Systemic and mesenteric hemodynamics, metabolism, and intestinal tonometry in a rat model of supraceliac aortic cross-clamping and declamping.
OBJECTIVE
To describe systemic and mesenteric hemodynamics, metabolism, and intestinal tonometry in a rat model of supraceliac aortic cross-clamping and declamping.


METHODS
Prospective, randomized, experimental study.


METHODS
University cardiovascular research laboratory.


METHODS
Twelve male anesthetized and ventilated Sprague-Dawley rats.


METHODS
Supraceliac aortic cross-clamping was performed for 30 minutes, followed by declamping and reperfusion for 180 minutes or sham clamping and sham declamping.


RESULTS
Mean arterial blood pressure; abdominal aortic, superior mesenteric, and carotid artery blood flow; intestinal mucosal tonometry; hemoglobin; lactate; and blood gases were measured before and after 30 minutes of aortic cross-clamping and 15, 30, 60, 120, and 180 minutes after declamping during reperfusion. Aortic cross-clamping induced an increase in mean arterial pressure (117+/-20 mm Hg to 147+/-12 mm Hg), an increase in right atrial hemoglobin saturation(66%+/-11% to 81%+/-6%), an increase in lactate levels (1.7+/-0.7 mmol/L to 4.3+/-1.3 mmol/L), and an increase in tonometric PCO2 (49.6+/-5.0 mm Hg to 75.6+/-8.6 mm Hg). Three hours of reperfusion after declamping resulted in significantly decreased mean arterial pressure (38+/-10 mm Hg); decreased aortic (101+/-12 mL/min/kg to 57+/-32 mL/min/kg), mesenteric (19+/-4 to 13+/-6 mL/min/kg), and carotid (12+/-4 mL/min/kg to 5+/-3 mL/min/ kg) blood flows; and elevated lactate levels (4.2+/-2.0 mmol/L). Tonometric PCO2 had normalized to baseline levels (51.9+/-3.8 mm Hg), but PCO2 gap was significantly higher than in sham clamped rats (17.9+/-7.8 mm Hg v. 7.0+/-2.6 mm Hg).


CONCLUSIONS
Hemodynamic and metabolic effects of aortic cross-clamping and declamping known from large animal models are reproducible using a rat model. Intestinal tonometry indicated mesenteric ischemia during aortic cross-clamping, which was reversible to preclamp values within 30 minutes of reperfusion after declamping.
Wu
X
X
Department of Anesthesia and Research, University of Basel, Switzerland.
Siegemund
M
M
Seeberger
M
M
Studer
W
W
D000818:Animals; D001011:Aorta / Q000601:surgery*; D001784:Blood Gas Analysis; D001794:Blood Pressure; D002245:Carbon Dioxide / Q000032:analysis; D006439:Hemodynamics / Q000502:physiology*; D006454:Hemoglobins / Q000032:analysis; D007413:Intestinal Mucosa / Q000378:metabolism; D007773:Lactates / Q000097:blood; D008297:Male; D008643:Mesentery / Q000098:blood supply*; D010313:Partial Pressure; D011446:Prospective Studies; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D015427:Reperfusion Injury / Q000503:physiopathology*; D013997:Time Factors; D014065:Tonometry, Ocular
D006454:Hemoglobins; D007773:Lactates; D002245:Carbon Dioxide