSIONS: We conclude that anaesthetists with experience in ultrasound guided internal jugular vein cannulation, have higher first pass success rate and less carotid artery puncture when a short axis, rather than a long axis, approach is employed.

Proactive error analysis of ultrasound-guided axillary brachial plexus block performance.

BACKGROUND: Detailed description of the tasks anesthetists undertake during the performance of a complex procedure, such as ultrasound-guided peripheral nerve blockade, allows elements that are vulnerable to human error to be identified. We have applied 3 task analysis tools to one such procedure, namely, ultrasound-guided axillary brachial plexus blockade, with the intention that the results may form a basis to enhance training and performance of the procedure. METHODS: A hierarchical task analysis of the procedure was performed with subsequent analysis using systematic human error reduction and prediction approach (SHERPA). Failure modes, effects, and criticality analysis was applied to the output of our SHERPA analysis to provide a definitive hierarchy to the error analysis. RESULTS: Hierarchical task analysis identified 256 tasks associated with the performance of ultrasound-guided axillary brachial plexus blockade. Two hundred twelve proposed errors were analyzed using SHERPA. Failure modes, effects, and criticality analysis methodology was applied to the output of SHERPA analysis to prioritize 20 errors. CONCLUSIONS: This study presents a formal analysis of (i) the specific tasks that might be associated with the safe and effective performance of the procedure and (ii) the most critical errors likely to occur as trainees learn to perform the procedure. Potential applications of these data include curricular development and the design of tools to teach and assess block performance.