Hemodynamic Changes during Thiopental Anesthesia

Thiopental, monosodium 5-ethyl-5(1-methylbutyl) -thiobarbiturate, is extensively used in clinical anesthesia either as a primary anesthetic agent for short surgical procedures or as a supplementary drug in conjunction with other anesthetics. Fatalities have been attributed to its use (1, 2) and cardiac arrest has occurred following its administration to patients under spinal anesthesia (3). Most of the information concerning the cardiocirculatory effects of thiopental has been derived from animal experimentation (4, 5). Although there have been numerous clinical reports describing changes in blood pressure, pulse rate and respiration during its administration, quantitative investigations on the effect of this agent on the cardiocirculatory dynamics in man are meagre (6, 7). In view of its extensive use and the complications ascribed to its administration, a critical analysis of the hemodynamic changes which occur at various levels of thiopental narcosis in patients prior to surgery will form the basis of this communication.