Effects of intravenous anesthetics on bacterial elimination in XXXX blood in vitro.

@entity1 @entity3652 @entity1875 @entity1363 @entity526
BACKGROUND: Since anesthetics are widely used in critically ill @entity1 , this study investigates anesthetic effects on neutrophil and monocyte function concerning bacterial elimination in @entity1 whole blood. METHODS: The effects of thiopental (20 and 200 microg/ml), @entity1875 (5 and 50 microg/ml), @entity1363 (0.15 and 1.5 microg/ml) and @entity3652 (3 and 30 microg/ml) on elimination of @entity526 ( @entity526 from whole blood were investigated in vitro after incubation for 1 h in both clinical (1) (n=10) and 10-fold higher (h) (n=11) concentrations. These data were compared to neutrophil and monocyte phagocytosis (1; n=6) and burst activity (1; n=10, h; n=11), measured by flow cytometry. To enable quantification of the clearance process, a defined number of 10(5) colony forming units of @entity526 were added to the blood assays and bacterial growth was determined. RESULTS: All anesthetics delayed bacterial clearance from the blood in the 10-fold concentration (P<0.05). Thiopental (1+h) and @entity1875 (h) suppressed neutrophil (59+/-3% and 38+/-6%) and monocytic (45+/-6% and 30+/-11%) oxidative burst (P<0.01). Phagocytosis was reduced even after @entity1875 (1) in polymorphonuclear leukocytes (PMN) (34+/-9%; P<0.05) and monocytes (35+/-11%). @entity3652 (h) prolonged bacterial elimination (P<0.01), which did correlate with inhibition of monocytic phagocytosis, by 26+/-14%. @entity1363 application (h) resulted in an inhibition of PMN-respiratory burst by 19+/-6% (P<0.05) and impaired bacterial clearance (P<0.05). CONCLUSION: Thiopental, @entity1875 , @entity1363 and @entity3652 affect @entity526 clearance and neutrophil and monocyte oxidative burst and phagocytosis in vitro only in high concentrations, while thiopental inhibited monocytic burst and @entity1875 impaired PMN phagocytosis even in clinically used concentrations. These data suggest that i.v. anesthetics in concentrations recommended for general anesthesia seem to have minor influence on the investigated host defense mechanisms.
