Sciatic nerve block

Peripheral nerve blockade (PNB) is a conventional strategy for the management of acute postoperative pain. However, the short duration of the associated analgesia and the potential systemic toxicity due to the low molecular weights of local anesthetics limit their application. Methods: An in situ forming injectable Gel-microsphere (Gel-MS) system consisting of PLGA-PEG-PLGA Gel (Gel) and Gel-immobilized bupivacaine-loaded microsphere (MS/BUP) was prepared for precision-guided long-acting analgesia. A series of in vitro characterizations, such as scanning electron microscopy, rheology analysis, confocal laser scanning microscopy, drug release, and erosion and degradation, were carried out...

BACKGROUND: Management of neuropathic pain is a real clinical challenge. Despite intense investigation, the mechanisms of neuropathic pain remain substantially unidentified. Matrix metalloproteinase (MMP)-9 and MMP-2 have been reported to contribute to the development and maintenance of neuropathic pain. Therefore, inhibition of MMP-9/2 may provide a novel therapeutic approach for the treatment of neuropathic pain. In this study, we aim to investigate the effect of procyanidins (PC), clinically used health product, on MMP-9/2 in neuropathic pain...

BACKGROUND AND OBJECTIVES: Although intravenous lipid emulsion has been proved a powerful antidote for local anesthetic toxicity, there are few pharmacokinetic data on using lipid infusion as a pretreatment for other clinical applications. We assessed the influence of lipid pretreatment on the pharmacodynamics and pharmacokinetics of levobupivacaine. METHODS: Altogether, 12 patients undergoing below-knee surgery for a fracture were randomly assigned to 2 groups (6 patients per group): pretreatment with 1...

Since Cav 3.2 T-type Ca2+ channels (T-channels) expressed in the primary afferents and CNS contribute to intractable pain, we explored T-channel-blocking components in distinct herbal extracts using a whole-cell patch-clamp technique in HEK293 cells stably expressing Cav 3.2 or Cav 3.1, and purified and identified sophoraflavanone G (SG) as an active compound from SOPHORAE RADIX (SR). Interestingly, hop-derived SG analogues, (2S)-6-prenylnaringenin (6-PNG) and (2S)-8-PNG, but not naringenin, also blocked T-channels; IC50 (μM) of SG, (2S)-6-PNG and (2S)-8-PNG was 0...

BACKGROUND AND OBJECTIVES: Percutaneous peripheral nerve stimulation (PNS) is an analgesic modality involving the insertion of a lead through an introducing needle followed by the delivery of electric current. This modality has been reported to treat chronic pain as well as postoperative pain the day following knee surgery. However, it remains unknown if this analgesic technique may be used in ambulatory subjects following foot procedures beginning within the recovery room immediately following surgery, and with only short series of patients reported to date, the only available data are derived from strictly observational studies...

BACKGROUND AND AIM: The severe pain after total knee arthroplasty (TKA) brings many patients more suffering, longer hospital stay and higher expenses. This study was designed to assess the relative efficacy of several clinical treatments for postoperative analgesia of TKA through network meta-analysis (NMA) based on multiple published randomized controlled trials. METHODS: Embase and PubMed were utilized to conduct this network meta-analysis from inception until 2016...

Injection pressure monitoring provides valuable information to prevent intraneural injections and possibly consequent nerve damage during peripheral nerve block. However, the measurement of injection pressure along the injection line is inaccurate as it is influenced by several variables. The aim of this study was to test a new system for precise injection pressure monitoring at the needle tip in a cadaveric model. The system consists of a miniaturised pressure sensor embedded within the needle shaft that is connected via an optical fibre to an external control unit...

Animal data have demonstrated increased block duration after local anaesthetic injections in diabetic rat models. Whether the same is true in humans is currently undefined. We, therefore, undertook this prospective cohort study to test the hypothesis that type-2 diabetic patients suffering from diabetic peripheral neuropathy would have increased block duration after ultrasound-guided popliteal sciatic nerve block when compared with patients without neuropathy. Thirty-three type-2 diabetic patients with neuropathy and 23 non-diabetic control patients, scheduled for fore-foot surgery, were included prospectively...

INTRODUCTION: An obturator nerve block (ONB) and a femoral triangle block (FTB) provide effective analgesia after total knee arthroplasty (TKA) without impeding the ambulation, although the ONB produces motor blockade of the hip adductor muscles. The popliteal plexus (PP) in the popliteal fossa is formed by contribution from the tibial nerve and the posterior obturator nerve, innervating intraarticular genicular structures and the posterior capsule of the knee. We hypothesised that a popliteal plexus block (PPB) as a supplement to an FTB would reduce pain after TKA without anaesthetising motor branches from the sciatic nerve in the popliteal fossa...

BACKGROUND: Combining continuous femoral nerve blockade with single injection sciatic nerve blockade is standard peripheral nerve block practice for total knee arthroplasty (TKA) during the first 24 postoperative hours. OBJECTIVES: To assess the analgesic benefits and mobilisation capability of continuous sciatic blockade in conjunction with continuous femoral nerve blockade for 72 h after arthroplasty. DESIGN: Randomised, triple-blinded controlled trial...

Schwannoma is a common neoplasm in the peripheral and central nervous systems. Sciatic nerve schwanommas are rare. We report the case of a 50-year-old woman who was referred for treatment of persistent neuropathic pain in the left lower limb after resection of a schwannoma on the left S1 nerve root. The patient's history goes back when she was 27 years old and started to have electric-like pain in her lower left limb upon intercourse. Examination revealed a left ovarian cyst which was surgically removed. Her pain persisted despite taking nonsteroidal anti inflammatory drugs (NSAIDs)...

Postsynaptic density-95 (PSD-95) is a synaptic scaffolding protein that plays a crucial role in the development of neuropathic pain. However, the underlying mechanism remains unclear. To address the role of PSD-95 in N-methyl-D-aspartate receptor subtype 2B (NR2B) -mediated chronic pain, we investigated the relationship between PSD-95 activation and NR2B function in the spinal cord, by using a rat model of sciatic nerve chronic constriction injury (CCI). We demonstrate that the expression levels of total PSD-95 and cAMP response element binding protein (CREB), as well as phosphorylated NR2B, PSD-95, and CREB, in the spinal dorsal horn, and the interaction of NR2B with PSD-95 were increased in the CCI animals...

BACKGROUND: Both extra- and intraneural sciatic injection resulted in significant axonal nerve damage. This study aimed to establish the minimum effective volume of intraneural ropivacaine 1% for complete sensory-motor sciatic nerve block in 90% of patients, and related electrophysiologic variations. METHODS: Forty-seven consecutive American Society of Anesthesiologists physical status I-II patients received an ultrasound-guided popliteal intraneural nerve block following the up-and-down biased coin design...

BACKGROUND: During several anesthesiological procedures, needles are inserted through the skin of a patient to target nerves. In most cases, the needle traverses several tissues-skin, subcutaneous adipose tissue, muscles, nerves, and blood vessels-to reach the target nerve. A clear identification of the target nerve can improve the success of the nerve block and reduce the rate of complications. This may be accomplished with diffuse reflectance spectroscopy (DRS) which can provide a quantitative measure of the tissue composition...

MicroRNAs have been implicated in nerve injury and neuropathic pain. In the previous study we had shown that miR-96 can attenuate neuropathic pain through inhibition of Nav1.3. In this study, we investigated the role of miR-183, a same cluster member of microRNA with miR-96, in neuropathic pain and its potential mechanisms. We found that the expression level of miR-183-5p in dorsal root ganglion was decreased with the development of neuropathic pain induced by chronic constriction sciatic nerve injury (CCI)...

Nerve blocks are frequently performed by anesthesiologists to control pain. For sciatic nerve blocks, the optimal placement of the needle tip between its paraneural sheath and epineurial covering is challenging, even under ultrasound guidance, and frequently results in nerve puncture. We performed needle penetration tests on cadaveric isolated paraneural sheath (IPS), isolated nerve (IN), and the nerve with overlying paraneural sheath (NPS), and quantified puncture force requirement and fracture toughness of these specimens to assess their role in determining the clinical risk of nerve puncture...

BACKGROUND: Autoimmune neuropathies are common PNS disorders and effective treatment is challenging. Environmental influence and dietary components are known to affect the course of autoimmune diseases. Capsaicin as pungent component of chili-peppers is common in human nutrition. An influence of capsaicin on autoimmune diseases has been postulated. METHODS: We tested capsaicin in the animal model of experimental autoimmune neuritis (EAN) in Lewis rat. Rats were immunized with P2-peptide and were treated with capsaicin in different preventive settings...

BACKGROUND AND OBJECTIVES: Major ankle surgery causes intense postoperative pain, and whereas the importance of a sciatic nerve block is well established, the clinical significance of a supplemental saphenous nerve block has never been determined in a prospective, randomized, double-blind, placebo-controlled trial. We hypothesized that a saphenous nerve block reduces the proportion of patients experiencing significant clinical pain after major ankle surgery. METHODS: Eighteen patients were enrolled and received a popliteal sciatic nerve block...

Both local infiltration analgesia (LIA) and nerve block are common analgesic modalities for pain relief after surgery. The aim of the current study was to investigate the effects of those two modalities on pain behavior and the expression of pro-inflammatory cytokines such as interleukin (IL)-1β and IL-6 and tumor necrosis factor-α (TNF-α) in the spinal cord and dorsal root ganglion (DRG) in a rat model of perioperative fentanyl induced hyperalgesia. Rats were injected with fentanyl (60 μg/kg) 4 times and received a plantar incision after the second injection or they received pre-incision LIA and sciatic nerve block (SNB) or post-incision LIA with levobupivacaine (0...

BACKGROUND AND OBJECTIVES: Various animal models have historically been used to study iatrogenic nerve injury during performance of conduction nerve blocks. Our aims were to compare the microstructures of nerves in commonly used species to those of humans and to explore the validity of the extrapolating these findings to humans. METHODS: High-resolution, light-microscopic images were obtained from cross sections of sciatic nerves at their bifurcation from fresh rat, rabbit, pig, sheep, dog, and human cadavers...