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Transtubular Potassium Gradient
Aka: Transtubular Potassium Gradient
- See Also
- Potassium Homeostasis
- Serum Potassium
- Urine Potassium
- Hyperkalemia
- Hypokalemia
- Indications
- Hyperkalemia
- Precautions
- Results altered by Hyperkalemia Management
- Obtain lab sample prior to intervention if possible
- Do not delay treatment in emergent Hyperkalemia
- Labs
- Serum Potassium and Serum Osmolality
- Spot urine for Urine Potassium and Urine Osmolality
- Calculation: Transtubular Potassium Gradient (TTPG)
- TTPG = (Urine K++ x Serum Osm)/(Serum K++ x Urine Osm)
- Where K+ is Potassium and Osm is Osmolality
- Interpretation: Fractional Excretion of Potassium
- TTPG <6-8%: Renal cause of Hyperkalemia
- Hypoaldeosteronism suggested by very low TTPG
- TTPG >6-8: Extrarenal cause of Hyperkalemia
- May also be increased in Chronic Renal Failure