Monitoring urine oxygen tension during acute change in cardiac
output in dogs.
Kitashiro, Shuji, Toshiji Iwasaka, Tetsuro Sugiura, Yasuo Takayama,
Teruhiro Tamura, Koji Tamura, Mitsuo Inada.
The Second Department of Internal Medicine Kansai Medical
University
APStracts 2:0095A, 1995.
To evaluate whether renal blood flow (RBF) can be monitored during
acute change in cardiac index, ureter urine oxygen tension (PuO2) and
bladder urine oxygen tension (PbO2) were measured in six mongrel
dogs. PuO2, cardiac index and RBF increased after dobutamine infusion
and decreased after propranolol infusion. PuO2 had an excellent
correlation with RBF (r=0.94) and a fair relation with cardiac index
(r=0.50) and mean blood pressure (r=0.56), RBF had a fair relation
with mean blood pressure (r=0.52 p<0.05), but was not related with
cardiac index. When three variables (PuO2, cardiac index, mean blood
pressure) were used in the multivariate analysis, PuO2 was found to
be the significant factor related to RBF. Although PbO2 was lower
than PuO2, PbO2 had a good correlation with PuO2 (r=0.94) at control.
Furthermore, when two dogs were added to evaluate relations among
PbO2, PuO2 and RBF, PbO2 had an excellent relations with PuO2
(r=0.92) and RBF (r=0.91). These data indicate that PuO2 is a more
sensitive predictor of RBF than cardiac index and mean blood
pressure, and PbO2 can be a noninvasive indicator reflecting RBF
during acute circulatory change in dogs. Bedside hemodynamic
monitoring provides useful information regarding the differential
diagnosis of various pathologic mechanisms of congestive heart
failure and prompt evaluation of therapeutic interventions. However,
noninvasive measurement of renal blood flow (RBF) is desirable to
detect early azotemia in patients with congestive heart failure.
Earlier investigators suggested that urine oxygen tension (PuO2) is
related to renal medullary blood flow, renal medullary tissue oxygen
tension and RBF in various conditions in dogs (1,6,7,8,10,11,19).
Kaimura et al. reported that PuO2 can reflect acute RBF changes
during abdominal aortic constriction (7). However, the relationship
between PuO2 and RBF may depend on the circulatory manipulation which
is used to effect alterations of cardiac output. Therefore, the aim
of this study was to evaluate whether PuO2 can reflect RBF during
acute change in cardiac output caused by administration of
catecholamines and beta blocking agents. Furthermore, bladder urine
oxygen tension (PbO2) was measured to evaluate whether PbO2 can be a
noninvasive indicator of RBF changes.
Received 11 October 1994; accepted in final form 2 March 1995.
APS Manuscript Number A1048-4.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 21 March 1995.