Experimental posttraumatic pulmonary microembolism. Effects of methylprednisolone on its development.

The effects of methylprednisolone sodium succinate on the course of posttraumatic pulmonary microembolism were studied in pigs submitted to a reproducible high-energy trauma of the limb and then observed under long-term anesthesia. Methylprednisolone sodium succinate (30 mg/kg of body weight) was given one hour after trauma and thereafter every eighth hour during a 72-hour observation period. Intrapulmonary microembolism was quantitatively measured by repeated external detection of chromium 51-labeled platelets and iodine 125-labeled fibrinogen, sequential chest roentgenograms, and morphologic examination of the lungs post mortem. Methylprednisolone delayed the onset of pulmonary roentgenogram changes and modulated Pao2 and platelet count reductions, but, at the end of the observation period, the signs of microembolism changes were as pronounced as in the nontreated traumatized pigs. Methylprednisolone thus did not prevent posttraumatic pulmonary microembolism in this experimental situation.