Effects of dobutamine on splanchnic tissue perfusion during partial superior mesenteric artery occlusion.
OBJECTIVE
To evaluate the effects of dobutamine and fluid treatment on splanchnic hemodynamics and tissue oxygenation during partial superior mesenteric artery occlusion.


METHODS
Prospective, open randomized, full-factorial design.


METHODS
University research laboratory.


METHODS
Forty-eight female pigs.


METHODS
In 24 anesthetized pigs (ischemic group), superior mesenteric artery (SMA) blood flow was reduced to 30% from the baseline for 120 mins; 24 pigs (sham group) served as nonischemic controls. The animals were further assigned into four treatment arms. In the control arm, the animals were administered only basic fluid therapy. In the fluid therapy arm, pulmonary artery occlusion pressure was maintained at 10 mm Hg with fluids. In the dobutamine treatment arm, dobutamine hydrochloride was infused at a dose of 10 microg/min/kg. In the combined dobutamine-fluid therapy arm, dobutamine at 10 microg/min/kg was administered and pulmonary artery occlusion pressure was maintained at 10 mm Hg with fluids.


RESULTS
Systemic and regional hemodynamics and oxygen transport, as well as jejunal intramucosal pH, intramucosal-arterial PCO2 gradient, and portal venous-arterial lactate gradient were measured. Ischemia did not modify the effects of fluids or dobutamine on systemic hemodynamics and oxygen transport. Dobutamine-treated animals had a higher cardiac index compared with control animals (218 +/- 22 vs. 135 +/- 13 mL/min/kg; p = .012), and the effect was enhanced when dobutamine was combined with fluid treatment (365 +/- 23 mL/ min/kg; p = .019). Fluid treatment alone did not influence cardiac index, whereas it increased SMA blood flow compared with control groups (15 +/- 2 vs. 12 +/- 2 mL/min/kg; p = .023). Dobutamine also decreased the proportion of SMA blood flow of cardiac output compared with control groups (6 +/- 1 vs. 9% +/- 1%; p = .024). Other treatments had no effect on SMA blood flow. Ischemia increased intramucosal-arterial Pco2 gradient to 54.8 +/- 10.7 torr (7.31 +/- 1.43 kPa) (p = .002 vs. sham control) and decreased intramucosal pH to 7.13 +/- 0.06 (p = .028 vs. sham control). In the ischemic animals, dobutamine without fluid therapy reduced intramucosal pH further to 7.00 +/- 0.09 (p = .023 vs. ischemic control) and increased portal venous-arterial lactate gradient (p = .033).


CONCLUSIONS
Dobutamine alone worsened splanchnic tissue perfusion during partial superior mesenteric artery occlusion. As compared with fluid treatment alone, the combination of fluid and dobutamine therapy did not improve tissue perfusion.
Heino
A
A
Department of Surgery, Kuopio University Hospital, Finland.
Hartikainen
J
J
Merasto
M E
ME
Koski
E M
EM
Tenhunen
J
J
Alhava
E
E
Takala
J
J
D000818:Animals; D002245:Carbon Dioxide / Q000378:metabolism; D002316:Cardiotonic Agents / Q000494:pharmacology / Q000627:therapeutic use*; D003131:Combined Modality Therapy; D004195:Disease Models, Animal; D004280:Dobutamine / Q000494:pharmacology / Q000627:therapeutic use*; D004353:Drug Evaluation, Preclinical; D005260:Female; D005440:Fluid Therapy / Q000379:methods*; D006439:Hemodynamics / Q000187:drug effects*; D006863:Hydrogen-Ion Concentration; D007413:Intestinal Mucosa / Q000098:blood supply* / Q000378:metabolism; D007511:Ischemia / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology*; D007583:Jejunum / Q000098:blood supply*; D019344:Lactic Acid / Q000097:blood; D017538:Mesenteric Artery, Superior; D008641:Mesenteric Vascular Occlusion / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology*; D010101:Oxygen Consumption / Q000187:drug effects; D011446:Prospective Studies; D011897:Random Allocation; D013152:Splanchnic Circulation / Q000187:drug effects*; D013552:Swine
D002316:Cardiotonic Agents; D002245:Carbon Dioxide; D019344:Lactic Acid; D004280:Dobutamine