Failure of fluorocarbon propellants to alter the electrocardiogram of mice and dogs

Abstract

Mice anesthetized with sodium pentobarbital exhibited no significant changes in heart rate or ECG recordings after the administration of fluorocarbon propellants (fluorocarbon 11, trichlorofluoromethane; fluorocarbon 12, dichlorodifluoromethane; and fluorocarbon 114, 1,2-dichloro-1,1,2,2-tetrafluoroethane) or after fluorocarbons plus isoproterenol. When asphyxia alone (4 min) was induced, changes in heart rate and ECG recordings were seen. Treatment with fluorocarbons alone or fluorocarbons plus isoproterenol, just before asphyxia, produced no significant differences from asphyxia alone. In a similar manner, pentobarbitalized dogs showed no significant changes in heart rate or ECG recordings after asphyxia for 2 min. Further, no changes were produced by 5, 10 and 20 valve actuations of fluorocarbon propellants 11, 12 or 114, the combination of the 3, or after 20 valve actuations plus asphyxia. Evidence of transpulmonary absorption was detected in 3 dogs by determining arterial blood levels of fluorocarbon 11. From the elimination curves, a 2-compartment system was seen with extremely short half-lives in each: 0.60 ± 0.10 min in the initial portion and 4.03 ± 0.25 min in the terminal portion.