hrvatski

Uloga medicinskog biokemičara u procesu postavljanja dijagnoze pseudohiperkalemije – prikaz slučaja

Introduction: Pseudohyperkalemiarepresents false elevated blood potassium level that can not be associated with in vivo pathophysiological conditions. The aim of this abstract is to present a patient`s case report of pseudohyperkalemia and show the diagnostic algorithm for hyperkalemia management. Case report: Patient (58) was admitted to Internal Clinic for treatment of persistent hyperkalemia during the past 2 years with values of 5.3 to 6.2 mmol/L. During hospitalization, all available laboratory diagnostic tools were used to exclude etiological factors of hyperkalemia. Results: Anamnestic data excluded existence of iatrogenic causes of hyperkalemia as Euthyrox was the only therapy. Potassium intake was limited by restriction diet. Laboratory tests determined regular kidney function and absence of neoplasms and metabolic acidosis. The Synachten test, normal level of insulin, aldosterone and renin activity excluded Addison’s disease. Pseudohypoaldosteronism was excluded due to normal osmolality of plasma and urine, normal urine concentration test and stable electrolyte secretion. Also, intra- and extravascualar haemolysis, leukocytosis and thrombocytosis were excluded. Sampling and transport to laboratory were performed according to current recommendations. Determination of potassium in heparin plasma after incubation at different temperatures (4 °C, 25 °C and 37 °C) with intervals of 2 and 4 hours after sampling, excluded heritable pseudohyperkalemia, as no increase in potassium at lower temperatures was observed. Cytologic examination showed no changes in erythrocytes morphology. Effect of any additives in serum test tubes was excluded. However, simultaneous sampling of serum, heparin plasma and heparinized full blood showed differences in potassium level more than 0.3-0.4 mmol/L. Conclusion: Etiology of true hyperkalemia remains undetermined. However, differences in potassium level between serum, plasma and full blood samples confirm pseudohyperkalemia as a result of potassium release from cells during coagulation process. This case is an example of successful and necessary communication between clinicians and medical biochemists in process of establishing final diagnosis.

hiperkalemija, pseudohiperkalemija

nije evidentirano