Effects of pentoxifylline on hemodynamics, gas exchange and multiple organ platelet sequestration in experimental endotoxic shock.

In an intensive care setting we studied the effects of pentoxifylline on hemodynamics, gas-exchange and platelet sequestration in multiple organs in three groups of sheep exposed to endotoxin shock (n = 7 in each). Group P-E was given pentoxifylline before and group E-P after E. coli endotoxin infusion, while group E received normal saline (controls). The endotoxin infusion caused a three-fold increase in pulmonary artery pressure (PAP) and a significant decrease in mean arterial pressure (25-30%; MAP), respiratory compliance (CT; 60%) and arterial oxygen tension (65-70%; Pao2) in all groups after 30 min. After 4 h MAP had improved significantly in the pretreated animals (group P-E) and arterial pH, Pao2 and CT improved in both pentoxifylline-treated groups compared with the controls. On the other hand, the effects of endotoxin on PAP and cardiac index were not significantly influenced by pentoxifylline treatment. In addition, there was a pronounced platelet sequestration in the lungs and in the liver in groups E and E-P during the 4 h study, but in the pretreated group (group P-E) the changes were significantly less marked (P < 0.01). The wet-to-dry weight ratios of the lungs were significantly lower in both pentoxifylline-treated groups compared with the controls (P < 0.01). It was concluded that pentoxifylline modified the effects of endotoxin on hemodynamics, gas exchange and platelet sequestration in the lungs and liver in sheep when it was given prior to endotoxin. However, when it was given after hemodynamic and respiratory signs of shock had appeared, the effects were more moderate.