A case of factitious hyponatremia and hypokalemia due to the presence of fibrin gel in serum

Abstract

Abstract:We describe here the case of a 84-year-old woman under warfarin therapy for atrial fibrillation, who was admitted to the Emergency Department for severe gluteal hemorrhage. Blood samples were drawn after patient admission and transported within 20 min to the laboratory. Results of laboratory testing revealed a markedly increased value of international normalized ratio and extremely low values of serum sodium (60 mmol/L) and potassium (1.4 mmol/L). A second serum sample was collected approximately 2 h after the former, showing normal values of both sodium (145 mmol/L) and potassium (3.5 mmol/L). The analysis of the specimen collected upon patient admission revealed the presence of a small, transparent fibrin gel in the serum, which was partially aspirated by the sample probe of the instrument. This case underscores the importance that serum samples need to be allowed to clot completely prior to centrifugation and analysis, especially those collected from patients under anticoagulant treatment.

Multiple myeloma and acquired von Willebrand disease: a combined cause of preanalytical interference causing gel formation?

“…Fibrin gel formation in clot activator tubes sufficient to cause interference in biochemical analysis has been reported as an issue in patients on anticoagulant therapy; their samples may require longer to clot prior to centrifugation than those from other patients. 18 Our patient had a low factor VIII level consistent with the diagnosis of acquired VWD and this would lead to prolongation of his clotting time via the intrinsic pathway.…”

The economic impact of poor sample quality in clinical chemistry laboratories: results from a global survey

“…For example, measurement of electrolytes with instruments using an ion selective electrode might be associated with an increased risk of aspirating fibrin and/or gel in samples and affecting probe performance. 24 Given these important considerations, future studies (including follow-on surveys or observational laboratory-based studies) focused on evaluating the comparative ability and corresponding cost-effectiveness of the various methods used to detect sample quality issues (e.g. visual inspection, preanalytics, detection by automated analyser and discovery of rejected results) are warranted.…”