Anesthesiology
-
Comparative Study
Severe bradycardia during spinal and epidural anesthesia recorded by an anesthesia information management system.
Bradycardia and asystole can occur unexpectedly during neuraxial anesthesia. Risk factors may include low baseline heart rate, first-degree heart block, American Society of Anesthesiologists physical status 1, beta-blockers, male gender, and high sensory level. Anesthesia information management systems automatically record large numbers of physiologic variables that are combined with data input from the anesthesiologist to form the anesthesia record. Such large databases can be scanned for episodes of bradycardia. ⋯ Moderate or severe bradycardia may occur at any time during neuraxial anesthesia, regardless of the duration of anesthesia. Low baseline heart rate increases the risk for bradycardia.
-
Biography Historical Article
Mervyn Maze, M.B., Ch.B., F.R.C.P.: recipient of the 2003 Excellence in Research Award.
-
Randomized Controlled Trial Comparative Study Clinical Trial
Use of a continuous local anesthetic infusion for pain management after median sternotomy.
The use of large doses of opioid analgesics to treat pain after cardiac surgery can prolong the time to tracheal extubation and interfere with recovery of bowel and bladder function in the postoperative period. Therefore, the authors investigated the efficacy of a continuous infusion of bupivacaine 0.25% or 0.5%, at the median sternotomy site, for 48 h after cardiac surgery in reducing the opioid analgesic requirement and improving the recovery process. ⋯ A continuous infusion of bupivacaine 0.5% at 4 ml/h is effective for decreasing pain and the need for opioid analgesic medication as well as for improving patient satisfaction with their pain management after cardiac surgery. Patients in the bupivacaine-0.5% group were able to ambulate earlier, leading to a reduced length of hospital stay.
-
Randomized Controlled Trial Comparative Study Clinical Trial
Pharmacodynamic effect of morphine-6-glucuronide versus morphine on hypoxic and hypercapnic breathing in healthy volunteers.
Morphine-6-glucuronide (M6G) is an active metabolite of morphine that is generally associated with less respiratory depression than morphine. Because M6G will be on the market in the near future, the authors assessed the time profile and relative potency of M6G's effect versus morphine's effect on carbon dioxide-driven and hypoxic breathing. ⋯ Morphine is more potent in affecting hypoxic ventilatory control than M6G, with a potency ratio ranging from 1:19 for Vi45 to 1:50 for AHR. At drug concentrations causing 25% depression of Vi45, M6G caused only 15% depression of AHR, whereas morphine caused greater than 50% depression of AHR. Furthermore, the speed of onset/offset of M6G is faster than morphine by a factor of approximately 2. The authors discuss some of the possible mechanisms for the observed differences in opioid behavior.
-
Randomized Controlled Trial Comparative Study Clinical Trial
Sevoflurane provides greater protection of the myocardium than propofol in patients undergoing off-pump coronary artery bypass surgery.
Sevoflurane, like other halogenated anesthetics, has been shown to have a protective effect on the myocardium at risk after an ischemic injury. The current study tested the hypothesis that such beneficial effects, so far mainly seen in the laboratory, are reproducible in humans. ⋯ Patients receiving sevoflurane for off-pump coronary artery surgery had less myocardial injury during the first 24 postoperative hours than patients receiving propofol. The results further support cardioprotective effects of sevoflurane.