Distribution of blood flow with anesthetics

The microsphere technique is a reliable method to study cardiac output and distribution of blood flow in the rat with halothane and enflurane anesthesia. The cardiovascular changes induced by halothane or enflurane are similar to that which is known to occur in man. One important exception is the increase in per cent blood flow to the kidneys in the animals anesthetized with halothane. Ketamine anesthesia results in a loss of microspheres that are originally 'trapped' in muscle and skin but then are found in the lung. The supposition that microspheres remain stationary once they have been 'trapped' in various tissues is not supported by the experiments with ketamine anesthesia. Ketamine anesthesia results in cardiovascular changes that are not always seen in man.