Inhibition of Diuresis by Hypnotics

The depression of diuretic function by anesthetics or hypnotics has often been attributed to certain effects peculiar to the type of anesthetic under consideration. Dooley and Wells 1 have suggested that ether anuria may be explained as a reflex arising from pulmonary irritation. Pick and collaborators^{2, 3, 4, 5} have reported widely varying results with different hypnotics, some increasing diuresis in contrast to the more usual depression of function. Experiments in this laboratory, on the other hand, have indicated a more uniform depression of diuresis and have suggested that the effect is also associated with the condition of anesthesia in general. The chief exception to such a view is the reported diuretic effect of paraldehyde. The most prominent of these reports dealing with the effect on dogs is that by Bonsmann, 5 who used 9 different hypnotics and obtained results varying widely between the 2 extremes represented by paraldehyde and sodium luminal. The effect of these 2 drugs on dogs has been reinvestigated in this study, approximately according to a procedure previously described by the writer. 6 This requires a regularity in diet and a normal diuretic capacity for 2 or more days immediately preceding the day of experiment.

Orally administered doses of paraldehyde ranging from 0.75 cc. to 2.0 cc. kg. depressed the diuretic function to 24% of the normal for the 2-hour period following oral administration of water, 20 cc. kg. (av. of 15 exp.; lowest, 11%; highest, 45%). Diuresis with doses of 2.0 cc. kg. corresponded to 19% of the normal (av. of 6 exp.; lowest, 11%; highest, 29%). At this dose a dog is not ordinarily able to lift its head in 10 min. and does not recover this ability for 8 1/2 hours.