Partial reversal of the cerebral effects of isoflurane in the dog by theophylline.

Abstract

The cerebral effects of adding theophylline to 1.4% isoflurane anaesthesia were studied in five dogs by a sagittal sinus outflow technique with direct measurement of the cerebral blood flow (CBF) and calculation of the cerebral metabolic rate for oxygen (CMRo2). Three 3 mg.kg-1 doses of theophylline were given with intervals of 10 min. Five min after the second and third dose, when the mean theophylline plasma concentration was 41 and 65 mumols.1(-1), respectively, CMRo2 had increased significantly with a mean value varying between 15% and 13%, and the EEG had changed from a sleep pattern to a more awake pattern in the four dogs with evaluable recordings. There were no significant changes in CBF or mean arterial blood pressure (MABP). It is concluded that the adenosine receptor antagonist theophylline in this study partially reversed the cerebral effects of isoflurane.