We have recently shown improved survival following intestinal ischemia-reperfusion in a model that utilized aggressive crystalloid resuscitation sufficient to eliminate reperfusion-induced cardiovascular instability. The aims of this study were to determine whether the salutary effects associated with this regimen were due to: 1) prevention of systemic metabolic derangements; 2) attenuation of secondary organ injury; or 3) modulation of the systemic immune response. Under anesthesia, 4-week-old (65-85 g) male Sprague-Dawley rats (N = 63) received crystalloids at either 15 or 65 ml-kg−1.h−1 intravenously and were subjected to 90 min of superior mesenteric artery occlusion followed by 90 min of reperfusion (IR15, IR65) or timematched sham (SH) operation (SH15, SH65). Results indicate that inadequate fluid resuscitation following intestinal IR was associated with significant serum hyperkalemia and hyperphosphatemia, acute renal insufficiency, and enhanced serum interleukin-6 levels. Maintenance of cardiovascular stability with aggressive fluid resuscitation was associated with an attenuation of these alterations. Therefore, the prevention of circulatory shock and the attenuation of distant organ injury and inflammatory response are associated with improved survival when an aggressive crystalloid resuscitation regimen is applied after intestinal ischemia-reperfusion in immature rats. © 1994 The Shock Society.