Effect of unilateral phrenic nerve section on lung function.

Abstract

The phrenic nerve was sectioned in 14 patients with facial nerve paralysis. This provided an opportunity to observe in persons with healthy lungs, the effect of phrenic nerve section on diaphragmatic motion, vital capacity, maximal breathing capacity, maximal flow rates, and the distribution of inspired air. The vital capacity was normal before operation and significantly reduced during the 1st 6 months after operation. After this period of time, the vital capacity returned to normal. The tests of air flow maximal breathing capacity and maximal flow rates were low before operation, probably because of facial paralysis, and improved after operation. Distribution of inspired air was normal before and after operation. Unilateral phrenic nerve section has remarkably littie effect on ventilating capacity in subjects with normal lungs.