Ultrasound-guided Peripheral Nerve Blocks Research Articles

Ultrasound-Guided peripheral nerve blocks for major amputation in critically ill patients with peripheral artery disease

Objective The aim of this study was to assess the safety and efficacy of major amputation under ultrasound-guided peripheral nerve blocks in critical peripheral artery disease (PAD) patients. Methods We reviewed the medical records of consecutive patients who underwent major amputation at our center between December 2012 and December 2020. The patients’ baseline demographics and comorbidities were collected. The primary outcomes were 30-day and 12-month mortality. The secondary outcomes were intraoperative events, complications and intensive care unit (ICU) admission. Results Fifteen patients classified as American Society of Anesthesiologist (ASA) III and 13 ASA IV (mean age: 76.07 ± 11.78 years) were included in the study. These patients were critically ill and had many comorbidities, such as coronary artery disease. All amputations were successfully performed under ultrasound-guided PNB without conversion to GA, but intravenous analgesia was given in 7 patients during the operation. The majority of the patients had stable hemodynamics except for 2 patients who had hypoxia, so none of the patients were transferred to the ICU postoperatively. None of the patients suffered from acute cardio-cerebral events. However, 5 patients had wound infections, and 4 of 5 patients had to receive reamputation. None of the patients died within 48 h after amputation. However, the 30-day mortality was 3.57%, and the 12-month mortality was up to 35.71%. Conclusion This study demonstrates that major amputation could be safely and effectively performed under ultrasound-guided peripheral nerve blocks for critically ill patients, and ultrasound-guided peripheral nerve blocks could be an alternative for patients at high risk of general anesthesia or spinal anesthesia.

The erector spinae block: a novel approach to pain management in acute appendicitis

BackgroundAcute abdominal pain is one of the most common complaints that patients present with in the emergency room and has long been a challenge to effectively manage without relying on opioid analgesia. The use of ultrasound-guided peripheral nerve blocks (UGRA) represents a new frontier in multimodal pain control regimens in the acute setting. An erector spinae plane (ESP) block is believed to mediate pain relief in multiple dermatomes through blockage of both visceral and somatic nerves. Analgesia provided by a single injection can help keep a patient comfortable for hours without breakthrough pain and the subsequent need for frequent redosing of opioid pain medication. To this date, there is very limited evidence of an ESP block in the utilization of acute appendicitis in the emergency department.Case reportThis case report presents a 26-year-old female with a past medical history of polycystic ovarian syndrome (PCOS) and a tubal ligation that presented with 7/10 right lower quadrant abdominal pain that began 1 h prior to arrival. She stated that she felt like this was similar to her PCOS exacerbations in the past. During her evaluation, she underwent a computed tomography (CT) scan of her abdomen and pelvis that was remarkable for acute, uncomplicated appendicitis. She was given 4 mg of morphine for her pain with little response, so the offer was made for an erector spinae block that the patient elected to receive. After being consented both for the procedure and for research, she received a right-sided erector spinae block with 20 mL’s of 0.2% ropivacaine (2 mg/mL) at the L1 vertebral level. After approximately 15 min, she stated that she had a reduction in her pain from a 6/10 to a 1/10 that persisted throughout the rest of her stay in the emergency department.

An algorithm for management of failed ultrasound-guided peripheral nerve blocks.

An algorithm for management of failed ultrasound-guided peripheral nerve blocks.

Ultrasound-Guided Sciatic and Femoral Block in Patient with Recent Embolism Stroke Undergo Amputation Above the Knee

Background: Patients undergoing amputation of the lower extremities usually have poor circulation and other comorbidities and, therefore, present a challenge to the anesthesiologist. The combination of sciatic and femoral nerve block is reported to be an effective anesthetic technique for patients undergoing knee surgery, and it is known to be an effective method of postoperative analgesia in patients undergoing major surgery on the subject's lower extremities. Case: A 70-year-old man with a recent embolism stroke, death of his limb on the right cruris region, and underwent an amputation above the knee. Preoperative physical examination showed GCS E4 V, motor aphasia M6, blood pressure 131/82 mmHg, pulse 114 bpm, RR 20 times/minute with bodyweight 70 kg, height 160 cm, SpO2 97%. There was cyanosis in the right cruric region with motor power of 1/5 1/5. The value of leukocytes 18,600/ul, platelets 309,000/ul, Prothrombin Time (PT) 15.8 seconds, Activated partial thromboplastin time (APTT) 25.9 seconds, International normalized ratio (INR) 1,330, neutrophils 81.7%, lymphocytes 12.6%, creatinine 1.8 mg/dl, urea 137 mg /dl, blood sugar at the time 258 mg/dl, Cl 95 mmol/l. This case report suggests that ultrasound-guided peripheral nerve blocks may be useful for major lower extremity surgery in patients with severe hemodynamic impairment. Conclusion: Perioperative management of embolism stroke patients undergoing above-knee amputation requires special attention in selecting anesthetics. Ultrasound-guided peripheral nerve blocks minimize patient hemodynamic changes and provide better postoperative pain control.

Neuromuscular treatment approach for women with chronic pelvic pain syndrome improving pelvic pain and functionality.

Reporting the effects of treating underlying myofascial dysfunction and neuropathic pain in women with chronic pelvic pain syndrome (CPPS). Retrospective longitudinal study of 186 women with CPPS treated with ultrasound-guided peripheral nerve blocks and trigger point injections to pelvic floor muscles alongside pelvic floor physical therapy once weekly for 6 weeks in an outpatient setting. Visual Analogue Scale (VAS) and Functional Pelvic Pain Scale (FPPS) questionnaires quantified pain and function in the pelvis. Working, intercourse, sleeping, walking, running, lifting, bladder, and bowel were the function categories. Statistical significance was established by p value less than .05 in paired two-sample t-test. VAS improved by 2.14 where average VAS before treatment was 6.61 (standard deviation [SD] 2.45; p < .05, 95% confidence interval [CI] = 6.26-6.96) and average VAS after treatment was 4.47 (SD 2.71; p < .05, 95% CI = 4.08-4.86). Total FPPS decreased by 3.38 from 11.26 (SD 6.51; p < .05, 95% CI = 10.32-12.19) before treatment to 7.88 (SD 6.22; p < .05, 95% CI = 6.99-8.78) after treatment. Working, intercourse, and sleeping accounted for the highest statistically significant improvement. Findings support the success of the comprehensive treatment protocol. Patients who had persistent symptoms after a full course of pelvic floor physical therapy experienced improvements in pain levels and function once it was combined with ultrasound-guided nerve blocks and trigger point injections, interactively treating underlying neuromuscular dysfunction.

Combination of real-time needle-tip pressure sensing and minimal intensity stimulation limits unintentional intraneural injection during an ultrasound-guided peripheral nerve block procedure: A randomized, parallel group, controlled trial

Study objectiveUltrasound guidance does not eliminate the risk of intraneural injection, which must be avoided during PNB. Combining ultrasound guidance (USG), nerve stimulation (NS), and injection pressure monitoring is advocated to prevent nerve injury during PNB. We hypothesized that combining patient-tailored dynamic NS and real-time pressure sensing (RTPS) could reduce the incidence of intraneural injection and nerve puncture during USG PNB compared with a traditional fixed thresholds (Control) procedure. DesignRandomized, prospective study. SettingOperating room. PatientsOne hundred ASA physical status I to III patients undergoing orthopedic surgery. InterventionsPatient anesthetized using axillary, sciatic or femoral USG PNB were randomized to the PresStim group (Dynamic RTPS and NS set at 1.5 mA then decreased; n = 50) or Control group (fixed thresholds for in-line pressure mechanical manometer and NS at 0.2 mA; n = 50). MeasurementsProcedural ultrasound images and videos were recorded, stored and reviewed in random order by two experts in ultrasound-guided PNB blinded to the group. They noted the needle-to-nerve relationship and intraneural injection for all blocked nerves. Main resultsOne hundred and twenty-three USG PNBs were performed (56 axillary brachial plexus blocks, 40 femoral nerve blocks and 27 sciatic popliteal nerve blocks); 235 blocked nerves and videos were recorded and analyzed (PresStim, 118; Control, 117). Less paresthesia was noted in the PresStim group (12.7%) compared with the Control group (18.8%). The risk of intraneural injection was significantly higher in the Control group (odds ratio [OR], 17.1; 95% confidence interval [CI], 2.2–135, P = 0.007). The risk of nerve puncture (OR, 22.7; 95% CI, 2.9–175, p = 0.003) and needle-nerve contact (OR, 4.7; 95% CI, 2.4–9.5, p < 0.001) was significantly higher in the Control group than the PresStim group. ConclusionsUnder the conditions of the study, dynamic triple monitoring combining RTPS, NS and USG decreases intraneural injection and unintentional needle-nerve contact and puncture during a PNB procedure.

An Update on Postoperative Opioid Use and Alternative Pain Control Following Spine Surgery.

Opioids are commonly prescribed postoperatively for pain control, especially in spine surgery. Not only does this pose concerns for potential abuse, but it also has been shown to worsen certain outcomes. Risk factors for increased use include preoperative opioid use, female sex, psychiatric diagnoses, and drug and alcohol use. Over the past few decades, there have been increasing efforts mostly spearheaded by governmental agencies to decrease postoperative opioid use via opioid prescription limitation laws regulating the number of days and amounts of analgesics prescribed and promotion of the use of enhanced recovery after surgery (ERAS) protocols, multimodal pain regimens, epidural catheters, and ultrasound-guided peripheral nerve blocks. These strategies collectively have been efficacious in decreasing overall opioid use and better controlling patients' postoperative pain while simultaneously improving other outcomes such as postoperative nausea, vomiting, and length of stay. With an aging population undergoing an increasing number of spinal surgeries each year, it is now more important than ever to continue these efforts to improve the quality and safety of pain control methods after spinal surgery and limit the transition of acute management to the development of opioid dependence and addiction long-term.

High-Impact Clinical Studies That Fomented New Developments in Anesthesia: History of Achievements, 1966-2015.

The aim of this work is to identify the most influential initial clinical studies that fomented important developments in anesthesiology over the past 50 years. Studies fomenting new development can be selected using vastly different approaches and, therefore, might provide diverse outcomes. In the present work, two basic aspects of study assessments – the stage of development (eg, generation of idea, preclinical studies, clinical trials) and the method of selection (eg, committee vote, various types of citation analysis, method of finding the invention disclosure) – were chosen according to the following model. The stage of development: the initial clinical studies demonstrating the basic advantage of an innovation for providing anesthesia. The method: a combination of two factors – the study priority in terms of the time of its publication and the degree of its acknowledgement in the form of citation impact; the time of study publication was regarded as a primary factor, but only if the study’s citation count was =/>20. The initial high-impact studies were selected for 16 drug-related topics (ketamine, isoflurane, etomidate, propofol, midazolam in anesthesia, vecuronium, alfentanil, atracurium, sevoflurane, sufentanil, rocuronium, desflurane, ropivacaine, remifentanil, dexmedetomidine in anesthesia, and sugammadex), and 9 technique-related topics (ultrasound-guided peripheral nerve block, capnography in anesthesia, target-controlled intravenous anesthesia, pulse oximetry in anesthesia, total intravenous anesthesia, transesophageal echocardiography in anesthesia, combined spinal-epidural anesthesia, and bispectral index). Twenty-five studies were designated the first high-impact studies (one for each topic); 16 are drug-related and 9 are technique-related. Half of the first high-impact studies had a citation count of =/>100, (range: 100 to 555). The citation count of the other half of high-impact studies did not reach the 100-citation threshold (range: 41 to 97). If a selected first high-impact study had a citation count <100, a next-on-timeline, additional study with citation count =/>100 was also selected; (range: 100 to 344). The present results show that an initial high-impact clinical study on a new development in anesthesiology can be determined and that related citations usually vary from one hundred to five hundred.

Retrospective Single-Center Comparative Analysis of Ultrasound-Guided Versus Non-ultrasound-Guided Nerve Blocks in Extremity Surgeries.

Although ultrasound-guided peripheral nerve blocks have become increasingly popular, it is arguable at present whether ultrasound guidance is a necessary tool for peripheral nerve blocks. The purpose of this study was to assess the significance of ultrasound-guided peripheral nerve blocks in reducing complications. From January 2013 to January 2019, 17,823 patients who underwent peripheral nerve blocks with/without ultrasound guidance were reviewed, recording data on their age, sex, height, weight, American Society of Anesthesiologists, block type, operation type, operation duration, and complications. The patients were divided into 2 groups: 9372 cases with ultrasound guidance (US Group) and 8451 cases without ultrasound guidance (No-US Group). To control selection bias, a total of 16,236 patients were finally included in this study after 1:1 propensity score matching, including 8118 cases in the US Group and 8118 cases in the No-US Group. Outcome measures included local anesthetic systemic toxicity (LAST), nerve injury, incomplete block anesthesia (IBA), local hematoma, and infection at the block site. Baseline characteristics of patients were similar between the two groups (P >.05, respectively). Our study revealed that the incidence of infection was similar between the two groups (P >.05). However, the incidences of LAST, nerve injury, IBA, and local hematoma in the US Group were significantly lower than those in the No-US Group (P <.05, respectively). Our findings suggest that ultrasound-guided peripheral nerve blocks are associated with fewer complications and higher success rates, compared with the paresthesia approach.

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.

Comparison of Ultrasound-Guided Transversus Abdominis Plane Block with Sub-Arachnoid Block for Open Inguinal Hernia Repair.

Background:Open inguinal hernia repair is one of the routine day-care procedures performed across the world. A multitude of anesthetic techniques have been outlined for painless inguinal hernia repair, comprising general anesthesia and regional anesthesia such as spinal, epidural, and nerve blocks; with regional anesthetic techniques often favored for uncomplicated open inguinal hernia repair. Ultrasound-guided peripheral nerve blocks have made rapid strides and are gaining popularity because of the reduced incidence of adverse events.Aims:We aim to compare the efficacy of two regional anesthesia techniques to compare the adequacy of surgical anesthesia and their efficacy to ease postoperative pain with least potential side effects.Settings and Design:This prospective, interventional, single-centric, double-blind, randomized, parallel-group, active-controlled, Helsinki protocol-compliant clinical study was registered with the Clinical Trial Registry of India (CTRI/2021/04/033109). It was conducted after obtaining written informed consent from all patients and approval from the institutional review board.Materials and Methods:Sixty patients of American Society of Anesthesiologists physical status classes I/II, in the age group of 18–60 years of either sex, scheduled for elective open inguinal hernia repair, were enrolled into two groups of 30 patients each according to the anesthetic technique used. Group T comprised patients receiving ultrasound-guided transversus abdominis plane block (TAP block), whereas the Group S comprised patients administered spinal anesthesia for elective open inguinal hernia repair. The primary end points of this study were to assess the adequacy of surgical anesthesia and duration of postoperative analgesia, whereas the secondary end points included assessment of patients’ hemodynamic profile post institution of the block and comparing the incidence of adverse events associated with the two techniques.Statistical Analysis:SPSS version 20.0 was used for analysis. Frequency, mean distribution, standard deviation, Chi Square test and student t Test were calculated to p value. P < 0.05 was considered statistically significant. Continuous variables were expressed as mean + SD, whereas categorical variables were expressed as absolute numbers and percentages. Intergroup nominal categorical data were compared by Chi-square test.Results:The visual analog scale score was found significantly lower in Group T at all time points except immediate postsurgery (3, 6, 12, 24, and 48 h) as compared to Group S (0.357 ± 0.4880 vs. 1.393 ± 1.8527; P = 0.006, 1.393 ± 0.4973 vs. 2.893 ± 2.3148; P = 0.001, 2.429 ± 0.9201 vs. 3.321 ± 2.0377; P = 0.039, 1.214 ± 0.4179 vs. 2.286 ± 1.9217; P = 0.006, and 1.143 ± 0.3563 vs. 1.643 ± 1.5685; P = 0.106, respectively), and the duration of postoperative analgesia was highly significant (P < 0.001) in Group T (724.00 ± 103.2914 min) as compared to Group S (256.643 ± 73.4218 min). Difference in the number of rescue analgesics administered over the first 24 and 24–48 h was significantly higher in the spinal group which comprised patients administered with the TAP block.Conclusion:Ultrasound-guided TAP block provides better intra-operative and postoperative analgesia as compared to subarachnoid block especially in respiratory and cardiovascular cripples without any significant adverse events and hemodynamic changes.

Ultrasound-Guided Peripheral Nerve Blocks Performed by Orthopedic Surgeons: A Retrospective, Multicenter Study in Akita Prefecture, Japan.

The shortage of doctors is a societal problem, especially in rural areas such as Akita Prefecture, Japan. Therefore, it is not unusual in Akita for orthopedic surgeons to perform upper and lower limb surgeries under ultrasound-guided peripheral nerve blocks managed by the operators themselves. Multicenter studies of ultrasound-guided peripheral nerve blocks performed by orthopedic surgeons have not been reported. The purpose of this study was to clarify the safety and reliability of ultrasound-guided peripheral nerve blocks performed by orthopedic surgeons in Akita. A total of 1,674 upper extremity surgery cases operated under ultrasound-guided peripheral nerve blocks at 8 hospitals in Akita prefecture from April 2016 to April 2018 were investigated retrospectively. These blocks were performed by a total of 37 orthopedic surgeons, including senior surgeons and residents. In 321 of the 1,674 cases (19%), local anesthetics were added to the surgical field. Two cases with special factors were converted to general anesthesia. There were 2 cases of complications associated with the nerve block, but they were all transient and recovered promptly. The block site and the hospital where the block was performed showed a significant relationship with the addition of local anesthetics to the surgical site (P < 0.001). Surgery time, age at surgery, and surgical site showed no significant relationships with the addition of local anesthetics. The volume of the anesthetic used for the nerve block showed a significant inverse relationship with the addition of local anesthetics (P=0.040). Many orthopedic surgeons in Akita prefecture began to perform ultrasound-guided peripheral nerve blocks, which had a reliable anesthesia effect with no noticeable complications, whether performed by residents or senior orthopedic surgeons, and this is a useful anesthetic technique for orthopedic surgeons.

Minimum Effective Volume of 0.75% Ropivacaine for Ultrasound-Guided Axillary Brachial Plexus Block.

BackgroundUltrasound-guided peripheral nerve block provides direct visualization of nerve and reduces the complications associated with classical landmark guided technique, by reducing the dosage of local anesthetic drugs. This study aims to determine the minimum effective volume (MEAV) of 0.75% ropivacaine for ultrasound-guided axillary brachial plexus block.MethodologyA total of 23 patients of age group 18-75 years belonging to ASA grade 1, 2, and 3 were selected based on inclusion criteria. The MEAV was determined by using Dixons & Massey Step-up and Step-down method. The initial volume was selected as 15 mL based on previous studies. Depending on block success or failure, 1 mL of the drug was decreased or increased. Block was assessed in terms of motor and sensory components. The study was aborted after attaining five cases of block failure, followed by five cases of a successful block.ResultsThe MEAV to be given for a successful block in 50% of patients (MEAV50) was 8.62 mL (95%CI 3.54-9.89). The MEAV to be given for a successful block in 90% of patients (MEAV 90) was 11.82 mL (95% CI 9.9-75.7).Conclusion Ultrasound guidance reduces the dosage of local anesthetic drugs to be used and provides surgical anesthesia without any complications or adverse effects.

Real-Time Injection Pressure Sensing and Minimal Intensity Stimulation Combination During Ultrasound-Guided Peripheral Nerve Blocks: An Exploratory Observational Trial.

Nerve damage can occur after peripheral nerve block (PNB). Ultrasound guidance does not eliminate the risk of intraneural injection or nerve injury. Combining nerve stimulation and injection pressure (IP) monitoring with ultrasound guidance has been suggested to optimize needle tip location in PNB. In this prospective observational study, we hypothesized that measured pairs of IP and minimum intensity of stimulation (MIS) might differentiate successive needle tip locations established by high-resolution ultrasound during PNB. For this exploratory study, 240 observations for 40 ultrasound-guided PNBs were studied in 28 patients scheduled for orthopedic surgery. During the progression of the needle to the nerve observed by ultrasonography, the IP was measured continuously using a computerized pressure-sensing device with a low flow rate of solution. Stimulation thresholds and electrical impedance were obtained by an impedance analyzer coupled to the nerve stimulator at 6 successive needle positions. The median (quartile) or mean (95% confidence interval [CI]) was reported. A mixed model analysis was used, and the sample was also explored using a classification and regression tree (CART) algorithm. Specific combinations of IP and MIS were measured for subcutaneous, epimysium contact, intramuscular, nerve contact (231 mm Hg [203-259 mm Hg] and 1.70 mA [1.38-2.02 mA]), intraneural location (188 mm Hg [152-224 mm Hg] and 0.58 mA [0.46-0.70 mA]), and subparaneural location (47 mm Hg [41-53 mm Hg] and 1.35 mA [1.09-1.61 mA]). The CART algorithm shows that the optimal subparaneural needle tip position might be defined by the lowest pressure (<81.3 mm Hg) and MIS (<1.5 mA) cutoffs. Our exploratory study evaluated concepts to generate hypotheses. The combinations of IP and MIS might help the physician during a PNB procedure. A low IP and low MIS might confirm a subparaneural location, and a high IP and a low MIS might be an alert for the intraneural location of the needle tip.

Quadratus Lumborum Block as a Rescue Block Following Total Hip Arthroplasty.

Total hip arthroplasty (THA) is a common surgical procedure for various hip diseases that has been associated with severe postoperative pain. A multimodal pain management regimen is a mandatory component to successful rehabilitation and patient satisfaction. By incorporating regional blocks into the perioperative surgical home model for THA, we help to achieve the “triple aim”: a better patient experience, better health care, and lower costs [1]. Traditionally, neuraxial analgesia has been the mainstay for analgesia for this set of patients. With the advent of ultrasound-guided peripheral nerve blocks such as fascia iliaca (FI) blocks, more practitioners have begun to perform the latter type of procedure. Recently, quadratus lumborum (QL) blocks have gained attention as a suitable option for analgesia for various types of surgeries, including hip arthroplasty [2]. A QL block is an ultrasound-guided fascial plane block that has been found to be easy to perform...

An Interventional Pain Algorithm for the Treatment of Postmastectomy Pain Syndrome: A Single-Center Retrospective Review.

Breast cancer is the most common female malignancy worldwide. Breast surgery and adjuvant oncological therapies are often required to increase survival. Treatment-related pain may persist and evolve into postmastectomy pain syndrome (PMPS) in a significant subset of breast cancer survivors. In this retrospective investigation, we will present our experience in applying an interventional algorithmic approach to treat PMPS. A retrospective study. An academic cancer hospital. Adult females with PMPS diagnosis. We reviewed 169 records with the diagnosis of PMPS from 2015 to 2019 within our health system. Pre- and post-injection pain scores, relief duration, and medication usage changes were collected. The decision to perform each procedure was based on the anatomic location of the painful area with the corresponding peripheral sensory innervation. Decision-making flow diagrams were created to present our experience in managing PMPS beyond peripheral nerve blocks. Ultrasound-guided peripheral nerve block results (n=350) were analyzed. The mean baseline pain score was 7, compared with the post-treatment mean score of 3 (95% confidence interval: 3.58 to 3.98, P = 0.0001). Among the responders, the mean pain relief duration was 45 days, with a median of 84 days. Opioid medication consumption was reduced by 11% (t = 0.72, P = 0.47). Ultrasound-guided nerve blocks of this area could be performed safely and effectively after breast surgeries. We also present our proposed algorithm to provide a stepwise application for selecting the appropriate therapies in the management of more complex PMPS.

Surgeon-administered Ultrasound-guided Peripheral Nerve Blocks in Outpatient Procedures of the Upper Extremity.

SummaryOutpatient hand surgery is often performed in the operating room, which can result in prolonged waiting times for patients when operating room resources are limited. Few studies have explored the application of ultrasound-guided nerve blocks in the setting of outpatient hand surgery. Fifty patients were enrolled in this prospective study. Ultrasound-guided peripheral nerve blocks were performed at the level of the elbow and proximal forearm for outpatient hand surgeries. A timer was used to record the time to administer the block and time to affect. A post-procedure survey was administered, which included a numerical analogue scale (0–10) and Likert rating scale questions to characterize the patients’ pain experience for receiving the block and pain during the procedure: pain experienced by patients receiving the ultrasound-guided nerve block(s) (0–10), mean: 1.84; pain experienced by patients during a procedure (0–10), mean: 0.56; surgeon satisfaction during the procedure (0–10), mean 9.78. Average time to perform the ultrasound-guided nerve block(s) was 4 minutes 58 seconds; average time from completion of the block to effect reported by patients, 5 minutes 42 seconds; the average time for performing the procedure, 21 minutes 30 seconds. Our study shows that the use of ultrasound to block peripheral nerves of the forearm is effective; <10% of patients required additional local anesthetic. The technique is safe; no complications were reported. The technique is efficient in an outpatient hand surgery setting.

Injection pressure monitoring during peripheral nerve blocks: from bench to operating theatre

BackgroundNerve damage can occur after ultrasound-guided peripheral nerve block (PNB). Injection pressure monitoring could improve the safety of PNB. The aim was to analyse parameters affecting pressure measurements during PNB. MethodsThe flow characteristics of needles connected to a pressure-sensing device were evaluated. Needles were placed under ultrasound guidance extra or epineurally in nerves/plexus of fresh cadavers. Using three flow rates, 4 mL of saline was injected and plateau pressure was measured. Finally, orthopaedic surgery patients receiving PNB were enrolled for an observational real-time pressure monitoring study. During PNB, periods with pressure > 50 mmHg were noted (high pressure ≥ 750 mmHg). A blinded investigator recorded injection pressure curves and peak pressure. ResultsThe needle diameter influenced the injection pressure (β = 66.8; P < 0.0001). Non-echogenic needles increased the injection pressure (β = 82; P = 0.0009) compared with echogenic needles. Cadaver injection pressure was higher for intraneural (255 [122.5–555] mmHg) versus extraneural needle tip location (90 [50–158] mmHg; P < 0001); for high flow (9.6 mL/min; 470 [265; 900] mmHg) versus low flow (1.2 mL/min; 120 [71–250] mmHg) (P < 0.001) and for cervical roots (900 mmHg, intraneurally) compared with nerves (300 mmHg, intraneurally). In 37 patients and 61 procedures, there were 7 [1–18] peaks of injection pressure per procedure. Pressure was noted > 750 mmHg during 13.80% of the procedural time. ConclusionsNeedle diameter, needle tip location, type of nerve/plexus, flow rates, and the anaesthetist can have a significant effect on injection pressure values and monitoring.Trial registration: ClinicalTrials.gov ID: NCT03430453

Regional anesthesia training model for resource-limited settings: a prospective single-center observational study with pre–post evaluations

Background and objectivesEducational initiatives are a sustainable means to address provider shortages in resource-limited settings (RLS), yet few regional anesthesia curricula for RLS have been described. We sought to design...

Peripheral nerve blocks in the cervical region: from anatomy to ultrasound-guided techniques.

Cervical plexus nerve blocks have been employed in various head and neck operations. Both adequate anaesthesia and analgesia are attained in clinical practice. Nowadays, ultrasound imaging in regional anaesthesia is driven towards a certain objective that dictates high accuracy and safety during the implementation of peripheral nerve blocks. In the cervical region, ultrasound-guided nerve blocks have routinely been conducted only for the past few years and thus only a small number of publications pervade the current literature. Moreover, the sonoanatomy of the neck, the foundation stone of interventional techniques, is very challenging; multiple muscles and fascial layers compose a complex of compartments in a narrow anatomic region, in which local anaesthetics are injected. Therefore, this review intends to deliver new insights into ultrasound-guided peripheral nerve block techniques in the neck. The sonoanatomy of the cervical region, in addition to the cervical plexus, cervical ganglia, superior and recurrent laryngeal nerve blocks are comprehensively discussed.