Anesthesia and analgesia
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Anesthesia and analgesia · Aug 1996
Randomized Controlled Trial Comparative Study Clinical TrialIntubating conditions and onset of action after rocuronium, vecuronium, and atracurium in young children.
To evaluate muscle relaxant onset times and tracheal intubating conditions, 60 children (ASA physical status I or II) aged 18 to 72 mo were randomly assigned to receive a bolus of either rocuronium 0.6 mg/kg, vecuronium 0.1 mg/kg, or atracurium 0.5 mg/kg. After induction of anesthesia with etomidate 0.2-0.4 mg/kg and fentanyl 1-3 mg/kg, lungs were ventilated with 50% nitrous oxide in oxygen via a face mask. The evoked electromyogram of the adductor pollicis to a train-of-four stimulation every 20 s was monitored. ⋯ The quality of intubating conditions at the time of completed intubation was rated significantly better with rocuronium than with vecuronium or atracurium. However, onset to 95% block at the adductor pollicis muscle was not significantly different after rocuronium (92 +/- 46.9 s), vecuronium (112 +/- 33.3 s), or atracurium (134 +/- 57.1 s), and mean neuromuscular block achieved at the point of successful intubation was not complete in all groups. We conclude that clinically acceptable intubating conditions are produced more rapidly with rocuronium than with atracurium or vecuronium.
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Anesthesia and analgesia · Aug 1996
Clinical Trial Controlled Clinical TrialAlfentanil dose-response relationships for relief of postoperative pain.
The aim of this study was to characterize within-patient alfentanil dose-response curves for the relief of spontaneous postoperative pain and to test the closeness of relationships 1) between pain intensity and alfentanil analgesic requirements, and 2) between alfentanil requirements for analgesic and nonanalgesic (sedative and miotic) effects. The effects of alfentanil were studied in 23 patients after elective abdominal surgery. During a 40- to 60-min testing session, the patient received two intravenous (i.v.) injections of saline (placebo) and up to six 3-micrograms/kg increments of alfentanil at 5-min intervals. ⋯ A strong correlation was found between interpatient variabilities in the analgesic and sedative effects of alfentanil (r = 0.75, P < 0.002). At the same time, the relationship between alfentanil requirements for pain relief and that for pupil constriction did not demonstrate any significant correlation. The results suggest that, in a population of patients with postoperative pain, the intensity of spontaneous pain cannot be the primary factor determining the dose of alfentanil necessary for its relief.
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Anesthesia and analgesia · Aug 1996
Heparin neutralization with methylene blue, hexadimethrine, or vancomycin after cardiopulmonary bypass.
There are no clinically available alternatives for reversing heparin in protamine-allergic patients. This study examined the ability of methylene blue, hexadimethrine, and vancomycin to reverse circulating heparin so that these compounds can be carefully examined in future placebo-controlled studies in humans. Heparin activity in blood obtained from extracorporeal circuits was reversed by adding protamine (13.5, 27.0, 81.1, 135.1, and 270.3 micrograms/mL), methylene blue (13.5, 27.0, 135.1, 202.7, 270.3, 337.8, 405.4, 473.0, 540.5, and 810.8 micrograms/mL), hexadimethrine (6.8, 13.5, 20.3, 27.0, 81.1, and 135.1 micrograms/mL), or vancomycin (13.5, 27.0, 135.1, 270.3, 540.5, and 810.8 micrograms/mL), and activated clotting times (ACTs) were measured with kaolin (n = 18). ⋯ Heparin concentrations were 3.3 +/- 0.3 U/mL with ACT values of 485 +/- 97 s. The ACT at a protamine concentration of 81.1 micrograms/mL and at hexadimethrine concentrations of 81.1 and 135.1 micrograms/mL was not statistically different from heparinase-ACT; however, methylene blue or vancomycin did not reverse the anticoagulation at any concentrations. Hexadimethrine can reverse heparin-induced anticoagulation after cardiopulmonary bypass as well as protamine, although methylene blue or vancomycin did not neutralize heparin in vitro.