Articles: nerve-block.
-
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.
-
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.
-
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.
-
The alteration of extracranial blood flow in conjunction with clinical signs of autonomic nervous system dysfunction have led to various explanations concerning the pathophysiology of migraine headache. Reflex sympathetic dystrophy, a painful disorder of the sympathetic nervous system, can be treated by blocking the sympathetic nerves located in the stellate ganglion, resulting in vasodilation, ptosis, miosis, and anhydrosis. In theory, these changes could trigger a migraine headache attack secondary to autonomic dysfunction reflecting an imbalance between sympathetic and parasympathetic nervous systems. ⋯ We report a 56-year-old man with no previous history of migraine who developed migraine with aura after a stellate ganglion block. These episodic headaches occurred with decreasing frequency and severity for over 6 months, with eventual complete resolution. This interesting phenomenon has not been reported in the English literature and may help to better understand the pathophysiology of migraine.