MONITORING URINE OXYGEN-TENSION DURING ACUTE CHANGE IN CARDIAC-OUTPUTIN DOGS

To evaluate whether renal blood flow (RBF) can be monitored during acu te change in cardiac index, ureter urine oxygen tension (Pu-O2) and bl adder urine oxygen tension (Pb-O2) were measured in six mongrel dogs. Pu-O2 cardiac index, and RBF increased after dobutamine infusion and d ecreased after propranolol infusion. Pu-O2 had an excellent correlatio n with RBF (r = 0.94) and a fair correlation with cardiac index (r = 0 .50) and mean blood pressure (r = 0.56); RBF had a fair correlation wi th mean blood pressure (r = 0.52, P < 0.05) but was not related to car diac index. With multiple-regression analysis, Pu-O2 was found to be t he significant factor related to RBF. Pb-O2 had a good correlation wit h Pu-O2 (r = 0.94) at control levels. Furthermore, when two dogs were added to evaluate relationships among Pb-O2, Pu-O2, and RBF, Pb-O2 had an excellent correlation with Pu-O2 (r = 0.92) and RBF (r = 0.91). Th ese data indicate that Pu-O2 is a more sensitive predictor of RBF than cardiac index and mean blood pressure and that Pb-O2 can be a noninva sive indicator reflecting RBF during acute circulatory change in dogs.