Iloprost attenuates trauma-related pulmonary sequestration of leucocytes and platelets

The purpose of this study was to investigate the effects of iloprost, a synthetic prostacyclin analogue, on the pulmonary cellular trapping after a standardized soft tissue trauma. In two groups 1 and 2 iloprost was given in doses of 100 ng/kg/min commencing 30 and 20 min respectively prior to trauma and ceasing 10 min after trauma. 111Indium-oxine was used to label neutrophils in 6 animals from each group. Platelets were labelled in 6 and 7 animals respectively. A third group of 11 pigs served as a control and did not receive iloprost. The pulmonary sequestration of platelets and neutrophils was studied dynamically with a gamma camera and directly after trauma was significantly less in group 1 when compared to the control group. A rise in pulmonary vascular resistance and pulmonary arterial pressure was seen in the control group immediately after trauma but this was not evident in the iloprost groups. PaO 2 decreased significantly in group 1 and 2 during the iloprost infusion. The results indicate that iloprost attenuates the pulmonary cellular sequestration and changes in central hemodynamics during trauma in this model.