Effect of antibiotic heterogeneity on the development of infections with antibiotic-resistant gram-negative organisms in a non-intensive care unit surgical ward.

Abstract

Heterogeneous antibiotic use has been suggested to limit the emergence of resistance, but determining the optimal strategy is difficult. We developed a new strategy, termed "periodic antibiotic monitoring and supervision" (PAMS) program in a non-ICU surgical ward. The 2-year prospective study was divided into a 1-year observation period and a 1-year PAMS period. The use of four major classes of antibiotics in empirical therapy for Gram-negative rod (GNR) infections was supervised. During the PAMS program, recommended, restricted, and off-supervised classes of antibiotics were changed every 3 months according to the usage pattern of the antibiotics in the preceding term. Cefepime (45.5%) and imipenem/cilastatin (39.4%) were the most common antibiotics of choice during the observation period. The use of these antibiotics decreased significantly during the PAMS period, and that of fluoroquinolones and extended-spectrum penicillin/beta-lactamase inhibitor increased (4.8% vs. 21.4% and 2.4% vs. 21.4%, P<0.01 respectively). Outcome analysis demonstrated a tendency toward reduction in the incidence of resistant GNR infections (P=0.079) and that of Pseudomonas aeruginosa (P=0.053). The incidence of resistant Gram-positive core infections did not decrease. Analysis of antibiotic susceptibility to GNR revealed no significant beneficial results for any antibiotics. As significant changes were not observed, the PAMS program is not generally applicable and heterogeneous antibiotic use as a way of reducing infections with resistant GNR in non-ICU surgical wards was not established.