Search results
Results from the WOW.Com Content Network
Whereas osmolality (with an "l") is defined as the number of osmoles (Osm) of solute per kilogram of solvent (osmol/kg or Osm/kg), osmolarity (with an "r") is defined as the number of osmoles of solute per liter (L) of solution (osmol/L or Osm/L). As such, larger numbers indicate a greater concentration of solutes in the plasma.
According to IUPAC, osmolality is the quotient of the negative natural logarithm of the rational activity of water and the molar mass of water, whereas osmolarity is the product of the osmolality and the mass density of water (also known as osmotic concentration). [1]
Urine osmolality in humans can range from approximately 50 to 1200 mOsm/kg, depending on whether the person has recently drunk a large quantity of water (the lower number) or has gone without water for a long time (the higher number). [2] Plasma osmolality with typical fluid intake often averages approximately 290 mOsm/kg H 2 O in humans. [2]
[2] 290 mOsm/kg is the presumed stool osmolality, and the measured concentration of sodium and potassium cations is doubled to account for the corresponding anions which must be present. [citation needed] A normal gap is between 50 and 100 mOsm/kg, [3] corresponding to the concentration of other solutes such as magnesium salts and sugars ...
The osmol gap is typically calculated with the following formula (all values in mmol/L): = = ([+] + [] + []) In non-SI laboratory units: Calculated osmolality = 2 x [Na mmol/L] + [glucose mg/dL] / 18 + [BUN mg/dL] / 2.8 + [ethanol/3.7] [3] (note: the values 18 and 2.8 convert mg/dL into mmol/L; the molecular weight of ethanol is 46, but empiric data shows that it does not act as an ideal ...
Importantly, it has a low osmolality, 240 mOsm/kg, according to Lauren Streicher, M.D., a professor of clinical obstetrics and gynecology at Northwestern University Feinberg School of Medicine in ...
Urine osmolality in mOsm/kg, after fluid deprivation [3] After desmopressin [3] or vasopressin; Normal > 800 > 800 (<10% increase) a defect in ADH production (central/neurogenic diabetes insipidus) < 300 > 800 (>50% increase) a defect in the kidneys' response to ADH production (nephrogenic diabetes insipidus) < 300 < 500 (<50% increase)
The fractional excretion of sodium (FE Na) is the percentage of the sodium filtered by the kidney which is excreted in the urine.It is measured in terms of plasma and urine sodium, rather than by the interpretation of urinary sodium concentration alone, as urinary sodium concentrations can vary with water reabsorption.