Pulmonary platelet trapping in Escherichia coli endotoxin-injected dogs treated with methylprednisolone, ibuprofen and naloxone.

Adult respiratory distress syndrome (ARDS) is a common and serious complication of septic shock. Pulmonary trapping of platelets (PPT) and leukocytes, and release of vasoactive and toxic substances such as prostaglandins, lysozymes and oxygen-radicals have been implicated as mediators of the lung injury. beta-Endorphin is regarded as one of the substances released during shock, and has been shown to cause cell damage similar to that seen with endotoxin, and also PPT. We recently reported that combined treatment with methylprednisolone, ibuprofen and naloxone significantly increased lasting survival in an LD100 canine endotoxin shock model. In the present study the effects of these drugs in various combinations were evaluated as regards blood pressure, hematocrit, peripheral platelet and leukocyte counts, intestinal damage and PPT in the same model. The effects of combined treatment were significantly decreased PPT, rise in blood pressure and abolition of bloody diarrhea. We concluded that ibuprofen and naloxone have additive action and that methylprednisolone has no effect on PPT.