Articles: nerve-block.
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Randomized Controlled Trial Clinical Trial
Specificity of diagnostic nerve blocks: a prospective, randomized study of sciatica due to lumbosacral spine disease.
Temporary nerve blocks using local anesthetic are employed extensively in the evaluation of pain problems, particularly lumbosacral spine disease. Their specificity and sensitivity in localizing anatomic sources of pain have never been studied formally, however, and so their diagnostic and prognostic value is questionable. There have been anecdotal reports of relief of pain by temporary blocks directed to areas of pain referral, as opposed to areas of documented underlying pathology; but there has been no study to define the frequency or magnitude of this effect. ⋯ Our findings indicate a limited role for uncontrolled local anesthetic blocks in the diagnostic evaluation of sciatica and referred pain syndromes in general. Negative blocks or a pattern of responses may have some predictive value, but isolated, positive blocks are non-specific. This lack of specificity may, however, be advantageous in therapeutic applications.
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Clinical Trial Controlled Clinical Trial
Assessment of neuromuscular block at the thumb and great toe using accelography in infants.
We assessed neuromuscular block at the thumb and great toe using accelography after the administration of vecuronium in infants. Train-of-four stimuli were simultaneously applied to the ulnar and tibial nerves using cutaneous electrodes. Anaesthesia was maintained with nitrous oxide (66%) in oxygen and sevoflurane (1%). ⋯ The times from maximal block to 25% recovery of twitch height at the thumb and great toe were 46 (9.1) min and 45 (9.0) min, respectively. The reversal time from 25% to 75% of the train-of-four ratio after the administration of neostigmine was 136 (49.1) s. We conclude that neuromuscular monitoring of the great toe in infants may be a suitable alternative when the thumb is inaccessible.
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Randomized Controlled Trial Comparative Study Clinical Trial
Comparison of bupivacaine and lidocaine/bupivacaine for local anesthesia/digital nerve block.
We compared the efficacy, degree of discomfort, and time elapsed before anesthesia of digital block with a combination of 1% lidocaine/.25% bupivacaine and with .25% bupivacaine alone. ⋯ Bupivacaine .25% digital block induces anesthesia in the same period of time and with equivalent pain of injection as a 1:1 lidocaine 1%/bupivacaine .25% combination. It is not necessary to use lidocaine/bupivacaine in an attempt to achieve faster onset of local anesthesia.
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The Mayo block is an extremely efficacious regional anesthetic technique used to provide anesthesia of the forefoot. Patients requiring surgical correction of hallux deformity, bunionectomy, and first metatarsal surgery may benefit from this technique. The Mayo block is a field block that anesthetizes the specific nerves of the forefoot that innervate the surgical field. ⋯ This technique has been used at one military hospital on more than 275 patients. The failure rate of the block is less than 1%. Learning this technique adds to the anesthetist's armamentarium of regional anesthesia, aids in rapid case turnover, and avoids the risks associated with major conduction and general anesthesia.
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Clinically, phenol is used often as a neurolytic agent to treat pain and spasticity. The purpose of this study was to examine the time course of denervation and recovery in several hindlimb muscles following application of a 5% aqueous solution of phenol to the sciatic nerve. Phenol was applied to the sciatic nerve of adult female rats either by intraneural or perineural injection. ⋯ Following denervation, the soleus became slower in that all of the fibers expressed the slow myosin heavy chain (MHC). At 5 months, maximum tension of the soleus was 74% of control and the muscle consisted of more fast fibers on average, some of which expressed IIx MHC. These data suggest that 5% phenol causes an injury to the nerve that is more severe than a crush injury, and that reinnervation of denervated muscles may be by motoneurons other than those that originally innervated the muscles.