Abstract
Background Acute mesenteric ischemia following cardiovascular surgery is a rare but fatal complication.
We established a new rat model for hemodynamic monitoring during mesenteric ischemia/reperfusion
(I/R) and evaluated the impact of mesenteric I/R on hemodynamics and remote organ
injury.
Methods Mesenteric I/R was induced in male Wistar rats by superior mesenteric artery occlusion
for 90 minutes, followed by 120 minutes of reperfusion. Before I/R, ventilation and
hemodynamic monitoring including mean arterial blood pressure (MAP) and cardiac output
(CO) were established. During reperfusion Geloplasma (I/R + Geloplasma, N = 6) and Ringer's solution (I/R + Ringer, N = 6) were titrated according to CO and compared with I/R without volume resuscitation
(I/R only, N = 6) and a sham group (sham, N = 6). Blood samples were regularly taken for serum marker measurements. After reperfusion
organs were harvested for histology studies.
Results After acute mesenteric I/R, MAP and CO decreased (p < 0.01) while systemic and pulmonary vascular resistance increased (p < 0.01) continuously in the I/R group. Volume substitution according to CO initially
stabilized hemodynamic parameters, but CO declined independently in the late stage.
Compared with the I/R + Ringer group, the I/R + Geloplasma group required less volume
for resuscitation (p < 0.01), experienced less metabolic acidosis. I/R groups had more organ injuries,
more neutrophils sequestration, and higher creatine phosphokinase-MB levels than sham
group.
Conclusion A new model for CO monitoring after mesenteric I/R injury demonstrated severe hypovolemic
shock during reperfusion followed by remote myocardial and lung injury. Far less colloid
volume is needed for hemodynamic stabilization after I/R compared with crystalloid
volume.
Keywords
mesenteric ischemia - cardiac output - hemodynamics - remote organ injury - neutrophil
