Anesthesiology
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Randomized Controlled Trial Comparative Study Clinical Trial
Use of desflurane for outpatient anesthesia. A comparison with propofol and nitrous oxide.
Desflurane's induction and recovery characteristics were compared to those of propofol-nitrous oxide in outpatients undergoing laparoscopic procedures. Ninety-two healthy patients were randomized to receive either: 1) propofol induction and propofol-nitrous oxide maintenance (control), 2) propofol induction and desflurane-nitrous oxide maintenance, 3) desflurane-nitrous oxide, or 4) desflurane alone for induction and maintenance of anesthesia. Inhalation induction with desflurane-nitrous oxide was faster than with desflurane alone (100 +/- 35 vs. 124 +/- 43 s). ⋯ In conclusion, induction of anesthesia with desflurane was rapid but is associated with a high incidence of airway irritation. Emergence and recovery profiles after maintenance of anesthesia with desflurane compared favorably to a propofol-nitrous oxide combination. However, propofol was associated with a lower incidence of nausea than was desflurane after outpatient anesthesia for laparoscopic surgery.
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Randomized Controlled Trial Clinical Trial
The additive contribution of nitrous oxide to isoflurane MAC in infants and children.
The purpose of this study was to determine the contribution of nitrous oxide to isoflurane MAC in pediatric patients. MAC was determined in 47 infants and small children (mean ages 16.6 +/- 6.7 months) during isoflurane and oxygen anesthesia (n = 11) and isoflurane and nitrous oxide anesthesia (25% nitrous oxide [n = 12], 50% nitrous oxide [n = 12], and 75% nitrous oxide [n = 12]). After assigning patients to one of four groups, anesthesia was induced with increasing inspired concentrations of isoflurane in oxygen. ⋯ The mean duration of constant end-tidal concentrations prior to skin incision was 14 +/- 7 min (range 6-46 min). The ratio of expired to inspired nitrous oxide and isoflurane concentrations during the period of constant end-tidal concentrations was 0.96 +/- 0.01 and 0.93 +/- 0.03 respectively. The MAC of isoflurane in oxygen was 1.69 +/- 0.13 vol% (mean +/- standard deviation).(ABSTRACT TRUNCATED AT 250 WORDS)
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Comparative Study
Comparative effects of halothane, isoflurane, and sevoflurane on the liver with hepatic artery ligation in the beagle.
Recently, there has been increasing interest in the alterations in splanchnic and hepatic circulation and preservation of hepatic oxygenation and function during anesthesia and surgery. However, the effects of volatile anesthetics under a condition of marginal hepatic oxygen supply are not well understood. Using a crossover design, we therefore studied the effects of equianesthetic concentrations (1.5 MAC) of halothane, isoflurane, and sevoflurane on hepatic oxygenation and function in nine beagles in which the hepatic artery had been ligated. ⋯ Consequently, the hepatic oxygen supply/uptake ratio and the hemoglobin oxygen saturation and oxygen partial pressure in hepatic venous blood during sevoflurane anesthesia were significantly less than they were with the other anesthetics. Indocyanine green clearance was better preserved during sevoflurane anesthesia (39.7 +/- 12.0 ml.min-1) than during halothane anesthesia (30.9 +/- 8.4 ml.min-1; P less than 0.05). We conclude that sevoflurane is accompanied by a smaller oxygen supply/uptake ratio than is halothane and isoflurane, while it preserves hepatic function.(ABSTRACT TRUNCATED AT 250 WORDS)
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Arterial tonometry is a technique used to measure arterial blood pressure noninvasively. The authors developed a new tonometer system containing an array of 15 piezoresistive pressure transducers, a mechanical positioning system, signal conditioning and multiplexing electronics, and a display and control console. The authors evaluated the accuracy, reliability, and clinical acceptability of this system by comparing tonometric blood pressure measurements with intraarterial blood pressure measurements in 60 anesthetized patients. ⋯ Mean absolute values of error (precision) for the systolic, mean, and diastolic measurements did not differ significantly among the five systolic, five mean, and four diastolic pressure groups and ranged from 3.6 to 6.6 mmHg, with negligible bias, with intraarterial pressure used as the reference. Bias for the various pressure groups was small: -0.9-3.6 mmHg for systolic; -3.0-0.7 mmHg for mean; and -2.1-4.5 mmHg for diastolic. The "limits of agreement" (mean difference +/- two standard deviations) were within an acceptable range for clinical anesthesia.(ABSTRACT TRUNCATED AT 250 WORDS)
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Randomized Controlled Trial Comparative Study Clinical Trial
Effect of propofol on the incidence of postoperative vomiting after strabismus surgery in pediatric outpatients.
Vomiting is a common problem after strabismus surgery in pediatric outpatients. We compared the effects of propofol with and without N2O and droperidol to the effects of a conventional regimen consisting of halothane-N2O-droperidol on the recovery characteristics and the incidence of postoperative emesis after strabismus surgery in 120 ASA physical status 1 or 2 children. After induction of anesthesia with halothane-N2O, patients were randomly assigned to one of four groups. ⋯ Patients in group B had more episodes of intraoperative oculocardiac reflex responses than patients in group A, but had shorter times to extubation, oral intake, ambulation, and discharge, as well as a lower incidence of postoperative emesis (P less than 0.05). The addition of N2O to the propofol anesthetic regimen (group C) was associated with an increased incidence of emesis (P less than 0.05), whereas the addition of droperidol to the propofol-N2O regimen (group D) did not affect the incidence of emesis compared to the other three groups. We conclude that maintenance of anesthesia with a total intravenous regimen using propofol results in a more rapid recovery and less postoperative emesis than with a halothane-N2O-droperidol regimen.(ABSTRACT TRUNCATED AT 250 WORDS)