PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Nerve Block”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 127 records · Page 7Linked to original sources

Evidence that spinal segmental nitric oxide mediates tachyphylaxis to peripheral local anesthetic nerve block.

BACKGROUND: Tachyphylaxis to sciatic nerve blockade in rats correlates with hyperalgesia. Spinal inhibition of nitric oxide synthase with N(G)nitro-L-arginine methyl ester (L-NAME) has been shown to prevent hyperalgesia. Given systemically, L-NAME also prevents tachyphylaxis. The action of L-NAME in preventing tachyphylaxis therefore may be mediated at spinal sites. We compared systemic versus intrathecal potency of L-NAME in modulating tachyphylaxis to sciatic nerve block. METHODS: Rats were prepared with intrathecal catheters. Three sequential sciatic nerve blocks were placed. Duration of block of thermal nocifensive, proprioceptive and motor responses was recorded. We compared spinal versus systemic dose-response to L-NAME, and examined effects of intrathecal arginine on tachyphylaxis. An additional group of rats underwent testing after T10 spinal cord transection. In these rats duration of sciatic nerve block was assessed by determining the heat-induced flexion withdrawal reflex. RESULTS: L-NAME was 25-fold more potent in preventing tachyphylaxis given intrathecally than intraperitoneally. Intrathecal arginine augmented tachyphylaxis. Spinalized rats exhibited tachyphylaxis to sciatic block. CONCLUSION: The increased potency of intrathecal versus systemic L-NAME suggests a spinal site of action in inhibiting tachyphylaxis. Descending pathways are not necessary for the development of tachyphylaxis since it occurs even after T10 spinal cord transection. Thus tachyphylaxis, like hyperalgesia, is mediated at least in part by a spinal site of action.

Anesthetics, Local↗

Reevaluation of the sciatic nerve block.

BACKGROUND AND OBJECTIVES: Sciatic nerve blocks are perceived as unreliable, technically demanding, and uncomfortable. With strict criteria to define success rates, we designed a study to examine the efficacy of two techniques of sciatic nerve block. METHODS: All blocks were performed by a novice in sedated patients using an insulated needle and a nerve stimulator. RESULTS: Overall success with both techniques was 87.5%. One transient neurologic deficit attributed to the sciatic nerve block was observed; otherwise, the technique provided satisfactory anesthesia without complications. CONCLUSIONS: Patient acceptance was excellent.

Adult↗

[Continuous versus single-dose sciatic nerve block to complement a femoral block after total knee replacement surgery: a randomized clinical trial].

INTRODUCTION: Performing a sciatic nerve block to complement a continuous femoral nerve block for analgesia after total knee arthroplasty is a subject of controversy. We compared the efficacy of a continuous sciatic nerve block to that of a single-dose block of the same nerve combined with a continuous femoral nerve block. MATERIAL AND METHODS: Patients received a continuous femoral nerve block by infusion of 0.2% ropivacaine, 0.4 mL x kg(-1), plus patient controlled analgesia and were randomized to receive a sciatic nerve block either by continuous infusion (0.5% ropivacaine, 20 mL, plus continuous infusion of 5 mh(-1)) or by a single 20 mL dose of 0.5% ropivacaine. The stimulating catheters remained indwelling for 72 hours after the operation. The main outcome measure was assessment of postoperative pain on a verbal numerical scale from 0 (no pain) to 10 (greatest pain) at rest and upon movement. RESULTS: The pain assessments upon movement of the operated joint were significantly greater after 24 hours in the group receiving a single dose of ropivacaine to block the sciatic nerve. The back of the knee was most often named as the location of pain. No adverse effects related to the analgesic technique were recorded, and the level of satisfaction was higher among patients receiving the continuous sciatic nerve block. CONCLUSION: Twenty-four hours after total knee replacement surgery, better analgesia was achieved with a continuous sciatic nerve block than with a single-dose block combined with a continuous femoral nerve block.

Aged↗

Treatment of acquired muscle spasticity using phenol peripheral nerve blocks.

The use of phenol motor nerve blocks is advantageous in the early period of acquired spasticity (ie, that occurring following traumatic brain injury or incomplete spinal cord injury), when increased muscle tone is often the most severe. Because acquired spasticity is dynamic and usually improves slowly, a temporary treatment method used to ameliorate increased muscle tone is desirable. Phenol nerve infiltration provides a temporary motor nerve block that lasts for weeks or months. It allows passive limb mobilization in a comprehensive rehabilitation program that attempts to prevent fixed soft tissue contractures. Permanent or irreversible methods such as operative tendon lengthening, muscle release or recession, or neurectomy are usually best delayed until the spasticity has become static, when the need for surgical correction becomes more firmly indicated, and outcomes of operative intervention are more predictable. Although phenol nerve blocks were initially administered at the spinal cord level to control spasticity, the potential side effects have caused a loss of popularity of this method of administration. The safer and more common use of phenol infiltration at the peripheral nerve level is now more accepted for brain injury and spinal cord injury patients. This report reviews the indications, current concepts, and development of the different methods used to administer phenol nerve blocks. Comparisons to other methods to control spasticity are discussed.

Animals↗

Anesthesia for neonatal circumcision: local anesthesia is better than dorsal penile nerve block.

Several studies document the benefit of dorsal penile nerve block for neonatal circumcision, but the literature does not address the use of local anesthesia. A randomized, controlled, prospective study was conducted to compare the efficacy of dorsal penile nerve block versus local anesthesia. Thirty infants were randomly divided into three equal groups (N = 10): an unanesthetized control group, a group given dorsal penile nerve block, and a group given local anesthesia. Heart rate, transcutaneous oxygen saturation, and crying were monitored continuously before, during, and after circumcision. During circumcision, both the dorsal penile nerve block group and the local-anesthesia group demonstrated smaller increases in heart rate, smaller drops in oxygen saturation, and less crying compared with unanesthetized controls (P less than .05). Both techniques worked well in anesthetizing the dorsal aspect of the penis; however, during those steps of circumcision involving trauma to the ventral aspect of the penis, the local-anesthesia group demonstrated smaller increases in heart rate and less crying compared with infants given dorsal penile nerve block (P less than .05). Cortisol levels measured 30 minutes postoperatively were lower in the local-anesthesia group than in either the controls or the dorsal penile nerve block group (P less than .05). Dorsal penile nerve block had no effect on postoperative cortisol levels. No complications occurred. Although both types of anesthesia attenuated the physiologic responses to circumcision, local anesthesia demonstrated greater efficacy than dorsal penile nerve block while being simpler to perform.

Anesthesia, Local↗

Lateral popliteal sciatic nerve block: a single injection targeting the tibial branch of the sciatic nerve is as effective as a double-injection technique.

BACKGROUND: Evidence indicating that single- and double-injection techniques for inducing a sciatic nerve block via a posterior subgluteal approach yield a similar success rate prompted us to investigate whether the two anesthetic techniques yield a similar success rate via a lateral approach. We also hypothesized that, owing to the peculiar anatomic features of the sciatic nerve at the popliteal level, a single injection via the lateral approach might induce effective anesthesia by targeting the tibial nerve only. METHODS: Ninety-six patients undergoing popliteal sciatic nerve block via a lateral popliteal approach for foot surgery were randomized to receive a single 30-ml injection of ropivacaine 7.5 mg/ml to block the tibial nerve (TN group, n= 32) or the common peroneal nerve (CPN group, n= 32), or two separate 15-ml injections (TN + CPN group, n= 32), after stimulation to evoke motor responses from the target nerves. RESULTS: The mean time to obtain a complete sensory blockade (surgical anesthesia) was shorter in the TN group than in the CPN and TN + CPN groups (14 +/- 7 min vs. 23 +/- 17 and 21 +/- 14 min, respectively; P < 0.05). The success rate was similar in the TN and TN + CPN groups (94%) and, 25 min after the initial injection, was already better in these groups than in the CPN group (94% vs. 75%; P < 0.05). CONCLUSIONS: A lateral popliteal sciatic nerve block obtained with a single 30-ml injection of ropivacaine 7.5 mg/ml after electrostimulation to locate the tibial nerve is as effective as multiple TN + CPN stimulation and injection, and local anesthesia has a significantly shorter onset time.

Amides↗

A treatment of detrusor-sphincter dyssynergia: pudendal nerve block by phenolglycerin under the guide of direct nerve stimulation.

While applying direct electrical stimulation to the pudendal nerve and recording of electromyographic reactions of bulbocavernosus muscle and/or transverse perineal muscle, pudendal nerve block by phenol was performed for the treatment of dysuria due to detrusor-sphincter dyssynergia, resulting in a favourable response. The technique and the cases treated with this nerve block are presented.

Adult↗

Effects of bilateral hypoglossal and glossopharyngeal nerve blocks on epiglottic and soft palate position in exercising horses.

OBJECTIVE: To determine the effect of bilateral hypoglossal and and glossopharyngeal nerve block on epiglottic and soft palate position and tracheal and pharyngeal pressures in exercising horses. ANIMALS: 5 Standardbreds. PROCEDURE: Tracheal and pharyngeal pressures were measured in 5 Standardbreds exercising at the speed at which the horses achieved 50, 75, and 100% of maximal heart rate after bilateral hypoglossal and glossopharyngeal nerve block and without nerve block. Nerve block was achieved by injection of 1 to 2 ml of 2% mepivicaine hydrochloride between the glossopharyngeal and hypoglossal nerves, as they coursed through the medial compartment of the diverticulum of the auditory tube (guttural pouch), using videoendoscopic guidance and an injection apparatus. RESULTS: Compared with control values, peak inspiratory tracheal pressure was significantly (P = 0.02) more negative, and peak pharyngeal inspiratory pressure was less negative (P = 0.004) after bilateral hypoglossal and glossopharyngeal nerve block. Respiratory frequency was significantly (P = 0.024) lower after nerve block, compared with control values. The epiglottis was unstable and retroflexed through the rima glottis during inspiration after bilateral hypoglossal and glossopharyngeal nerve block. Despite loss of contact between the epiglottis and the caudal free margin of the soft palate, dorsal displacement of the soft palate did not occur. CONCLUSIONS AND CLINICAL RELEVANCE: Loss of contact of the epiglottis with the soft palate did not affect soft palate position, suggesting that when the soft palate is normal, the epiglottis does not function as a support, holding the soft palate in a ventral position. Therefore, epiglottic dysfunction is not solely responsible for intermittent dorsal displacement of the soft palate in horses, and neuromuscular dysfunction involving the hyoepiglotticus muscle, geniohyoideus muscle, or the hypoglossal nerve may cause epiglottic retroflexion in horses.

Animals↗

Sciatic nerve block under fluoroscopic guidance.

Sciatic nerve block under fluoroscopic guidance was performed in 17 patients. This anesthetic technique along with femoral nerve block was found to be effective in patients having unilateral femoral arteriography or occlusive arteriography of their extremities. No complication was encountered in this group of patients.

Bupivacaine↗

[Experiences with continuous nerve block of the wrist].

Continuous nerve blocks are effective analgesics for physiotherapy following operative procedures on gliding tissues. In the upper extremity, continuous axillary blocks are regularly used, leading to weak muscular action and even paralysis, although active muscle action is wanted. With continuous wrist blocks, extrinsic motor function of the hand remains undisturbed. Placement of a polyethylene catheter near the nerves with instillation of a local anesthetic (carbostesine 0.5, 3-4 ml per nerve) provides complete anesthesia of the hand without loss of extrinsic motor function. After 124 nerve blocks in 60 patients, no complications (infections, nerve irritations or lesions) have been observed. Continuous wrist blocks are indicated for postoperative treatment after tenolysis, joint mobilisation or arthrolysis, open reduction and internal fixation and in certain cases of chronic pain care.

Analgesia↗

Does a regional nerve block change cutaneous perception thresholds outside the anaesthetic area? Implications for the interpretation of diagnostic blocks.

The present study was performed on pain-free subjects and patients to analyse if local anaesthetics (LA) normally used for nerve blocks in the orofacial region resulted in generalised changes in cutaneous somatosensory perception thresholds outside the territory of the primarily blocked nerve. Five subjects received an intra-oral nerve block and 5 patients received epidural anaesthesia, serving as a reference group considering the larger amounts of LA used in this latter type of anaesthesia. No differences (after vs. prior to LA) were detected regarding thresholds to tactile, cold, warmth or heat pain stimuli in skin areas outside the regions directly blocked. This was also true for the difference limens between warm-cold thresholds. Our data do not indicate any generalised influence on tactile, thermal and pain perception thresholds in pain-free subjects.

Adult↗

Peripheral nerve blocks improve analgesia after total knee replacement surgery.

UNLABELLED: Total knee replacement (TKR) produces severe postoperative pain. Peripheral nerve blocks can be used as analgesic adjuncts for TKR, but the efficacy of femoral nerve blocks alone is controversial. The sciatic nerve innervates posterior regions of the knee; thus, performance of both sciatic and femoral nerve blocks may be necessary to improve analgesia after TKR. We performed this study to determine whether peripheral nerve blocks improve analgesia after TKR. In a randomized, double-blind fashion, 36 patients undergoing TKR received either femoral, sciatic-femoral, or sham nerve blocks after a standardized spinal anesthetic. Further postoperative analgesia was provided by patient-controlled i.v. morphine and ketorolac. Pain at rest and with physical therapy, morphine use, nausea, pruritus, sedation, and patient satisfaction were assessed. Patients receiving peripheral nerve blocks reported better analgesia at rest for at least 8 h after transfer to the hospital ward (P < 0.05). Morphine use was decreased by approximately 50% in the peripheral nerve block groups until the second postoperative day (P < 0.02). Side effect profiles and patient satisfaction were similar between groups. We conclude that femoral nerve blocks improve analgesia and decrease morphine use after TKR. The addition of a sciatic nerve block to the femoral nerve block did not further improve analgesic efficacy. IMPLICATIONS: Performance of femoral nerve blocks improves analgesia and decreases the need for morphine after total knee replacement surgery. The addition of a sciatic nerve block to the femoral nerve block does not provide additional benefits.

Aged↗

[Combined block of femoral, sciatic, obturator nerves and lateral cutaneous nerve block with ropivacaine for leg amputation above the knee].

A 76-yr-old male presented for leg amputation above the knee. The patient complained of dyspnea due to pulmonary embolism occurring 3 weeks before operation. In addition, the patient could not report paresthesias because he had suffered from a cerebral infarction. Anesthesia was performed with combined block of femoral, sciatic, obturator nerves and the lateral cutaneous nerve of the thigh. The nerves were anesthetized with 0.75% ropivacaine solution 31 ml by use of an electrical nerve stimulator and an insulated needle. Nerve stimulation technique is the best choice for patients who are unable to report paresthesias reliably.

Aged↗

Nerve blocks around the knee in children.

Analgesia below the knee can be achieved by blocking the tibial nerve and the common peroneal nerve in the popliteal fossa, and the saphenous nerve adjacent to the knee. The anatomy and technique of nerve block in the popliteal fossa is described, the nerve being located prior to blockade using a peripheral nerve stimulator. The block as described has been used in children for postoperative analgesia, as a diagnostic block, and as an adjunct to the physiotherapy management of severe equinus deformity after brain injury.

Child↗

Use of the peripheral nerve stimulator and standard, unsheathed needles in performing regional nerve blocks.

Although the use of peripheral nerve stimulators and unsheathed needles in performing nerve blocks has been previously described, there has been a growing emphasis on the use of specific, expensive equipment to ensure success. The availability of equipment designed for use in peripheral nerve blocks, insulated needles and nerve stimulators, will help promote the use of these techniques, but the expense of purchasing this specialized equipment may contribute to a decline in performance of certain types of blocks. This article reviews the use of standard equipment, available in most anesthesia departments, for performing peripheral nerve blocks successfully.

Electric Stimulation↗

Current uses of open phenol nerve block for adult acquired spasticity.

Forty-nine open phenol nerve injections were performed for acquired spasticity during a five-year period. The most common etiology of acquired spasticity was closed head injury (70%). Thirteen phenol injections to the musculocutaneous nerve were performed for excessive elbow flexion. The immediate results were absence of biceps and brachialis muscle activity, and an average gain of 43 degrees in extension. The effects of the nerve block subsided within six months. Nine nerve blocks were followed for more than one year. In two patients the upper extremities were almost normal. In the remaining seven the upper extremities were nonfunctional. Twenty-eight phenol injections to the posterior tibial nerve were performed for uncontrolled excessive plantar flexion and/or fixed equinus. The immediate result was cessation of gastrocnemius and soleus activity. Twenty-seven ankles attained a neutral position. The effects of the nerve block subsided within six months. Thirteen patients with 19 blocks were followed for more than eight months. Nine patients underwent lengthening of the Achilles tendon and six patients required orthotic devices for control of plantar flexion spasticity. In general, patients with acquired spasticity who require open phenol nerve blocks are unlikely to have normal functioning extremities when the effects of the nerve block have subsided.

Adolescent↗

Ultrasonography for ilioinguinal/iliohypogastric nerve blocks in children.

BACKGROUND: The ilioinguinal/iliohypogastric nerve block is a popular regional anaesthetic technique for children undergoing inguinal surgery. The success rate is only 70-80% and complications may occur. A prospective randomized double-blinded study was designed to compare the use of ultrasonography with the conventional ilioinguinal/iliohypogastric nerve block technique. METHODS: One hundred children (age range, 1 month-8 years) scheduled for inguinal hernia repair, orchidopexy or hydrocele repair were included in the study. Following induction of general anaesthesia, the children received an ilioinguinal/iliohypogastric block performed either under ultrasound guidance using levobupivacaine 0.25% until both nerves were surrounded by the local anaesthetic or by the conventional 'fascial click' method using levobupivacaine 0.25% (0.3 ml kg(-1)). Additional intra- and postoperative analgesic requirements were recorded. RESULTS: Ultrasonographic visualization of the ilioinguinal/iliohypogastric nerves was possible in all cases. The amount of local anaesthetic used in the ultrasound group was significantly lower than in the 'fascial click' group (0.19 (SD 0.05) ml kg(-1) vs 0.3 ml kg(-1), P<0.0001). During the intraoperative period 4% of the children in the ultrasound group received additional analgesics compared with 26% in the fascial click group (P=0.004). Only three children (6%) in the ultrasound-guided group needed postoperative rectal acetaminophen compared with 20 children (40%) in the fascial click group (P<0.0001). CONCLUSIONS: Ultrasound-guided ilioinguinal/iliohypogastric nerve blocks can be achieved with significantly smaller volumes of local anaesthetics. The intra- and postoperative requirements for additional analgesia are significantly lower than with the conventional method.

Ambulatory Surgical Procedures↗