THE EFFECTS OF CONTINUOUS PRESSURE BREATHING ON KIDNEY FUNCTION 1

Abstract

Four subjects submitted to 30-min. periods of continuous pressure breathing at 10, 20, 30 and 40 mm. Hg above ambient pressure showed a progressive reduction of kidney function which, with higher pressures, reached approx. 20-50% normal values. This depression persisted for 1-2 hrs. after cessation of the pressure breathing period. This is caused by reduction in circulation of the kidney during the pressure breathing period and the resultant temporary impairment of the kidney cells after normal blood flow is re-established. These results support the view that estimations of kidney function may be used as a measure of the circulatory stress induced by a reduction of effective blood vol. It is suggested that pressure breathing should be investigated as a test of circulatory fitness by employing estimations of disturbance of kidney function as an index of the extent of its effect upon the circulatory system.