Adverse outcomes associated with nerve stimulator-guided and ultrasound-guided peripheral nerve blocks by supervised trainees: update of a single-site database

Enhancing Safety in Regional Anesthesia: Guidelines from the Italian Society of Anesthesia, Analgesia, Resuscitation and Intensive Care (SIAARTI)

BACKGROUND

Regional anesthesia techniques have become integral to modern perioperative care, offering enhanced pain management and recovery outcomes. However, their application in patients with specific conditions, such as anticoagulation therapy or preexisting comorbidities, raises concerns regarding safety and efficacy. Current guidelines addressing these issues are fragmented, necessitating comprehensive, evidence-based recommendations.

METHODS

A multidisciplinary panel of experts in anesthesiology and pain management was convened under the auspices of the Italian Society of Anesthesia, Analgesia, Resuscitation, and Intensive Care (SIAARTI). The guidelines presented herein were developed according to the GRADE system (Grading of Recommendations of Assessment Development and Evaluations), in compliance with the methodological manual for the production of clinical practice guidelines published by the National Center for Clinical Excellence, Quality, and Safety of Care, Italian National Institute of Health.

RESULTS

The guidelines encompass recommendations on neuraxial blocks in anticoagulated patients, the dual guidance use in peripheral nerve blocks, the role of sterile field preparation, and post-procedural monitoring. Evidence from meta-analyses and large-scale observational studies supported most recommendations, though limitations in study heterogeneity were noted.

CONCLUSIONS

These guidelines provide a structured framework for clinicians to enhance patient safety and procedural efficacy in regional anesthesia. Further research is encouraged to address identified gaps, particularly regarding specific patient subgroups and novel regional anesthesia techniques.

Peripheral Nerve Stimulation for Pain Management: A Survey of Clinical Practice Patterns

BACKGROUND

Clinical interest in and utilization of peripheral nerve stimulation (PNS) for treating chronic pain has significantly increased in recent years owing to its potential for providing analgesia and improved function and quality of life in comparison with pharmacologic treatments. However, the relative infancy of PNS-specific systems and limited clinical practice guidance likely contribute to significant variation in PNS utilization patterns.

OBJECTIVES

We sought to conduct a survey study to characterize PNS-specific clinical practices and propose the next steps in standardizing key practices for PNS utilization.

MATERIALS AND METHODS

A 19-question survey exploring PNS-relevant clinical parameters was disseminated online to pain physicians in practice. Descriptive statistics were used to summarize results.

RESULTS

A total of 94 responses were collected. Regarding patient selection, most practitioners would apply PNS to treat nociceptive pain from major joint osteoarthritis (77.7%) and chronic low back pain (64.9%), but not for axial neck pain (50.0%). In contrast, most would apply PNS to treat neuropathic pain from peripheral neuralgia (94.7%), pericranial neuralgia (77.7%), and cancer-related neuropathic pain (64.9%). In treating complex regional pain syndrome, most practitioners would apply PNS before all other forms of neuraxial neuromodulation (>50% for each form). Similarly, for treating nonsurgical low back pain, most would apply PNS before neuraxial neuromodulation (>50% for each form) but not before radiofrequency ablation (19.2%). Most routinely performed nerve blocks before PNS, mainly to confirm anatomical coverage (84.0%), and regarded a 50% to 75% interquartile range as the minimum analgesic benefit required before proceeding with PNS. Regarding nerve target selection for treating complex regional pain syndrome of the wrist/hand or ankle/foot, or knee osteoarthritis, we observed a very wide variance of PNS target locations and discrete nerves. Regarding "minor" adverse events, most reported not changing PNS utilization on encountering skin/soft tissue reactions (85.1%), minor infections (76.6%), or lead migration/loss of efficacy (50.0%). In comparison, most reported reducing PNS utilization on encountering skin erosion (58.5%), major infections (58.5%), or lead fractures (41.5%).

CONCLUSIONS

There is significant practice variation regarding the utilization of PNS across numerous key clinical considerations. Future research that explores the reasons driving these differences might help optimize patient selection, target selection, periprocedural management, and ultimately outcomes.

Risk profiles of common brachial plexus block sites: results from the net-ra registry

INTRODUCTION

Regional anesthesia is frequently used for upper limb surgeries and postoperative pain control. Different approaches to brachial plexus blocks are similarly effective but may differ in the frequency and severity of iatrogenesis. We, therefore, examined large-scale registry data to explore the risks of typical complications among different brachial plexus block sites for regional anesthesia.

METHODS

26,947 qualifying adult brachial plexus blocks (2007-2022) from the Network for Safety in Regional Anesthesia and Acute Pain Therapy registry were included in a retrospective cohort analysis. Interscalene, supraclavicular, infraclavicular, and axillary approaches were compared for block failure and bloody punctures using generalized estimating equations. For continuous procedures, we analyzed the influence of the approach on catheter failure, neurological disorders, and infections.

RESULTS

The axillary plexus block had the highest risk of block failure (adjusted OR, 2.3; 95% CI 1.02 to 5.1; p=0.04), catheter failure (adjusted OR, 1.4; 95% CI 1.1 to 2.0; p=0.02), and neurological dysfunction (adjusted OR, 3.0; 95% CI 1.5 to 5.9; p=0.002). There was no statistically significant difference among block sites for bloody punctures, while infraclavicular blocks had the highest odds for catheter-related infections.

DISCUSSION

The axillary approach to the brachial plexus had the highest odds for block failure and neurological dysfunction after catheter placement, as well as a significant risk for catheter failure. However, considering that the axillary approach precludes other complications such as pneumothorax, none of the four common approaches to the brachial plexus has a fundamentally superior risk profile.

Ultrasound-guided supracondylar radial nerve block for closed reduction of a distal radius fracture in the emergency department: Case report

Background

Closed reduction and a closed cast are common treatments for patients with acute distal radius fractures in the emergency room. Many of the common analgesic techniques such as hematoma block may not be effective, which can hinder the stabilization and reduction of fractures.

Case report

An 81-year-old woman who had a Colle's fracture (metaphyseal fracture with dorsal angulation) of the left distal radius arrived at the emergency room. Due to intense pain and need for proper pain management, an ultrasound-guided block of the radial nerve prior to its bifurcation into deep and superficial branches was carried out as an alternative to infiltration of the fracture site. The fracture could be reduced and immobilized with a closed cast as a result of the peripheral nerve block, which caused the patient the least amount of discomfort.

Conclusions

The reduction of a distal radius fracture in the emergency room can be accomplished with safe and efficient analgesia using an ultrasound-guided supracondylar radial nerve block close to the beginning of the deep and superficial branches. This is, as far as we are aware, the first report of an ultrasound-guided supracondylar nerve block utilized to treat a distal radius fracture in our nation.

Point-of-Care Ultrasound: A Vital Tool for Anesthesiologists in the Perioperative and Critical Care Settings

Point-of-care ultrasound (POCUS) is an essential skill in various specialties like anesthesiology, critical care, and emergency medicine. Anesthesiologists utilize POCUS for quick diagnosis and procedural guidance in perioperative and critical care settings. Key applications include vascular ultrasound for challenging venous and arterial catheter placements, gastric ultrasound for aspiration risk assessment, airway ultrasound, diaphragm ultrasound, and lung ultrasound for respiratory assessment. Additional utilities of POCUS can include multi-organ POCUS evaluation for undifferentiated shock or cardiac arrest, ultrasound-guided central neuraxial and peripheral nerve blocks, focused cardiac ultrasound, and novel applications such as venous excess ultrasound. This review highlights these POCUS applications in perioperative and intensive care and summarizes the latest evidence of their accuracy and limitations.

Regional Anesthesia Complications and Contraindications

Regional anesthesia has a strong role in minimizing post-operative pain, decreasing narcotic use and PONV, and, therefore, speeding discharge times. However, as with any procedure, regional anesthesia has both benefits and risks. It is important to identify the complications and contraindications related to regional anesthesia, which patient populations are at highest risk, and how to mitigate those risks to the greatest extent possible. Overall, significant complications secondary to regional anesthesia remain low. While a variety of different regional anesthesia techniques exist, complications tend to fall within 4 broad categories: block failure, bleeding/hematoma, neurological injury, and local anesthetic toxicity.

Regional Anesthesia in the Elite Athlete

Elite athletes are exposed to an elevated risk of musculoskeletal injury which may present a significant threat to an athlete's livelihood. The perioperative anesthetic plan of care for these injuries in the general population often incorporates regional anesthesia procedures due to several benefits. However, some concern exists regarding the potential for regional anesthesia to adversely impact functional recovery in an elite athlete who may have a lower tolerance for this risk. This article aims to review the data behind this concern, discuss strategies to improve the safety of these procedures and explore the features of consent in this patient population.

Quality Improvement Projects and Anesthesiology Graduate Medical Education: A Systematic Review

Quality improvement (QI) projects are essential components of graduate medical education and healthcare organizations to improve patient outcomes. We systematically reviewed the literature on QI projects in anesthesiology graduate medical education programs to assess whether these projects are leading to publications. A literature search was conducted in July 2023, using PubMed, Embase, and the Central Register of Controlled Trials (CENTRAL) for articles describing QI initiatives originating within the United States and applicable to anesthesiology residency training programs. The following data were collected: intervention(s), sample size (number of participants or events), outcome metric(s), result(s), and conclusion(s). One hundred and fifty publications were identified, and 31 articles met the inclusion criteria. A total of 2,259 residents and 72,889 events were included in this review. Educational modalities, such as simulation, training sessions, or online curricula, were the most prevalent interventions in the included studies. Pre-intervention and post-intervention assessments were the most common outcome metrics reported. Our review of the literature demonstrates that few QI projects performed within anesthesiology training programs lead to published manuscripts. Further research should aim at increasing the impact of required QI projects within the sponsoring institution and specialty.

Neurological injury following peripheral nerve blocks: a narrative review of estimates of risks and the influence of ultrasound guidance

BACKGROUND

Peripheral nerve injury or post-block neurological dysfunction (PBND) are uncommon but a recognized complications of peripheral nerve blocks (PNB). A broad range of its incidence is noted in the literature and hence a critical appraisal of its occurrence is needed.

OBJECTIVE

In this review, we wanted to know the pooled estimates of PBND and further, determine its pooled estimates following various PNB over time. Additionally, we also sought to estimate the incidence of PBND with or without US guidance.

EVIDENCE REVIEW

A literature search was conducted in six databases. For the purposes of the review, we defined PBND as any new-onset sensorimotor disturbances in the distribution of the performed PNB either attributable to the PNB (when reported) or reported in the context of the PNB (when association with a PNB was not mentioned). Both prospective and retrospective studies which provided incidence of PBND at timepoints of interest (>48 hours to <2 weeks; >2 weeks to 6 weeks, 7 weeks to 5 months, 6 months to 1 year and >1 year durations) were included for review. Incidence data were used to provide pooled estimates (with 95% CI) of PBND at these time periods. Similar estimates were obtained to know the incidence of PBND with or without the use of US guidance. Additionally, PBND associated with individual PNB were obtained in a similar fashion with upper and lower limb PNB classified based on the anatomical location of needle insertion.

FINDINGS

The overall incidence of PBND decreased with time, with the incidence being approximately 1% at <2 weeks' time (Incidence per thousand (95% CI)= 9 (8; to 11)) to approximately 3/10 000 at 1 year (Incidence per thousand (95% CI)= 0. 3 (0.1; to 0.5)). Incidence of PBND differed for individual PNB with the highest incidence noted for interscalene block.

CONCLUSIONS

Our review adds information to existing literature that the neurological complications are rarer but seem to display a higher incidence for some blocks more than others. Use of US guidance may be associated with a lower incidence of PBND especially in those PNBs reporting a higher pooled estimates. Future studies need to standardize the reporting of PBND at various timepoints and its association to PNB.

Ultrasound-Guided Fascia Iliaca Compartment Block Simulation Training in an Emergency Medicine Residency Program

Introduction Geriatric hip fractures present a difficult challenge in the emergency department (ED) to achieve adequate analgesia. Opioid-sparing ultrasound-guided fascia iliaca compartment blocks (UFIB) have been shown to be both safe and effective in treating pain from hip fractures. In this study, we investigated the teachability of UFIB to emergency medicine (EM) residents using simulation models and also assessed if UFIB training increases its utility in the ED. Methods We created a UFIB model to simulate the procedure in a controlled environment. Sixteen residents from Loma Linda Emergency Medicine Residency participated in a pre-workshop survey and hands-on UFIB workshop. Comfort level in performing UFIB and confidence level in needle finding skills during UFIB were analyzed, plotted, and represented graphically. Results Comfort level in performing UFIB increased by approximately 50% (p < 0.01). Success rates also increased by 460% (p<0.05) after the workshop. However, the UFIB continued to be underutilized as 44% of respondents expressed that there is a "lack of time" to perform UFIB during their shifts. Conclusion A single one-hour workshop increased comfort level in performing UFIB and helped residents successfully achieve better pain control in patients with hip fractures. However, residents continued to refrain from using UFIB because it is too time-consuming.

Neuropathies Following an Ultrasound-Guided Axillary Brachial Plexus Block

Purpose

Ultrasound-guided brachial plexus block (UGBPB) has interscalene, supraclavicular, infraclavicular, and axillary approaches. The axillary block is considered to be the safest and with fewer adverse events compared to the interscalene (eg, phrenic nerve block, spinal cord or vertebral artery puncture) and supraclavicular (eg, pneumothorax). However, with regard to postoperative neurological symptoms (PONS), it is controversial whether its incidence after an axillary block was higher than that after non-axillary approaches". In this study, we investigated whether the incidence of a neuropathy after an axillary block was higher than that after non-axillary approaches.

Patients and Methods

This was a single-center, retrospective cohort study. All UGBPBs were performed under general anesthesia between January 2014 and March 2020. The outcomes included the overall incidence of PONS and neuropathies for axillary and non-axillary approaches. The etiology, symptoms, and outcomes of patients were investigated.

Results

Of the 992 patients, 143 (14%) and 849 (86%) were subjected to axillary and non-axillary approaches, respectively. Among 19 cases (19.2:1000; 95% confidence interval [CI], 18.2-20.1) of PONS, four (4.0:1000; 95% CI, 3.8-4.2) were neuropathies attributed to the UGBPB, three (21.0:1000; 95% CI, 18.1-23.8) to the axillary and one (2.8:1000; 95% CI, 2.6-3.1) to non-axillary approaches. The incidence of neuropathies after an axillary block was significantly higher than that after non-axillary approaches (P = 0.005).

Conclusion

The incidence of neuropathies after US-guided axillary block under general anesthesia was significantly higher than that after non-axillary approaches.

Learning Effect for Large Joint Diagnostic Aspirations With Fluoroscopy and Ultrasound

OBJECTIVE

The first objective was to identify whether increased experience, gauged by number of procedures performed posttraining, is correlated with greater likelihood of obtaining joint fluid in diagnostic aspirations. The second objective was to identify whether trainee involvement at the time of procedure affected the success rate of the procedure (which in this case was obtaining fluid on aspiration).

DESIGN

This was a retrospective analysis of fluoroscopic- and ultrasound-guided large joint aspirations. Logarithmic fit was performed to identify the presence of a learning curve to the successful attainment of fluid with experience. Logistic regression analysis was used to identify whether trainee presence for a procedure affected fluid attainment.

RESULTS

Ultrasound did not demonstrate a significant fit to the logarithmic curve ( P = 0.447), whereas fluoroscopy did ( P < 0.001), indicative of a learning curve for fluoroscopy. After adjusting for covariates, joint fluid was successfully attained at a similar rate whether trainees were present or not. Significant independent factors related to successful joint fluid attainment were image guidance technique ( P = 0.001), body mass index ( P = 0.032), and joint aspirated (overall P < 0.001).

CONCLUSION

There was a statistically significant learning curve for fluoroscopic-guided joint aspirations, but not with ultrasound guidance. Trainee involvement did not affect the success rate of joint aspirations.

A Practical Guide to Lower Extremity Nerve Blocks for the Sports Medicine Surgeon

BACKGROUND

Peripheral nerve blocks (PNBs) are vital in the administration of surgical analgesia and have grown in popularity for use in lower extremity arthroscopic procedures because of their capacity to safely and effectively control pain. The number and specificity of PNBs, however, have made choosing the best option for a procedure nebulous for orthopaedic surgeons.

PURPOSE

To present a narrative literature review of the PNBs available for arthroscopic hip and knee procedures that is adapted to an audience of orthopaedic surgeons.

STUDY DESIGN

Narrative literature review.

METHODS

A combination of the names of various lower extremity PNBs AND "hip arthroscopy" OR "knee arthroscopy" was used to search the English medical literature including PubMed, Cochrane Library, ScienceDirect, Embase, and Scopus. Placement technique, specificity of blockade, efficacy, and complications were assessed. Searches were performed through May 2, 2021.

RESULTS

A total of 157 studies were included in this review of lower extremity PNBs. Femoral nerve, lumbar plexus, sciatic nerve, and fascia iliaca compartment blocks were most commonly used in arthroscopic hip surgery, while femoral nerve, 3-in-1, and adductor canal blocks were preferred for arthroscopic knee surgery. Each block demonstrated a significant benefit (P > .05) in ≥1 of the following outcomes: intraoperative morphine, pain scores, nausea, and/or opioid consumption. Combination blocks including the lateral femoral cutaneous nerve block, obturator nerve block, quadratus lumborum block, and L1 and L2 paravertebral block have also been described. Complication rates ranged from 0% to 4.8% in those administered with ultrasound guidance. The most commonly reported complications included muscular weakness, postoperative falls, neuropathy, intravascular and intraneural injections, and hematomas.

CONCLUSION

When administered properly, PNBs were a safe and effective adjuvant method of pain control with a significant potential to limit postoperative narcotic use. While blockade choice varies by surgeon preference and procedure, all PNBs should be administered with ultrasound guidance, and vigilant protocols for the risk of postoperative falls should be exercised in patients who receive them.

Pediatric lower limb peripheral nerve blocks: Indications, effectiveness, and the incidence of adverse events

AIM

While the proportion of pediatric anesthetics with regional anesthesia in pediatric patients has steadily increased, there are only a few series that describe the use of lower limb peripheral nerve blocks in children. Our aim was to describe the indications, anesthetic approach, and complications associated with lower limb blocks in children undergoing orthopedic surgery in a center with a large caseload of complex patients.

METHODS

In a retrospective analysis of prospectively collected data, we reviewed children who had a peripheral nerve block for orthopedic surgery placed between January 2016 and January 2021 at the Royal Children's Hospital Melbourne. Block data were sourced from the electronic medical record and departmental regional anesthesia database. Data collected included demographics, the site of catheter placement and technique of nerve block, presence of sensory/motor blockade, the use of perioperative opioids, and any complications related to peripheral nerve block.

RESULTS

A total of 1438 blocks were performed in 1058 patients. Four patients had clinical features of perioperative neurological injury giving an incidence of 3 per 1000 blocks (95% CI 1.1-8:1000). Only one patient had a sensory deficit persisting longer than 6 months for an incidence of 0.8 per 1000 blocks (95% CI 0.1-5:1000). All four peripheral nerve injury followed tibial osteotomy for lengthening procedures or correction of tibial torsion. The etiology of the injury could not be determined despite imaging and surgical exploration and the contribution of popliteal sciatic nerve block to the subsequent PNI could not be confirmed. There were no cases of local anesthetic systemic toxicity.

CONCLUSION

An increased risk of perioperative peripheral nerve injury is associated with pediatric tibial osteotomy for congenital deformity. While popliteal sciatic nerve block was not directly implicated in the nerve injury the presence of a prolonged sensory block can delay early recognition and treatment of peripheral nerve injury.

Local anesthetic systemic toxicity: A narrative review for emergency clinicians

INTRODUCTION

Emergency clinicians utilize local anesthetics for a variety of procedures in the emergency department (ED) setting. Local anesthetic systemic toxicity (LAST) is a potentially deadly complication.

OBJECTIVE

This narrative review provides emergency clinicians with the most current evidence regarding the pathophysiology, evaluation, and management of patients with LAST.

DISCUSSION

LAST is an uncommon but potentially life-threatening complication of local anesthetic use that may be encountered in the ED. Patients at extremes of age or with organ dysfunction are at higher risk. Inadvertent intra-arterial or intravenous injection, as well as repeated doses and higher doses of local anesthetics are associated with greater risk of developing LAST. Neurologic and cardiovascular manifestations can occur. Early recognition and intervention, including supportive care and intravenous lipid emulsion 20%, are the mainstays of treatment. Using ultrasound guidance, aspirating prior to injection, and utilizing the minimal local anesthetic dose needed are techniques that can reduce the risk of LAST.

CONCLUSIONS

This focused review provides an update for the emergency clinician to manage patients with LAST.

A Case of Late-Onset Local Anesthetic Toxicity Observed as Seizure Activity

Most of the local anesthetic toxicity cases develop within the first five minutes of peripheral block administration. Late local anesthetic toxicity has been rarely reported in the literature. However, it is an important life-threatening problem that can lead to seizures, hemodynamic collapse, and cardiac arrest if it is ignored and not considered. Here we present the case of an 18-year-old male patient who had ultrasonography-guided infraclavicular brachial plexus block administration with a 30 mL local anesthetic. The patient had convulsions 210 minutes after the block administration and was treated with intravenous diazepam. Intraoperative and postoperative courses were uneventful. He had no neurologic signs or symptoms afterward. All laboratory tests and radiologic investigation tests were normal. This report demonstrates that late local anesthetic toxicity is still possible after several hours of the uneventful peripheral neural blockade, although it is rarely reported.

Regional Anesthesia in the Elite Athlete

Elite athletes are exposed to an elevated risk of musculoskeletal injury which may present a significant threat to an athlete's livelihood. The perioperative anesthetic plan of care for these injuries in the general population often incorporates regional anesthesia procedures due to several benefits. However, some concern exists regarding the potential for regional anesthesia to adversely impact functional recovery in an elite athlete who may have a lower tolerance for this risk. This article aims to review the data behind this concern, discuss strategies to improve the safety of these procedures and explore the features of consent in this patient population.

Regional Anesthesia Complications and Contraindications

Regional anesthesia has a strong role in minimizing post-operative pain, decreasing narcotic use and PONV, and, therefore, speeding discharge times. However, as with any procedure, regional anesthesia has both benefits and risks. It is important to identify the complications and contraindications related to regional anesthesia, which patient populations are at highest risk, and how to mitigate those risks to the greatest extent possible. Overall, significant complications secondary to regional anesthesia remain low. While a variety of different regional anesthesia techniques exist, complications tend to fall within 4 broad categories: block failure, bleeding/hematoma, neurological injury, and local anesthetic toxicity.

Postoperative neurological complications after brachial plexus block: a retrospective study conducted at a teaching hospital

PURPOSE

Serious complications after ultrasound-guided regional anaesthesia can be devastating for the patient. The pathogenesis of postoperative neurological complications (PONC) is multifactorial and includes mechanical, vascular and chemical factors besides the nerve puncture itself. The primary aim of this study was to assess the incidence of PONC after brachial plexus block (BPB).

METHODS

This is an observational retrospective single-centre study conducted at the regional anaesthesia unit of a teaching hospital. All BPBs performed from January 2011 to November 2019 were included. The outcomes analysed were the incidence, aetiology and diagnosis of PONCs and the incidence of other postoperative complications such as local anaesthetic systemic toxicity (LAST), pneumothorax, wrong-side block, etc. The performance of trainees and experienced anaesthesiologists was compared across all the outcomes.

RESULTS

From a total of 5340 BPBs included, 15 cases developed PONC, yielding a rate of 2.81:1000 (95% CI 1.70-4.63). Thirteen patients underwent neurophysiological exams which confirmed nine neuropathies. The rate of PONCs for supervised trainees was 1.80:1000 (95% CI 0.701-4.62), not statistically different from that of experienced anaesthesiologists (p = 0.241). Three cases were considered to present with a PONC probably related to BPB [0.562:1,00 (95% CI 0.191-1.65)]. The incidence of long-term PONCs was 1.12:1000 (95% CI 0.515-2.45). Such complications proved irreversible in 2 cases. The incidences of LAST, pneumothorax and other complications observed were 0.749:1000 (95% CI 0.291-1.92), 0.187:1000 (95% CI 0.0331-1.06) and 4.31:1000 (95% CI 2.87-6.46), respectively.

CONCLUSIONS

This survey suggests that complications after ultrasound-guided BPB, including blocks performed by trainees, are uncommon.

TRIAL REGISTRATION

Clinicaltrials.gov ID: NCT04451642.

Reliability and Quality of YouTube Videos on Ultrasound-Guided Brachial Plexus Block: A Programmatical Review

BACKGROUND

Ultrasound-guided regional anesthesia has gained popularity over the last decade. This study aimed to assess whether YouTube videos sufficiently serve as an adjunctive tool for learning how to perform an ultrasound-guided brachial plexus block (BPB).

METHODS

All YouTube videos were classified, based on their sources, as either academic, manufacturer, educational, or individual videos. The metrics, accuracy, utility, reliability (using the Journal of American Medical Association Score benchmark criteria (JAMAS)), and educational quality (using the Global Quality Score (GQS) and Brachial Plexus Block Specific Quality Score (BSQS)) were validated.

RESULTS

Here, 175 videos were included. Academic (1.19 ± 0.62, mean ± standard deviation), manufacturer (1.17 ± 0.71), and educational videos (1.15 ± 0.76) had better JAMAS accuracy and reliability than individual videos (0.26 ± 0.67) (p < 0.001). Manufacturer (11.22 ± 1.63) and educational videos (10.33 ± 3.34) had a higher BSQS than individual videos (7.32 ± 4.20) (p < 0.001). All sources weakly addressed the equipment preparation and post-procedure questions after BSQS analysis.

CONCLUSIONS

The reliability and quality of ultrasound-guided BPB videos differ depending on their source. As YouTube is a useful educational platform for learners and teachers, global societies of regional anesthesiologists should set a standard for videos.

[Peripheral Regional Anaesthesia for Perioperative Analgesia]

Peripheral Regional Anaesthesia for Perioperative Analgesia Abstract. Peripheral regional anaesthesia is the actual gold standard of opioid-sparing perioperative analgesia and is mainly used for surgery of the shoulder, arm and leg. Well-trained anaesthesiologists are the prerequisite for the correct individual risk-benefit assessment and the performance of the nerve blocks using a combination of ultrasound guidance and peripheral nerve stimulation (dual guidance). The postoperative care of the patients requires trained staff.

Use of regional analgesia and risk of delirium in older adults with multiple rib fractures: An Eastern Association for the Surgery of Trauma multicenter study

BACKGROUND

Single-center data demonstrates that regional analgesia (RA) techniques are associated with reduced risk of delirium in older patients with multiple rib fractures. We hypothesized that a similar effect between RA and delirium would be identified in a larger cohort of patients from multiple level I trauma centers.

METHODS

Retrospective data from seven level I trauma centers were collected for intensive care unit (ICU) patients 65 years or older with ≥3 rib fractures from January 2012 to December 2016. Those with a head and/or spine injury Abbreviated Injury Scale (AIS) score of ≥ 3 or a history of dementia were excluded. Delirium was defined as one positive Confusion Assessment Method for the Intensive Care Unit score in the first 7 days of ICU care. Poisson regression with robust standard errors was used to determine the association of RA (thoracic epidural or paravertebral catheter) with delirium incidence.

RESULTS

Data of 574 patients with a median age of 75 years (interquartile range [IQR], 69-83), Injury Severity Score of 14 (IQR, 11-18), and ICU length of stay of 3 days (IQR, 2-6 days) were analyzed. Among the patients, 38.9% were women, 15.3% were non-White, and 31.4% required a chest tube. Regional analgesia was used in 19.3% patients. Patient characteristics did not differ by RA use; however, patients with RA had more severe chest injury (chest AIS, flail segment, hemopneumothorax, thoracostomy tube). In univariate analysis, there was no difference in the likelihood of delirium between the RA and no RA groups (18.9% vs. 23.8% p = 0.28). After adjusting for age, sex, Injury Severity Score, maximum chest AIS, thoracostomy tube, ICU length of stay, and trauma center, RA was associated with reduced risk of delirium (incident rate ratio [IRR], 0.65; 95% confidence interval [CI], 0.44-0.94) but not with in-hospital mortality (IRR, 0.42; 95% CI, 0.14-1.26) or respiratory complications (IRR, 0.70; 95% CI, 0.42-1.16).

CONCLUSION

In this multicenter cohort of injured older adults with multiple rib fractures, RA use was associated with a 35% lower risk of delirium. Further studies are needed to standardize protocols for optimal pain management and prevention of delirium in older adults with severe thoracic injury.

LEVEL OF EVIDENCE

Therapeutic, level IV; Epidemiologic, level III.

Complications Associated with Peripheral Nerve Blocks

Outpatient orthopedic surgery is gradually becoming the standard across the country, as it has been found to significantly lower costs without compromising patient care. Peripheral nerve blocks (PNBs) are largely what have made this transition possible by providing patients excellent pain control in the immediate postoperative period. However, with the increasing use of PNBs, it is important to recognize that they are not without complications. Although rare, these complications can cause patients a significant amount of morbidity. It is important for surgeons to know the risks of peripheral nerve blocks and to inform their patients.

Combination Lower Extremity Nerve Blocks and Their Effect on Postoperative Pain and Opioid Consumption: A Systematic Review

The purpose of this study was to perform a systematic review of the literature examining postoperative outcomes following single site and combined peripheral nerve blocks (PNBs), including (1) sciatic and femoral nerve, (2) popliteal and saphenous nerve, and (3) popliteal and ankle nerve, during elective foot and ankle surgery. We hypothesized that combination blocks would decrease postoperative narcotic consumption and afford more effective postoperative pain control as compared to general anesthesia, spinal anesthesia, or single site PNBs. A review of the literature was performed according to the PRISMA guidelines. Medline, EMBASE, and the Cochrane Library were searched from January 2009 to October 2019. We identified studies by using synonyms for "foot," "ankle" "pain management," "opioid," and "nerve block." Included articles explicitly focused on elective foot and ankle procedures performed under general anesthesia, spinal anesthesia, PNB, or with some combination of these techniques. PNB techniques included femoral, adductor canal, sciatic, popliteal, saphenous, and ankle blocks, as well as blocks that combined multiple anatomic sites. Outcomes measured included postoperative narcotic consumption as well as patient-reported efficacy of pain control. Twenty-eight studies encompassing 6703 patients were included. Of the included studies, 57% were randomized controlled trials, 18% were prospective comparison studies, and 25% were retrospective comparison studies. Postoperative opioid consumption and postoperative pain levels were reduced over the first 24 to 48 hours with the use of combined PNBs when compared with single site PNBs, both when used as primary anesthesia or when used in concert with general anesthesia either alone or combined with systemic/local anesthesia in the first 24 to 48 hours following surgery. Studies demonstrated higher reported patient satisfaction of postoperative pain control in patients who received combined PNB. Nine of 14 (64%) studies reported no neurologic related complications with an overall reported rate among all studies ranging from 0% to 41%. Our study identified substantial improvement in postoperative pain levels, postoperative opioid consumption, and patient satisfaction in patients receiving PNB when compared with patients who did not receive PNB. Published data also demonstrated that combination PNB are more effective than single-site PNB for all data points. Notably, the addition of a femoral nerve block to a popliteal nerve block during use of a thigh tourniquet, as well as addition of either saphenous or ankle blockade to popliteal nerve block during use of calf tourniquet, may increase overall block effectiveness. Serious complications including neurologic damage following PNB administration are rare but do exist.

The practice of regional anesthesia in Belgium – a national survey

Background : National surveys are useful to assess the state of regional anaesthesia (RA) practice in a particular country. Given that such information was lacking in Belgium, we conducted a survey to evaluate the Belgian practice of peripheral nerve blocks (PNBs) with a particular focus on its safety aspects. Methods : A survey was sent by email to 1510 Belgian anesthesiologists. No identifying information was collected. Data were collected between September 2019 and October 2019. Results : We collected 324 questionnaires (response rate 21%). Eighty five percent of respondents perform regularly PNB. 99% place a venous access before performing a block, and more than 90% monitor patients with minimum peripheral pulse oximetry. The majority monitor patients for a minimum of 30 minutes after the injection of local anesthetic (LA). Ultrasound-guided technique for RA is used by 89% of respondents. Neurostimulation is totally abandoned by 20% of them. Monitoring of injection pressures is performed by 21% of respondents. More than 50% of respondents use sterile gloves, surgical drapes and a mask. With regards to the solution of LA used, 52% of respondents never mix LAs. An adjuvant is always used by 15% of the respondents while 10% of them never use them. Conclusions : This survey suggests that the practice of PNBs in Belgium is in line with the current international guidelines. This survey can serve as a benchmark for future evaluation and comparison between RA techniques. These observations should be taken into account for the implementation of national guidelines and therefore for the improvement of safety in the practice of PNBs.

A real-time anatomy ıdentification via tool based on artificial ıntelligence for ultrasound-guided peripheral nerve block procedures: an accuracy study

We aimed to assess the accuracy of an artificial intelligence (AI)-based real-time anatomy identification software specifically developed to ease image interpretation intended for ultrasound-guided peripheral nerve block (UGPNB). Forty healthy participants (20 women, 20 men) were enrolled to perform interscalene, supraclavicular, infraclavicular, and transversus abdominis plane (TAP) blocks under ultrasound guidance using AI software by anesthesiology trainees. During block practice by a trainee, once the software indicates 100% scan success of each block associated anatomic landmarks, both raw and labeled ultrasound images were saved, assessed, and validated using a 5-point scale by expert validators. When trainees reached 100% scan success, accuracy scores of the validators were noted. Correlation analysis was used whether the relationship (r) according to demographics (gender, age, and body mass index: BMI) and block type exist. The BMI (kg/m²) and age (year) of participants were 22.2 ± 3 and 32.2 ± 5.25, respectively. Assessment scores of validators for all blocks were similar in male and female individuals. Mean assessment scores of validators were not significantly different according to age and BMI except for TAP block, which was inversely correlated with age and BMI (p = 0.01). AI technology can successfully interpret anatomical structures in real-time sonography while assisting young anesthesiologists during UGPNB practice.

Ultrasound-Guided Thoracic Paravertebral Block for Pulmonary Radiofrequency Ablation

Surgical resection is the treatment of choice both for early-stage lung cancer and pulmonary metastatic disease. For patients with lung tumors who are not eligible for surgery, the minimally invasive modality of radiofrequency ablation (RFA) may be curative and, thus, should be considered. However, opinions regarding the optimal anesthetic technique for pulmonary RFA differ. Here the authors report their experience with the use of ultrasound-guided paravertebral block in minimally-sedated patients undergoing pulmonary RFA. This retrospective study was conducted at a single institution. The 17 consecutive patients underwent 19 pulmonary RFA procedures for primary lung tumor or lung metastases. In all patients, RFA was performed according to the protocol of the hospital. Anesthesia in patients receiving RFA for lung tumors consisted of a thoracic paravertebral block (TPVB), performed between T4 and T8, with minimal sedation. This approach allowed intraoperative communication with the patient and apnea pauses as needed. There were no complications after TPVB, which was well-tolerated by all patients. Only two patients required an alfentanil bolus during RFA because of pleuritic pain. No patient required conversion from sedation to general anesthesia. There were no episodes of hemodynamic instability or desaturation (SaO₂ ≤95%), and excessive sedation prevented patient collaboration in only one patient. In conclusion, ultrasound-guided single-injection TPVB is a safe and effective anesthetic technique for high-risk patients undergoing RFA for a primary lung tumor or lung metastases.

Factors associated with low levels of patient satisfaction following peripheral nerve block

Peripheral nerve blocks can provide surgical anaesthesia as well as excellent postoperative analgesia. When questioned postoperatively, however, some patients report low levels of satisfaction with their nerve block experience. At our hospital, patients undergoing regional anaesthesia have their patient characteristics, block characteristics and postoperative feedback routinely recorded in a block registry. We analysed data from 979 consecutive patients undergoing peripheral nerve block for orthopaedic surgery to identify factors associated with low levels of patient satisfaction. The primary outcome was patient satisfaction with their peripheral nerve block (scale 1-5: 4-5 is 'satisfied', 1-3 is 'not satisfied'). Eighty-nine percent (871/979) of patients reported being 'satisfied' with their block. Factors negatively associated with patient satisfaction were rebound pain (adjusted odds ratio (aOR) 0.19, 95% confidence interval (CI) 0.04 to 0.85 for moderate rebound pain; aOR 0.11, 95% CI 0.03 to 0.48 for severe rebound pain), discomfort during the block (aOR 0.37, 95% CI 0.16 to 0.82 for moderate discomfort; aOR 0.19, 95% CI 0.05 to 0.76 for severe discomfort) and pain in the post-anaesthesia care unit (aOR 0.30, 95% CI 0.17 to 0.55 for pain ≥8/10). Only 24% (26/108) of patients who reported being 'not satisfied' stated that they would be unwilling to undergo a hypothetical future nerve block. Rebound pain of at least moderate intensity, procedural discomfort of at least moderate intensity and severe pain in the post-anaesthesia care unit are all negatively associated with patient satisfaction. Of these factors, rebound pain occurs most frequently, being present in 52% (403/777) of our respondents.

Safety of treatment options available for postoperative pain

IntroductionPostoperative pain is one of the most common adverse events after surgery and has been shown to increase the risk of other complications. On the other hand, liberal opioid use in the perioperative period is also associated with risk of adverse events. The current consensus is therefore to provide multimodal, opioid minimizing analgesia after surgery.Areas CoveredIn this review, we will discuss the benefits and risks associated with non-opioid analgesics, including non-steroidal anti-inflammatory drugs, gabapentinoids, ketamine, α-2 agonists, and corticosteroids. In addition, we will discuss the general and block-specific risks associated with regional anesthestic techniques.Expert OpinionAdverse events associated with non-opioid analgesics are rare outside their specific contraindicated patient groups, especially when dosed appropriately. α-2 agonists can cause transient hypotension and bradycardia, and gabapentinoids may cause sedation in higher risk patient populations. Regional anesthesia techniques are generally safe when done by an experienced practitioner. We therefore encourage the development of standardized multimodal analgesic protocols, which may facilitate opioid minimization and lead to better patient outcomes.

European Society of Anaesthesiology and Intensive Care Guidelines on peri-operative use of ultrasound for regional anaesthesia (PERSEUS regional anesthesia): Peripheral nerves blocks and neuraxial anaesthesia

Nowadays, ultrasound-guidance is commonly used in regional anaesthesia (USGRA) and to locate the spinal anatomy in neuraxial analgesia. The aim of this second guideline on the PERi-operative uSE of UltraSound (PERSEUS-RA) is to provide evidence as to which areas of regional anaesthesia the use of ultrasound guidance should be considered a gold standard or beneficial to the patient. The PERSEUS Taskforce members were asked to define relevant outcomes and rank the relative importance of outcomes following the GRADE process. Whenever the literature was not able to provide enough evidence, we decided to use the RAND method with a modified Delphi process. Whenever compared with alternative techniques, the use of USGRA is considered well tolerated and effective for some nerve blocks but there are certain areas, such as truncal blocks, where a lack of robust data precludes useful comparison. The new frontiers for further research are represented by the application of USG during epidural analgesia or spinal anaesthesia as, in these cases, the evidence for the value of the use of ultrasound is limited to the preprocedure identification of the anatomy, providing the operator with a better idea of the depth and angle of the epidural or spinal space. USGRA can be considered an essential part of the curriculum of the anaesthesiologist with a defined training and certification path. Our recommendations will require considerable changes to some training programmes, and it will be necessary for these to be phased in before compliance becomes mandatory.

Femoral nerve blocks for the treatment of acute pre-hospital pain: A systematic review with meta-analysis

BACKGROUND

Pain management is one of the most important interventions in the emergency medical services. The femoral nerve block (FNB) is, among other things, indicated for pre- and post-operative pain management for patients with femoral fractures but its role in the pre-hospital setting has not been determined. The aim of this review was to assess the effect and safety of the FNB in comparison to other forms of analgesia (or no treatment) for managing acute lower extremity pain in adult patients in the pre-hospital setting.

METHODS

A systematic review (PROSPERO registration (CRD42018114399)) was conducted. The Cochrane and GRADE methods were used to assess outcomes. Two authors independently reviewed each study for eligibility, extracted the data and performed risk of bias assessments.

RESULTS

Four studies with a total of 252 patients were included. Two RCTs (114 patients) showed that FNB may reduce pain more effectively than metamizole (mean difference 32 mm on a 100 mm VAS (95% CI 24 to 40)). One RCT (48 patients) compared the FNB with lidocaine and magnesium sulphate to FNB with lidocaine alone and was only included here for information regarding adverse effects. One case series included 90 patients. Few adverse events were reported in the included studies. The certainty of evidence was very low. We found no studies comparing FNB to inhaled analgesics, opioids or ketamine.

CONCLUSIONS

Evidence regarding the effectiveness and adverse effects of pre-hospital FNB is limited. Studies comparing pre-hospital FNB to inhaled analgesics, opioids or ketamine are lacking.

Regional Nerve Block Complication Analysis Following Peripheral Nerve Block During Foot and Ankle Surgical Procedures

Background

Foot and ankle surgeries are frequently accompanied by a peripheral nerve block in order to reduce postoperative pain. Higher than expected complication rates with peripheral nerve blocks have led to increased concern among surgeons and patients. To our knowledge, no study conducted by the treating surgeon has identified risk factors that may predispose a patient to complications. Our goal was to attempt to identify those risk factors.

Methods

We reviewed patient charts of those who underwent an orthopedic foot and ankle procedure between 2013 and 2018, as performed by the senior author. This yielded 992 procedures performed across four surgical locations. Of these procedures, 137 procedures were removed because no block was used. The remaining cases were analyzed for nerve complications, defined as sensory or motor deficits along the distribution of a nerve. The patients were divided into those with and without complications and were evaluated for differences. Statistical analysis was performed using the SAS^® software (SAS Institute Inc., Cary, North Carolina, USA).

Results

The overall short-term complication rate was 10.1% and the long-term complication rate was 4.3%, with a total of 855 blocks given. Electromyographies (EMGs) were performed on 24.4% of the patients with a complication. Of the EMGs, 95.2% confirmed nerve complications in the distribution of the blocked nerve. The significant factors associated with complications were age, BMI, location, and smoking status. A regression analysis was performed to determine the odds ratio for individual factors. Those with significantly higher odds ratio were between 40 and 65 years of age, had normal or underweight BMI, underwent surgery at an outpatient surgery center, and were current smokers.

Conclusions

Our study suggests that there are significant epidemiological factors in predicting postoperative complications related to a peripheral nerve block. The study also shows a similar short-term complication rate but a higher long-term complication rate than other studies. This data are important because it allows for an informed decision to be made between a surgeon, anesthesiologist, and the patient regarding the safety and necessity of delivering a preoperative peripheral nerve block based on patient risk factors.

Incidence and etiology of postoperative neurological symptoms after peripheral nerve block: a retrospective cohort study

Background

Nerve injury from peripheral nerve block (PNB) is an uncommon but potentially serious complication. We present a retrospective cohort study to evaluate the incidence and etiology of new postoperative neurological symptoms after surgery and regional anesthesia.

Methods

We performed a retrospective cohort study of all PNBs performed on elective orthopedic and plastic surgical patients over 6 years (2011–2017). We collected patient and surgical data, results of neurophysiological and imaging tests, neurology and chronic pain consultations, etiology and outcome for patients with prolonged neurological symptoms (lasting ≥10 days).

Results

A total of 26 251 PNBs were performed in 19 219 patients during the study period. Transient postoperative neurological symptoms (<10 days) were reported by 14.4% (95% CI 13.1% to 15.7%) of patients who were reached by telephone follow-up. Prolonged postoperative neurological symptoms (≥10 days) were identified and investigated in 20 cases (1:1000, 95% CI 0.6 to 1.6). Of these 20 cases, three (0.2:1000, 95% CI 0.04 to 0.5) were deemed to be block related, seven related to surgical causes, three due to musculoskeletal causes or pain syndromes, one was suspected of having an inflammatory etiology and six remained of undetermined etiology. Of those who completed follow-up, 56% had full recovery of their symptoms with the remaining having partial recovery.

Conclusion

This retrospective review of 19 219 patients receiving PNBs for anesthesia or analgesia suggests that determining the etiology and causative factors of postoperative neurological symptoms is a complex, often challenging process that requires a multidisciplinary approach. We suggest a classification of cases based on the etiology. A most likely cause was identified in 70% of cases. This type of classification system can help broaden the differential diagnosis, help consider non-regional anesthesia and non-surgical causes and may be useful for clinical and research purposes.

A prospective, randomized comparison of ultrasonographic visualization of proximal intercostal block vs paravertebral block

BACKGROUND

Thoracic paravertebral blockade is an accepted anesthetic and analgesic technique for breast surgery. However, real-time ultrasound visualization of landmarks in the paravertebral space remains challenging. We aimed to compare ultrasound-image quality, performance times, and clinical outcomes between the traditional parasagittal ultrasound-guided paravertebral block and a modified approach, the ultrasound-guided proximal intercostal block.

METHODS

Women with breast cancer undergoing mastectomy (n = 20) were randomized to receive either paravertebral (n = 26) or proximal intercostal blocks (n = 32) under ultrasound-guidance with 2.5 mg/kg ropivacaine prior to surgery. Block ultrasound images before and after needle placement, and anesthetic injection videoclips were saved, and these images and vidoes independently rated by separate novice and expert reviewers for quality of visualization of bony elements, pleura, relevant ligament/membrane, needle, and injectate spread. Block performance times, postoperative pain scores, and opioid consumption were also recorded.

RESULTS

Composite visualization scores were superior for proximal intercostal compared to paravertebral nerve block, as rated by both expert (p = 0.008) and novice (p = 0.01) reviewers. Notably, both expert and novice rated pleural visualization superior for proximal intercostal nerve block, and expert additionally rated bony landmark and injectate spread visualization as superior for proximal intercostal block. Block performance times, needle depth, opioid consumption and postoperative pain scores were similar between groups.

CONCLUSIONS

Proximal intercostal block yielded superior visualization of key anatomical landmarks, possibly offering technical advantages over traditional paravertebral nerve block.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT02911168. Registred on the 22nd of September 2016.

Getting to know a familiar face: Current and emerging focused ultrasound applications for the perioperative setting

Ultrasound technology is available in many pediatric perioperative settings. There is an increasing number of ultrasound applications for anesthesiologists which may enhance clinical performance, procedural safety, and patient outcomes. This review highlights the literature and experience supporting focused ultrasound applications in the pediatric perioperative setting across varied disciplines including anesthesiology. The review also suggests strategies for building educational and infrastructural systems to translate this technology into clinical practice.

Combined ultrasound and nerve stimulator-guided deep nerve block may decrease the rate of local anesthetics systemic toxicity: a randomized clinical trial

Background

Ultrasound guidance might decrease the incidence of local anesthetics systemic toxicity (LAST) for many peripheral nerve blocks compared with nerve stimulator guidance. However, it remains uncertain whether ultrasound guidance is superior to nerve stimulator guidance for deep nerve block of the lower extremity. This study was designed to investigate whether deep nerve block with ultrasound guidance would decrease the incidence of LAST compared with that with nerve stimulator guidance, and to identify associated risk factors of LAST.

Methods

Three hundred patients undergoing elective lower limb surgery and desiring lumbar plexus blocks (LPBs) and sciatic nerve blocks (SNBs) were enrolled in this study. The patients were randomly assigned to receive LPBs and SNBs with ultrasound guidance (group U), nerve stimulator guidance (group N) or dual guidance (group M). The primary outcome was the incidence of LAST. The secondary outcomes were the number of needle redirection, motor and sensory block onset and nerve distribution restoration time, as well as associated risk factors.

Results

There were 18 patients with LAST, including 12 in group U, 4 in group N and 2 in group M. By multiple comparisons among the three groups, we found that the incidence of LAST in group U (12%) was significantly higher than that in group N (4%)(P = 0.037) and group M(2%)(P = 0.006). The OR of LAST with hepatitis B (HBV) infection and the female sex was 3.352 (95% CI,1.233–9.108, P = 0.013) and 9.488 (95% CI,2.142–42.093, P = 0.0004), respectively.

Conclusions

Ultrasound guidance, HBV infection and the female sex were risk factors of LAST with LPBs and SNBs. For patients infected with HBV or female patients receiving LPBs and SNBs, we recommended that combined ultrasound and nerve stimulator guidance should be used to improve the safety.

Trial registration

This study was approved by the Ethical Committee of the First Affiliated Hospital of Army Medical University. The protocol was registered prospectively with the Chinese Clinical Trial Registry (ChiCTR-IOR-16008099) on March 15, 2016.

Negative Influence of femoral nerve block on quadriceps strength recovery following total knee replacement: A prospective randomized trial

BACKGROUND

Postoperative pain is a major concern after total knee replacement (TKR) and can be relieved using different methods, including femoral nerve block (FNB). Quadriceps strength recovery (QSR) is the most sensitive objective indicator of functional recovery after TKR. The goal of this study was to compare the QSR following TKR between three approaches to analgesia.

HYPOTHESIS

FNB delays QSR at short- and mid-term follow-up.

METHODS

In this prospective randomized trial, with single-blind assessment involving 135 patients admitted for TKR in an academic center, the three following groups included were: (A) Continuous FNB 48h+PCA, (B) Single-shot FNB+PCA and (C) PCA alone. No intra-articular local anesthesia was carried out for all patients. Groups were comparable for demographic and surgical data. FNB was carried out and controlled (electric stimulation) by an expert anesthesiologist prior to the surgery. Follow-up was standardized in all groups using blinded assessors. Quadriceps strength was measured using a certified dynamometer at 6 weeks, 6 months and 12 months. Multivariate analysis (Kruskal-Wallis, Mann-Whitney) was used for the main outcome.

RESULTS

A total of 135 patients were included. Two patients in group B were excluded due to a direct fall in the first postoperative week with extensor mechanism rupture and peri-prosthetic femoral fracture. QSR was significantly decreased in patients with FNB at all times (mean±SD): 6 weeks (A: 51.3±23.3%; B: 62.2±21.9%;C: 77.4±19.5%; p<0.01), 6 months (A: 65.4±22.9%; B: 82.1±24.2%;C: 95.7±20.7%; p<0.01) and 12 months (A: 87.8±17.6%; B: 97.8±26.9%;C: 104.8±25.2%; p=0.02). No significant difference between continuous or single-shot FNB was observed.

CONCLUSION

FNB has a negative influence on QSR at short- and mid-term follow-up. FNB should not yet be recommended for analgesia after TKR.

LEVEL EVIDENCE

I High-quality randomized controlled trial with statistically significant difference.

Lower extremity regional anesthesia: essentials of our current understanding

The advent of ultrasound guidance has led to a renewed interest in regional anesthesia of the lower limb. In keeping with the American Society of Regional Anesthesia and Pain Medicine's ongoing commitment to provide intensive evidence-based education, this article presents a complete update of the 2005 comprehensive review on lower extremity peripheral nerve blocks. The current review article strives to (1) summarize the pertinent anatomy of the lumbar and sacral plexuses, (2) discuss the optimal approaches and techniques for lower limb regional anesthesia, (3) present evidence to guide the selection of pharmacological agents and adjuvants, (4) describe potential complications associated with lower extremity nerve blocks, and (5) identify informational gaps pertaining to outcomes, which warrant further investigation.

Updated Retrospective Single-Center Comparative Analysis of Peripheral Nerve Block Complications Using Landmark Peripheral Nerve Stimulation Versus Ultrasound Guidance as a Primary Means of Nerve Localization

OBJECTIVES

The purpose of this study was to perform an updated analysis of complications associated with upper and lower extremity peripheral nerve blocks (PNBs) performed with ultrasound (US) guidance versus the landmark approach.

METHODS

We conducted a single-center retrospective cohort analysis to compare the incidence of PNB complications between the techniques. The primary outcome was local anesthetic systemic toxicity (LAST), whereas the secondary outcomes included short- and long-term nerve injuries. The current query included cases performed between 2012 and 2015. A combined analysis included data extending to 2006. The Statistical examination relied on the χ² test.

RESULTS

During this 4-year period, we performed 7789 US-guided and 498 landmark-guided blocks with no statistically significant difference in the incidence of nerve injury or LAST between the groups. Our 10-year analysis, however, revealed a significant increase (P < .01) in the rate of LAST with the landmark technique: 7 of 5932 versus 0 of 16,858 cases. The combined data also revealed a significant increase (P < .01) in short-term injuries associated with the landmark approach (30 of 5932 versus 33 of 16,858) but no significant difference in the incidence of long-term injuries.

CONCLUSIONS

Our analysis supports a conclusion that the use of US guidance during PNBs leads to a significant reduction in the incidence of LAST, adding to growing evidence from similar investigations. The impact of US on the incidence of nerve injuries remains unclear, considering that the nature of transient deficits is thought to be multifactorial, and the frequency of lasting injuries did not differ significantly in this study.

Local Anesthetic Systemic Toxicity in Total Joint Arthroplasty: Incidence and Risk Factors in the United States From the National Inpatient Sample 1998-2013

BACKGROUND

Local anesthetic systemic toxicity (LAST) is a rare and potentially devastating complication of regional anesthesia. Single-institution registries have reported a decreasing incidence, but these results have limited broad applicability. A recent study using a US database found a relatively high incidence of LAST. We used the National Inpatient Sample, a US database of inpatient admissions, to identify the national incidence and associated risk factors for LAST in total joint arthroplasties.

METHODS

In this retrospective study, we studied patients undergoing hip, knee, or shoulder arthroplasty, from 1998 to 2013, with an adjunct peripheral nerve blockade. We used a multivariable logistic regression to identify patient conditions, hospital level variables, and procedure sites associated with LAST.

RESULTS

A total of 710,327 discharges met inclusion criteria. The average adjusted incidence was 1.04 per 1000 peripheral nerve blocks, with decreasing trend over the 15-year study period (odds ratio [OR], 0.90; P = 0.002). Shoulder arthroplasty (OR, 4.35; P = 0.0001) compared with knee or hip arthroplasty and medium-size (OR, 3.34; P = 0.003) and large-size (OR, 2.40; P = 0.025) hospitals as compared with small hospitals were associated with increased odds of LAST.

CONCLUSIONS

The incidence of LAST nationally in total joint arthroplasty with adjunct nerve blocks is similar to recent estimates from academic centers, with a small decreasing trend through the study period. Despite an overall low incidence rate, practitioners should continue to maintain vigilance for manifestations of LAST, especially as the use of regional anesthesia continues to increase.

Local anesthetic systemic toxicity: current perspectives

Local anesthetic systemic toxicity (LAST) is a life-threatening adverse event that may occur after the administration of local anesthetic drugs through a variety of routes. Increasing use of local anesthetic techniques in various healthcare settings makes contemporary understanding of LAST highly relevant. Recent data have demonstrated that the underlying mechanisms of LAST are multifactorial, with diverse cellular effects in the central nervous system and cardiovascular system. Although neurological presentation is most common, LAST often presents atypically, and one-fifth of the reported cases present with isolated cardiovascular disturbance. There are several risk factors that are associated with the drug used and the administration technique. LAST can be mitigated by targeting the modifiable risk factors, including the use of ultrasound for regional anesthetic techniques and restricting drug dosage. There have been significant developments in our understanding of LAST treatment. Key advances include early administration of lipid emulsion therapy, prompt seizure management, and careful selection of cardiovascular supportive pharmacotherapy. Cognizance of the mechanisms, risk factors, prevention, and therapy of LAST is vital to any practitioner using local anesthetic drugs in their clinical practice.

Complications After Multiple-Site Peripheral Nerve Blocks for Foot and Ankle Surgery Compared With Popliteal Sciatic Nerve Block Alone

BACKGROUND

Single or combined multiple-site peripheral nerve blocks (PNBs) are becoming popular for patients undergoing surgery on their feet or ankles. These procedures are known to be generally safe in surgical settings compared with other forms of anesthesia, such as spinal block. The purposes of this study were to assess the incidence of complications after the administration of multiple PNBs for foot and ankle surgery and to compare the rates of complications between patients who received a single PNB and those who received multiple blocks.

METHODS

Charts were reviewed retrospectively to assess peri- and postoperative complications possibly related to the PNBs. The records of 827 patients who had received sciatic nerve blocks, femoral nerve blocks adductor canal blocks, or combinations of these for foot and/or ankle surgery were analyzed for complications. The collected data consisted of age, sex, body mass index, presence of diabetes mellitus, smoking history, tourniquet time, and complications both immediately postoperatively and 1 year later.

RESULTS

Of these 827 patients, 92 (11.1%) developed neurologic symptoms after surgery; 22 (2.7%) of these likely resulted from the nerve blocks, and 7 (0.8%) of these were unresolved after the patients' last follow-up visits. There were no differences in complication rates between combined blocks and single sciatic nerve blocks.

CONCLUSION

There were more complications, both transient and long term, after anesthetic PNBs than previous literature has reported. Combined multiple-site blocks did not increase the rate of neurologic complications.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Optical signature of nerve tissue-Exploratory ex vivo study comparing optical, histological, and molecular characteristics of different adipose and nerve tissues

Background

During several anesthesiological procedures, needles are inserted through the skin of a patient to target nerves. In most cases, the needle traverses several tissues—skin, subcutaneous adipose tissue, muscles, nerves, and blood vessels—to reach the target nerve. A clear identification of the target nerve can improve the success of the nerve block and reduce the rate of complications. This may be accomplished with diffuse reflectance spectroscopy (DRS) which can provide a quantitative measure of the tissue composition. The goal of the current study was to further explore the morphological, biological, chemical, and optical characteristics of the tissues encountered during needle insertion to improve future DRS classification algorithms.

Methods

To compare characteristics of nerve tissue (sciatic nerve) and adipose tissues, the following techniques were used: histology, DRS, absorption spectrophotometry, high‐resolution magic‐angle spinning nuclear magnetic resonance (HR‐MAS NMR) spectroscopy, and solution 2D ¹³C‐¹H heteronuclear single‐quantum coherence spectroscopy. Tissues from five human freshly frozen cadavers were examined.

Results

Histology clearly highlights a higher density of cellular nuclei, collagen, and cytoplasm in fascicular nerve tissue (IFAS). IFAS showed lower absorption of light around 1200 nm and 1750 nm, higher absorption around 1500 nm and 2000 nm, and a shift in the peak observed around 1000 nm. DRS measurements showed a higher water percentage and collagen concentration in IFAS and a lower fat percentage compared to all other tissues. The scattering parameter (b) was highest in IFAS. The HR‐MAS NMR data showed three extra chemical peak shifts in IFAS tissue.

Conclusion

Collagen, water, and cellular nuclei concentration are clearly different between nerve fascicular tissue and other adipose tissue and explain some of the differences observed in the optical absorption, DRS, and HR‐NMR spectra of these tissues. Some differences observed between fascicular nerve tissue and adipose tissues cannot yet be explained but may be helpful in improving the discriminatory capabilities of DRS in anesthesiology procedures. Lasers Surg. Med. 50:948–960, 2018. © 2018 The Authors. Lasers in Surgery and Medicine Published by Wiley Periodicals, Inc.

Advances in Experimental Medicine and Biology: Intrafascicular Local Anesthetic Injection Damages Peripheral Nerve-Induced Neuropathic Pain

Peripheral nerve blockade (PNB) is advantageous for patients undergoing surgery to decrease the perioperative opioid consumptions and enhance recovery after surgery.Inadvertent local anesthetic (LA) administration into nerve fiber intrafascicularly easily results in unrecognized nerve injury. Using nerve block guidance either by ultrasound, electrical nerve stimulator, or using pressure devices does not prevent nerve damage, even though most of the nerve injury is transiently. The incidence of neurologic symptoms or neuropathy is in the range of 0.02-2.2%, and no significant difference of postoperative neurologic symptoms is found as compared with using ultrasound or guided nerve stimulator technique. However, intrafascicular lidocaine brought about macrophage migration into the damaged fascicle, Schwann cell proliferation, increased intensity of myelin basic protein, and shorten withdrawal time to mechanical stimuli. In dorsal root ganglion (DRG), intrafascicular LA injection increased the activated transcriptional factor 3 (ATF-3) and downregulated Nav1.8 (Nav1.8). In spinal dorsal horn (SDH), the microglia and astrocytes located in SDH were activated and proliferated after intrafascicular LA injection and returned to baseline gradually at the end of the month. This is a kind of neuropathic pain, so low injection pressure should be maintained, the correct needle bevel used, nerve stimulator or ultrasound guidance applied, and careful and deliberately slow injection employed as important parts of the injection technique to prevent intrafascicular LA administration-induced neuropathic pain.