Carbapenem restriction and its Effect on Bacterial Resistance in an Intensive Care unit of a Teaching Hospital

Development of antibiotic resistance in Intensive Care Units (ICUs) is a worldwide problem. The purpose of this study was to evaluate the effect of an antibiotic stewardship program (ASP) by carbapenems restriction on gram-negative antimicrobial resistance in ICU. The study was designed in a 21 bedded general ICU of a teaching hospital with two wings (one and two) in Tehran, Iran. Carbapenem prescription in ICU1 was restricted to only the culture proven multi-drug-resistant bacteria with the absence of sensitivity to other antimicrobial agents. Carbapenem had to be prescribed by a trained ICU physician with close consultation with infectious disease specialist and the clinical pharmacist posted in ICU. Post-prescription reviews and de-escalations were carried out by the same team on regular basis. Restriction policy was commenced in January 2011 in ICU1. All documented infections and resistance patterns of isolated pathogens were recorded in both ICUs during two periods of 6 months before and 9 months after restriction policy implementation. During this study bacterial growth was detected in 51.5% of 1601 samples. Carbapenem administration was decreased from 6.86 to 2.75 DDD/100 patients day (60% decreases) pre-restriction and post-restriction respectively. Significant increase in sensitivity of pseudomonas to imipenem was observed in ICU1 comparing with pre-restriction period six months post restriction (p = 0.000). Sensitivity of Klebsiella and Acinetobacter to imipenem did not change significantly during the study period. Our study demonstrated that restriction of carbapenems can increase sensitivity of P. aeroginosa to imipenem.