Effect of supplemental oxygen versus dobutamine administration on liver oxygen tension in dPP-guided normovolemic pigs.
BACKGROUND
Difference in pulse pressure (dPP) confirms adequate intravascular filling as a prerequisite for tissue perfusion. We hypothesized that both oxygen and dobutamine increase liver tissue oxygen tension (ptO(2)).


METHODS
Eight anesthetized pigs received dPP-guided fluid management. Hepatic pO(2) was measured with Clark-type electrodes placed subcapsularly, and on the liver surface. Pigs received: (1) supplemental oxygen (F(i)O(2) 1.0); (2) dobutamine 2.5 microg/kg/min, and (3) dobutamine 5 microg/kg/min. Data were analyzed using repeated-measures ANOVA followed by a Tukey post-test for multiple comparisons. ptO(2 )measured subcapsularly and at the liver surface were compared using the Bland-Altman plot.


RESULTS
Variation in F(i)O(2) changed local hepatic tissue ptO(2) [subcapsular measurement: 39 +/- 12 (F(i)O(2) 0.3), 89 +/- 35 mm Hg (F(i)O(2) 1.0, p = 0.01 vs. F(i)O(2) 0.3), 44 +/- 10 mm Hg (F(i)O(2) 0.3, p = 0.05 vs. F(i)O(2) 1.0); surface measurement: 52 +/- 35 (F(i)O(2) 0.3), 112 +/- 24 mm Hg (F(i)O(2) 1.0, p = 0.001 vs. F(i)O(2) 0.3), 54 +/- 24 mm Hg (F(i)O(2) 0.3, p = 0.001 vs. F(i)O(2) 1.0)]. Surface measurements were widely scattered compared to subcapsular measurements (bias: -15 mm Hg, precision: 76.3 mm Hg). Dobutamine did not affect hepatic oxygenation.


CONCLUSIONS
Supplemental oxygen increased hepatic tissue pO(2) while dobutamine did not. Although less invasive, the use of surface measurements is discouraged.
Pestel
G
G
Department of Anesthesiology, Johannes Gutenberg University, Mainz, Germany. gunther.pestel@gmx.net
Fukui
K
K
Hager
H
H
Kurz
A
A
Hiltebrand
L
L
D000818:Animals; D002316:Cardiotonic Agents / Q000494:pharmacology*; D004280:Dobutamine / Q000494:pharmacology*; D005440:Fluid Therapy; D006439:Hemodynamics; D008099:Liver / Q000737:chemistry / Q000187:drug effects* / Q000378:metabolism; D010100:Oxygen / Q000008:administration & dosage* / Q000032:analysis / Q000378:metabolism; D013552:Swine
D002316:Cardiotonic Agents; D004280:Dobutamine; D010100:Oxygen