Routine Blood Collections
Why is the light blue sodium citrate tube drawn before serum, heparin, and EDTA tubes?
- AAdditives from those tubes could alter coagulation results
- BCitrate tubes have the strongest vacuum and must go first
- CCitrate tubes need the fast flow that occurs at the start
- DCitrate flushes tissue fluid out of the needle for later tubes
Not B. Vacuum depends on each tube's draw volume, not its additive, and it does not set the order of draw.
A is right. Clot activator, heparin, and EDTA can all interfere with clotting tests if they are carried into the citrate tube. Drawing light blue before them protects coagulation results such as the PT and aPTT.