The Effect of Thiopental Sodium, Etomidate and Propofol on Systemic Vascular Resistance and Venous Capacitance during Cardiopulmonary Bypass. |
Hyun Woo Do, Jin Mo Kim, Ae Ra Kim, Jae Kyu Cheun |
Department of Anesthesiology, School of Medicine, Keimyung University, Taegu, Korea. |
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Abstract |
BACKGROUND The focus of this study is the effects of thiopental sodium, etomidate and propofol on systemic vascular resistance and venous capacitance during cardiopulmonary bypass with constant pump flow. METHODS Thirty patients (ASA III) scheduled for open heart surgery were randomly divided into three groups. Anesthesia was induced with thiopental sodium 5 mg/kg, fentanyl 5 microgram/kg and vecuronium 1 mg/kg. CPB was conduced with a membrane oxygenator using non-pulsatile flow and moderate hypothermia. When rectal temperature and pump flow had been stable for 5 min, patients randomly received thiopental sodium 4 mg/kg, etomidate 0.3 mg/kg and propofol 2 mg/kg.
Perfusion pressure and pump flow were measured 0, 1, 3, 5, 10, 15, 20 and 30 min after administration. RESULTS The systemic vascular resistance index (SVRI) decreased to 84.3% of the control values after thiopental sodium 4 mg/kg, to 74.7% of the control after etomidate 0.3 mg/kg and to 79.8% of the control after propofol 2 mg/kg.
SVRI returned to control value levels 3 min after the administration of thiopental sodium, 20 min after etomidate, and 5 min after propofol. Thiopental sodium, etomidate and propofol reduced venous reservoir volume 1 min after injection and the reduction was sustained throughout the all period of the cardiopulmonary bypass. CONCLUSIONS The results indicate that thiopental sodium, etomidate and propofol dilate both resistance and capacitance vessels, but there was no correlation between the two vessels. |
Key Words:
Anesthetics, intravenous: etomidate; propofol; thiopental sodium; Heart: cardiopulmonary bypass; systemic vasculas resistance; venous capacitance |
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