Infection reduction strategies including antibiotic stewardship protocols in surgical and trauma intensive care units are associated with reduced resistant gram-negative healthcare-associated infections

Abstract

Background: Resistance to broad-spectrum antibiotics by gram-negative organisms is increasing. Resistance demands more resource utilization and is associated with patient morbidity and death. We describe the implementation of infection reduction protocols, including antibiotic stewardship, and assess their impact on multi-drug-resistant (MDR) healthcare-acquired gram-negative infections.

Methods: Combined infection reduction and antibiotic stewardship protocols were implemented in the surgical and trauma intensive care units at Vanderbilt University Hospital beginning in 2002. The components of the program were: (1) Protocol-specific empiric and therapeutic antibiotics for healthcare-acquired infections; (2) surgical antibiotic prophylaxis protocols; and (3) quarterly rotation/limitation of dual antibiotic classes. Continuous healthcare-acquired infection surveillance was conducted by independent practitioners using National Heath Safety Network criteria. Linear regression analysis was used to estimate trends in MDR gram-negative healthcare-acquired infections.

Results: A total of 1,794 gram-negative pathogens were isolated from healthcare-acquired infections during the eight-year observation period. The proportion of healthcare-acquired infections caused by MDR gram-negative pathogens decreased from 37.4% (2001) to 8.5% (2008), whereas the proportion of healthcare-acquired infections caused by pan-sensitive pathogens increased from 34.1% to 53.2%. The rate of total healthcare-associated infections per 1,000 patient-days that were caused by MDR gram-negative pathogens declined by -0.78 per year (95% confidence interval [CI] -1.28, -0.27). The observed rate of healthcare-acquired infections per 1,000 patient days attributable to specific MDR gram-negative pathogens decreased over time: Pseudomonas -0.14 per year (95% CI -0.20, -0.08), Acinetobacter-0.49 per year (95% CI -0.77, -0.22), and Enterobacteriaceae -0.14 per year (95% CI -0.26, -0.03).

Conclusion: Implementation of an antibiotic stewardship protocol as a component of an infection reduction campaign was associated with a decrease in resistant gram-negative healthcare-acquired infections in intensive care units. These results further support widespread implementation of such initiatives.