Abstract P69: Reduction of Contaminated Blood Culture Rates in a Cardiovascular Intensive Care Setting

Abstract

Background: Blood cultures are an invaluable tool for diagnosing and guiding bacteremia therapy. The validity of culture results can be jeopardized when specimens are contaminated with bacteria from patient or collector's skin or catheter hubs. Because common skin bacteria can represent true bacteremia, their presence cannot automatically be dismissed. Contaminated blood cultures (CBCs) increase risk and cost of subsequent care. For patients in the cardiovascular intensive care unit (CVICU) with prosthetic valves, grafts and implanted devices and for those awaiting transplant, the implications of CBCs are exponential. The current Clinical and Laboratory Standards Institute (CLSI) recommendation is to maintain a contamination rate of less than 3%. Despite education on the implications of false positives, communication of target and actual rates, and encouragement to avoid central line sampling, the CVICU's average CBC rate from July - December of 2009 was 6.1% (monthly range: 2.7 - 9.6%). Objectives: Reduce the CVICU's CBC rate to less than 3%. Methods: Draw sites for cultures were reviewed during central line-associated blood stream infection (CLABSI) and CBC case-reviews and eventually through retrospective review of 1800 CVICU cultures. The CVICU Leadership then determined that all CVICU blood cultures were to be collected by venipuncture. A concurrent quality initiative was occurring in our Emergency Department. Following an observational review of 50 culture draws, they concluded that use of a clean procedure for culture collection resulted in frequent contamination risk opportunities. They designed a blood culture collection kit and a sterile collection procedure. The CVICU joined the pilot study for this kit and method. Results: The CVICU's average CBC rate from January 2010 - January 2011 was 2.7%. (monthly range: 0% - 6.9%) Reduction in CBC has also contributed to a decrease in the unit's CLABSI rates. Conclusions: Quality improvement initiatives often focus on education and results communication. The CVICU was unable to sustain improvement in blood culture contamination rates with these interventions alone. Process study and subsequent policy and procedure changes have netted sustained improvement in reduced CBC rates.