System and Diagnosis: mechanical disruption and hyperkalemia
Sometimes when a clinician heard about “the system” seems like a strange and theoretical issue. But there is a real influence of the environment in our practice as we can see in the next clinical vignette
CLINICAL CASE: A 72-year-old patient stayed at the hospital after a diagnosis of non-Hodgkin lymphoma with a leukemic pattern (more than 600X109/uL) and a pseudohyperkalemia (22,2 mE/L).
COMMENTS: Hyperleukocytosis is a a cause of pseuhyperkalemia. But in this case another factor is also related with this analytical finding: the mechanical disruption of the leukocytes produced during the transportation in a pneumatic tube.
Pseudohyperkalemia was first described by Hartmann and Mellinkof (1) associated with thrombocytosis and it was defined as measured potassium values not representing true potassium levels (serum to plasma difference > 0,4 mEq/L)in the abscence of clinical or electrocardiological data of hyperkalemia.
(1) Relationship of platelets to serum potassium concentration. J Clin Investigation 1955; 34:938(abstract).
Also: Kellerman PS, Thornbery JM. Pseudohyperkalemia Due to Pneumatic Tube Transport in a Leukemic Patient. Am J Kidney Dis 2005; 46:746-748