Halothane Reversibly Inhibits Human Neutrophil Bacterial Killing

Abstract

The effect of halothane, at clinically relevant concentrations, on the ability of human polymorphonuclear leukocytes (PMNL) to kill the most frequently isolated gram-negative organisms responsible for human bacteremias, Escherichia coli and Klebsiella pneumoniae, was studied. Exposure of PMNL or 0.75% halothane in air significantly inhibited the killing of E. coli (from 81 to 65%) but not K. pneumoniae. At 1.0% halothane there was no killing of E. coli and the killing of K. pneumoniae was reduced from 98 to 82%. With 1.5% halothane, the killing of K. pneumoniae by PMNL was reduced to 65%. This inhibition of bacterial killing was reversed after exposure of halothane-treated PMNL to air. The mechanism of inhibition may be due in part to a deleterious effect of halothane on the oxidative microbicidal activity of human PMNL. Although halothane reversibly inhibited the ability of PMNL to kill bacteremic culture isolates, the degree of susceptibility of bacteria to halothane-treated PMNL may vary.