CARBapenem utilizatiON evaluation in a large community hospital (CARBON): A Quality Improvement Study.

Carbapenems constitute a class of broad-spectrum antibiotics for the treatment of documented multidrug-resistant organisms and for use as empiric therapy in severe, life-threatening conditions,1,2 Hospital-acquired infections due to organisms such as Clostridium difficile and multidrug-resistant Pseudomonas aeruginosa are responsible for significant morbidity and mortality in the institutional health care setting.3 Increased use of carbapenems has been linked with a rising incidence of carbapenem-resistant Enterobacteriaceae, C. difficile, and other multidrug-resistant organisms.4 The Lower Mainland Pharmacy Services (British Columbia) drug formulary currently lists 3 drugs in this class, all of which are subject to restrictions: ertapenem, imipenem– cilastatin, and meropenem. For multidrug-resistant organisms where other agents are ineffective and cases in which the patient is intolerant to alternatives, imipenem–cilastatin is recommended as the first-line carbapenem, with meropenem to be used if imipenem–cilastatin is unsuitable, and ertapenem being reserved for patients undergoing treatment in an outpatient setting. Because of cost considerations, meropenem was used as the primary carbapenem at Abbotsford Regional Hospital during the period of this study. A recent evaluation of carbapenem prescribing practices within 13 acute care sites serviced by the Lower Mainland Pharmacy Services5 revealed that use of carbapenems at Abbotsford Regional Hospital was higher than the regional mean when corrected for patient numbers. Given that this class of antibiotic should be reserved for severe cases and that the excessive and inappropriate use of carbapenems has been linked to plasmidmediated carbapenem resistance,2,6 it is important to understand how this drug class is being prescribed and to identify whether carbapenems are being overprescribed. This quality improvement review was undertaken to describe the patients receiving carbapenems at Abbotsford Regional Hospital in an effort to guide future interventions aimed at changing practice. The primary objective of the study was to identify the indications for use of carbapenems and to assess the appropriateness of carbapenem orders written between May 1 and July 31, 2013. Secondary objectives were to identify the frequency of risk factors for multidrug-resistant organisms among patients who received carbapenems, to determine the proportion of patients with step-down to appropriate narrow-spectrum therapies, and to determine the number of patients who received carbapenems and subsequently tested positive for C. difficile toxin B or gramnegative multidrug-resistant organisms during the same admission.