I am keen to hear what others are doing = particularly in paediatrics with regard to blood collection from a CVC and whether blood is discarded - our current policy is to draw off 5 mL and discard - not great for children - but have been asked to find the evidence to help change the policy - our head of Biochemistry is concerned because the labs continued to get contaminated specimens so was keen to see the 5 mL stay - but is happy if I can provide alternate evidence - I have checked the SOP but its not directly mentioned but I do need to read that document more - happy to hear from anyone with comments and maybe guidelines for children's hospitals would be great too. thanks... Karen
Although this article is a bit old by now, it still ocntains very useful information.
1. Frey A. Drawing blood from vascular access devices: Evidence-based practice. Journal of Infusion Nursing. 2003;26(5):285-295.
For peds, you can use a stopcock method and a heparinized syringe attached to one side. Draw the discard volume, usually 3 times the internal volume of the catheter into the heparinzed syringe and leave it attached. Turn the stopcock to an empty syringe to draw your blood sample, then reinfuse the blood from the heparinized syringe followed by saline flushing. Then transfer the blood to the vacutainers using a needleless transfer devices. You can never reinfuse from a plain syringe or after it has been disconnected - clots and infection risks.
The other method is the mixing method explained in this lit review. Lynn
Lynn Hadaway, M.Ed., RN, BC, CRNI
Lynn Hadaway Associates, Inc.
126 Main Street, PO Box 10
Milner, GA 30257
Website http://www.hadawayassociates.com
Office Phone 770-358-7861
I consider 5 ml to be a large volume to discard and if the lab is getting erroneous results with that volume, I wonder what volume would be sufficient. I might look at other aspects of the procedure...is there an infusion going at the time...is it stopped for at least 60 seconds? Is saline flushed through the line before getting waste and sample?
The push-pull method can be effective in pediatric CVLs (but not small PICCs) and I think is what Lynn is referring to when she says mixing. I've also refered to it as rinsing. There are at least two articles that describe it in detail, sorry , don't have it in front of me but a search should yeild them.