Metabolic and hemodynamic effects of saline infusion to maintain volemia on temporary abdominal aortic occlusion.

OBJECTIVE To analyze hemodynamic and metabolic effects of saline solution infusion in the maintenance of blood volume in ischemia-reperfusion syndrome during temporary abdominal aortic occlusion in dogs. METHODS We studied 20 dogs divided into 2 groups: the ischemia-reperfusion group (IRG, n=10) and the ischemia-reperfusion group with saline solution infusion aiming at maintaining mean pulmonary arterial wedge pressure between 10 and 20 mmHg (IRG-SS, n=10). All animals were anesthetized with sodium thiopental and maintained on spontaneous ventilation. Occlusion of the supraceliac aorta was obtained with inflation of a Fogarty catheter inserted through the femoral artery. After 60 minutes of ischemia, the balloon was deflated, and the animals were observed for another 60 minutes of reperfusion. RESULTS IRG-SS dogs did not have hemodynamic instability after aortic unclamping, and the mean systemic blood pressure and heart rate were maintained. However, acidosis worsened, which was documented by a greater reduction of arterial pH that occurred especially due to the absence of a respiratory response to metabolic acidosis that was greater with the adoption of this procedure. CONCLUSION Saline solution infusion to maintain blood volume avoided hemodynamic instability after aortic unclamping. This procedure, however, caused worsening in metabolic acidosis in this experimental model.