Articles: nerve-block.
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Comparative Study
Differential use-dependent (frequency-dependent) effects in single mammalian axons: data and clinical considerations.
The potential clinical scope of use-dependent block of conduction (UDB) was assessed by studying characteristics of UDB in vitro in individual mammalian axons. Single and repetitive stimulation was applied to rabbit cervical sympathetic and vagus nerves exposed to solutions containing lidocaine 0, 0.3, or 0.6 mmol/l (9.1 or 18.2 mg/dl) at 37 degrees C. Unit responses were recorded in dissected filaments or extracellularly in the vagus nodose ganglion. ⋯ With lidocaine 0.6 mM, the incidence of equilibrium conduction block was too high among sympathetic axons to assess UDB, and significantly higher than among nonsympathetic myelinated and unmyelinated units. The observations support the hypothesis that the differential block of sympathetics observed clinically with spinal anesthesia may be, at least in part, a use-dependent (frequency-dependent) effect. UDB seems unlikely to contribute to local anesthetic block of pain impulses.
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For decades it has been known that the combined sciatic and femoral nerve block could be used for operations on the leg. Nevertheless, it is used in very few hospitals as a routine method for surgical anesthesia and only few publications exist in this area. To highlight some practical aspects, we have produced a retrospective study of 660 cases of femoral and sciatic nerve blocks used exclusively for operating purposes. ⋯ The most important factor influencing the failure rate was the anesthesiologist. The individual failure rate of the first 30 blocks of each anesthesiologist (V30) was nearly equal to the overall individual failure rate (Fig. 3). The form and time of premedication and the extent of sedation did not influence the results.(ABSTRACT TRUNCATED AT 250 WORDS)
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Obstetrics and gynecology · Sep 1987
Comparative Study Clinical Trial Controlled Clinical TrialPenile nerve block for newborn circumcision.
Circumcision in neonates is performed, almost universally, without anesthesia or analgesia. It is associated with pain, crying, agitation, and physiologic stress. Twenty infants receiving penile nerve block for circumcision were compared with ten infants having circumcision without anesthesia. ⋯ Anesthetized infants were less agitated and cried less. Peak plasma concentrations of the local anesthetic lidocaine averaged 0.51 +/- 0.17 microgram/mL (range 0.1-1.6), well below accepted toxic levels. There were no local or systemic complications.