Ultrasound-guided Sciatic Nerve Research Articles

Ultrasound-Guided Sciatic Nerve Hydrodissection Can Improve the Clinical Outcomes of Patients with Deep Gluteal Syndrome: A Case-Series Study.

Deep gluteal syndrome (DGS) is caused by sciatic nerve entrapment. Because fascial entrapment neuropathies may occur in multiple locations, ultrasound-guided nerve hydrodissection is a key component of DGS treatment. In this study, we examined the clinical outcomes of patients with DGS undergoing ultrasound-guided sciatic nerve hydrodissection. A 10 mL mixture consisting of 5% dextrose, 0.2% lidocaine (Xylocaine), and 4 mg betamethasone (Rinderon) was used for nerve hydrodissection. Clinical outcomes were evaluated using Numeric Rating Scale (NRS) scores of pain, the proportion of patients with favorable outcomes (reduction of ≥50% in pain), the duration for which patients exhibited favorable outcomes (percentage of follow-up duration), and the occurrence of major complications and minor side effects. A total of 53 patients were consecutively included and followed up for 3 to 19 months. After the initial injection, the NRS scores significantly improved at 1 week, 1 month, 3 months, and the final follow-up. Specifically, 73.6%, 71.7%, 64.2%, and 62.3% of the patients exhibited favorable outcomes at 1 week, 1 month, 3 months, and the final follow-up, respectively. The median duration for which the patients exhibited favorable outcomes was 84.7% of the follow-up period. Three patients (5.7%) experienced transient dizziness and vomiting, which resolved without further treatment. No vessel or nerve puncture was observed. Overall, ultrasound-guided sciatic nerve hydrodissection is a safe procedure that mitigates the pain associated with DGS. To achieve favorable outcomes, three consecutive injections 3 weeks apart are required.

Evaluating the impact of ultrasound-guided subsheath versus extrasheath sciatic nerve block on postoperative wound pain in tibial and foot surgeries: A systematic review and meta-analysis.

This systematic review and meta-analysis evaluate the impact of ultrasound-guided subsheath versus extrasheath sciatic nerve blocks on postoperative wound pain in tibial and foot surgeries, crucial for effective pain management and patient recovery. Adhering to PRISMA guidelines, this study used a PICO framework, focusing on patients undergoing tibial and foot surgeries and comparing the efficacy and safety of subsheath and extrasheath sciatic nerve blocks. The literature search spanned four databases without time restrictions, assessing various outcomes like success rate, onset time, duration of analgesia and complication rates. Quality assessment employed the Cochrane Collaboration's risk of bias tool, and statistical analyses included heterogeneity assessment, fixed-effect and random-effects models, sensitivity analysis and publication bias evaluation using funnel plots and Egger's linear regression test. From an initial pool of 1213 articles, six met the inclusion criteria. The subsheath group showed a significantly higher success rate of complete sensory blockade within 30 min compared with the extrasheath group (OR = 5.39; 95% CI: 2.82-10.28; p < 0.01). No significant differences were found in procedure duration or incidence of nerve-related complications between the two techniques. The subsheath approach also demonstrated a quicker onset time of sensory blockade (MD = -8.57; 95% CI: -11.27 to -5.88; p < 0.01). Sensitivity analysis confirmed the stability of the results, and no significant publication bias was detected. Ultrasound-guided subsheath sciatic nerve blocks are more effective than extrasheath blocks in achieving rapid and complete sensory blockade for tibial and foot surgeries, with a quicker onset time and comparable safety profile. Subsheath injections are thus recommended as a preferred method for anaesthesia and postoperative pain management in these surgical procedures, enhancing overall patient outcomes.

Ultrasound-Guided Sciatic Nerve Block vs. Caudal Analgesia in Cerebral Palsy Undergoing Lower Limb Surgeries

Background: Continuous advancements in ultrasound (US)-guided neuraxial and peripheral nerve blocks (PNB) have allowed the safe and successful use of these blocks as adjuvants to general anesthesia in pediatric patients. Objectives: This study was designed to compare the analgesic efficacy of 2 US-guided regional techniques, caudal epidural block (CEB) and subgluteal sciatic nerve block (SNB), in children with cerebral palsy (CP). Methods: The current randomized comparative study was conducted on 30 patients with spastic CP aged 2-12 years who were scheduled for unilateral lower limb multilevel soft tissue corrective surgeries, randomly distributed using a computerized program into 2 equal groups. The CEB group received a US-guided caudal block, and the SNB group received a US subgluteal sciatic nerve block. The time to the first postoperative analgesia requirement (primary outcome), postoperative pain score, total postoperative analgesic consumption, and perioperative complications (secondary outcomes) were assessed in both groups. Results: The duration of postoperative analgesia was significantly longer in patients of the SNB (14.65 ± 3.08 h) than in the CEB group (5.93 ± 1.68 h). The postoperative pain scores recorded at 6th-12th h and the postoperative 24-h rescue analgesic consumption were significantly lower in the SNB compared to the CEB group. Conclusions: Ultrasound-guided subgluteal sciatic nerve block is a safe and effective alternative to US-guided caudal analgesia in pediatric patients with spastic CP scheduled for lower limb surgeries, with longer postoperative analgesia and similar perioperative safety profiles.

Ultrasound-guided sciatic nerve block in Wistar rat cadavers: Relevant anatomy and injection distribution

ObjectiveTo investigate the feasibility of an ultrasound-guided sciatic nerve block by describing the sonoanatomy and comparing the distribution of two volumes of bupivacaine dye solution for nerve staining. Study designRandomized, experimental, assessor-blinded cadaveric study. AnimalsA total of 40 adult female Wistar rat cadavers. MethodsAfter studying the sonoanatomy of the sciatic nerve and adjacent structures using a high-resolution linear transducer (19–5 MHz), rat cadavers were randomly divided into two groups that were administered either 0.1 mL (group 0.1) or 0.2 mL (group 0.2) of bupivacaine dye solution per nerve, delivered via an in-plane technique. The extent of nerve staining was subsequently evaluated following dissection. Statistical analysis consisted of assessing data distribution using the Shapiro–Wilk test, followed by paired t-tests for continuous data, Mann–Whitney U test and McNemar’s test for categorical data. Statistical significance was defined as p < 0.05. ResultsThe sciatic nerve was identified bilaterally as a double ellipsoid-shaped image, surrounded by a hyperechoic fascia separating the biceps femoris from the adductor muscle. The hypoechoic structure formed by the bupivacaine dye solution around the nerve was effectively visualized using ultrasound imaging. Sciatic nerve staining was successfully achieved in all pelvic limbs, with dye spread of 4.82 ± 1.55 mm and 5.47 ± 2.18 mm in groups 0.1 and 0.2, respectively (p = 0.128). Conclusions and clinical relevanceThis study achieved a detailed understanding of the sonoanatomy of the sciatic nerve and its adjacent structures, highlighting the feasibility of the ultrasound-guided technique for injection in Wistar rats. Furthermore, the results show a comparable distribution of dye solution in both groups. Use of the ultrasound-guided sciatic nerve block technique in rats not only exhibits substantial potential for regional anesthesia but also opens avenues for translational studies.

Quantitative assessment of ultrasound-guided sciatic nerve block - A comparison of a single-point versus two-point injection technique: A randomised controlled, double-blinded trial.

Sciatic nerve block at the popliteal level for lower limb procedures provides unpredictable success rates even with ultrasonographic (USG) guidance. This study aimed to compare USG-guided single-point versus two-point injection techniques. Sixty patients posted for foot surgeries under USG-guided sciatic nerve block were randomised into Group Single Point, receiving a single injection of 20 mL of 1.5% lignocaine with adrenaline just proximal to the sciatic nerve bifurcation, and Group Double Point, receiving two injections of 10 mL of 1.5% lignocaine with adrenaline, one at the point similar to the first group and a second injection 6 cm above the first point. Sensory blockade onset, time to complete sensory blockade, time to complete motor blockade, length of the nerve exposed and analgesia duration were evaluated. Statistical analysis was performed with Statistical Package for the Social Sciences (SPSS) statistics version 20 software. Double-point injection technique showed a significantly faster time to complete motor blockade [14.46 (9.93) min], increased length of nerve exposed to local anaesthetic [23.23 (7.209) cm] and extended duration of analgesia [420.40 (99.34) min] compared to the single-point injection technique [20.89 (12.62) min, 18.78 (5.95) cm and 344.28 (125.97) min, respectively]. The onset of sensory blockade and the time to complete sensory blockade were comparable between the two groups. USG-guided popliteal sciatic nerve block with a double-point injection technique does not significantly shorten the time to complete the sensory block. However, the time to complete motor nerve block and duration of analgesia are prolonged significantly, which may be clinically beneficial for postoperative analgesia.

Evaluation of a New Method of Sciatic Nerve Block: A Prospective Pilot Study.

The location of the sciatic nerve deep within the thigh tissue makes it challenging to locate while the patient is in a supine position. The posterior intermuscular septum of the thigh, which encircles the posterior surface of the adductor magnus muscle (AMM), is where the sciatic nerve is located. Our hypothesis was that administering local anesthetic injections into this area could block the sciatic nerve. Therefore, our aim was to evaluate the effectiveness of sciatic nerve block achieved by injecting local anesthetic into the posterior intermuscular septum of the thigh, named the AMM approach. Twenty-six patients undergoing total knee arthroplasty were included in the study. We performed an ultrasound-guided sciatic nerve block by injecting 20 mL of 0.25% ropivacaine into the posterior surface of the adductor magnus muscle, using the AMM approach. Additionally, we administered a femoral nerve block with 20 mL of 0.4% ropivacaine. We assessed the sensory and motor effects of the blockade in the operated lower limb and recorded postoperative pain scores at 0, 4, 8, 12, 24, and 48 hours after the operation. The AMM approach successfully block the sciatic nerve in all 26 patients. The onset of the sensory and motor blockades was achieved within 5.4 ± 1.9 min and 8.7 ± 3.5 min, respectively. We achieved a satisfactory position with the first puncture in 19 of 26 patients (73.1%). The muscle strength of the tibialis anterior immediately after surgery was 4 (ranging from 2 to 5). Additional rescue analgesics were required in 5 of the 26 patients (19.2%) during the first 24 hours postoperatively. The AMM approach is an innovative and effective method for sciatic nerve block. When combined with simultaneous femoral nerve block in patients undergoing total knee arthroplasty, it provides a useful analgesic treatment option.

Comparison of Ultrasound-Guided Anterior and Posterior Approaches to Sciatic Nerve Block for Lower Limb Surgeries: A Randomised Clinical Study

Introduction: Sciatic nerve block is used for anaesthesia and analgesia in lower limb surgeries. The anterior approach to the sciatic nerve is rarely performed due to unreliable anatomical surface markings. Aim: To compare the anterior and posterior approaches to sciatic nerve block in terms of patient comfort and technical difficulty. Materials and Methods: This randomised clinical study was conducted at the Department of Anaesthesiology, BLDE (Deemed to be University) Shri BM Patil Medical College, Hospital and Research Centre, Bijapur, Karnataka, India. A total of 84 patients who underwent lower limb surgeries from November 2020 to August 2022 were included. Informed consent was obtained, and patients were randomised into two groups-Group-A and Group-P-using the card method. Ultrasound-guided sciatic nerve block was performed using the anterior approach in Group-A and the posterior approach in Group-P. Sensory and motor blockade, time to perform the block, number of attempts, duration of analgesia, and patient satisfaction were recorded. Statistical analysis was performed using the Chi-square test, Analysis of Variance (ANOVA), student t-test, and the results were represented in tables. Results: The median age in Group-A was 42.95±12.69 years, and in Group-P was 43.95±8.68 years. Males were higher in number with 26 (31%) in Group-A and 23 (27%) in Group-P, respectively. Patient satisfaction, duration of analgesia (10.3±3.5 years Group-P and 10.5±4.0 years Group-A), onset of sensory (11.85±7.35 years Group-P and 9.53±5.40 years Group-A), and motor blockade (18.67±7.05 years Group-P years and 17.82±5.70 years Group-A) were similar in both groups. The number of attempts (2.85±0.90 years Group-P and 3.05±0.91 years Group-A) and time taken for performing the sciatic nerve block (6.75±1.10 years Group-P and 7.44±1.00 years Group-A) was higher in the anterior approach compared to the posterior approach. Conclusion: Although both approaches to sciatic nerve block are equally effective, this study concludes that the posterior approach is simpler to perform, requires less time, and provides better patient comfort and satisfaction. Ultrasound-guided posterior sciatic nerve block offers effective anaesthesia and excellent post-operative analgesia.

Comparison of Safety and Efficacy of Unilateral Spinal Anaesthesia and Ultrasound-guided Sciatic Femoral Nerve Block in below Knee Surgery: A Randomised Clinical Study

Introduction: With modern advances, Ultrasonography (USG)- guided regional block techniques have improved nerve blockade with lesser drug usage and maximum safety for patient care. The widely appreciated outpatient surgical care has compelled us to apply the fastest and safest anaesthesia technique. For lower limb surgeries, USG-guided Sciatic Femoral Nerve Block (SFNB) is an emerging alternative to Spinal Anaesthesia (SA). Aim: To compare the safety and efficacy of both techniques in terms of haemodynamic stability, quality of block, and postoperative analgesia. Materials and Methods: A randomised double-blind study conducted at GCS Medical College, Hospital, and Research Centre, Ahmedabad, Gujarat, India, on 80 patients aged 18 to 70 years of either sex, with American Society of Anaesthesiology (ASA) Grade 1 to 3, undergoing below-knee surgeries was divided into two groups. Group A received USA with 1.5 mL hyperbaric inj. ropivacaine 0.75%, and Group B received USGguided SFB with inj. ropivacaine 0.5% 30 mL (15 mL for sciatic nerve and 15 mL for femoral nerve block). Preparation Time (PT), Surgical Anaesthesia Time (SAT), haemodynamic changes, quality of block, Longevity of Anaesthesia (LoA), time of first rescue analgesia, time of spontaneous urination, readiness to discharge, and patient satisfaction were recorded. The statistical analysis was carried out using Statistical Package for Social Sciences version 23.0 (SPSS Inc., Chicago II, USA). The p-value was derived by unpaired t-test and Chi-square test. Results: PT and SAT were higher in Group B (12.10±2.02 mins and 15.74±1.58 mins) than in Group A (6.15±1.12 mins and 8.23±1.45 mins). LoA time and time to first rescue analgesic were higher in Group B (284.10±54.44 mins and 265.71±33.69 mins) than in Group A (138.75±23.30 mins and 132.40±17.41 mins). Time to first spontaneous urination and readiness to discharge were shorter in Group B (136.42±18.40 mins and 158.39±10.78 mins) than in Group A (162.20±26.54 mins and 181.53±18.18 mins). Haemodynamic stability was excellent in both groups with no significant fluctuation. Motor blockade of Bromage 3 grade was achieved in 40 and 38 patients in Group A and B, respectively. The development of VAS score &gt;3 was faster in Group A than in Group B (35 versus 2) at the end of three hours. No adverse events were observed in any patient. Conclusion: USG-guided SFB offers a safe and efficient alternative to Unilateral SA (USA) with satisfactory blockage, stable haemodynamics, and better postoperative analgesia for below-knee surgeries.

Examining the impact perceptual learning artificial-intelligence-based on the incidence of paresthesia when performing the ultrasound-guided popliteal sciatic block: simulation-based randomized study

ObjectiveTo explore the impact of artificial-intelligence perceptual learning when performing the ultrasound-guided popliteal sciatic block.MethodsThis simulation-based randomized study enrolled residents who underwent ultrasound-guided sciatic nerve block training at the Department of Anesthesiology of Beijing Jishuitan Hospital between January 2022 and February 2022. Residents were randomly divided into a traditional teaching group and an AI teaching group. All residents attended the same nerve block theory courses, while those in the AI teaching group participated in training course using an AI-assisted nerve identification system based on a convolutional neural network instead of traditional training.ResultsA total of 40 residents were included. The complication rates of paresthesia during puncture in the first month of clinical sciatic nerve block practice after training were significantly lower in the AI teaching group than in the traditional teaching group [11 (4.12%) vs. 36 (14.06%), P = 0.000093]. The rates of paresthesia/pain during injection were significantly lower in the AI teaching group than in the traditional teaching group [6 (2.25%) vs. 17 (6.64%), P = 0.025]. The Assessment Checklist for Ultrasound-Guided Regional Anesthesia (32 ± 3.8 vs. 29.4 ± 3.9, P = 0.001) and nerve block self-rating scores (7.53 ± 1.62 vs. 6.49 ± 1.85, P < 0.001) were significantly higher in the AI teaching group than in the traditional teaching group. There were no significant differences in the remaining indicators.ConclusionThe inclusion of an AI-assisted nerve identification system based on convolutional neural network as part of the training program for ultrasound-guided sciatic nerve block via the popliteal approach may reduce the incidence of nerve paresthesia and this might be related to improved perceptual learning.Clinical trialCHiCTR2200055115, registered on 1/ January /2022.

248 Ultrasound-Guided Transgluteal Sciatic Nerve Block in Emergency Department Patients With Sciatic Radiculopathy: A Multicenter Prospective Study

Acute-on-chronic pain secondary to sciatica is a common emergency department (ED) presentation and often leads to loss of work, decreased function, and emotional distress. The transgluteal sciatic nerve block (TGSNB) is used by anesthesiologists for chronic, acute, and perioperative sciatic nerve pain. The objective of this study is to assess the efficacy and safety of ED performed TGSNB for acute sciatic radiculopathy.

Block duration is substantially longer with a liposomal suspension of bupivacaine than with 0.5% bupivacaine HCl potentiated with dexmedetomidine following an ultrasound-guided sciatic nerve block in Beagles

To compare the duration of bupivacaine liposome suspension in the dog with that of bupivacaine and dexmedetomidine following a perineural injection. 8 healthy Beagles. The left sciatic nerve of each dog was randomly assigned to an ultrasound-guided perineural injection with either bupivacaine liposome suspension (BLS) or with 0.5% bupivacaine with dexmedetomidine (1 µg/mL) (BUP-DEX). The contralateral nerve was assigned to the alternate agent. The sensory, motor, and proprioceptive functions were evaluated before the injection (baseline) and at 4, 10, 24, 48, 72, and 96 hours. The block in 1 limb in the BLS treatment appeared to have failed (data set excluded). The motor scores of 2 individuals could not be evaluated leaving 5 limbs to evaluate in the BLS treatment and 6 in the BUP-DEX. A total of 6 out of 7 limbs in the BLS achieved a complete sensory block. In 3 out of 5 treatments with BLS, motor block was only partial and in 2 not apparent at all. Proprioceptive block was partial in 5 out of 7 dogs in the BLS treatment. All functions were still completely obliterated at 10 hours in 6 cases in treatment BUP-DEX. All functions were restored in all cases by 96 and 24 hours after administration of BLS and BUP-DEX, respectively. The blockade characteristics of bupivacaine liposome suspension were effective and long lasting. Motor and proprioceptive deficits may be inconsistent over time.

Post-operative nausea and vomiting (PONV) observed in a clinical study designed to assess the analgesic effects of intravenous and subcutaneous methadone in dogs

Opioids are a key component of multimodal analgesia. Methadone is licensed in Europe for IV, IM and SC use in dogs despite there being no published studies assessing the analgesic efficacy of SC administration. Our intention was to compare the analgesic effect of IV or SC methadone. Fifteen dogs presenting for stifle surgery were administered 0.4 mg/kg methadone IV followed by a randomised 0.0.4 mg/kg methadone IV or SC dose 3 h later. All dogs received ultrasound-guided sciatic and saphenous nerve blocks with bupivacaine prior to surgery. This protocol resulted in opioid adverse effects (hypersalivation, vomiting and/or regurgitation) in 5/15 dogs (33%). Thus, in consultation with the ethical review committee, an otherwise identical protocol using a revised 0.2 mg/kg methadone dose was implemented. In the next three dogs studied, similar opioid adverse effects were found in all three dogs and the study was terminated. This paper highlights the potential for post operative nausea and vomiting (PONV), which may have been induced by methadone when used in combination with efficacious locoregional anaesthesia.

Eye-Tracking Technology to Determine Procedural Proficiency in Ultrasound-Guided Regional Anesthesia.

Eye-tracking measures attention patterns, which may offer insight into evaluating procedural expertise. The purpose of this study was to determine the feasibility of using eye tracking to assess visual fixation patterns when performing an ultrasound-guided regional anesthesia procedure and to assess for differences between experienced, intermediate, and novice practitioners. Participants performed an ultrasound-guided sciatic nerve block 3 times on a fresh cadaver model while wearing eye-tracking glasses. Gaze fixation and dwell time on each location were compared between participants. Eye-gaze paths were used to derive a measure of entropy, or how often participants switched gaze fixations between locations. Five attending anesthesiologists, 5 third-year anesthesiology residents with prior ultrasound-guided regional anesthesia experience, and 5 medical students completed the study. Individuals with more experience were more likely to successfully perform the sciatic nerve block (5/5 attendings, 5/5 residents, 0/5 students; P = .002) and performed the procedure faster (average: attendings 62.6 seconds, residents 106.4 seconds, students 134.4 seconds; P = .089). Participants were progressively faster with practice (Trial 1: 41.8 seconds, Trial 2: 29.2 seconds, Trial 3: 28.9 seconds; P = .012), and the average number of eye shifts per trial decreased from 10.8 to 6.5 to 6 (P = .010). Attending physicians spent significantly less time fixating on the ultrasound monitor compared to trainees (P = .035). Average visual entropy progressively decreased from Trial 1 to Trial 3 (P = .03) and with greater experience (P = .15). There was a strong correlation between entropy and time on task (r(16) = 0.826, P = .001). Experienced providers make fewer back-and-forth visual fixations, spend less time in the procedure, and demonstrate less entropy during ultrasound-guided regional anesthesia procedures. Mobile eye-tracking has the potential to provide additional objective measures of performance that may help not only determine procedural competence but also distinguish between levels of proficiency.

A preliminary animal study on the prediction of nerve block success using ultrasonographic parameters

This study aimed to evaluate the diagnostic value of ultrasonographic parameters as an indicator for predicting regional nerve block success. Ultrasound-guided sciatic nerve block was performed in seven dogs using either 2% mepivacaine (nerve-block group) or saline (sham-block group). The cross-sectional area (CSA), nerve blood flow (NBF), and shear wave velocity (SWV) of the sciatic nerve (SWVN), SWV of the biceps femoris muscle (SWVM), and their ratio (SWVNMR) were measured at 0, 30, 60, and 90 min after the nerve block as well as the change rate of each parameter from the baseline. A receiver operating characteristic (ROC) curve analysis was performed to determine the diagnostic value of each parameter in the prediction of nerve block success. No significant changes were observed in the CSA or NBF in association with the nerve block. The SWVN and SWVNMR in the nerve-block group were significantly higher than those in the sham-block group at 90 min and at 30, 60, and 90 min, respectively (p < 0.05). The change rates of SWVN and SWVNMR in the nerve-block group were significantly higher than those in the sham-block group at all time points (p < 0.05). The ROC curve analysis showed that SWVN had a moderate diagnostic accuracy (area under the curve [AUC], 0.779), whereas SWVNMR and change rates of SWVN and SWVNMR had a high diagnostic accuracy (AUC, 0.947, 0.998, and 1.000, respectively). Ultrasonographic evaluation of the SWVN and SWVNMR could be used as indicators for predicting nerve block success.

How I Do It: Ultrasound-Guided Sciatic Nerve Block at the Popliteal Fossa

How I Do It: Ultrasound-Guided Sciatic Nerve Block at the Popliteal Fossa

Estimation of the minimum effective volume of 0.5% bupivacaine for ultrasound-guided popliteal sciatic nerve block in diabetic patients with neuropathy.

Background and Aims:The safety of conventional regional nerve block techniques in patients with established neuropathies, such as diabetic peripheral neuropathy (DPN), is still unclear. We designed this prospective dose finding study to identify the minimum effective local anaesthetic volume of 0.5% bupivacaine for ultrasound-guided subparaneural popliteal sciatic nerve block in 90% of DPN patients undergoing below-knee surgery (MELAV90).Methods:Fifty-three patients with diabetic peripheral neuropathy and scheduled for below knee surgical procedure received popliteal sciatic nerve block under ultrasound guidance. The initial local anaesthetic volume used was 10 ml of 0.5% bupivacaine. The subsequent local anaesthetic volume allocation was based on biased-coin-design. Accordingly, the local anaesthetic volume given to each subject was based on the block outcome of the previous patient. The study included patients prospectively until 45 successful blocks were obtained. The primary measurement was the minimum effective local anaesthetic volume resulting in a successful subparaneural popliteal sciatic nerve block in 90% of DPN patients. The MELAV90 was calculated using isotonic regression and a 95% confidence interval bootstrapping method.Results:The study included 53 patients to obtain 45 successful blocks. The MELAV90 of 0.5% bupivacaine was obtained at 5.85 ml (95% confidence interval, 5.72 to 6.22 ml). Eight patients needed supplemental anaesthesia to complete the surgery. No other complications were noted.Conclusion:For patients with diabetic peripheral neuropathy undergoing below-knee surgery, the MELAV90 of 0.5% bupivacaine for subparaneural popliteal sciatic nerve to achieve surgical anaesthesia was 5.85 ml.

Effect of perioperative sciatic nerve block on chronic pain in patients undergoing below-knee amputation: A randomised controlled trial

Many pain syndromes such as chronic phantom limb pain (PLP) and stump pain (SP), involving nociceptive and neuropathic pain, develop after amputation. Recent literature suggests that the use of regional blocks reduces repeated stimulation of transected nerve roots and thus prevents central sensitisation. This randomised, double-blind study was conducted to evaluate the effect of pre-emptive ultrasound-guided single-shot lateral sciatic nerve block on the occurrence of chronic pain at six months after traumatic below-knee amputation. Thirty patients undergoing traumatic lower limb amputation under general anaesthesia were randomised into two groups: Group B received sciatic nerve block pre-emptively using ultrasound with 20 ml of 0.75% ropivacaine, whereas group C received 20 ml of normal saline. Follow-up of patients was done till six months post-amputation. The primary objective was to assess the occurrence of chronic pain at six months. Pain at 15 days and one month after surgery, post-operative morphine consumption and post-operative nausea and vomiting (PONV) were the secondary outcomes assessed. The occurrence of PLP at six months was comparable in the two groups, group B (46.7%) and C (66.7%). None of the patients developed SP at six months. Median intensities of phantom pain were 1.0 (range, 1-2.0) versus 1.0 (range, 1-2.0) (P = 0.36), and median intensities of SP 2 (range, 2-3.0) versus 3 (range, 2-3.0) (P = 0.39) at 1 month. Pre-emptive sciatic nerve block did not decrease the occurrence or severity of chronic pain after traumatic below-knee amputation.

Color Doppler ultrasonography of an agitated solution is predictive of accurate catheter placement for a continuous popliteal sciatic nerve block

BackgroundContinuous peripheral nerve catheters (PNCs) have been shown to provide superior postoperative analgesia, decrease opioid consumption, and improve patient satisfaction compared with single injection techniques. In order to achieve success and reliability, accurate catheter positioning is an essential element of PNC placement. An agitated solution of normal saline, D5W, or a local anesthetic solution can be produced by the introduction of air to the injectate, creating air bubbles that can enhance ultrasonographic visualization and possibly improve block success.MethodsEighty-three patients were enrolled. Ultrasound-guided continuous popliteal sciatic nerve blocks were performed by positioning the tip of a Tuohy needle between the tibial and common peroneal branches of the sciatic nerve and threading a catheter. An agitated local anesthetic solution was injected through the catheter, viewed with color Doppler ultrasound and video recorded. A peripheral block score (lower score = greater blockade, range 0-14) was calculated based upon the motor and sensory testing at 10, 20, and 30 min after block completion. The color Doppler agitation coverage pattern for the branches of the sciatic nerve was graded as follows: complete (> 50%), partial (> 0%, ≤ 50%), or none (0%).ResultsThe degree of nerve blockade at 30 min as judged by median (10th, 90th percentile) peripheral block score was significant for partial or complete color Doppler coverage of the sciatic nerve injectate compared to no coverage [3 (0, 7) vs 8 (4, 14); p < 0.01] and block onset was faster (p = 0.03). The block success was higher in groups with partial or complete coverage of the branches of the sciatic nerve vs no coverage (96% vs 70%; p = 0.02).ConclusionsInjection of an agitated solution through a popliteal sciatic perineural catheter is predictive of accurate catheter placement when partial or complete coverage of the sciatic nerve branches is visualized with color Doppler ultrasound.Trial registrationNCT01591603

Comparison of unilateral spinal anaesthesia with ultrasound-guided combined sciatic and femoral nerve block in elective arthroscopic knee surgeries

BackgroundArthroscopic knee surgeries are commonly performed orthopaedic procedures, which can be done under unilateral spinal anaesthesia (USA) or ultrasound-guided combined sciatic and femoral nerve block (USFB). However, not many studies have compared both these techniques. Hence this study was undertaken to compare USA and USFB in arthroscopic knee surgeries in terms of time to readiness for discharge (TRD). MethodsEighty patients were randomised into the USA (n = 40) and USFB groups (n = 40). They were administered either USA or USFB on the affected side. The TRD values were compared. Patients were considered fit for discharge after voiding urine, ambulation and obtaining a visual analogue scale (VAS) score of <3. The maximum time required for any of the three parameters was taken as the TRD for that particular patient. ResultsThe mean TRD was 595.41 ± 195.69 min in the USA group and 351.86 ± 129.51 min in the USFB group (p < 0.001). The median VAS scores for postoperative pain assessment were lower in the USFB group at 2, 4, 12 and 24 h (p < 0.05). The number of patients requiring rescue analgesia was lower in the USFB group at 6 and 12 h after surgery (p < 0.05). ConclusionPatients undergoing arthroscopic knee surgeries under USFB have an advantage when it comes to TRD as these patients have comparatively better postoperative analgesia, less requirement of rescue analgesia, early voiding of urine and early ambulation.

Ultrasound-guided single popliteal sciatic nerve block is an effective postoperative analgesia strategy for calcaneal fracture: a randomized clinical trial

ObjectivesThe aim of this study was to evaluate the postoperative analgesia effect of ultrasound-guided single popliteal sciatic nerve block for calcaneal fracture.MethodsA total of 120 patients scheduled for unilateral open reduction and internal fixation of calcaneal fracture were enrolled in this prospective randomized study. Patients in group B received ultrasound-guided single popliteal sciatic nerve block after operation, but Patients in group A did not. All patients received patient-controlled intravenous analgesia (PCIA) after operation. The time to initiation of PCIA, the time of first pressing the analgesia pump, duration of analgesia pump use and the total number of times the patient pressed the analgesia pump were recorded. The time of rescue analgesia and the adverse reactions were recorded. Pain magnitude of the patients immediately after discharge from operating room (T1), and at 4th (T2), 8th (T3), 12th (T4), 16th (T5), 24th (T6) and 48th (T7) h after the operation were assessed with visual analog scale (VAS). In addition, patient, surgeon and nurse satisfaction were recorded.ResultsThe VAS scores at T2 ~ T5, the time of rescue analgesia and the adverse reactions, the total number of times the patient pressed the analgesia pump were significantly declined in group B (p < 0.001). The time to initiation of PCIA, the time of first pressing the analgesia pump, duration of analgesia pump use were prolonged and patient surgeon and nurse satisfaction were improved in group B (p < 0.05).ConclusionUltrasound-guided single popliteal sciatic nerve block is an effective postoperative analgesia strategy for calcaneal fracture.Trial registrationChiCTR, ChiCTR2100042340. Registered 19 January 2021, URL of trial registry record: http://www.chictr.org.cn/showproj.aspx?proj=66526.