Anesthesiology
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Although gas exchange during partial liquid ventilation (PLV) depends on perfluorocarbon liquid, the effect of perfluorocarbon dose on the ventilation-perfusion (VA/Q) distribution is not known. This study investigated how VA/Q distribution of an acutely injured lung is affected during PLV at increasing perfluorocarbon dose. ⋯ With increasing perfluorocarbon dose during PLV, shunt was reduced from a small dose. The majority shunt units were converted to units showing low VA/Q ratios rather than normal VA/Q ratios. The presence of considerable amount of low VA/Q units across the varying doses of perfluorocarbon suggested that additional measures are necessary during PLV to augment its effect on gas exchange.
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Randomized Controlled Trial Clinical Trial
Minimum local analgesic dose of intrathecal bupivacaine in labor and the effect of intrathecal fentanyl.
Combining bupivacaine with fentanyl for intrathecal analgesia in labor is well recognized, but dosages commonly used are arbitrarily chosen and may be excessive. This study aimed to determine the median effective dose (ED50) of intrathecal bupivacaine, defined as the minimum local analgesic dose (MLAD), and then use this to assess the effect of different doses of fentanyl. ⋯ Under the conditions of this study, the addition of intrathecal fentanyl 5 microg offers a similar significant bupivacaine dose-sparing effect as 15 and 25 microg. Analgesia in the first stage of labor can be achieved using lower doses of fentanyl, resulting in less pruritus but with a shortening of duration of action.
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Ropivacaine is a new long-acting amino-amide local anesthetic. However, there are no data on its use in infants. In the current study, the authors investigated the pharmacokinetics of caudal ropivacaine in 30 infants younger than 12 months. ⋯ Total and free plasma ropivacaine concentrations after caudal ropivacaine (0.2%, 2 mg/kg) in infants were within the range of concentrations previously reported in adults and older children. Age and percentage of free ropivacaine were significant covariates of clearance.
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Randomized Controlled Trial Clinical Trial
Intrathecal ropivacaine and clonidine for ambulatory knee arthroscopy: a dose-response study.
The aim of this study was to evaluate the association of a small dose of intrathecal ropivacaine with small doses of intrathecal clonidine for ambulatory surgery. ⋯ Small-dose intrathecal clonidine (15 microg) plus 8 mg intrathecal ropivacaine produces adequate and short-lasting anesthesia for knee arthroscopy.
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Randomized Controlled Trial Clinical Trial
Minimum alveolar concentration (MAC) of xenon with sevoflurane in humans.
Although more than 30 yr ago the minimum alveolar concentration (MAC) of xenon was determined to be 71%, that previous study had technological limitations, and no other studies have confirmed the MAC value of xenon since. The current study was designed to confirm the MAC value of xenon in adult surgical patients using more modern techniques. ⋯ The authors could not determine whether interaction in blocking somatic responses in 50% of patients is additive. The MAC of xenon is in the range of the values that were predicted in a previous study.