Diversion of initial blood flow to prevent whole-blood contamination by skin surface bacteria: an in vitro model.

BACKGROUND: Sepsis arising from the transfusion of bacterially contaminated platelet components continues to be an infrequent, yet serious transfusion complication. Skin organisms are implicated in a number of these septic episodes. A model system was used to investigate if a skin organism's bioburden in blood components could be reduced by diverting the first few mL of whole blood away from the primary container. STUDY DESIGN AND METHODS: A sterile medication site was inserted into a bag containing sterile saline or whole blood; the site was deliberately contaminated with Staphylococcus aureus and allowed to dry. After needle puncture of the contaminated medication site, bacteria levels were measured 1) in successive 7-mL tubes of blood or saline drawn through a diversion arm, 2) in 40 mL of a connected transfer pack, and 3) in blood or saline from a needle puncture of the original container via another sterile medication port.
RESULTS: Diverting the first 21 to 42 mL of saline or whole blood reduces the downstream bioburden of deliberately introduced surface S. aureus by approximately 1 log.
CONCLUSION: Development of a diversion system for collection of whole blood in sample tubes before filling the primary container may reduce the bioburden of subsequently prepared components and thereby the frequency of sepsis due to skin organisms.