Articles: nerve-block.
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Anesthesia and analgesia · Jun 1996
Comparative StudyThe neuromuscular effects of mivacurium chloride during propofol anesthesia in children.
Previous studies examined the neuromuscular effects of mivacurium in doses up to, but not exceeding, 2.5 times 95% effective dose (ED95) in children. To determine whether larger doses offer clinical advantages, we compared the onset and duration of neuromuscular block, intubating conditions, and changes in plasma histamine concentration (PHC) after mivacurium (0.2, 0.3, or 0.4 mg/kg) with those after succinylcholine (2.0 mg/kg) during propofol/N2O anesthesia in 48 children aged 3-10 yr. The evoked electromyograph (EMG) of the adductor digiti minimi after supramaximal train-of-four (TOF) stimulation was recorded. ⋯ PHC increased significantly after mivacurium 0.3 and 0.4 mg/kg; however, mean arterial pressure did not change significantly. We conclude that mivacurium 0.3 mg/kg provides a relatively rapid onset and short duration of neuromuscular block in healthy children. Increasing the dose to 0.4 mg/kg does not significantly accelerate the onset of neuromuscular block.
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Biodegradable microspheres are a useful method of drug delivery because they are both injectable and biodegradable, eliminating the need for surgical implantation or removal. Previous work has characterized implantable preparations of local anesthetics in polymer pellets for prolonged regional anesthesia. In this article, the authors characterize injectable suspensions of bupivacaine-polymer microspheres and examine whether they can produce prolonged blockade of the sciatic nerve in rats. ⋯ Prolonged percutaneous blockade of peripheral nerves is feasible. The recovery from blockade is complete, and plasma bupivacaine levels are far below the range associated with systemic toxicity. The mechanisms underlying the dexamethasone block-prolonging effect are under investigation.
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Anesthesia and analgesia · May 1996
Randomized Controlled Trial Comparative Study Clinical TrialThe role of hyaluronidase on lidocaine and bupivacaine pharmacokinetics after peribulbar blockade.
Orbital regional anesthesia is the only circumstance where hyaluronidase is routinely added to local anesthetics to accelerate the onset of the block. The aim of this study was to compare the pharmacokinetics of lidocaine and bupivacaine with or without hyaluronidase for peribulbar blockade. Twenty-one patients scheduled for cataract surgery with lens implantation were included in this prospective randomized study. ⋯ The absorption of lidocaine and bupivacaine from the peribulbar space are hastened by the addition of hyaluronidase. The Tmax of lidocaine is not different from that of bupivacaine within each group suggesting that the absorption of local anesthetics is minimally influenced by the liposolubility of the drugs. Moreover, hyaluronidase influences the absorption kinetics of both lidocaine and bupivacaine in the same manner.
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Postoperative pain relief may be improved by reducing sensitization of nociceptive pathways caused by surgical trauma. Such a reduction may depend on the timing and efficacy of analgesia and the duration of the nociceptive block versus the duration of the nociceptive input. We examined whether a prolonged nerve block administered before a superficial burn injury could reduce local inflammation and late hyperalgesia after recovery from the block. ⋯ These data suggest that a prolonged, preemptive nerve block reduced late hyperalgesia after thermal injury, whereas the erythema and blister formation were not significantly affected.