Extreme care should be taken in order to avoid hemolysis of the specimen. When the specimen is hemolyzed, the concentration of analytes is changed and results are inaccurate. Some falsely increased results include potassium, magnesium, iron, lactate dehydrogenase, phosphorus, ammonia, and total protein. Some of the results falsely decreased include red blood cell count, hemoglobin, and hematocrit.
Reasons for hemolysis include contamination of the specimen with alcohol from the skin, milking the site, scraping the blood instead of allowing the blood to flow in the collection container. Vigorous mixing of the specimen tube will also cause hemolysis. In infant patients, there is an increase in red blood cell (RBC) fragility and increased RBC volume, which can cause hemolysis.