Alterations of bacterial clearance induced by propofol

Background: The purpose of the study was to investigate the potential influ ence of the anaesthetic agent propofol on immune function in terms of syste mic clearance and organ distribution of injected Escherichia coli in a rabb it model. Methods: Defined numbers of E. coli (1.3X10(8) colony-forming units, CFU) w ere injected intravenously 1 h after starting a 4-h infusion of the anaesth etic propofol (2 mi kg-l h-l, Disoprivan(R) 1%; n=6) or after saline applic ation (n=6). As propofol is formulated in a 10% lipid emulsion, the lipid v ehicle Intralipid(R) (2 ml kg(-1) h(-1); n=6) alone was investigated in a s eparate group. Parameters monitored were arterial pressure and rates of bac terial elimination from the blood. Three hours after bacterial injection, t he animals were killed, and tissue samples of liver, spleen, lung, and kidn ey were collected for microbiological examinations. Results: Compared to saline-treated animals, infusion of propofol induced i ncreased accumulation of E. coli in lung and spleen, thus reflecting reticu loendothelial system dysfunction. Conclusion: As the lipid emulsion by itself induced the same effects, the i mpaired immune function due to propofol is thought to be attributed to its solvent Intralipid(R).