Anesthesia and analgesia
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Anesthesia and analgesia · May 1986
Influence of moderate hypothermia on posterior tibial nerve somatosensory evoked potentials.
Posterior tibial nerve somatosensory evoked potentials (PTN-SSEP) were recorded in eight patients during cardiac surgery with cardiopulmonary bypass and moderate hypothermia (25-28 degrees C). There was no correlation between changes in amplitude and temperature; however, latencies of potentials recorded over the tibial nerve in the popliteal fossa, the lumbar spinal cord, and the cortex increased linearly as temperature decreased. ⋯ In this study P1 prolonged 1.15 msec/degree C (r = 0.89, P less than 0.001). This implies that a temperature decrease of 2-3 degrees C may prolong P1 latency by more than 3 msec.
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Anesthesia and analgesia · May 1986
Comparative StudyIntravenous fluid temperature, shivering, and the parturient.
The effect of warmed vs room-temperature intravenous fluids is examined for decreasing shivering in parturients undergoing epidural anesthesia for elective cesarean sections. Forty-four women were studied, 22 receiving warmed and 22 receiving room-temperature fluid therapy for preblock prophylaxis of hypotension and intraoperative maintenance and replacement. Of those given room-temperature balanced salt solutions, 64% shivered, as opposed to 14% in the warm fluid group, an observation significant at less than a P of 0.005 by chi 2-analysis.
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The purpose of this study was to determine the ideal priming and total dose of vecuronium when used as the relaxant during rapid sequence induction of anesthesia and tracheal intubation. Seventy patients were studied. Various priming and total dose schedules using vecuronium were compared with succinylcholine, 1.5 mg/kg. ⋯ A priming dose of 15 micrograms/kg of vecuronium with 100 micrograms/kg total dose, on the other hand, not only produced excellent intubating conditions but also resulted in a mean onset time not significantly different from succinylcholine, 1.5 mg/kg. This latter dose schedule of vecuronium is recommended for rapid sequence induction when succinylcholine is contraindicated. Vecuronium is preferable to pancuronium for rapid sequence induction because of its lack of cardiovascular side effects and short duration.
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Anesthesia and analgesia · May 1986
Cardiovascular toxicity of local anesthetics: an alternative hypothesis.
The current study examined the possibility that high local anesthetic concentrations within the central nervous system could contribute to the toxic cardiovascular effects observed clinically after an accidental intravenous injection. Equal numbers of molecules of lidocaine (1.6 microliter of a 2% solution) and bupivacaine (1.0 microliter of a 4% solution) were injected at three vasomotor and cardioactive areas in the rat medulla by means of a 28-gauge hypodermic needle and a microsyringe. These areas were the C1 region, the intermediolateral column (IML), and the nucleus tractus solitarius (NTS). ⋯ These data demonstrate that direct application of local anesthetics within the medullary region of the central nervous system can result in hypotension, bradycardia, and ventricular arrhythmias similar to what may be seen in humans after accidental intravenous injections of local anesthetics. Moreover, the sites and mechanisms of action appear to be identical for bupivacaine and lidocaine. Thus bupivacaine does not appear to be an aberrant local anesthetic, as some have suggested, but rather produces more profound effects related to its potency and physicochemical properties.