No abstract available.
Hemodynamics* ; Nitroprusside*

The purpose of the present study was to compare prapofol, newly introduced anesthetic agnet, & thiopental as to the characteristics of induction & recovery as well as the safety of both anents. Fifty patients who presented for termination of pregnancy were allocated at random to recieve either propofol 2 mg/kg IV or thiopental 4 mg/kg IV. In addition all patients recevied fentanyl, 1 ug/kg IV, one minute befor the induction. Repeated bolus doses of either propofol 20 mg or thiopental 50 mg were given, if the patient respond to surgical stimulation by moving. The result were as follows. 1) Both propofol and thiopental produced smooth and rapid induction, but caused significant respiratory depression. 2) There was more cardiovascular depression with propofol than with thiopental. 3) Postoperative recovery(time to ambulation) was faster with propofol than with thiopental (36.5+/-1.4 vs 72.9+/-5.1 min, p<0.001). 4) Propofol was associated with less side effects(Nausea, vomithing, and dizziness) than thiopental. These results suggest 1) that propofol has significant advantage over thiopental in outpatient surgery, where early ambulation and discharge is desirable, and 2) that both propofol and thiopental should be administered by expert anesthesiologist only when ventiatory assistant device with oxygen is immediately available.
Ambulatory Surgical Procedures* ; Anesthesia* ; Depression ; Early Ambulation ; Fentanyl ; Humans ; Oxygen ; Pregnancy ; Propofol* ; Respiratory Insufficiency ; Thiopental*

BACKGROUND: Stunned myocardium may be mediated by intracellular Ca2+ overloading or oxygen derived-free radicals. Halothane and propofol have been shown to block Ca2+ channels. Propofol is also known to have antioxidant properties. The present study was aimed to investigate the effects of anesthetics on recovery of postischemic, reperfused myocardium in open-chest dogs. Incidence of ventricular arrhythmia upon ischemia and reperfusion was also determined. METHODS: Forty dogs were subjected to 15 min occlusion of left anterior descending coronary artery (LAD) followed by 3 hr reperfusion during halothane (n=10), fentanyl (n=12), or propofol plus fentanyl (n=11) anesthesia. Regional contractile function was assessed using percent systolic shortening (%SS), the preload recruitable stroke work slope (Mw), and peak systolic intramyocardial pressure (IMPs). Diastolic function was evaluated using time constant for isovolumic intramyocardial pressure decline of left ventricle (IMP-tau) and percent post-systolic shortening (%PSS). RESULTS: %SS in the halothane, fentanyl, and propofol-fentanyl groups was similar at 3 hours of reperfusion (58%, 60%, and 55% of baseline value, respectively). Moreover, Mw recovered to the baseline values in the early reperfusion period in all three groups. However, IMP-tau was significantly prolonged in the halothane group throughout the 3 hour reperfusion period, whereas it remained unchanged in the fentanyl and propofol-fentanyl groups. Coronary occlusion was associated with 9, 33, and 0% mortality rate due to ventricular fibrillation upon ischemia and reperfusion in the halothane, fentanyl, and propofol-fentanyl groups, respectively. CONCLUSION: These findings indicate that halothane, but not fentanyl and propofol- fentanyl, impairs myocardial relaxation, while recovery pattern of contractile function do not differ among three groups, and that halothane and propofol reduce reperfusion arrhythmia in the canine model of myocardial stunning.
Anesthesia* ; Anesthetics ; Animals ; Arrhythmias, Cardiac ; Coronary Occlusion ; Coronary Vessels ; Dogs* ; Fentanyl* ; Halothane* ; Heart Ventricles ; Incidence ; Ischemia ; Mortality ; Myocardial Stunning* ; Myocardium ; Oxygen ; Propofol ; Relaxation ; Reperfusion ; Stroke ; Ventricular Fibrillation

Endothelin(ET), is the most potent endogenous vasoconstrictor. Myocardial ischemia and chemical stimuli including calcium ionophores are known to release ET-1. Recently, halothane has been shown to block calcium channel. Thus, halothane might attenuate coronary endothelial ET-1 production during myocardial ischemia-reperfusion. To test this hypothesis, we measured plasma ET-1 level continuously in open chest dogs subjected to 15 min of left anterior coronary arterial occlusion and 1 hour of reperfusion during fentanly(n=8) or halothane(n=7) anesthesia. The results were as follows. I) Baseline ET-1 levels of both femoral artery and great cardiac vein in the halothane group were lower than in the fentanly group(NS). 2) ET-1 level of femoral artery and great coronary vein in both halothane and fentanyl group remained unchanged 10 min into ischemia. 3) Coronary blood flow increased by 325, 250% in the halothane group and by 315, 258% in the fentanly group 2, 5 min into reperfusion, respectively. 4) ET-1 production increased from baseline of -2.9+/-1.7 pg/min to 66.0+/-21.5(p<0.05), 20.8+/-5.1 (p<0.01), 13.2+/-6.2(p<0.05) pg/min 5, 15, 30 min into reperfusion, respectively in the fentanyl group, but it remained unchanged from baseline of 0.8+/-3.1 pg/min in the halothane group. These findings suggest that ET-1 production or release is diminished by halothane during myocardial ischemia-reperfusion. Thus, halothane provides an advantage over fentanyl in patients with myocarial ischemic episodes.
Analgesics ; Anesthesia* ; Anesthetics ; Animals ; Calcium Channels ; Calcium Ionophores ; Coronary Vessels ; Dogs* ; Endothelin-1* ; Endothelins ; Femoral Artery ; Fentanyl* ; Halothane* ; Humans ; Ischemia ; Myocardial Ischemia ; Plasma ; Reperfusion ; Thorax ; Veins

The purpose of this study was to evaluate the efficacy of adenosine triphosephate (ATP) in comparison to sodium nitroprusside (SNP) in reducing left ventricular afterload in 20 patients, ASA physical status I, during ethrane-N2O anesthesia. Hemodynamic effects of intravenous ATP (30~250 ug/kg/min) were compared with those of SNP (0.3~2.5 ug/kg/min) in group 1 (n=10). In group 2 (n=10), hemodynamic and intrapulmonary shunt effects of dobutamine (1 ug/kg/min) alone and in combination with ATP or SNP, required to maintain mean arterial pressure around 70 mmHg, were compared. The results were as follows. 1) Both ATP and SNP reduced arterial pressure rapidly resulting from a marked decrease in systemic vascular resistance in a dose-related manner. 2) Cardiac index increased from 3.31+/-0.201/min/m2 to 4.04+/-0.281/min/m2 (p<0.01) following dobutamine alone, and increased further to 5.71+/-0.38 1/min/m2 (p<0.001) and decreased to 3.77+/-0.28 1/min/m (NS) in combination with ATP and SNP, respectively. 3) At equivalent decrease in mean arterial pressure, ATP increased heart rate significantly less than SNP. 4) Hypotensive response was more stable during ATP infusion than during SNP infusion. 5) Arterial oxygen tension was significantly higher during dobutamine/ATP infusion than during dobutamine/SNP infusion (268+/-6 vs 256+/-9 mmHg, p<0.05). 6) Intrapulmonary shunt fraction increased from 4.49+/-0.65% to 5.51+/-0.71% (p<0.05) following dobutamine alone, and increased further to 9.92+/-1.13 (p<0.001) and to 7.21+/-0.77% (p<0.01) in combination with ATP and SNP, respectively. These results suggest, although ATP increases intrapulmonary shunt fraction more than does SNP, ATP has significant advantage over SNP, either alone or in combination with dobutamine, in improving cardiac performance in patients with low output states due to high peripheral vascular resistance.
Adenosine Triphosphate* ; Adenosine* ; Anesthesia ; Arterial Pressure ; Dobutamine* ; Heart Rate ; Hemodynamics* ; Humans ; Lung ; Nitroprusside* ; Oxygen ; Pharmacology ; Sodium* ; Sympathetic Nervous System ; Vascular Resistance