Division of Infectious Diseases

UNMC Study Documents Value of Blood Diversion Device to Prevent Contamination of Blood Cultures

A prospective controlled trial conducted by Rupp and colleagues in the UNMC ID Division demonstrates a significant 87.6% decrease in blood culture contamination.  Results were recently published in Clinical Infectious Diseases and are available on open access at:  https://academic.oup.com/cid/article/3099374/Reduction-in-Blood-Culture-Contamination-Through

The study was conducted in the Nebraska Medicine Emergency Department and involved 971 patients and 1,942 blood cultures.  Patients needing blood cultures who granted informed consent had one culture obtained in the standard fashion and the other obtained using an innovative device that diverts and sequesters the first 1.5-2.0 mL of blood.  It is thought that the first portion of blood carries contaminating skin cells and microbes. Blood culture contamination was significantly reduced through use of the initial specimen diversion device (ISDD) compared to standard procedures: (2/904 (0.22%) ISDD vs 16/904 (1.78%) standard practice, P=0.001).  Sensitivity was not compromised: true bacteremia was noted in 65/904 (7.2%) ISDD vs 69/904 (7.6%) standard procedure, P=0.41. No needle stick injuries or potential blood borne pathogen exposures were reported. Seventy-three percent of phlebotomists completed a post-study anonymous survey and widespread user satisfaction was noted.

Blood culture contamination is a common and clinically significant problem. False positive blood cultures increase laboratory costs by approximately 20%, are associated with nearly 40% increase in antibiotic charges, are treated with antimicrobials up to one-half of the time, extend the length of hospital stay up to five days and subject patients to the real harms associated with antibiotic exposures such as toxicity, side effects, interactions and emergence of resistance.  It is estimated that a contaminated blood culture costs somewhere between $1,000 (1998) and $8,700 (2009) per case.  Approximately 30,000,000 blood cultures are performed in the United States each year. If our findings were extended to all blood cultures in the United States, and a midpoint cost of $4,850 was applied, it would result in approximately 467,000 fewer contaminated blood cultures and a cost saving of $2,270,000,000-that’s real money!


Rupp ME, Cavalieri RJ, Marolf C, Lyden E. Reduction in Blood Culture Contamination Through Use of Initial Specimen Diversion Device. Clinical Infectious Diseases. Electronic ahead of print April3, 2017.  https://academic.oup.com/cid/article/3099374/Reduction-in-Blood-Culture-Contamination-Through


– Content courtesy of Dr. Mark Rupp

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