Objective: General anesthesia has been considered an
independent risk factor for postcesarean infection, but the mechanism for this association
has not been delineated. The purpose of this prospective investigation was to determine
if phagocytic response of neutrophils was impaired by in vitro exposure to isoflurane, a
commonly used anesthetic.Methods: Twelve milliliter venous blood samples were withdrawn from
18 term patients during labor. Neutrophils were separated by Ficoll gradient centrifugation.
Aliquots of 2 × 106
neutrophils/ml were exposed to anesthesia using an airtight modular
incubator chamber through which a 0.5% isoflurane:50% N2O + 50% O2
mixture flowed
at a rate of 4 l/min for 90 min at 37℃. Neutrophils were assayed for phagocytosis by
incubation with Escherichia coli conjugated with fluorescein isothiocyanate for 30 min
at 37℃. Phagocytosis was assessed by flow cytometry. Neutrophils from the same
patient that were not exposed to anesthesia served as controls.Results: The mean percentage of phagocytizing neutrophils in the
isoflurane-treated group was 82.8 ± 24 compared to 83.5 ± 22 in the control group.
The difference between the two groups was not significant.Conclusions: In vitro exposure to the general anesthetic isoflurane
for 90 min does not significantly alter the phagocytic capacity of neutrophils.
