AJP - Regulatory, Integrative and Comparative Physiology, Vol 264, Issue 3 622-R629, Copyright © 1993 by American Physiological Society
Prevention of secondary cardiovascular instability after intestinal ischemia and reperfusion improves survival
P. J. O'Neill, L. M. Cobb, C. K. Steigman and I. H. Chaudry
Department of Surgery, Michigan State University, East Lansing 48824.
Previous studies of small intestinal ischemia and reperfusion (I/R) in
immature rats report secondary systemic organ injury and low survival
rates; however, in these studies the cardiovascular stability of the rat
was not established. To prevent the secondary hemodynamic deterioration
accompanying intestinal I/R, we have developed a model that utilizes
aggressive fluid resuscitation. Under anesthesia, 4-wk-old male
Sprague-Dawley rats (n = 189) underwent 90 min of I/R (superior mesenteric
artery occlusion) or sham (SH) operation while receiving lactated Ringer
with 5% dextrose at 15 (IR15, SH15) or 65 (IR65, SH65) ml.kg-1 x h-1 i.v.
The results indicate that aggressive fluid resuscitation in the IR65 group
significantly attenuated the hypotension, hemoconcentration, metabolic
acidosis, and amount of gross bowel injury observed in the IR15 group,
while increasing postreperfusion renal and intestinal blood flow,
prolonging survival time of nonsurvivors, and improving overall group
survival. These findings suggest that maintenance of hemodynamic stability
is necessary in models of bowel I/R. Furthermore, this model allows for
selective study of the isolated effects of intestinal I/R without the
additional complications resulting from secondary cardiovascular
instability.
