To calculate the osmolality of urine:
\[ Osm = 2 \times (Na + K) + \left(\frac{Glucose}{18}\right) + \left(\frac{BUN}{2.8}\right) \]
Where:
Osmolality urine is a medical test that measures the concentration of solutes in the urine. Solutes are substances that are dissolved in a liquid, in this case, the liquid is urine. The test is used to evaluate the kidney’s ability to concentrate or dilute urine, which is a key function of the kidneys. It can help diagnose various conditions that can affect the balance of fluids in the body, such as diabetes insipidus, dehydration, or overhydration. The test is usually performed by collecting a urine sample in a clean container, which is then sent to a laboratory for analysis. The results are expressed in milliosmoles per kilogram (mOsm/kg) and the normal range can vary depending on the laboratory, but it is typically between 500 to 800 mOsm/kg in adults.
Let's assume the following values:
Using the formula:
\[ Osm = 2 \times (140 + 40) + \left(\frac{90}{18}\right) + \left(\frac{30}{2.8}\right) = 2 \times 180 + 5 + 10.71 = 360 + 5 + 10.71 = 375.71 \, \text{mOsm/kg} \]
The Osmolality of Urine is 375.71 mOsm/kg.
Let's assume the following values:
Using the formula:
\[ Osm = 2 \times (150 + 50) + \left(\frac{100}{18}\right) + \left(\frac{35}{2.8}\right) = 2 \times 200 + 5.56 + 12.5 = 400 + 5.56 + 12.5 = 418.06 \, \text{mOsm/kg} \]
The Osmolality of Urine is 418.06 mOsm/kg.