Decreasing the Rate of Contaminated Blood Cultures

1University of Texas Health Science Center at San Antonio, San Antonio, TX
2University of Texas Health Science Center at San Antonio, San Antonio, TX

Meeting: Hospital Medicine 2010, April 8-11, Washington, D.C.

Abstract number: 156


Contaminated blood cultures in the hospital setting are a potentially preventable cause of increased length of stay, unnecessary resource utilization, and unnecessary use of antibiotics. Estimates of the impact of contaminated blood cultures range from $1000 to $4385 and up to an additional 4.5 days of length of stay for each inpatient admission during which a false‐positive blood culture is reported. In our hospital, overall blood culture contamination rates averaged 6.2%, or 786 contaminated cultures/year.


Our goal was to reduce our blood culture contamination rates from 4.4% on a single general medicine ward to a rate of less than 2%, as the recommended benchmark in The infection control literature is a rale not exceeding 2%‐3%.


We surveyed nursing and laboratory staff, as well as hespitalist faculty, to identify factors related to possible contamination of blood cultures. Responses were used to develop a preintervention flow chart to identify particular points in the process of drawing blood cultures where we could intervene. Based on these points, we implemented the following approaches to decrease contamination rates. (1) A checklist for the processes of drawing blood cultures from a peripheral vein and a central line. (2) An educational program using the checklist, a model arm, and equipment to educate staff regarding sterile technique lor obtaining blood cultures. This program emphasized sterilization of the blood culture bottle tops, and the use of chlorhexidine for sterilizing skin and central line ports. (3) Creation of kits to bundle supplies for drawing cultures from peripheral veins and central lines. Hospital volunteers and nursing assistants assigned to close observation were utilized to create these kits. (4) Implementation of a PICC nurse backup system through which the PICC team could be called to obtain a blood culture if 2 RNs were unable to do so, thereby eliminating the use of existing peripheral IVs for blood draws in patients who were “difficult sticks.” (5) Biweekly reporting of contamination rates to provide feedback to nursing staff regarding the “real‐time” contamination rate, with review of rates during nursing staff meetings.


In the 22 weeks following implementation of our intervention, the contamination rate dropped from 4.4% to 19%. To assess the potential annual savings to the hospital based on this decrease, we estimated the impact of decreasing the number of contaminated cultures to 336 from 786. Based on the published literature, this decrease would represent a cost avoidance of $448,000 to $19 million and a potential prevention of 2016 days of unnecessary length of slay. By decreasing the blood culture contamination rate from 4.4% to 1.9%, we have significantly improved the quality and safety of our patient care while decreasing hospital length of stay, medical costs, and unnecessary antibiotic use.

Author Disclosure:

G, Bowling, none; L Leykum, none.

To cite this abstract:

Bowling G, Leykum L. Decreasing the Rate of Contaminated Blood Cultures. Abstract published at Hospital Medicine 2010, April 8-11, Washington, D.C. Abstract 156. Journal of Hospital Medicine. 2010; 5 (suppl 1). Accessed April 3, 2020.

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