21 g needle vs 23 g butterfly

Published

I work in geriatrics and I have noticed that I get a higher rate of hemolysis and false positive hyperkalemia with a 21 g needle versus a 23 g butterfly. I tried not to tie the tourniquet too tightly. I've even tried drawing without a tourniquet. Same results. What am I doing wrong? Does anyone have any tips to prevent this from happening?

Up Vote Up Vote ×
Specializes in Vascular Access.

Logically it does not compute, I agree.. but I'd have to ask you: How long was the tourniquet on? Did you make sure the alcohol was dry, before cannulating? Did you erroneously shake the red top after drawing the specimen? Did the specimen get overheated? Was the blood tube expired? How was it transported? Now, not all of these will create a situation where K elevates, but proper procedure and care is essential for good outcomes.

Up Vote Up Vote ×
Logically it does not compute, I agree.. but I'd have to ask you: How long was the tourniquet on? Did you make sure the alcohol was dry, before cannulating? Did you erroneously shake the red top after drawing the specimen? Did the specimen get overheated? Was the blood tube expired? How was it transported? Now, not all of these will create a situation where K elevates, but proper procedure and care is essential for good outcomes.

Thank you for your response. I think that I did in fact shake the red tube. I thought this was required :( None of the other things you suggested happened. Thanks again.

Up Vote Up Vote ×
Specializes in Pediatrics, Emergency, Trauma.
Thank you for your response. I think that I did in fact shake the red tube. I thought this was required :( None of the other things you suggested happened. Thanks again.

You can do a gentle inversion of the tubes:

BD Vacutainer® LabNotes - The Evolution of Evacuated Blood Collection Tubes

Up Vote Up Vote ×
Specializes in Vascular Access.

Gently invert the tubes with anticoagulants in them (purple top, blue top) Shaking a red top can rupture cells.

Up Vote Up Vote ×
Specializes in ICU, CVICU, E.R..

You're not supposed to shake the vacutainers. Just gently invert them back and forth.

Up Vote Up Vote ×
Specializes in Med-Surg, Emergency, CEN.

I agree with the above posters. Blood work is like a baby. Never shake or drop the blood work.

Up Vote Up Vote ×
+ Join the Discussion