Anesthesiology
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Randomized Controlled Trial Comparative Study Clinical Trial
Prospective examination of epidural catheter insertion.
Although it is generally accepted that inserting epidural catheters 3-4 cm into the epidural space minimizes complications, no prospective randomized examination of epidural catheter insertion length has been published. ⋯ Epidural catheters should be inserted either 2 cm when rapid labor is anticipated or 6 cm when prolonged labor or cesarean delivery is likely. Additionally, epidural catheters that result in intravenous cannulation or unilateral sensory analgesia can be manipulated effectively to provide analgesia for labor and delivery.
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Randomized Controlled Trial Comparative Study Clinical Trial
Cardiac outcome after peripheral vascular surgery. Comparison of general and regional anesthesia.
Despite evidence that regional anesthesia may be associated with fewer perioperative complications than general anesthesia, most studies that have compared cardiac outcome after general or regional anesthesia alone have not shown major differences. This study examines the impact of anesthetic choice on cardiac outcome in patients undergoing peripheral vascular surgery who have a high likelihood of associated coronary artery disease. ⋯ The choice of anesthesia, when delivered as described, does not significantly influence cardiac morbidity and overall mortality in patients undergoing peripheral vascular surgery.
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Randomized Controlled Trial Clinical Trial
Hemodynamic responses to intravascular injection of epinephrine-containing epidural test doses in adults during general anesthesia.
Epidural anesthesia is sometimes initiated during general anesthesia, yet few data exist concerning efficacy of epinephrine-containing test doses. ⋯ Hemodynamic responses to intravascular injection of test doses vary with dose of epinephrine and depth and type of general anesthetic used. Thus, the 15 micrograms epinephrine contained in the standard test dose may not be sufficient during all anesthetic conditions.
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Comparative Study Clinical Trial
Prediction of movement during propofol/nitrous oxide anesthesia. Performance of concentration, electroencephalographic, pupillary, and hemodynamic indicators.
Movement in response to painful stimulation is the end point classically used to assess the potency of anesthetic agents. In this study, the ability of modeled propofol effect-site concentration to predict movement in volunteers during propofol/nitrous oxide anesthesia was tested, then it was compared with the predictive abilities of the Bispectral Index and 95% spectral edge frequency of the electroencephalogram, pupillary reflex amplitude, and systolic arterial blood pressure. In addition, the relationships between simple end points of loss and recovery of consciousness, and pupillary, hemodynamic, and propofol concentration indicators were studied. ⋯ Indicators of pharmacodynamic effect, such as the electroencephalogram, pupillary light reflex, and systolic arterial blood pressure, predict movement as well as effect-site concentration during propofol/nitrous oxide anesthesia. Loss and return of the eyelash reflex correspond to a deeper level of anesthesia than syringe-dropping or recall of the birth date.
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Comparative Study
Comparison of the spinal actions of the mu-opioid remifentanil with alfentanil and morphine in the rat.
mu-Opioids administered spinally produce a potent, dose-dependent analgesic response in preclinical and clinical investigations. Side-effect profile of these compounds may be altered as a function of pharmacokinetics. The effects of intrathecal and intraperitoneal remifentanil, an esterase-metabolized mu opioid, alfentanil, and morphine were compared. ⋯ These observations indicate that remifentanil has a powerful spinal opioid action. Consistent with its lipid-solubility, it has an early onset like alfentanil but displays a shorter duration of action after bolus delivery. Despite lipid solubility, remifentanil has a significant spinal therapeutic ratio. These observations likely reflect the rapid inactivation of systemically redistributed agent by plasma esterases.