[Pseudo-hyperkalaemia and chronical lymphoïd leukaemia: about one observation].

Mrs D., 82 years old, is addressed to the emergency department for back pain and dyspnea associated with heart failure. This patient had a venous potassium to 7.4 mmol/L (without hemolysis) without clinical repercussions or electrocardiographic signs. A significant gap is found with arterial kaliema (4.3 mmol/L) determined using gazometric apparatus. This gap is explained by the high leukocytosis of this patient (561 G/L) within a context of chronic lymphocytic leukemia as well as by the fragility of these cells revealed by specific rules for samples transport between the clinical departments and the central laboratory. An efficient talk between biologist and clinician identified this phenomenon for this patient and avoid mistakenly initiation of treatment. This event allows us to recall the different causes leading to overestimate the true value of kaliema when samples are managed at the central laboratory, and to describe the care of patients with true hyperkalemia.