Anesthesia and analgesia
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Anesthesia and analgesia · Jun 1980
Glycopyrrolate-neostigmine and atropine-neostigmine mixtures affect postanesthetic arousal times differently.
Atropine-neostigmine and glycopyrrolate-neostigmine mixtures used in 54 premedicated patients for reversal of non-depolarizing neuromuscular blockade were compared for their effects on postanesthetic arousal times. Anesthesia was induced in all patients with thiopental and was maintained with N2O-O2. Atropine-neostigmine significantly delayed arousal for the first 30 minutes following cessation of anesthesia and reversal of neuromuscular blockade. The difference between the two mixtures following reversal of neuromuscular blockade is attributed to the fact that atropine is a tertiary amine that crosses the blood-brain barrier and delays arousal, whereas glycopyrrolate is a quaternary ammonium compound that does not cross this barrier.
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Anesthesia and analgesia · Jun 1980
Comparative StudyDeaths from local anesthetic-induced convulsions in mice.
Median convulsant (CD50) and median lethal (LD50) doses of three representative local anesthetics were determined in adult mice to evaluate the threat to life of local anesthetic-induced convulsions. The CD50 and LD50, respectively, were 57.7 and 58.7 mg/kg for bupivacaine, 111.0 and 133.1 mg/kg for lidocaine, and 243.4 and 266.5 mg/kg for chloroprocaine. ⋯ A CD50 dose of local anesthetic (causing convulsions in 50% of mice) was fatal in 90% of bupivacaine-induced seizures, in 57% of the chloroprocaine group, and in 6% of the lidocaine group. The narrow gap between convulsant and lethal doses of local anesthetics indicates that untreated convulsions present much more of a threat to life than heretofore appreciated.
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Anesthesia and analgesia · May 1980
Assessment of vaporizer performance in low-flow and closed-circuit anesthesia.
The performance of five of the most commonly used halothane vaporizers and three enflurane vaporizers was tested under conditions encountered in low-flow and closed-circuit anesthesia. Anesthetic gas concentrations were measured continuously with a mass spectrometer connected to a circle system. ⋯ One should be aware, however, that the concentration of nitrous oxide affects vaporizer output, that changes in output occur during positive-pressure ventilation, and that the output of some of the vaporizers may increase when a change from high flow to low flow is made. It is also strongly recommended that upstream oxygen flushing be abandoned in the practice of low-flow or closed-circuit anesthesia.