Isotonic hyponatremia Isotonic hyponatremia Isotonic hyponatremia is a form of hyponatremia with mOsm measured between 280 and 295. It can be associated with pseudohyponatremia, or with isotonic infusion of glucose or mannitol. Certain conditions, such as extraordinarily high blood levels of lipid (hyperlipidemia/hypertriglyceridemia) or protein (hyperparaproteinemia), magnify the electrolyte exclusion effect. This interferes with the measurement of serum sodium concentration by certain methods, leading to an erroneously low "measurement" of sodium, or pseudohyponatremia. The methods affected are the flame-photometric and indirect (but not direct) ion-selective electrode assays. This is distinct from a true dilutional hyponatremia that can be caused by an osmotic
Serum (blood) Serum (blood) In blood, the serum () is the component that is neither a blood cell (serum does not contain white blood cells- leukocytes, or red blood cells- erythrocytes), nor a clotting factor; it is the blood plasma not including the fibrinogens. Serum includes all proteins not used in blood clotting and all the electrolytes, antibodies, antigens, hormones, and any exogenous substances (e.g., drugs and microorganisms). The study of serum is serology. Serum is used in numerous diagnostic tests, as well as blood typing. Measurements of serum concentrations has proved useful in many fields including clinical trials of therapeutic vs