Anesthesia and analgesia
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Anesthesia and analgesia · Apr 1994
Randomized Controlled Trial Clinical TrialClonidine in pediatric caudal anesthesia.
Extradural clonidine produces analgesia in adults. To assess its efficacy in children, we randomized 45 pediatric patients aged 1-7 yr presenting for a subumbilical surgery into three groups of 15 each. After halothane and N2O/O2 induction, and with a double-blind protocol, caudal anesthesia was performed with 1 mL/kg of 0.25% bupivacaine. ⋯ More patients in the CG (n = 7) than in the EG (n = 1) and BG (n = 2) required no postoperative analgesia; P < 0.05. No differences were found among the groups for the minimal respiratory rate and minimal Spo2 values in the postoperative phase, and there were no differences among the groups for heart rate and systolic arterial pressure during the 3 h after caudal anesthesia. We conclude that the duration of postoperative analgesia with caudal bupivacaine was significantly increased by the addition of 1 microgram/kg of clonidine.
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Anesthesia and analgesia · Apr 1994
Randomized Controlled Trial Clinical TrialFacilitation of fiberoptic orotracheal intubation with a flexible tracheal tube.
Advancement of a tracheal tube (TT) over a flexible fiberoptic bronchoscope (FOB) is often impeded by obstruction at the arytenoid cartilage or epiglottis. We tested the hypothesis that the use of a flexible, spiral-wound TT, rather than the standard, preformed TT would facilitate tube passage into the trachea over the FOB. Forty patients scheduled to undergo general anesthesia with tracheal intubation were randomized to two groups. ⋯ In the patients randomized to the spiral-wound TT, 95% (19/20) of first attempts were successful (P < 0.0001). Of the 13 regular TTs that were not successfully advanced on the first attempt, seven could not be passed after the second or third attempt (necessitating the use of the cross-over spiral-wound TT). In the only instance in which a spiral-wound tube was not successfully passed into the trachea on the first attempt, passage also was not achieved after the second or third attempt.(ABSTRACT TRUNCATED AT 250 WORDS)
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Anesthesia and analgesia · Apr 1994
Randomized Controlled Trial Comparative Study Clinical TrialEfficacy of methylnaltrexone versus naloxone for reversal of morphine-induced depression of hypoxic ventilatory response.
Methylnaltrexone (MNTX) is a quaternary derivative of naltrexone. It does not cross the blood-brain barrier and, thus, it reverses peripherally mediated effects of morphine without blocking its centrally located analgesic effects. The effects of MNTX on morphine-induced depression of hypoxic ventilatory response are unknown. ⋯ MNTX slope (69%) was not statistically different from the control, whereas VE80 (70%) was still depressed (P < 0.05). Placebo slope and VE80, at 120 min, remained lower than the control (P < 0.05). These data show that MNTX is not as effective as naloxone for reversal of morphine-mediated depression of respiration during acute hypoxia.
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Anesthesia and analgesia · Apr 1994
Randomized Controlled Trial Clinical TrialQuantifying the interaction of rocuronium (Org 9426) with etomidate, fentanyl, midazolam, propofol, thiopental, and isoflurane using closed-loop feedback control of rocuronium infusion.
The present study was designed to evaluate the interactions of rocuronium with etomidate, fentanyl, midazolam, propofol, thiopental, and isoflurane using closed-loop feedback control of infusion of rocuronium. Sixty patients were randomly assigned to one of six sequences where anesthesia was maintained with etomidate, fentanyl, midazolam, propofol, or thiopental and nitrous oxide, or with isoflurane and nitrous oxide. The possible interaction of rocuronium with the anesthetics was quantified by determining the asymptotic steady-state rate of infusion (Iss) of rocuronium necessary to produce a constant 90% neuromuscular block. ⋯ Iss values calculated per lean body mass were 0.64 +/- 0.22, 0.60 +/- 0.15, 0.61 +/- 0.21, 0.67 +/- 0.31, 0.63 +/- 0.15, and 0.39 +/- 0.17 mg.kg-1.h-1 in the etomidate, fentanyl, midazolam, propofol, thiopental, and isoflurane groups, respectively. The isoflurane group had a lower steady-state rate of infusion of rocuronium than the other five groups (P < 0.05). Compared to intravenous anesthetics, etomidate, fentanyl, midazolam, propofol, or thiopental, isoflurane reduced the infusion requirement of rocuronium by 35%-40%.
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Anesthesia and analgesia · Apr 1994
Randomized Controlled Trial Comparative Study Clinical TrialThe laryngeal mask airway in pediatric patients: factors affecting ease of use during insertion and emergence.
Use of the laryngeal mask airway (LMA) permits the maintenance of a patent airway with successful insertion rates of the LMA on the first attempt varying between 67%-92% in children. The recommended insertion technique involves deflation of the mask using a syringe, and application of a lubricant jelly. In a randomized study of 122 children, we compared the time to complete LMA insertion, the number of attempts before successful placement, and the occurrence of laryngospasm and Spo2 < 90% during insertion using the standard deflated method and an alternative method of insertion with the LMA cuff partially inflated. ⋯ Insertion of the LMA partially inflated required significantly less time (16 vs 23 s, P < 0.05), and was associated with a higher success rate on first attempts (85.5% vs 96.7%, P < 0.05). In those who did not receive morphine, 2% lidocaine topical solution decreased the incidence of coughing on emergence (10.3% vs 36.4%). The ease of insertion of the LMA in children was improved by partial inflation of the cuff and in addition, 2% lidocaine topical solution was as beneficial as morphine in reducing coughing on emergence.