Journal of anesthesia
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Journal of anesthesia · Mar 1996
Oral clonidine reduces thiamylal requirement for induction of anesthesia in adult patients.
Although preanesthetic clonidine, an α-2 agonist, is known to reduce anesthetic requirements, the effect of preanesthetic oral clonidine medication per se on the requirement of thiamylal in adult humans has not yet been examined. One hundred and sixty-one adult patients (14-78 years of age) were randomly assigned to groups that received oral clonidine (5μg·kg(-1) (n=51), 2.5μg·kg(-1) (n=55), or none (n=55)) in addition to 20mg oral famotidine 90min before anesthesia induction. ⋯ Thiamylal requirements were significantly less in both clonidine groups (2.95±0.09 and 3.14±0.10 mg·kg(-1) (mean±SE) for patients receiving 5μg·kg(-1) and 2.5μg·kg(-1) clonidine, respectively) than in the control group (3.81±0.11 mg·kg(-1),P<0.05); however, no difference was found between the two clonidine groups. Although mean blood pressure and heart rate during the study period were significantly lower in both clonidine groups than in the control group, no profound hypotension or marked bradycardia were noted in the clonidine groups.
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We compared the effects of normothermic cardiopulmonary bypass (CPB) with those of hypothermic CPB in patients who underwent coronary artery bypass grafting (CABG) with respect to hemodynamics and oxygen balance. The patients in our study were divided into two groups according to temperature during CPB: systemic normothermia combined with warm blood cardioplegia (group W,n=36) and systemic hypothermia combined with cold crystalloid cardioplegia (group C,n=26). In group W, the use of directcurrent (DC) defibrillators was less frequent after release of the cross clamp, and the duration of CPB and of reperfusion was shorter. ⋯ Mixed venous oxygen saturation ([Formula: see text]) was maintained above 65% during and after CPB in group W and group C. Our results showed that normothermia may be superior to hypothermia during CPB with respect to recovery of cardiac function and avoidance of hyperglycemia. The whole-body oxygen demand-supply balance may be preserved during normothermic as well as hypothermic CPB.
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Journal of anesthesia · Mar 1996
Halothane anesthesia suppresses reflex tachycardia caused by calcitonin gene-related peptide in dogs.
Calcitonin gene-related peptide (CGRP) is known to produce vasodilation, hypotension, and tachycardia. To investigate the interaction between CGRP and anesthetics, the hemodynamic response to infusions of CGRP was studied in dogs anesthetized with halothane or pentobarbital. In halothane-anesthetized dogs given 0.4 μg·kg(-1) of CGRP, mean arterial pressure (MAP) did not change significantly. ⋯ The results show that the hemodynamic profiles induced by CGRP during halothane or pentobarbital anesthesia are a decrease in MAP accompanied by a reduction in SVR and no consistent alterations in CI. However, CGRP effects on HR showed in a different way. The results also show that HR response differs depending on the anesthetics used: HR increases during pentobarbital anesthesia, while it does not increase during halothane anesthesia.