Endotoxic shock in the awake young pig: absence of beneficial effect of prednisolone sodium succinate treatment

Abstract

In nonanesthetized young pigs, the influence of prednisolone sodium succinate therapy on a 65% lethal dose of Escherichia coli endotoxin was studied by evaluating clinical signs, several hemodynamic variables, survival rate, and changes seen at necropsy. Endotoxin infusion induced reproducible clinical signs characterized by nausea, vomiting, dyspnea, cyanosis, and moderate excitement followed by severe CNS depression. Among the hemodynamic variables, there were decreases in arterial blood pressure and cardiac output and increases in pulmonary arterial pressure, heart rate, and total peripheral and pulmonary vascular resistances. Core temperature and arterial pH did not change significantly. Survival rate at 30 hours after the start of the endotoxin infusion was 35%. According to the necropsy, marked edema and hemorrhages were in several organs. Treating the experimental animals with prednisolone sodium succinate (3 injections of 10 mg/kg of body weight after the start of the endotoxin infusion) did not influence any of the monitored hemodynamic variables, except for arterial blood pressure, which was higher at the end of the hemodynamic recording period (270 minutes after the start of the endotoxin infusion). Clinical signs, survival rate, and changes at necropsy were similar in both treated and nontreated pigs. This lack of effect can be due to an inappropriate dosage of the steroid or failure of steroid treatment to alleviate endotoxin-mediated effects.