Adjustment of lactate dehydrogenase concentration results according to the haemolysis index following in vitro haemolysis.

In the presence of haemolysis, the interpretation of the Lactate dehydrogenase (LDH) activity result is a major operational challenge for medical laboratories: if the origin is intravascular, then the measurement will reflect the clinical reality, but in extravascular haemolysis, the laboratory will be confronted with an artefactual increase leading to false-positive high results. The aim of our study was to evaluate the adjustment of LDH concentration results according to the haemolysis index (HI). After designed a mathematical model to correct the LDH measured as a function of the haemolysis index using a Cobas 8000 analyser (Roche diagnostics, Mannheim, Germany), LDH measurement of seventy-four duplicate samples were tested before and after exposure to extravascular haemolysis process.

Study of haemolysis interference limit on serum potassium assay on Roche Cobas 8000 and evaluation of corrected potassium.

Roche Diagnostics decided a more restrictive haemolysis index (≤20 HI) for approval the release of serum potassium results. This study examined the risk of overestimating serum potassium results related to the HI according to the Ricos total error (±5.6%) and evaluated the approach of Martinez-Morillo and Alvarez to determine a corrected potassium.