118 - Eliminating Blood Culture Contamination with an Initial-specimen Diversion Device

Background: Blood samples obtained via traditional venipuncture can become contaminated by superficial and deeply embedded skin flora.  We evaluated the hospital-wide use of an initial-specimen diversion device (ISDD) designed to shunt these microorganisms away from the culture bottle to reduce blood culture contamination (BCC) and sequelae: false-positive central line-associated bloodstream infections (CLABSIs), repeat blood culture draws, inappropriate antibiotic usage, increased patient length-of-stay and misdiagnosis.  The study aimed to show the proportion of blood cultures containing contaminants drawn by phlebotomy staff using the ISDD versus those drawn using traditional methods.  Nursing staff continued to use traditional methods to draw blood cultures in the emergency department (ED) and from inpatients.

Methods: Over a four-month trial at Stanford Health Care (SHC), 4,462 blood cultures were drawn by phlebotomy staff using the ISDD (Steripath Gen2, Magnolia Medical Technologies) in the ED and from inpatients; 922 blood cultures were obtained by phlebotomy staff using standard methods.  Additionally, 1,413 blood cultures were drawn by nursing staff using standard methods.  The number of matched sets (2 bottles [aerobic/anaerobic] plus 2 bottles [aerobic/anaerobic], with total volume 40 ml) obtained through traditional methods and by the ISDD were recorded.  Contaminants were defined by the National Healthcare Safety Network (NHSN).  In addition, sets in which 1 out of 4 bottles contained vancomycin-resistant Enterococcus (VRE) or Candida sp. were also recorded, even though these are not considered contaminants by the NHSN.

Results: Of 4,462 blood cultures obtained using the ISDD there were zero contaminants found (BCC rate 0%) versus 29 contaminated sets using traditional methods (BCC rate 3.15%).  Twenty-eight contaminants were observed from nursing staff blood culture draws (BCC rate 1.98%).  Zero false-positive CLABSIs were associated with use of the ISDD for the trial period.  No matched sets containing 1 of 4 bottles with VRE or Candida sp. were observed.Table: Stanford Health Care blood culture collection methods and contamination events (March 15, 2019 - July 21, 2019)


Conclusion: The trial results encourage adoption of the ISDD as standard practice for blood culture at SHC.