Anesthesiology
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Randomized Controlled Trial Comparative Study
Naloxone reversal of morphine- and morphine-6-glucuronide-induced respiratory depression in healthy volunteers: a mechanism-based pharmacokinetic-pharmacodynamic modeling study.
Opioid-induced respiratory depression is antagonized effectively by the competitive opioid receptor antagonist naloxone. However, to fully understand the complex opioid agonist-antagonist interaction, the effects of various naloxone doses on morphine and morphine-6-glucuronide (M6G)-induced respiratory depression were studied in healthy volunteers. ⋯ Naloxone reversal of the opioid effect is dependent on the receptor association-dissociation kinetics of the opioid that needs reversal with respect to the rate of reversal. The pharmacodynamics of naloxone determines reversal magnitude and duration.
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Experimental research in cardiac and neuronal tissue has shown that besides volatile anesthetics and xenon, the nonanesthetic noble gas helium also reduces ischemia-reperfusion damage. Even though the distinct mechanisms of helium-induced organ protection are not completely unraveled, several signaling pathways have been identified. ⋯ Because of its favorable characteristics and the lack of hemodynamic side effects, helium is suitable for use also in critically ill patients. This review covers the cellular effects of helium, which may lead to new clinical strategies of tissue salvage in ischemia-reperfusion situations, both within and outside the perioperative setting.
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Comparative Study
Isoflurane causes greater neurodegeneration than an equivalent exposure of sevoflurane in the developing brain of neonatal mice.
We hypothesized that isoflurane has a greater potency to induce neurodegeneration than sevoflurane in the developing brains of neonatal mice based on our previous studies in cell culture. ⋯ At equipotent exposures, isoflurane has a greater potency than sevoflurane to cause neurodegeneration in the developing brains of neonatal mice.
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Comparative Study
Learning curves for bag-and-mask ventilation and orotracheal intubation: an application of the cumulative sum method.
In this study, the authors determined the success and failure rates for interns learning bag-and-mask ventilation and orotracheal intubation. Their goal was to determine the amount of experience needed to perform these procedures correctly. ⋯ Participating interns developed mask ventilation skills faster than orotracheal intubation skills, and there was more variability in the rate at which intubation skills developed. A median of 29 procedures was required to achieve an 80% orotracheal intubation success rate.
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Comparative Study
Pharmacokinetics of lidocaine, bupivacaine, and levobupivacaine in plasma and brain in awake rats.
We have compared the pharmacokinetics and brain distribution of lidocaine, racemic bupivacaine (bupivacaine), and levobupivacaine in awake, spontaneously breathing rats. ⋯ Although the ratio of total brain concentration to total plasma concentrations of lidocaine, bupivacaine, and levobupivacaine was similar, concentration ratio of bupivacaine in the cerebral extracellular fluid to plasma unbound fraction was significantly higher than lidocaine and levobupivacaine.