ANODYNE study: A double-blind randomized trial of greater occipital nerve block of methylprednisolone and lignocaine versus placebo as a transitional preventive treatment for episodic cluster headache.

BACKGROUND: There is inadequate evidence of the efficacy of greater occipital nerve block (GONB) for the preventive treatment of cluster headaches. We assessed the efficacy and tolerability of GONB injections as a transitional preventive treatment for episodic cluster headaches (ECH). METHODS: This randomized, double-blind, placebo-controlled, parallel-group trial conducted at GB Pant Institute of Postgraduate Medical Education and Research, New Delhi, India, included ECH patients diagnosed by ICHD-3 criteria, aged 18-65, with one or more attacks per 24 h for seven days before randomization (baseline). ECH patients were either not on preventive medications or on stable doses for at least three months. ECH patients were randomized to receive active GONB (2 ml methylprednisolone (80 mg) and 2 ml lignocaine (2%)) and placebo (4 ml saline injections). Before giving GONB, lignocaine jelly was applied topically to mask the effect of numbness following the GONB. The primary efficacy endpoint was the mean change in weekly attack frequency from baseline to Week 4. Efficacy analyses were performed in a modified intention-to-treat population that included all patients who received at least one injection of GONB and had a follow-up for one week following GONB. The safety analysis included treatment-emergent adverse effects (TEAE) in all patients who received at least one dose of investigational product. The trial was registered with the Clinical Trials Registry of India (CTRI/2021/21/038397). RESULTS: Forty ECH patients were randomized between December 2021 and January 2023. Thirty-nine patients (19 in the active and 20 in the placebo groups) were available for efficacy analysis. The change in weekly attack frequency from baseline to Week 4 was -11.1 (95% CI: -8.5 to -4.4) for the active group compared to -7.7 (95% CI: -11.8 to -9.8) for placebo (mean difference -3.4 (95% CI: -5.2 to -1.7, p < 0.001). We noted TEAE in 18 (90%) of 20 patients who received the active drug and in 18 (90%) of 20 patients who received a placebo (p = 0.38). The common TEAE were local site bleeding and pain, which were mild and transient. No serious adverse events were reported. CONCLUSION: This study found that GONB with methylprednisolone and lignocaine significantly reduced the weekly attack frequency from baseline to Week 1 through Week 4 in ECH patients compared to a placebo. GONB was well tolerated.

Ultrasound-guided genitofemoral nerve block for femoral arterial access gain and closure: a randomized controlled trial.

OBJECTIVES: This study aimed to compare the analgesic efficacy and safety of the femoral branch block of the genitofemoral nerve (FBB) versus local infiltration anesthesia (LIA) for femoral arterial access gain and closure. METHODS: Eighty-two patients (age, 64.8 ± 10.9 years; female, 30.5%) undergoing endovascular procedures using 5-Fr femoral sheath were assigned to either FBB (n = 41) or LIA (n = 41). In both groups, 2% lidocaine HCL with 1:100,000 epinephrine was used as an anesthetic solution. Pain scores during access gain and closure were evaluated using a visual analog scale (score 0-10), patient satisfaction levels with the quality of anesthesia were scored on a 7-point Likert scale, and adverse events were recorded. RESULTS: The primary endpoint, pain scores during access closure, was significantly lower in the FBB group than in the LIA group (0.1 ± 0.37 vs 1.73 ± 0.92; p < 0.001). The FBB group also had significantly lower pain scores during access gain compared to the LIA group (0.83 ± 0.83 vs 2.78 ± 1.26; p < 0.001). There was an inverse relationship between pain scores and FBB after adjustment for age, gender, and body mass index (p < 0.001). FBB group reported significantly higher satisfaction with anesthesia quality compared to the LIA group (6.49 ± 0.64 vs 4.05 ± 1.05; p < 0.001). No complications were recognized in either group. CONCLUSIONS: Ultrasound-guided genitofemoral nerve blocks offered better acute pain relief and higher patient satisfaction than LIA during femoral arterial access gain and closure. CLINICAL RELEVANCE STATEMENT: In this prospective randomized controlled trial, ultrasound-guided genitofemoral nerve blocks offered better acute pain relief than local infiltration anesthesia, resulting in enhanced patient satisfaction. KEY POINTS: • FBB provided better pain relief during access gain and closure than LIA. • FBB offered higher patient satisfaction with the quality of anesthesia than LIA. • No anesthesia-related or access site complications were recognized in either treatment group.

Endovascular revascularization of critical limb ischemia: the role of ultrasound-guided popliteal sciatic nerve block for the procedural pain management.

OBJECTIVES: To evaluate the impact of the ultrasound-guided popliteal sciatic nerve block (PSNB) for pain management during endovascular treatment of chronic limb-threatening ischemia (CLTI). MATERIAL AND METHODS: From November 2020 to January 2022, 111 CLTI patients that underwent endovascular procedures were prospectively enrolled in this prospective single-arm interventional study. Ultrasound-guided PSNB was used for procedural pain control. Pain intensity was evaluated throughout the procedure (baseline, 10 min after the block, pain peak, and at the end of the procedure) with the visual analog scale (VAS). RESULTS: Forty-six patients underwent above-the-knee revascularization (ATK), 20/111 below-the-knee (BTK) revascularization, 20/111 to both ATK and BTK revascularization. In 25 cases, no endovascular option was feasible at diagnostic angiography. The PSNB was effective in 96% of patients, with no need for further pain management with a statistically significant reduction (p < 0.0001) in the mean value of the VAS from 7.86 ± 1.81 (pre-procedural) to 2.04 ± 2.20 after 10 min from the block and up to 0.74 ± 1.43 at the end of the procedure (mean time 43 min). Only 1 complication related to the popliteal sciatic nerve block was registered (a temporary foot drop, completely resolved within 48 h). The time necessary to perform the block ranged between 4 and 10 min. CONCLUSION: Ultrasound-guided PSNB is a feasible and effective method to manage patients with rest pain and increase comfort and compliance during endovascular procedures. CLINICAL RELEVANCE STATEMENT: An ultrasound-guided popliteal sciatic nerve block is a safe, feasible, and effective technique to manage pain during endovascular treatment of chronic limb-threatening ischemia, especially in frail patients with multiple comorbidities who are poor candidates for deep sedoanalgesia or general anesthesia. KEY POINTS: Endovascular treatment of CTLI may require long revascularization sessions in patients with high levels of pain at rest, which could be exacerbated during the revascularization procedure. The PSNB is routinely used for anesthesia and analgesia during foot and ankle surgery, but the experience with lower limb revascularization procedures is very limited and not included in any international guideline. Ultrasound-guided PSNB is a feasible and effective regional anesthesia technique to relieve procedural and resting pain. Because of its safety and availability, every interventional radiologist should know how to perform this type of loco-regional anesthesia.

Assessing the effectiveness of greater occipital nerve block in chronic migraine: a systematic review and meta-analysis.

BACKGROUND & AIMS: Chronic migraine poses a global health burden, particularly affecting young women, and has substantial societal implications. This study aimed to assess the efficacy of Greater Occipital Nerve Block (GONB) in individuals with chronic migraine, focusing on the impact of local anesthetics compared with placebo. METHODS: A meta-analysis and systematic review were conducted following the PRISMA principles and Cochrane Collaboration methods. Eligible studies included case-control, cohort, and randomized control trials in adults with chronic migraine, adhering to the International Classification of Headache Disorders, third edition (ICHD3). Primary efficacy outcomes included headache frequency, duration, and intensity along with safety assessments. RESULTS: Literature searches across multiple databases yielded eight studies for qualitative analysis, with five included in the final quantitative analysis. A remarkable reduction in headache intensity and frequency during the first and second months of treatment with GONB using local anesthetics compared to placebo has been reported. The incidence of adverse events did not differ significantly between the intervention and placebo groups. CONCLUSION: The analysis emphasized the safety and efficacy of GONB, albeit with a cautious interpretation due to the limited number of studies and relatively small sample size. This study advocates for further research exploring various drugs, frequencies, and treatment plans to enhance the robustness and applicability of GONB for chronic migraine management.

Review of craniofacial pain syndromes involving the greater occipital nerve: relevant anatomy, clinical findings, and interventional management.

Craniofacial pain syndromes exhibit a high prevalence in the general population, with a subset of patients developing chronic pain that significantly impacts their quality of life and results in substantial disabilities. Anatomical and functional assessments of the greater occipital nerve (GON) have unveiled its implication in numerous craniofacial pain syndromes, notably through the trigeminal-cervical convergence complex. The pathophysiological involvement of the greater occipital nerve in craniofacial pain syndromes, coupled with its accessibility, designates it as the primary target for various interventional procedures in managing craniofacial pain syndromes. This educational review aims to describe multiple craniofacial pain syndromes, elucidate the role of GON in their pathophysiology, detail the relevant anatomy of the greater occipital nerve (including specific intervention sites), highlight the role of imaging in diagnosing craniofacial pain syndromes, and discuss various interventional procedures such as nerve infiltration, ablation, neuromodulation techniques, and surgeries. Imaging is essential in managing these patients, whether for diagnostic or therapeutic purposes. The utilization of image guidance has demonstrated an enhancement in reproducibility, as well as technical and clinical outcomes of interventional procedures. Studies have shown that interventional management of craniofacial pain is effective in treating occipital neuralgia, cervicogenic headaches, cluster headaches, trigeminal neuralgia, and chronic migraines, with a reported efficacy of 60-90% over a duration of 1-9 months. Repeated infiltrations, neuromodulation, or ablation may prove effective in selected cases. Therefore, reassessment of treatment response and efficacy during follow-up is imperative to guide further management and explore alternative treatment options. Optimal utilization of imaging, interventional techniques, and a multidisciplinary team, including radiologists, will ensure maximum benefit for these patients.

Feasibility of ultrasound-guided nerve blocks in simulated microgravity: a proof-of-concept study for regional anaesthesia during deep space missions.

BACKGROUND: With crewed deep space exploration on the horizon, preparation for potential astronaut health crises in space missions has become vital. Administration of anaesthesia and analgesia presents many challenges owing to constraints specific to space (physiologic and ergonomic challenges associated with microgravity) and nonspecific factors (isolation and lack of supplies). Regional anaesthesia can be the safest option; however, we hypothesised that the ergonomics of microgravity would compromise ease and accuracy of nerve blocks. METHODS: We evaluated the feasibility of regional anaesthesia in a simulated microgravity environment (free-floating underwater conditions) using a meat (bovine muscle) model. Forty meat models were randomised for injection under simulated microgravity or normal gravity conditions. Success rates were determined by blinded assessors after injection. Parameters assessed included time to block, ease of image acquisition, and ease of needle placement. RESULTS: The median time to block in normal gravity was 27 (interquartile range 21-69) s vs 35 (interquartile range 22-48) s in simulated microgravity (P=0.751). Ease of image acquisition was similar in both conditions, as was ease of needle placement. There was no significant difference in the rate of accidental intraneural injections (5% vs 5%), with block success rates comparable in both scenarios (80% normal gravity vs 85% microgravity, P>0.999). CONCLUSIONS: Regional anaesthesia appears feasible for experts in simulated microgravity despite the ergonomic challenges. Although our model has limitations and might not fully capture the complexities of actual space conditions, it provides a foundation for future research into anaesthesia and analgesia during deep space missions.

Intravenous versus perineural dexamethasone to prolong analgesia after interscalene brachial plexus block: a systematic review with meta-analysis and trial sequential analysis.

BACKGROUND: The efficacy of perineural vs intravenous dexamethasone as a local anaesthetic adjunct to increase duration of analgesia could be particular to specific peripheral nerve blocks because of differences in systemic absorption depending on the injection site. Given this uncertainty, we performed a systematic review with meta-analysis and trial sequential analysis comparing dexamethasone administered perineurally or intravenously combined with local anaesthetic for interscalene brachial plexus block. METHODS: Following a search of various electronic databases, we included 11 trials (1145 patients). The primary outcome was the duration of analgesia defined as the time between peripheral nerve block or onset of sensory blockade and the time to first analgesic request or initial report of pain. RESULTS: The primary outcome, duration of analgesia, was greater in the perineural dexamethasone group, with a mean difference (95% confidence interval) of 122 (62-183) min, I2=73%, P<0.0001. Trial sequential analysis indicated that firm evidence had been reached. The quality of evidence was downgraded to low, mainly because of moderate inconsistency and serious publication bias. No significant differences were present for any of the secondary outcomes, except for onset time of sensory and motor blockade and resting pain score at 12 h, but the magnitude of differences was not clinically relevant. CONCLUSIONS: There is low-quality evidence that perineural administration of dexamethasone as a local anaesthetic adjunct increases duration of analgesia by an average of 2 h compared with intravenous injection for interscalene brachial plexus block. Given the limited clinical relevance of this difference, the off-label use of perineural administration, and the risk of drug crystallisation, we recommend intravenous dexamethasone administration. SYSTEMATIC REVIEW PROTOCOL: PROSPERO (CRD42023466147).

Peripheral regional anaesthesia and outcomes: a narrative review of the literature from 2013 to 2023.

The use of peripheral regional anaesthesia continues to increase, yet the evidence supporting its use and impact on relevant outcomes often lacks scientific rigour, especially when considering the use of specific blocks for a particular surgical indication. In this narrative review, we consider the relevant literature in a 10-yr period from 2013. We performed a literature search (MEDLINE and EMBASE) for articles reporting randomised controlled trials and other comparative trials of peripheral regional anaesthetic blocks vs systemic analgesia in adult patients undergoing surgery. We evaluated measures of effective treatment and complications. A total of 128 studies met our inclusion criteria. There remains variability in the technical conduct of blocks and the outcomes used to evaluate them. There is a considerable body of evidence to support the use of interscalene blocks for shoulder surgery. Saphenous nerve (motor-sparing) blocks provide satisfactory analgesia after knee surgery and are preferred to femoral nerve blocks which are associated with falls when patients are mobilised early as part of enhanced recovery programmes. There are additional surgical indications where the efficacy of cervical plexus, intercostal nerve, and ilioinguinal/iliohypogastric nerve blocks have been demonstrated. In the past 10 yr, there has been a consolidation of the evidence indicating benefit of peripheral nerve blocks for specific indications. There remains great scope for rigorous, multicentre, randomised controlled trials of many peripheral nerve blocks. These would benefit from an agreed set of patient-centred outcomes.

Celebrating the state of the art and innovations in regional anaesthesia in the British Journal of Anaesthesia.

To coincide with the annual scientific meeting of Regional Anaesthesia UK in London 2024, where there is a joint scientific session with the British Journal of Anaesthesia, a special regional anaesthesia edition of the journal has been produced. This editorial offers some highlights from the manuscripts contained within the special edition.

Nerve block, nerve damage, and fluid injection pressure: overturning the myth.

Histological and micro-ultrasound evidence rebuffs deep-rooted views on the nature of nerve block, nerve damage, and injection pressure monitoring. We propose that the ideal position of the needle tip for nerve block is between the innermost circumneural fascial layer and outer epineurium, with local anaesthetic passing circumferentially through adipose tissue. Thin, circumferential, subepineural expansion that is invisible to the naked eye was identified using micro-ultrasound, and could account for variability of outcomes in clinical practice. Pressure monitoring cannot differentiate between intrafascicular and extrafascicular injection. High injection pressure only indicates intraneural extrafascicular spread, not intrafascicular spread, because it is not possible to inject into the stiff endoneurium in most human nerves.

Defining the optimal local anaesthetic infusion regimen for erector spinae plane block catheters: the devil is in the details.

Ni Eochagain and colleagues report that programmed intermittent bolus and continuous infusion regimens in continuous erector spinae plane (ESP) block catheters produced similar quality of recovery (QoR-15) scores, pain scores, and use of rescue opioids after video-assisted thoracic surgery. This is a reassuring finding for practitioners without access to pumps with programmed intermittent bolus functionality. Nevertheless, it remains plausible that the benefit of one regimen over another might vary depending on the specific infusion parameters. There continues to be scope for research into optimising programmed intermittent bolus delivery and dosing regimens and identifying the most appropriate clinical applications for this mode of infusion.

Programmed intermittent bolus versus continuous infusion for catheter-based erector spinae plane block on quality of recovery in thoracoscopic surgery: a single-centre randomised controlled trial.

BACKGROUND: Regional anaesthesia techniques, including the erector spinae fascial plane (ESP) block, reduce postoperative pain after video-assisted thoracoscopic surgery (VATS). Fascial plane blocks rely on spread of local anaesthetic between muscle layers, and thus, intermittent boluses might increase their clinical effectiveness. We tested the hypothesis that postoperative ESP analgesia with a programmed intermittent bolus (PIB) regimen is better than a continuous infusion (CI) regimen in terms of quality of recovery after VATS. METHODS: We undertook a prospective, double-blinded, randomised, controlled trial involving 60 patients undergoing VATS. All participants received ESP block catheters and were randomly assigned to CI or PIB of local anaesthetic regimen for postoperative analgesia. The primary outcome was Quality of Recovery-15 (QoR-15) score 24 h after surgery. Secondary outcomes included postoperative respiratory function, opioid consumption, verbal rating pain score, time to first mobilisation, nausea, vomiting, and length of hospital stay. RESULTS: Overall QoR-15 scores at 24 h after VATS were similar (PIB 115.5 [interquartile range 107-125] vs CI 110 [93-128]; Δ<6, P=0.29). The only quality of recovery descriptor showing a significant difference was nausea and vomiting, which was favourable in the PIB group (10 [10-10] vs 10 [7-10]; P=0.03). Requirement for rescue antiemetics up to 24 h after surgery was lower in the PIB group (4 [14%] vs 11 [41%]; P=0.04). There were no differences in other secondary outcomes between groups. CONCLUSIONS: Delivering ESP block analgesia after VATS via a PIB regimen resulted in similar QoR-15 at 24 h compared with a CI regimen.

Prophylactic dexamethasone for rebound pain after peripheral nerve block in adult surgical patients: systematic review, meta-analysis, and trial sequential analysis of randomised controlled trials.

BACKGROUND: Rebound pain occurs after the resolution of peripheral nerve block and hampers patient recovery in the postoperative period. We sought to synthesise available data from randomised controlled trials (RCTs) evaluating the efficacy of prophylactic dexamethasone for rebound pain in adult patients undergoing surgery with a peripheral nerve block. METHODS: In this systematic review and meta-analysis, RCTs reporting rebound pain and use of dexamethasone in the context of a peripheral nerve block were searched in various databases and updated in May 2023. The primary outcome was the incidence of rebound pain; secondary outcomes included the severity and time to onset of rebound pain, patient satisfaction with pain control, sleep disturbance because of pain, and adverse effects of dexamethasone. Subgroup analysis was conducted based on the effect of route of administration (intravenous or perineural) on the incidence of rebound pain. Trial sequential analysis was performed to rule out the possibility of a false positive result. RESULTS: Seven RCTs comprising 574 patients were included in this review. The dexamethasone group was associated with a reduction in the incidence of rebound pain with an odds ratio of 0.16 (95% confidence interval 0.10-0.27, P=0.00, I2=0%) compared with the control group. Trial sequential analysis confirmed the adequate information size for the beneficial effect of dexamethasone. Subgroup analysis showed that both intravenous and perineural administration were associated with a significant reduction in the incidence of rebound pain. CONCLUSIONS: Current evidence suggests that both intravenous and perineural dexamethasone reduce the incidence of rebound pain after a peripheral nerve block provided for postoperative analgesia. SYSTEMATIC REVIEW PROTOCOL: PROSPERO CRD42023424031.

Dose-response relationships of intravenous and perineural dexamethasone as adjuvants to peripheral nerve blocks: a systematic review and model-based network meta-analysis.

BACKGROUND: Superiority of perineural over intravenous dexamethasone at extending nerve block analgesia has been suggested but without considering the dose-response relationships for each route of administration. METHODS: Randomised control studies that evaluated intravenous or perineural dexamethasone as an adjuvant to unilateral peripheral nerve blocks in adults were searched up to October 2023 in MEDLINE, Central, Google Scholar, and reference lists of previous systematic reviews. The Cochrane Risk-of-Bias tool was used. A maximum effect (Emax) model-based network meta-analysis was undertaken to evaluate the dose-response relationships of dexamethasone. RESULTS: A total of 118 studies were selected (9284 patients; 35 with intravenous dexamethasone; 106 with perineural dexamethasone; dose range 1-16 mg). Studies with unclear or high risk of bias overestimated the effect of dexamethasone. Bias-corrected estimates indicated a maximum fold increase in analgesia duration of 1.7 (95% credible interval (CrI) 1.4-1.9) with dexamethasone, with no difference between perineural and intravenous routes. Trial simulations indicated that 4 mg of perineural dexamethasone increased the mean duration of analgesia for long-acting local anaesthetics from 11.1 h (95% CrI 9.4-13.1) to 16.5 h (95% CrI 14.0-19.3) and halved the rate of postoperative nausea and vomiting. A similar magnitude of effect was observed with 8 mg of intravenous dexamethasone. CONCLUSIONS: Used as an adjuvant for peripheral nerve block, intravenous dexamethasone can be as effective as perineural dexamethasone in prolonging analgesic duration, but is less potent, hence requiring higher doses. The evidence is limited because of the observational nature of the dose-response relationships and the quality of the included studies. SYSTEMATIC REVIEW PROTOCOL: PROSPERO CRD42020141689.

The use of granisetron on bupivacaine induced sciatic nerve block in rats.

PURPOSE: The effects of the 5-hydroxytryptamine (5-HT3) receptor antagonists on regional anaesthesia are complex and unclear. The present study was designed to test the hypothesis that granisetron, a selective 5-HT3 receptor antagonist, would decrease the duration of motor block, sensory block, and proprioception in a dose-dependent fashion in a rat model of bupivacaine-induced sciatic nerve blockade. MATERIALS AND METHODS: Thirty-eight male Wistar Albino rats that received unilateral sciatic nerve blocks were randomly divided into five experimental groups. Group B received a perineural of 0.3 ml of bupivacaine alone; Group BG800 received perineural 0.3 ml of bupivacaine and 800 µg of granisetron 10 min later; Group BG1200 received perineural 0.3 ml of bupivacaine and 1200 µg of granisetron 10 min later; Group BG1200IP received a perineural 0.3 ml of bupivacaine and an intraperitoneal injection of 1200 µg of granisetron 10 min later; and Group S was sham operated. A blinded investigator assessed motor, sensory and proprioception function every 10 min until the return of normal function. RESULTS: The medians for recovery times in Group B, Group BG800, Group BG1200, and Group BG1200IP were 105, 64, 85, and 120 min for motor function, respectively; 80, 64, 84, and 104 min for sensory function; 80, 63, 85, and 108 min were calculated for the proprioception function. The time to the return of normal motor, sensory, and proprioception function was not statistically significantly different between the groups (p > 0.05). Motor block did not develop in any of the rats in Group S. CONCLUSIONS: Local and systemic application of granisetron was not significantly decrease the duration of bupivacaine induced motor, sensory, and proprioception block of sciatic nerve in rat.

Ultrasound-guided selective glossopharyngeal nerve block: posterior mandibular ramus approach.

OBJECTIVE: Glossopharyngeal nerve block is a useful interventional technique for pain management of the head and neck. It is performed with landmark techniques or ultrasound guidance. We propose a novel ultrasound-guided glossopharyngeal nerve block technique. METHODS: This new approach was performed in 3 patients in their twenties and thirties. A needle was inserted deeply under the stylohyoid muscle through the sternocleidomastoid muscle. Subsequently, an ultrasound-guided nerve block was performed with 1 mL of 1% xylocaine. The performance of our technique was evaluated with 2 tests: a cold sensitivity test and a gag reflex test. RESULTS: The effect of the nerve block was observed in the posterior third of the tongue on both sides, the tonsils, and the pharyngeal region. The effect lasted for approximately 1.5 hour. Motor efferent block was not observed. CONCLUSIONS: We designated the technique as ultrasound-guided selective glossopharyngeal nerve block: posterior mandibular ramus approach. No complications occurred during the bilateral application. This novel approach can be performed at a very shallow position, compared with conventional methods. There is no damage to tissues other than the muscles, which reduces postoperative complications and patient distress. Although our technique requires further safety assessments and technical refinements, it could represent a simpler alternative to conventional methods in daily clinical practice.

Introducing a novel intraoral mandibular nerve block technique for loco-regional analgesia in camels (Camelus dromedarius): a cadaveric study using computed tomography.

The aim of this study was to introduce a novel intraoral technique for performing mandibular nerve blocks in dromedary camels (Camelus dromedarius). In this study, 18 adult camel skulls of varying ages and breeds were examined to determine the position of the mandibular foramen. Using a Vernier caliper, three dimensions in millimeters were measured: (1) the distance between the mandibular foramen (MF) and the caudal edge of the third molar tooth at the occlusal surface level, (2) the distance between the MF and the rostral edge border of the mandible's ramus (RER) at the occlusal surface level, and (3) the distance between the MF and the ventral margin border of the mandible (VM). The technique was evaluated using five intact camel cadaver heads (n = 5), and a total of ten mandibular nerve blocks were described. An 18-gauge 80-mm Tuohy needle was inserted into the mouth commissure and advanced caudally while injecting a saline-methylene blue solution. The accuracy of the injection was confirmed through the infiltration of the contrast dye into the target area using computed tomography (CT) and post procedural dissection. Anatomical study of the mandibular nerve site was performed to aid the blind insertion of the needle. The findings contribute to the development of veterinary anesthesia techniques and provide anatomical considerations for clinicians performing oral surgeries in sedated camels. The results demonstrated the successful implementation of the intraoral technique, highlighting its efficacy and reliability in achieving local anesthesia for oral surgeries involving the lower jaw and teeth in sedated camels. Further research studies are needed to evaluate the long-term efficacy and safety of the technique and to compare it with existing approaches.

A novel extraoral ultrasound-guided approach for mandibular nerve block in Rahmani sheep.

BACKGROUND: Regional anesthesia is the favored choice in ruminant animals compared to general anesthesia, primarily due to its high safety margin and reduced demand for cost-intensive equipment in addition to its field applicability. Ultrasound-guided nerve block has gained significant attention in the field of veterinary medicine. This study utilized twenty-seven sheep of the native Rahmani breed to both demonstrate and evaluate the effectiveness of the ultrasound guided inferior alveolar nerve block technique. METHODS: The research comprised three phases: Phase 1 involved an anatomical examination of mandibles and sheep heads to locate the mandibular foramen and delineate the mandibular nerve course. Phase 2 included ultrasound-guided injection of methylene blue dye at specific sites along the mandibular nerve in cadaveric sheep heads. In Phase 3, clinical implementation of ultrasound-guided inferior alveolar nerve blocks was conducted in 27 live sheep, assessing efficacy, onset, and duration. RESULTS: Vertical extraoral ultrasound-guided nerve block was achieved successfully in 25 sheep (98%). A preliminary cadaveric study showed good distribution of the injectate at the mandibular nerve site. The mean onset time was 138 ± 18 s, and the mean duration time was 54 ± 4.1 min. Prominent analgesia of the ipsilateral mandible, medial surface of the cheek, and lateral border of the tongue was observed. CONCLUSIONS: Ultrasound-guided mandibular nerve block holds promise as a technique for providing effective and safe anesthesia in sheep undergoing mandibular procedures.

Evaluating Pain Management from Peripheral Nerve Block for Geriatric Patients following Bipolar Hemiarthroplasty for Displaced Femoral-Neck Fracture.

INTRODUCTION: The purpose of this study was to evaluate peripheral nerve block (PNB) effectiveness in postoperative pain management and surgical outcomes for displaced femoral-neck fracture in geriatric patients (>70 years) who underwent bipolar hemiarthroplasty (BHA). METHODS: From January 2017 to December 2021, 231 geriatric patients with displaced femoral-neck fracture who consecutively underwent BHA were retrospectively reviewed. Patients were divided into two groups: the patient-controlled analgesia (PCA) group (n = 132) who received only intravenous (IV) PCA for postoperative pain management, and all others who received PNB with IV PCA (PNB+PCA) such as femoral nerve block or fascia iliaca compartment block after surgery (n = 99). Primary outcomes were postoperative visual analog scale (VAS) at rest and during activity at 6, 24, and 48 h postoperatively. Secondary outcomes were postoperative complications, changes in hemoglobin, length of hospital stay, and total morphine usage after surgery. RESULTS: Postoperative resting VAS at 6 h and 48 h was significantly lower in the PNB+PCA group compared with the PCA group (p = 0.075, p = 0.0318, respectively). However, there was no significant difference in either resting VAS at 24 h or active VAS. Complications of pneumonia and delirium until 1 month postoperative were significantly lower in the PNB + PCA group than the PCA group (p = 0.0022, p = 0.0055, respectively). CONCLUSION: PNB with IV PCA seems to have a beneficial effect on geriatric femoral-neck patients who underwent BHA with postoperative analgesia for reducing postoperative resting pain and complications, especially pneumonia and delirium.

Mixing short- and long-acting local anaesthetics in peripheral nerve blocks: Protocol for a systematic review and meta-analysis.

INTRODUCTION: This protocol describes a systematic review and meta-analysis to evaluate the clinical effects of mixing short- and long-acting local anaesthetics in peripheral nerve blocks. Clinicians often combine short- and long-acting local anaesthetics to achieve a briefer onset time. However, this may come with a prize, namely a shorter total duration of the block, which is of clinical importance. OBJECTIVE: This systematic review aims to strengthen the knowledge of the clinical effects associated with this practice. The primary outcome is the duration of block analgesia. Secondary outcomes are block onset time, sensory and motor block duration. Exploratory outcomes are postoperative pain scores, cumulative 24-h opioid consumption and the prevalence of serious adverse events. METHODS: We will conduct a meta-analysis of the extracted data, and the risk of bias for each study will be evaluated. We will perform a Trial Sequential Analysis, subgroup, and sensitivity analyses and assess the overall risk of publication bias. Finally, we will evaluate the review using the GRADE principles.