Anesthesia and analgesia
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Anesthesia and analgesia · Aug 1985
Comparative StudyRegional blood flows during induced hypotension produced by nitroprusside or trimethaphan in the rhesus monkey.
In monkeys anesthetized with 70% nitrous oxide and 0.5% inspired halothane in oxygen, we measured changes in systemic hemodynamics and regional blood flows produced by nitroprusside and trimethaphan. Regional blood flow measurements were made using the radioactive microsphere technique. Control measurements were made before infusion of nitroprusside and trimethaphan into each animal in sequence in amounts adequate to reduce mean arterial pressure to approximately 55 +/- 5 mm Hg. ⋯ Neither drug produced changes in renal or total hepatic blood flows. We conclude that brain oxygen reserve is decreased during hypotension induced by trimethaphan. Blood flows to other organs are not significantly impaired in monkeys during hypotension to a mean arterial pressure of approximately 55 mm Hg induced by either nitroprusside or trimethaphan.
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Anesthesia and analgesia · Aug 1985
Decreased sensitivity to metocurine in patients with upper motoneuron disease.
Responses to the nondepolarizing muscle relaxant, metocurine, were studied in eight hemiplegic and eight unmatched patients with normal motor strength during the general anesthetic given for various neurosurgical operations. Metocurine, 0.3 mg/kg, was administered intravenously, and indirectly evoked thumb twitch tensions were measured on both sides in the hemiplegic patients, and on one side in the normal patients. Arterial blood samples were obtained as twitch tension was recovering, and serum metocurine concentrations were determined using a specific radioimmunoassay. ⋯ We were, however, unable to detect any significant deviation from parallelism among the three regression lines. We also measured time to 50% return of single twitch height for each data group as follows (mean +/- SEM: for NMS patients, 242 +/- 73 min; for the unaffected arm of hemiplegic patients, 116 +/- 60 min; and for the affected arm of hemiplegic patients, 59 +/- 36 min. By ANOVA and the Bonferroni test, each value was different from the other at P less than or equal to 0.01.(ABSTRACT TRUNCATED AT 250 WORDS)
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Anesthesia and analgesia · Jul 1985
Vecuronium and d-tubocurarine combination: potentiation of effect.
To evaluate possible potentiation of neuromuscular blocking effect of a combination of vecuronium and d-tubocurarine, cumulative dose-response curves were constructed to compare the potency of this combination with vecuronium and d-tubocurarine given alone. Ten patients each were given incremental injections of 80 micrograms/kg d-tubocurarine or 5 micrograms/kg vecuronium plus 40 micrograms/kg d-tubocurarine, the data for incremental administration of 10 micrograms/kg vecuronium being used from our previously published study (7). The results showed the combination of vecuronium plus d-tubocurarine to be significantly more potent (P less than 0.05) than would be expected from a simple additive effect of the individual drugs given alone. The ED95 doses of d-tubocurarine and vecuronium were 530 micrograms/kg and 57 micrograms/kg, respectively, when administered alone, but when administered together, the ED95 doses were 160 and 20 micrograms/kg, respectively.
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Questionnaires were sent to all anesthesia departments in Denmark to determine the total number of anesthetics given per year, and the distribution of different types of anesthesia. All cases of suspected malignant hyperthermia forwarded to the Danish Malignant Hyperthermia Register during a 6.5 yr period were reviewed and divided into subgroups according to clinical criteria. The incidence of suspected malignant hyperthermia in these subgroups was calculated in relation to type of anesthesia. ⋯ The incidence of fulminant malignant hyperthermia was low: 1 in 250,000 total anesthetic procedures, but 1 in 62,000 anesthetic procedures with a combination of potent inhalation agents and succinylcholine. Masseter spasm occurred in 1 of 12,000 anesthetic procedures in which succinylcholine was administered. Suspicion of malignant hyperthermia was raised in 1 of 16,000 anesthetics total, but in 1 of 4,200 anesthetics with the above-mentioned combination of agents.