Forum topic

8 posts / 0 new
Last post
Michelle Todd CRNI
Changing the injection cap prior to drawing a blood culture from a line

 How many of you are changing the injection cap to a sterile one just prior to doing a blood culture from a line? Have you seen any particular study on this. Our contam rates went down because nurses could not be trusted to scrub for 30 sec but they did place a sterile cap and then draw.

Alma Kooistra
Or how about removing the

Or how about removing the endcap, drawing the BC directly from the line and then placing a new sterile endcap?  This is up for discussion at our house right now........thinking about writing that into policy. 



Through a multidisciplinatry

Through a multidisciplinatry process we changed our policy to remove needleless connectors and draw directly from the catheter hub for central line blood cultures.  There was a study performed (can't remember off the top of my head) that showed a high incidence of false positives from central lines where the specimen was drawn through the connector as compared through a new needleless connector and a peripheral draw.  We decided to draw from the hub so that we knew the applied connector was free of any blood residue.

Drawing blood cultures from

Drawing blood cultures from any used needleless connector has a great chance of producing false positives. You can either remove and discard the old, add a new one then draw the BC or remove and discard the old one, draw the BC, then add a new one. There are no studies that have identified either of theses procedures to be superior to the other with regard to the accuracy of the BC. Lynn

Lynn Hadaway, M.Ed., RN, BC, CRNI

Lynn Hadaway Associates, Inc.

126 Main Street, PO Box 10

Milner, GA 30257


Office Phone 770-358-7861

drawing blood cultures

Lyn is so correct. What my staff does if remove the old cap, draw the blood and replace the cap with a new one.

Marvin Siegel RN CRNI

Director of Clinical Services

Town Total Health


Gwen Irwin
Changing the connector prior to drawing blood culture

There is one small published study (90 patients) that indicated the increased number of false positives with blood cultures drawn from existing connector.  Peripheral blood cultures closer matched the blood cultures drawn with new connector in place.  I will look for the reference.

Gwen Irwin

Austin, Texas

Gwen Irwin
Changing the connector prior to blood culture

Here is the reference:

Mathew A et al.  Central Catheter Blood Sampling; The Impact of Changing the Needleless Caps Prior to Collection.  JINS 30;4: 212-219.

Michelle Todd CRNI
We never draw directly from the hub for a BC

 We do change to a sterile injection cap just prior to drawing a BC, however, I never recommend drawing straight from the hub due to presumed increased risk of contamination. In addition, whenever I have seen a hub that has been drawn from, I usually see blood residue on the hub threads and I feel this is a great medium where microbes can grow. Apparently, the blood does not clear fully from the hub and when the new injection cap is placed, the blood in the hub transfers to the threads. What do you think Lynn?

Michelle Todd, CRNI--Head PICC Nurse, Vibra Specialty Hospital of Portland [email protected]

Log in or register to post comments