How is TTKG calculated?

TTKG = (Urine K+ / Serum K+) divided by (Urine Osmolality / Serum Osmolality). This corrects urine potassium for water reabsorption in the medullary collecting duct.

What does a low TTKG indicate in hyperkalemia?

TTKG < 5-7 in a hyperkalemic patient suggests reduced aldosterone effect (hypoaldosteronism) or tubular resistance to aldosterone (type IV RTA, spironolactone use).

What does TTKG indicate in hypokalemia?

TTKG > 3 in a hypokalemic patient suggests renal potassium wasting (hyperaldosteronism, diuretics, Bartter/Gitelman syndrome). TTKG < 3 suggests extrarenal losses.

Transtubular Potassium Gradient (TTKG) Calculator

Calculate TTKG to assess renal potassium handling. Formula: (urine K / serum K) divided by (urine osmolality / serum osmolality). Normal > 8 during hyperkalemia indicates appropriate renal excretion.

Use the full interactive calculator below, or

Related Calculators

K+ pH Shift

Medical

Renal Dose Adjust