Effects of ketamine and halothane on increased respiratory resistance provoked by ultrasonic aerosols.

Abstract

The effects of halothane and ketamine on respiratory resistance and compliance were determined in anesthetized, intubated patients in whom respiratory resistance was artificially increased by ultrasonic aerosols. Halothane caused a prompt decrease in respiratory resistance with no change in compliance. Ketamine had no effect on resistance. Isoproterenol given to the subjects who did not respond to ketamine resulted in a rapid decrease in resistance to control levels. Ketamine decreased compliance in subjects with normal or increased respiratory resistance. We conclude that halothane remains a useful drug for patients who have increased respiratory resistance. Any utility of ketamine in anesthetic management of asthmatie patients must be on a basis other than a bron-chodilator side-effect.