Pilot study of antibiotic cycling in a pediatric intensive care unit

Objective: This pilot study was performed to determine the safety and size of effect of antibiotic cycling to reduce colonization and infection with antibiotic-resistant bacteria. Design: Open, observational study. Setting: The study was performed in a 16-bed pediatric medical-surgical intensive care unit. Patients: Critically ill children requiring antibiotic therapy. Interventions: Three antibiotic classes were systematically cycled for 3-month intervals over 18 months. Antibiotic regimens were used for all empirical therapy and continued if the bacterial isolate was susceptible. Measurements: The primary outcome was colonization with antibiotic-resistant bacteria, determined by surveillance cultures obtained twice monthly from all patients in the unit. Rates of antibiotic-resistant, nosocomial blood stream infections, and risks of colonization over calendar time in the intensive care unit were also evaluated. Main results: The cycling of broad-spectrum, empirical antibiotics was safe and did not generate increased antibiotic resistance nor select for new organisms. Over the study period, the trend in prevalence of children colonized with antibiotic-resistant bacteria was from 29% to 24% (p = .41). The effect on prevalence of resistant blood stream infections was similar (p = .29). Changes in individual risks of colonization with resistant bacteria over calendar time were consistent with the ecologic effect in size and direction. Conclusions: Results of this pilot intervention suggest that cycling antibiotics may be a safe and viable strategy to minimize the emergence of antibiotic resistance in intensive care units. A definitive study will require a randomized and controlled trial of only four pediatric intensive care units over an 18-month period.