Anesthesiology
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Randomized Controlled Trial Clinical Trial
The influence of age on propofol pharmacodynamics.
The authors studied the influence of age on the pharmacodynamics of propofol, including characterization of the relation between plasma concentration and the time course of drug effect. ⋯ Semilinear canonical correlation defined a new measure of propofol effect on the EEG, the canonical univariate parameter for propofol. Using this parameter, propofol plasma effect-site equilibration is faster than previously reported. This fast onset was confirmed by inspection of the EEG data. Elderly patients are more sensitive to the hypnotic and EEG effects of propofol than are younger persons.
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Randomized Controlled Trial Comparative Study Clinical Trial
Determination of the potency of remifentanil compared with alfentanil using ventilatory depression as the measure of opioid effect.
Remifentanil is a new opioid with properties similar to other mu-specific agonists. To establish its pharmacologic profile relative to other known opioids, it is important to determine its potency. This study investigated the relative potency of remifentanil compared with alfentanil. ⋯ Based on depression of the minute ventilatory response to 7.5% CO2, remifentanil is approximately 40 (26-65) times more potent than alfentanil when remifentanil and alfentanil whole-blood concentrations are compared. As alfentanil is usually measured as a plasma concentration, remifentanil is approximately 70 (41-104) times more potent than alfentanil when remifentanil whole-blood concentration is compared with alfentanil plasma concentration. This information should be used when performing comparative studies between remifentanil and other opioids.
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Randomized Controlled Trial Comparative Study Clinical Trial
Comparison of ropivacaine and lidocaine for intravenous regional anesthesia in volunteers: a preliminary study on anesthetic efficacy and blood level.
Ropivacaine may be useful for intravenous regional anesthesia, but its anesthetic effectiveness and toxicity have not been evaluated. ⋯ Compared with lidocaine, intravenous regional anesthesia with ropivacaine appears to be comparable but has longer-lasting residual anesthesia.
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Randomized Controlled Trial Comparative Study Clinical Trial
Clinical effects and maternal and fetal plasma concentrations of 0.5% epidural levobupivacaine versus bupivacaine for cesarean delivery.
Bupivacaine exists as a mixture of two enantiomers, levobupivacaine and dexbupivacaine. Data suggest that levobupivacaine has equal local anesthetic potency, with reduced potential for central nervous system and cardiovascular toxicity. The present study compares the efficacy of 0.5% levobupivacaine with 0.5% bupivacaine for epidural anesthesia in parturients undergoing elective cesarean delivery. ⋯ The use of epidural 0.5% levobupivacaine for cesarean delivery results in equally efficacious anesthesia compared with 0.5% bupivacaine. Pharmacokinetic parameters were similar in the two groups.