A controlled study of isolation and endogenous microbial suppression in acute myelocytic leukemia patients

A prospective study of infectious morbidity in patients with acute myelocytic leukemia receiving chemotherapy was undertaken to test the effects of a reduction of ambient and/or endogenous microorganisms. Patients were randomly allocated to receive: (1) neither barrier isolation nor antimicrobial suppression; (2) antimicrobial suppression (gentamicin, vancomycin, and nystatin) in conventional ward reverse isolation; (3) barrier isolation and filtered air; or (4) barrier isolation, filtered air, and antimicrobial suppression. The presence of infection at the time of randomization was a significant factor (p < 0.02) accounting for an increased death rate. Individuals housed in the isolator who were initially uninfected demonstrated a decrease in the acquisition of severe infections after 23 study days, and fewer respiratory infections throughout the study period. Pseudomonas infections were decreased in isolator patients. Fewer fatalities from infection, but more from hemorrhage, were noted in patients who received endogenous antimicrobial suppression. An increased remission rate was seen in isolated patients not receiving antibiotics for gut flora suppression (not statistically significant). Significant improvement of leukemic remission rate or survival by these environmental manipulations was not found.