Anesthesia and analgesia
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Anesthesia and analgesia · Jul 1996
Twenty-four of twenty-seven studies show a greater incidence of emesis associated with nitrous oxide than with alternative anesthetics.
All obtainable investigations that have compared the incidence of vomiting in groups of patients who received nitrous oxide (N2O) and in patients who received anesthetics or analgesics without N2O were examined for a single, dichotomous variable: whether patients who received N2O experienced an absolutely higher incidence, as distinct from a statistically significantly higher incidence, of vomiting. The null hypothesis is that N2O has no effect on emesis, such that an increased incidence of vomiting should occur in about half of the studies examined. ⋯ The two-tailed probability that this result occurred by chance is < 0.00005. It follows that N2O increases the incidence of emesis compared to alternative anesthetics.
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Arterial blood pressure and heart rate changes after afferent somatic sensory nerve stimulation are termed the "somatosympathetic reflex" (SSR). Inhibition of the SSR may partially represent an antinociceptive action. This investigation examined the actions of the volatile anesthetic, desflurane, on the SSR evoked by peripheral nerve stimulation. ⋯ Sciatic nerve stimulation also elicited increases in heart rate which were significantly attenuated by desflurane (control; 37 +/- 6 bpm versus 1.5 MAC desflurane; 0 +/- 2 bpm). These findings demonstrate that desflurane produces dose-dependent cardiovascular depression in rats and, despite previous reports of sympathoexcitation, desflurane significantly attenuated both excitatory and inhibitory types of SSR. The results of this study also support a potential antinociceptive action for this anesthetic.