Anesthesiology
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Comparative Study Clinical Trial
Preoperative dipyridamole thallium imaging and ambulatory electrocardiographic monitoring as a predictor of perioperative cardiac events and long-term outcome.
Dipyridamole thallium imaging (DTI) and ambulatory electrocardiography (AEGC) have been advocated as means to stratify risk before vascular surgery. The purpose of this study was to compare the predictive value of both tests in noncardiac surgery patients for perioperative cardiac morbidity and long-term mortality. ⋯ AECG and DTI demonstrated a similar, although lower than initially reported, ability to stratify risk and predict short-term outcome. Only quantitative dipyridamole thallium also had predictive value for long-term prognosis.
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Comparative Study
One-day hypothermic preservation of isolated hearts with halothane improves cardiac function better than low calcium.
Halothane exerts a potent negative inotropic effect on the heart and mimics many of the cardiac effects of lowered extracellular CaCl2. Reduced slow inward Ca2+ current and sarcoplasmic reticular effects on intracellular Ca2+ are likely involved. The authors reported previously that halothane protects against hypoxic and ischemia reperfusion injury in isolated hearts. The aim of this isolated heart study was to compare protective effects of halothane and low CaCl2 (0.5 mM) administered during 1 day of hypothermic perfusion on return of normothermic perfusion. ⋯ Halothane administered during hypothermia restores left ventricular pressure, cardiac efficiency, basal coronary flow, and flow responses better than low CaCl2. Although halothane and low CaCl2 both reduce intracellular Ca2+, contractile force, and metabolic demand, the better protective effect of halothane is not likely simply due to a reduction in contractile function and metabolic rate before or initially after hypothermia because these were reduced much more by low CaCl2 than by halothane.
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Randomized Controlled Trial Comparative Study Clinical Trial
Cardiovascular effects of sevoflurane compared with those of isoflurane in volunteers.
Sevoflurane is a new inhalational anesthetic with desirable clinical properties. In some clinical situations, an understanding of the detailed cardiovascular properties of an anesthetic is important, so the authors evaluated the hemodynamic effects of sevoflurane in healthy volunteers not undergoing surgery. ⋯ At 1.0 and 1.5 MAC, sevoflurane was well tolerated by healthy volunteers. At 2.0 MAC, in subjects with mean arterial pressure > or = 50 mmHg, no adverse cardiovascular properties were noted. Similar to other contemporary anesthetics, sevoflurane caused evidence of myocardial depression. Hemodynamic instability was noted in some subjects at high anesthetic concentrations in the absence of surgical stimulation. The incidence was similar to that with isoflurane. The cardiovascular effects of sevoflurane were similar to those of isoflurane, an anesthetic commonly used in clinical practice since 1981.
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Randomized Controlled Trial Comparative Study Clinical Trial
Atracurium versus vecuronium in asthmatic patients. A blinded, randomized comparison of adverse events.
To determine which of atracurium or vecuronium is associated with fewer adverse cardiovascular and pulmonary events in high-risk patients, the authors administered these drugs to patients with known asthma. ⋯ The authors conclude that, in patients with asthma, adverse cardiovascular events are more common with atracurium than with vecuronium.
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Randomized Controlled Trial Comparative Study Clinical Trial
Dose-response curves of inhaled nitric oxide with and without intravenous almitrine in nitric oxide-responding patients with acute respiratory distress syndrome.
Inhaled nitric oxide, a selective pulmonary vasodilator, in combination with intravenous almitrine, a selective pulmonary vasoconstrictor, markedly improves arterial oxygenation in 50-60% of patients with acute lung injury. The goal of this study was to assess dose response of inhaled nitric oxide with and without almitrine in patients with acute respiratory distress syndrome responding to nitric oxide. ⋯ In 6 patients with early acute respiratory distress syndrome and highly responsive to inhaled nitrix oxide, the administration of intravenous almitrine at a concentration of 16 micrograms.kg-1.min-1 induced an additional increase in Pao2. Dose response of nitric oxide was not changed by the administration of almitrine and a plateau effect was observed at inspiratory nitric oxide concentrations of 1.5 ppm.