The reliability of serum potassium levels measured in blood from a central venous catheter
Nielsen, H.K.; Svanegaard, J.; Madsen, H.H.
Ugeskrift for Laeger 154(15): 1033-1035
1992
ISSN/ISBN: 0041-5782 PMID: 1566513 Document Number: 393751
A clinical investigation was undertaken to assess the agreement between serum potassium (S-K) (1) in the peripheral venous blood and S-K in ten samples of 2 ml blood taken via a central venous catheter (2) where fluid containing potassium had been infused prior to taking the blood-samples (3). The results revealed that in order that S-K in 95% (twice the SD) of the samples taken from the central venous catheter is to fall within +/- 0.5 mmol/l as compared with S-K in the peripheral blood, it is necessary to discard the first 12 ml of blood withdrawn.