Objective: To document the effects of propofol on the hemodynamic and inflammatory responses to endotoxemia in an animal model.
Design: Randomized, prospective laboratory study.
Setting: University experimental laboratory.
Subjects: Thirty-two male rats.
Interventions: The animals were randomly assigned to one of four groups: a) endotoxemia group (n = 8), which received intravenous Escherichia coli endotoxin (15 mg/kg over 2 mins); b) control group (n = 8), which was treated identically to the endotoxemia group except for the substitution of 0.9% saline for endotoxin; c) propofol group (n = 8), which was treated identically to the control group but also received propofol (10 mg/kg bolus, followed by infusion at 10 mg/kg/hr) immediately after the injection of 0.9% saline; and d) propofol-endotoxemia group (n = 8), which was treated identically to the endotoxemia group with the additional administration of propofol (10 mg/kg bolus, followed by infusion at 10 mg/kg/hr) immediately after endotoxin injection.
Measurements and main results: Hemodynamics, arterial blood gases, and acid-base status were recorded and the blood propofol concentrations and plasma cytokine concentrations were measured during the 5-hr observation. Microscopic findings of lung tissue for each group were obtained at necropsy. The systolic arterial pressure and heart rate of the propofol-endotoxemia group were similar to those of the endotoxemia group. The increases in the plasma cytokine (tumor necrosis factor, interleukin-6, and interleukin-10) concentrations, in the base deficit, and in the infiltration of neutrophils in the air space or vessel walls of the lungs were attenuated in the propofol-endotoxemia group compared with the endotoxemia group.
Conclusions: Propofol attenuated cytokine responses, base deficit, and activation of neutrophils to endotoxemia. These findings suggest that propofol may inhibit inflammatory response and prevent the development of metabolic acidosis during endotoxemia.