The protective effects of early treatment with propofol on endotoxin-induced shock in rats

Objective To investigate the effects of propofol administered at different intervals on acute lung injury induced by endotoxin shock and the mechanism in rats.Methods Seventy-six healthy adult male Wistar rats, weighing 250-290 g were anesthetized with 30 % pentobarbital sodium 30 mg. kg-1 ip. Carotid artery and jugular vein were cannulated for BP monitoring and administration of drugs and fluid. The animals were randomly divided into 5 groups : group A received only normal saline (NS) ( n = 8) ; group B received LPS 8 mg' kg and NS iv ( n =17); group C-E received a bolus of propofol 5 mg .kg-1 iv, 1 h before (group C) or together with (group D) or 1 h after intravenous LPS (group E) followed by propofol infusion at 10 mg . kg-1 . h-1 ( n = 17 in each group). The animals were observed for 5 h after LPS. Blood samples were taken from femoral artery before (baseline) and 1, 3 , 5 h after LPS for determination of PaO2 ,pH, and serum TNF-a and NO levels. The survival rates of the animals in the 5 groups during the 5 h after LPS were compared. The animals were sacrificed and the lungs were removed at the end of 5 hour observation for determination of lung TNF-a and MDA content and myeloperoxidase (MPO) activity and microscopic examination. Results Propofol given 1h before (group C) and simultaneously with LPS (group D) significantly attenuated the decrease in MAP, pH and PaO2 and increase in serum contents of TNF-a and NO and lung TNF-a, MDA contents and MPO activity induced by LPS. The 5 hour survival rate was also significantly higher in group C and D than that in group B. Conclusion Early propofol administration is beneficial during endotoxin-induced shock.