Research priorities in regional anaesthesia: where should we focus?

Using a modified Delphi technique, an international group of regional anaesthetists generated a list of top research priorities in regional anaesthesia. The list of unanswered research questions was created from a questionnaire completed by >500 anaesthetists and distilled into 11 priorities grouped into four themes: clinical practice and efficacy, pain management, technology and equipment, and training and assessment.

A systematic review of cardiac surgery clinical prediction models that include intra-operative variables.

BACKGROUND: Most cardiac surgery clinical prediction models (CPMs) are developed using pre-operative variables to predict post-operative outcomes. Some CPMs are developed with intra-operative variables, but none are widely used. The objective of this systematic review was to identify CPMs with intra-operative variables that predict short-term outcomes following adult cardiac surgery. METHODS: Ovid MEDLINE and EMBASE databases were searched from inception to December 2022, for studies developing a CPM with at least one intra-operative variable. Data were extracted using a critical appraisal framework and bias assessment tool. Model performance was analysed using discrimination and calibration measures. RESULTS: A total of 24 models were identified. Frequent predicted outcomes were acute kidney injury (9/24 studies) and peri-operative mortality (6/24 studies). Frequent pre-operative variables were age (18/24 studies) and creatinine/eGFR (18/24 studies). Common intra-operative variables were cardiopulmonary bypass time (16/24 studies) and transfusion (13/24 studies). Model discrimination was acceptable for all internally validated models (AUC 0.69-0.91). Calibration was poor (15/24 studies) or unreported (8/24 studies). Most CPMs were at a high or indeterminate risk of bias (23/24 models). The added value of intra-operative variables was assessed in six studies with statistically significantly improved discrimination demonstrated in two. CONCLUSION: Weak reporting and methodological limitations may restrict wider applicability and adoption of existing CPMs that include intra-operative variables. There is some evidence that CPM discrimination is improved with the addition of intra-operative variables. Further work is required to understand the role of intra-operative CPMs in the management of cardiac surgery patients.

Quantitative Neuromuscular Monitoring Permits Early Diagnosis of Abnormal Butyrylcholinestrase: Two Case Studies Demonstrating Prevention of Awareness from Premature Awakening.

Administration of succinylcholine to patients with a variant in the butyrylcholinesterase (BChE) gene increases the risk of anesthesia emergence prior to recovery from neuromuscular blockade (NMB). Application of quantitative neuromuscular monitoring (NMM) can identify residual NMB. We present two patients with abnormal BChE gene variants. In the first case, quantitative monitoring was applied too late to prevent awareness, but allowed diagnosis and prevented admission to the intensive care unit. In the second case, monitoring was applied prior to NMB, which enabled early diagnosis and prevented premature awakening from anesthesia. These cases illustrate the importance of quantitative NMM, even in short cases and with short-acting depolarizing agents such as succinylcholine. The clinical implications of this report include a more consistent use of NMM to identify and manage patients with undiagnosed abnormal BChE and to prevent premature anesthesia emergence.

Comparing Predictive Performance of Time Invariant and Time Variant Clinical Prediction Models in Cardiac Surgery.

Clinical prediction models are increasingly used across healthcare to support clinical decision making. Existing methods and models are time-invariant and thus ignore the changes in populations and healthcare practice that occur over time. We aimed to compare the performance of time-invariant with time-variant models in UK National Adult Cardiac Surgery Audit data from Manchester University NHS Foundation Trust between 2009 and 2019. Data from 2009-2011 were used for initial model fitting, and data from 2012-2019 for validation and updating. We fitted four models to the data: a time-invariant logistic regression model (not updated), a logistic model which was updated every year and validated it in each subsequent year, a logistic regression model where the intercept is a function of calendar time (not updated), and a continually updating Bayesian logistic model which was updated with each new observation and continuously validated. We report predictive performance over the complete validation cohort and for each year in the validation data. Over the complete validation data, the Bayesian model had the best predictive performance.

Risk Prediction Models for Long-Term Survival after Cardiac Surgery: A Systematic Review.

BACKGROUND: The reporting of alternative postoperative measures of quality after cardiac surgery is becoming increasingly important as in-hospital mortality rates continue to decline. This study aims to systematically review and assess risk models designed to predict long-term outcomes after cardiac surgery. METHODS: The MEDLINE and Embase databases were searched for articles published between 1990 and 2020. Studies developing or validating risk prediction models for long-term outcomes after cardiac surgery were included. Data were extracted using checklists for critical appraisal and systematic review of prediction modeling studies. RESULTS: Eleven studies were identified for inclusion in the review, of which nine studies described the development of long-term risk prediction models after cardiac surgery and two were external validation studies. A total of 70 predictors were included across the nine models. The most frequently used predictors were age (n = 9), peripheral vascular disease (n = 8), renal disease (n = 8), and pulmonary disease (n = 8). Despite all models demonstrating acceptable performance on internal validation, only two models underwent external validation, both of which performed poorly. CONCLUSION: Nine risk prediction models predicting long-term mortality after cardiac surgery have been identified in this review. Statistical issues with model development, limited inclusion of outcomes beyond 5 years of follow-up, and a lack of external validation studies means that none of the models identified can be recommended for use in contemporary cardiac surgery. Further work is needed either to successfully externally validate existing models or to develop new models. Newly developed models should aim to use standardized long-term specific reproducible outcome measures.

Standardizing nomenclature in regional anesthesia: an ASRA-ESRA Delphi consensus study of upper and lower limb nerve blocks.

BACKGROUND: Inconsistent nomenclature and anatomical descriptions of regional anesthetic techniques hinder scientific communication and engender confusion; this in turn has implications for research, education and clinical implementation of regional anesthesia. Having produced standardized nomenclature for abdominal wall, paraspinal and chest wall regional anesthetic techniques, we aimed to similarly do so for upper and lower limb peripheral nerve blocks. METHODS: We performed a three-round Delphi international consensus study to generate standardized names and anatomical descriptions of upper and lower limb regional anesthetic techniques. A long list of names and anatomical description of blocks of upper and lower extremities was produced by the members of the steering committee. Subsequently, two rounds of anonymized voting and commenting were followed by a third virtual round table to secure consensus for items that remained outstanding after the first and second rounds. As with previous methodology, strong consensus was defined as ≥75% agreement and weak consensus as 50%-74% agreement. RESULTS: A total of 94, 91 and 65 collaborators participated in the first, second and third rounds, respectively. We achieved strong consensus for 38 names and 33 anatomical descriptions, and weak consensus for five anatomical descriptions. We agreed on a template for naming peripheral nerve blocks based on the name of the nerve and the anatomical location of the blockade and identified several areas for future research. CONCLUSIONS: We achieved consensus on nomenclature and anatomical descriptions of regional anesthetic techniques for upper and lower limb nerve blocks, and recommend using this framework in clinical and academic practice. This should improve research, teaching and learning of regional anesthesia to eventually improve patient care.

Venous Excess Ultrasound (VExUS Grading to Assess Perioperative Fluid Status for Noncardiac Surgeries: a Prospective Observational Pilot Study.

Objectives: Perioperative fluid administration impacts the rate of complications following surgery. VExUS grading system is a standardized point of care ultrasound (POCUS)-based, comprehensive method to assess volume status. VExUS could serve as a tool to guide fluid management, if validated perioperatively. The primary aim was to assess the success rate of obtaining required windows for VExUS grading , as well as the feasibility within a perioperative setting among noncardiac surgery. Further, this study describes the incidence of perioperative venous congestion and associations with 30-day postoperative complications. Methods: This observational study was conducted in non-critically ill adults undergoing noncardiac surgery. Patients were scanned preoperatively, in the post anesthesia care unit (PACU), and 24 hours postoperatively for venous congestion. Researchers retrospectively captured 30-day complications for multivariate analyses. Results: The cohort included 69 participants. Ninety-one percent of scans over all timepoints were successfully completed. Pre-operatively, 57 (83%) scans were Grade 0, and 11 (16%) were Grade 1. Venous congestion was observed in 29 (44%) patients in the PACU (n=66). 22 (33%) patients were Grade 1, while 7 (11%) were Grade 2. At 24 hours (n=63), 31 patients (49%) had venous congestion: 20 (32%) Grade 1 and 11 (17%) Grade 2. Of the pre-operative Grade 0, 28 (50%) had at least one postoperative scan with venous congestion. No patients were Grade 3 at any timepoint. The 30-day complication rate was 32% (n=22). Eleven (16%) patients developed acute kidney injury (AKI). There was no statistically significant association between VExUS grading and all-cause complications or AKI. Conclusion: This study demonstrates that perioperative VExUS scoring is a feasible tool among a variety of noncardiac surgeries. We highlight that venous congestion is common and increases postoperatively within non-ICU populations. Larger studies are needed to assess the relationship between VExUS grading and postoperative complications.

Comparing preoperative fasting and ultrasound-measured intravascular volume status in elective surgery, enhanced recovery patients versus inpatient, urgent surgery patients and the ability of IVC collapsibility to predict post-induction hypotension.

Hypotension following induction of general anaesthesia has been shown to result in increased complications and mortality postoperatively. Patients admitted to the hospital undergoing urgent surgery are often fasted from fluids for significant periods compared to elective patients subject to Enhanced Recovery After Surgery protocols despite guidelines stating that a two-hour fast is sufficient. The aim of this prospective, observational study was to compare fasting times and intravascular volume status between elective surgery patients subject to enhanced recovery protocols and inpatient, urgent surgery patients and to assess differences in the incidence of post-induction hypotension. Fasting data was obtained by questionnaire in the preoperative area in addition to inferior vena cava collapsibility index, a non-invasive measure of intravascular volume. Blood pressure readings and drug administration for the ten minutes following induction were obtained from patients' charts. Inpatients undergoing urgent surgery were fasted significantly longer than enhanced recovery patients and had lower intravascular volume. However, no difference was found in the incidence of post-induction hypotension.

Outcomes after Conversion from Video-Assisted Thoracoscopic Lobectomy to Thoracotomy.

BACKGROUND: Lung cancer resections are increasingly being performed via video-assisted thoracoscopic surgery (VATS). Conversion to thoracotomy can occur for many reasons and may affect outcomes. The objective of this study was to investigate the impact of VATS conversion on short- and mid-term outcomes and identify reasons for conversion. METHODS: Consecutive patients undergoing lobectomy for primary non-small cell lung cancer between 2012 and 2019 in a single UK center were included. Primary outcomes were 90-day mortality, intraoperative conversion, and overall survival. Reasons for conversion were defined as bleeding or nonbleeding. Outcomes were compared between groups using univariable analysis. Multivariable logistic regression analysis was performed to identify risk factors for conversion. RESULTS: A total of 2,622 patients were included with 20.6% (n = 541) completing surgery via VATS and 79.4% (n = 2,081) via thoracotomy. The rate of completed VATS surgery increased significantly over time (2012: 6.9%, 2019: 55.1%, p < 0.001). Overall conversion rate was 14.3% (n = 90/631) and has reduced significantly over time (p < 0.001). The rate of conversion due to intraoperative bleeding was 31.1% (n = 28/90). Obesity, male sex, and stage III disease were independent risk factors for conversion. The 90-day mortality rate after conversion was not significantly different from the rate for planned thoracotomy (3.3 vs. 3.4%, p = 0.987). There was no significant difference in overall survival between patients experiencing intraoperative conversion and those undergoing planned thoracotomy (p = 0.135). CONCLUSION: This study demonstrates comparable outcomes for patients undergoing conversion from VATS to those undergoing planned surgery via thoracotomy. It remains unclear if reason for conversion is associated with outcomes.

The Relationship Between Cardiac Troponin in People Hospitalised for Exacerbation of COPD and Major Adverse Cardiac Events (MACE) and COPD Readmissions.

Background: No single biomarker currently risk stratifies chronic obstructive pulmonary disease (COPD) patients at the time of an exacerbation, though previous studies have suggested that patients with elevated troponin at exacerbation have worse outcomes. This study evaluated the relationship between peak cardiac troponin and subsequent major adverse cardiac events (MACE) including all-cause mortality and COPD hospital readmission, among patients admitted with COPD exacerbation. Methods: Data from five cross-regional hospitals in England were analysed using the National Institute of Health Research Health Informatics Collaborative (NIHR-HIC) acute coronary syndrome database (2008-2017). People hospitalised with a COPD exacerbation were included, and peak troponin levels were standardised relative to the 99th percentile (upper limit of normal). We used Cox Proportional Hazard models adjusting for age, sex, laboratory results and clinical risk factors, and implemented logarithmic transformation (base-10 logarithm). The primary outcome was risk of MACE within 90 days from peak troponin measurement. Secondary outcome was risk of COPD readmission within 90 days from peak troponin measurement. Results: There were 2487 patients included. Of these, 377 (15.2%) patients had a MACE event and 203 (8.2%) were readmitted within 90 days from peak troponin measurement. A total of 1107 (44.5%) patients had an elevated troponin level. Of 1107 patients with elevated troponin at exacerbation, 256 (22.8%) had a MACE event and 101 (9.0%) a COPD readmission within 90 days from peak troponin measurement. Patients with troponin above the upper limit of normal had a higher risk of MACE (adjusted HR 2.20, 95% CI 1.75-2.77) and COPD hospital readmission (adjusted HR 1.37, 95% CI 1.02-1.83) when compared with patients without elevated troponin. Conclusion: An elevated troponin level at the time of COPD exacerbation may be a useful tool for predicting MACE in COPD patients. The relationship between degree of troponin elevation and risk of future events is complex and requires further investigation.

Safety of curative-intent lung cancer surgery in older patients (octogenarians): A contemporary multicentre cohort study.

INTRODUCTION: Despite octogenarians representing an ever-increasing proportion of patients with lung cancer, there is a paucity of evidence describing outcomes after lung resection for these patients. We aimed to evaluate short and mid-term outcomes for octogenarians after lung resection. MATERIALS AND METHODS: A total of 5,470 consecutive patients undergoing lung resection for primary lung cancer from 2012-2019 in two UK centres were included. Primary outcomes were perioperative, 90-day, and one-year mortality in the octogenarian vs. non-octogenarian cohort. Appropriate statistical tests were used to compare outcomes between octogenarian and non-octogenarian patients. Secondary outcomes were post-operative complications and to validate the performance of the Thoracoscore model in the octogenarian cohort. RESULTS: Overall, 9.4% (n=513) of patients were aged ≥80. The rates of 90-day mortality, one-year mortality, and post-operative atrial fibrillation were significantly higher for octogenarians. The one-year mortality rate for octogenarians fell significantly over time (2012-2015: 16.5% vs 2016-2019: 10.2%, p=0.034). Subgroup analysis (2016-2019 only) demonstrated no significant difference in peri-operative, 90-day, or one-year mortality between octogenarian and non-octogenarian patients. Validation of the Thoracoscore model demonstrated modest discrimination and acceptable calibration. DISCUSSION: Mortality for octogenarians fell significantly over time in this study. Indeed, when confined to the most recent time period, comparable rates of both 90-day and one-year mortality for octogenarian and non-octogenarian patients were seen. Whilst preventative strategies to reduce the incidence of post-operative atrial fibrillation in octogenarians should be considered, these findings demonstrate that following appropriate patient selection, octogenarians can safely undergo lung resection for lung cancer.

Beyond the Brachial Plexus: Reapplication of the Thoracic Paravertebral Block for Upper Arm Fistula Surgery.

Patients requiring complex upper arm arteriovenous fistulas or grafts may not be suitable candidates for a single regional anesthesia technique and monitored anesthesia care because the necessary thoracic (T2) dermatomal area of the medial, upper arm remains spared by any solitary brachial plexus (C5-T1) technique. An infiltrative intercostobrachial nerve block can often be used in conjunction with a brachial plexus block; however, coverage may still be incomplete. This case report describes the use of a high thoracic paravertebral block in conjunction with a brachial plexus block to achieve adequate anesthetic coverage for an upper arm arteriovenous fistula creation procedure extending into the axilla. The result of this technique showed adequate coverage of the upper arm and demonstrates that paravertebral blocks are a reasonable adjunct for proximal upper arm arteriovenous fistula procedures.

Wedge resection versus lobectomy in T1 lung cancer patients: a propensity matched analysis.

OBJECTIVES: Performing wedge resection rather than lobectomy for primary lung cancer remains controversial. Recent studies demonstrate no survival advantage for non-anatomical resection compared to lobectomy in patients with early-stage lung cancer. The objective of this study was to investigate whether in patients with T1 tumours, non-anatomical wedge resection is associated with equivalent survival to lobectomy. METHODS: This was a retrospective cohort study of patients who underwent lung resection at the Lancashire Cardiac Centre between April 2005 and April 2018. Patients were subjected to multidisciplinary team discussion. The extent of resection was decided by the team based on British Thoracic Society guidelines. The primary outcome was overall survival. Propensity matching of patients with T1 tumours was also performed to determine whether differences in survival rates exist in a subset of these patients with balanced pre-operative characteristics. RESULTS: There were 187 patients who underwent non-anatomical wedge resection and 431 patients who underwent lobectomy. Cox modelling demonstrated no survival difference between groups for the first 1.6 years then a risk of death 3-fold higher for wedge resection group after 1.6 years (HR 3.14, CI 1.98-4.79). Propensity matching yielded 152 pairs for which 5-year survival was 66.2% for the lobectomy group and 38.5% for the non-anatomical wedge group (SMD = 0.58, p = 0.003). CONCLUSIONS: Non-anatomical wedge resection was associated with significantly reduced 5-year survival compared to lobectomy in matched patients. Lobectomy should remain the standard of care for patients with early-stage lung cancer who are fit enough to undergo surgical resection.

Healthcare utilisation in patients with long-term conditions during the COVID-19 pandemic: a population-based observational study of all patients across Greater Manchester, UK.

OBJECTIVES: Data on population healthcare utilisation (HCU) across both primary and secondary care during the COVID-19 pandemic are lacking. We describe primary and secondary HCU stratified by long-term conditions (LTCs) and deprivation, during the first 19 months of COVID-19 pandemic across a large urban area in the UK. DESIGN: A retrospective, observational study. SETTING: All primary and secondary care organisations that contributed to the Greater Manchester Care Record throughout 30 December 2019 to 1 August 2021. PARTICIPANTS: 3 225 169 patients who were registered with or attended a National Health Service primary or secondary care service during the study period. PRIMARY OUTCOMES: Primary care HCU (incident prescribing and recording of healthcare information) and secondary care HCU (planned and unplanned admissions) were assessed. RESULTS: The first national lockdown was associated with reductions in all primary HCU measures, ranging from 24.7% (24.0% to 25.5%) for incident prescribing to 84.9% (84.2% to 85.5%) for cholesterol monitoring. Secondary HCU also dropped significantly for planned (47.4% (42.9% to 51.5%)) and unplanned admissions (35.3% (28.3% to 41.6%)). Only secondary care had significant reductions in HCU during the second national lockdown. Primary HCU measures had not recovered to prepandemic levels by the end of the study. The secondary admission rate ratio between multi-morbid patients and those without LTCs increased during the first lockdown by a factor of 2.40 (2.05 to 2.82; p<0.001) for planned admissions and 1.25 (1.07 to 1.47; p=0.006) for unplanned admissions. No significant changes in this ratio were observed in primary HCU. CONCLUSION: Major changes in primary and secondary HCU were observed during the COVID-19 pandemic. Secondary HCU reduced more in those without LTCs and the ratio of utilisation between patients from the most and least deprived areas increased for the majority of HCU measures. Overall primary and secondary care HCU for some LTC groups had not returned to prepandemic levels by the end of the study.

Custodiol cardioplegia for temporary mechanical circulatory support.

Several patients requiring biventricular mechanical circulatory support in the acute setting will not be candidates for less invasive advanced heart failure therapies not requiring median sternotomy. Temporary biventricular assist device may provide reliable short term support bridging patients to recovery or further advanced treatments. However, this exposes patients to increased risk of reoperation due to bleeding and further exposure to blood products. This article outlines the practical details necessary in performing this technique while minimizing potential complications.

Evaluating Patterns of Injectate Spread After Rectus Sheath Block: A Cadaveric Dissection Study.

INTRODUCTION: This cadaveric dye study assesses the effect of volume and number of injections on the spread of solution after ultrasound-guided rectus sheath injections. In addition, this study evaluates the impact of the arcuate line on solution spread. MATERIALS AND METHODS: Ultrasound-guided rectus sheath injections were performed on seven cadavers on both sides of the abdomen, for a total of 14 injections. Three cadavers received one injection of 30 mL of a solution consisting of bupivacaine and methylene blue at the level of the umbilicus. Four cadavers received two injections of 15 mL of the same solution, one midway between the xiphoid process and umbilicus and one midway between the umbilicus and pubis. RESULTS: Six cadavers were successfully dissected and analyzed for a total of 12 injections, while one cadaver was excluded due to poor tissue quality that was inadequate for dissection and analysis. There was a significant spread of solution with all injections caudally to the pubis without limitation by the arcuate line. However, a single 30 mL injection showed inconsistent spread to the subcostal margin in four of six injections, including in a cadaver with an ostomy. A double injection of 15 mL showed consistent spread from xiphoid to pubis in five of six injections, except in a cadaver with a hernia. CONCLUSIONS: Injections deep to the rectus abdominis muscle, using the same technique as an ultrasound-guided rectus sheath block, achieve spread along a large and continuous fascial plane without limitation by the arcuate line and may provide coverage of the entire anterior abdomen. A large volume is necessary for complete coverage and spread is improved with multiple injections. We suggest that two injections with a total volume of at least 30 mL per side may be needed to achieve adequate coverage in the absence of preexisting abdominal abnormalities.

2023 American Society of Anesthesiologists Practice Guidelines for Monitoring and Antagonism of Neuromuscular Blockade: A Report by the American Society of Anesthesiologists Task Force on Neuromuscular Blockade.

These practice guidelines provide evidence-based recommendations on the management of neuromuscular monitoring and antagonism of neuromuscular blocking agents during and after general anesthesia. The guidance focuses primarily on the type and site of monitoring and the process of antagonizing neuromuscular blockade to reduce residual neuromuscular blockade.

Quality of Recovery After Rotator Cuff Repair With Interscalene Liposomal Bupivacaine Versus Interscalene Nerve Catheter.

Background: Interscalene nerve catheters have been proven to be effective in managing pain after rotator cuff repair (RCR) surgery. Liposomal bupivacaine is a newer approved therapy for use around the interscalene brachial plexus, but its analgesic efficacy has limited supporting data in various patient populations. Purpose/Hypothesis: The purpose of this study was to investigate the quality of recovery after arthroscopic RCR in patients who received either single-injection interscalene liposomal bupivacaine or an interscalene peripheral nerve catheter. It was hypothesized that interscalene peripheral nerve catheters would provide more reliable analgesia and improved patient satisfaction 48 hours after surgery. Study Design: Cohort study; Level of evidence, 2. Methods: Enrolled were 93 consecutive patients who underwent arthroscopic rotator cuff surgery at a single ambulatory surgery center between October 2020 and June 2021. Of these patients, 13 were lost to follow-up; thus, 80 patients were included in statistical analysis. One group of patients (n = 48) received a preoperative interscalene nerve block placed with 10 mL 0.5% bupivacaine and 10 mL 1.3% liposomal bupivacaine. The second group (n = 32) received a preoperative interscalene catheter with an initial bolus of 20 mL 0.25% bupivacaine and a 0.2% ropivacaine infusion by an elastomeric pump set at 10 mL/hr for 48 hours. The primary outcome was the difference between preoperative and 48-hour postoperative quality of recovery-15 (QoR-15) scores. Secondary outcomes included visual analog pain scores, opioid use, and patient satisfaction. Complications and adverse effects were also noted. The Kruskal-Wallis test was used to analyze means and standard deviations for continuous endpoints; Fisher exact test was used to analyze counts and proportions for categorical endpoints. Results: The liposomal bupivacaine group had a mean reduction of 3.9 in their postoperative QoR-15 scores, and the catheter group had a mean reduction of 25.1 in their postoperative QoR-15 scores, indicating a significantly worse functional recovery period compared with liposomal bupivacaine within the first 48 hours (P < .001). Patients who received liposomal bupivacaine also had significantly lower pain scores on the second postoperative day, improved quality of sleep, and improved satisfaction with analgesia (P < .05 for all). Conclusion: The use of interscalene liposomal bupivacaine demonstrated significantly improved quality of recovery when compared with interscalene nerve catheter after RCR.