Mesenteric blood flow during cardiopulmonary bypass in pigs.
BACKGROUND
Gastrointestinal complications represent a serious problem after cardiopulmonary bypass. Hypoperfusion of the gastrointestinal tract during bypass has been implicated as the cause. We therefore investigated blood flow in the superior mesenteric artery during cardiopulmonary bypass.


METHODS
Mature female pigs (n = 12) were investigated. While six sham-operated animals served as control (group I), six pigs underwent normothermic cardiopulmonary bypass for 180 minutes (group II). Bypass flow was 2.4 l/m2/minute. Standard regimens for anesthesia and cardiopulmonary bypass were used. Blood flow in the superior mesenteric artery was assessed by Doppler flowmetry.


RESULTS
Blood flow in the superior mesenteric artery did not change significantly in group I. In group II, mesenteric blood flow increased significantly from baseline at 120, 150, and 180 minutes. Oxygen consumption in the mesenteric circulation increased significantly in group II at 90 and 180 minutes compared to baseline, as well as oxygen extraction. Lactate content in the mesenteric vein in group II increased compared to control at 30, 90 and 180 minutes.


CONCLUSIONS
Overall gastrointestinal blood flow is not impaired during cardiopulmonary bypass in this animal model. Instead, gastrointestinal blood flow increased during normothermic cardiopulmonary bypass as well as oxygen consumption.
Rötker
J
J
Department of Thoracic Cardiovascular Surgery, Westphalian Wilhelms-University of Münster, Germany. Juergen.Roetker@t-online.de
Knichwitz
G
G
Erren
M
M
Twelker
L
L
Hammel
D
D
Scheld
H H
HH
D000818:Animals; D002315:Cardiopulmonary Bypass; D005260:Female; D007432:Intraoperative Period; D019344:Lactic Acid / Q000097:blood; D008643:Mesentery / Q000378:metabolism; D010101:Oxygen Consumption; D013152:Splanchnic Circulation; D013552:Swine; D014680:Veins
D019344:Lactic Acid