Anesthesiology
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Atrial tachyarrhythmias are a common manifestation of digitalis toxicity. Such arrhythmias could be due to enhanced automaticity of subsidiary atrial pacemakers (SAP) compared to the sinoatrial (SA) node. Halothane is known to oppose digitalis-induced ventricular arrhythmias. ⋯ Magnitude scores were summed for each test condition and normalized by dividing the total number of preparations tested. Preparations (n = 48) were exposed to 1 or 2% halothane (perfusate concentrations of 0.51 +/- 0.01 or 0.79 +/- 0.03 mM, respectively) and/or to low- or mid-therapeutic (2.5 or 5 x 10(-8) M) or borderline toxic ouabain (1 x 10(-7) M). Normalized magnitude scores were not significantly different from zero (control value) with any halothane or ouabain concentration alone.(ABSTRACT TRUNCATED AT 250 WORDS)
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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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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)