Regional anesthesia
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Twenty consecutive patients requiring surgical procedures on a lower extremity received leg blocks using a modification of Labat's classic approach. A Doppler ultrasound pencil probe was used to identify the dominant arterial structure exiting the sciatic notch with the sciatic nerve. A block needle was inserted in the same orientation as the probe until paraesthesias were elicited; then 25 ml of local anesthetic was injected. Successful block was achieved in one or two attempts in 70% of the patients.
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Regional anesthesia · Sep 1991
Randomized Controlled Trial Clinical TrialEpidural butorphanol augments lidocaine sensory anesthesia during labor.
To determine the efficacy and safety of epidural butorphanol combined with lidocaine, 50 healthy parturients were studied during labor and delivery. All patients received a test dose of 3 ml 1.5% lidocaine with 1:200,000 epinephrine. Patients were then randomly assigned to receive 7 ml of one of two epidural regimens in a double-blind fashion: Group 1 patients received 1.5% lidocaine plus 1 mg butorphanol plus 1:300,000 epinephrine; Group 2 patients received 1.5% lidocaine plus 1:300,000 epinephrine. ⋯ There were no difference between groups in duration of first and second stages of labor, method of delivery or neonatal outcome. Umbilical cord acid-base status and neurologic adaptive capacity scores did not differ significantly between the two groups. The authors conclude that adding small doses of butorphanol to epidural lidocaine during labor is effective and safe.
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Regional anesthesia · Sep 1991
Popliteal sciatic nerve block aided by a nerve stimulator: a reliable technique for foot and ankle surgery.
The reliability of popliteal sciatic nerve blocks was prospectively assessed in 625 blocks performed in 507 patients. The sciatic nerve was approached at the apex of the popliteal fossa, in the midline, with an insulated needle connected to a peripheral nerve stimulator partially designed by one of the authors. When needed, an inguinal paravascular femoral nerve block was also performed. ⋯ Overall satisfaction with perioperative analgesia was evaluated by 466 patients: 444 (95%) were completely satisfied, 20 (4%) expressed moderate reservations and two (1%) expressed major reservations. The authors conclude that the technique is a safe and reliable alternative to more common forms of anesthesia for surgery below the knee. They attribute the great success rate to a high popliteal approach, the use of insulated needles, a discriminating mode of nerve stimulation and the systematic search for optimal response to needle stimulation.
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The influence of digoxin on the systemic toxic effects of bupivacaine was studied in a rodent animal model. The experiment was undertaken with consideration to clinical situations such as pregnancy that are associated with the secretion of an endogenous digoxin-like factor. Twenty Wistar male rats, under barbiturate anesthesia and controlled ventilation, received either 5 micrograms/kg intravenous digoxin (n = 10) or saline (n = 10), blinded to the observer. ⋯ The threshold doses of bupivacaine toxic effects (first ventricular arrhythmia, 25% fall of baseline heart rate, 25% fall of baseline mean arterial blood pressure, first seizure activity, isoelectric electroencephalogram, and asystole) were significantly lower in the digoxin group, as were the lethal bupivacaine serum concentrations. Digoxin, in hyperoxic nonacidotic rats, increases the cardiac and central nervous system toxicity of bupivacaine. Based on the known electrophysiologic actions of these two drugs, a synergistic toxic interaction is demonstrated.