Plasma osmolality measures the solute concentration in blood and is vital for assessing the osmotic balance in the body. This calculator helps health professionals and patients quickly compute osmolality to aid in clinical decisions. It is particularly useful in diagnosing conditions related to fluid and electrolyte imbalances.
Formula of Plasma Osmolality Calculator
The calculation of plasma osmolality can be performed using the following formula:
Where:
- [Na+] is the sodium concentration in mmol/L, a major determinant of plasma osmolality.
- [Glucose], measured in mg/dL, influences osmolality as it is a key osmotically active molecule.
- [BUN] (Blood Urea Nitrogen), also in mg/dL, contributes to the total osmolality, especially in kidney-related conditions.
Useful Table for Common Conversions
To assist with calculations, here’s a table providing common values and conversions necessary for using the plasma osmolality calculator:
| Substance | Normal Range | Conversion Factor |
|---|---|---|
| Sodium | 135-145 mmol/L | – |
| Glucose | 70-110 mg/dL | /18 |
| BUN | 7-20 mg/dL | /2.8 |
This table is designed to simplify the use of the calculator by providing ready-to-use data, helping users avoid manual conversions.
Example of Plasma Osmolality Calculator
Let’s consider a patient with the following lab results:
- Sodium: 140 mmol/L
- Glucose: 90 mg/dL
- BUN: 14 mg/dL
Using the plasma osmolality formula: Plasma Osmolality = 2 * 140 + 90 / 18 + 14 / 2.8 = 296.93 mOsm/kg
This calculated value can help assess the patient’s hydration status and kidney function.
Most Common FAQs
Plasma osmolality is a measure of the concentration of solutes in the blood, important for managing fluid balance and diagnosing kidney and hormonal disorders.
It depends on the underlying condition but is crucial during the diagnosis and monitoring of critical conditions such as diabetes insipidus or kidney disease.
Yes, while the normal ranges might differ, the calculator can be adapt for use in veterinary medicine with appropriate adjustments to the input values.