What is the TTKG Calculator | Transtubular Potassium Gradient Tool?

The TTKG Calculator | Transtubular Potassium Gradient Tool is a free online tool that helps you perform health calculations quickly and accurately. Simply enter your values and get instant results.

How do I use the TTKG Calculator | Transtubular Potassium Gradient Tool?

Enter the required values in the input fields, select your preferred units if applicable, and the calculator will automatically compute the results. The interface is designed to be intuitive and easy to use.

Is the TTKG Calculator | Transtubular Potassium Gradient Tool free to use?

Yes, the TTKG Calculator | Transtubular Potassium Gradient Tool is completely free to use. There are no hidden fees, subscriptions, or limitations on the number of calculations you can perform.

Can I use the TTKG Calculator | Transtubular Potassium Gradient Tool on mobile devices?

Yes, the TTKG Calculator | Transtubular Potassium Gradient Tool is fully responsive and works seamlessly on all devices including smartphones, tablets, and desktop computers.

How accurate is the TTKG Calculator | Transtubular Potassium Gradient Tool?

The TTKG Calculator | Transtubular Potassium Gradient Tool uses precise mathematical formulas and algorithms to ensure accurate results. However, always verify critical calculations with professional standards or consultants when needed.

Home/Health/TTKG Calculator

Transtubular Potassium Gradient (TTKG)

Assess renal potassium handling in hyper- or hypokalemia

Enter Values

Clinical Context

Urine K+ (mEq/L)

Serum K+ (mEq/L)

Urine Osm (mOsm/kg)

Serum Osm (mOsm/kg)

Formula

TTKG = (UK/SK) / (UOsm/SOsm)

Requires: Urine Osm > Serum Osm, Urine Na > 25 mEq/L

TTKG Interpretation

In Hyperkalemia

TTKG >10: Appropriate (extrarenal cause)
TTKG <7: Impaired K+ excretion (renal cause)

In Hypokalemia

TTKG <3: Appropriate (extrarenal cause)
TTKG >4: Renal K+ wasting

Causes of Abnormal K+ Handling

Impaired K+ Excretion (Low TTKG in Hyperkalemia)

Hypoaldosteronism (Type 4 RTA)
ACE inhibitors / ARBs
K+-sparing diuretics (spironolactone, amiloride)
NSAIDs (decrease renin)
Heparin (inhibits aldosterone synthesis)
Trimethoprim (blocks ENaC)

Renal K+ Wasting (High TTKG in Hypokalemia)

Primary hyperaldosteronism
Diuretics (thiazides, loops)
Bartter syndrome
Gitelman syndrome
Hypomagnesemia
Cushing syndrome

Limitations of TTKG

Requirements for Valid TTKG

Urine osmolality > serum osmolality
Urine sodium > 25 mEq/L
Steady state (not acute K+ shifts)

Recent Controversy

Some studies question TTKG validity due to urea recycling assumptions. Consider as one piece of clinical picture, not definitive.

Frequently Asked Questions

What does TTKG measure?

TTKG estimates the potassium gradient in the cortical collecting duct, reflecting aldosterone activity and renal K+ secretion capacity.

Why must urine be concentrated?

The formula assumes water reabsorption in the medullary collecting duct. Dilute urine violates this assumption and makes TTKG unreliable.

Can I use TTKG if patient is on diuretics?

Use with caution. Diuretics affect urine electrolytes and osmolality. Results may be difficult to interpret. Consider stopping diuretics if safe.

What is the normal TTKG?

On a normal diet, TTKG is typically 8-9. It should increase to >10 in hyperkalemia (more K+ excretion) and decrease to <3 in hypokalemia (K+ conservation).

How does aldosterone affect TTKG?

Aldosterone increases K+ secretion in the collecting duct. High aldosterone = high TTKG. Low aldosterone = low TTKG.

Should I rely solely on TTKG?

No. TTKG is one tool among many. Use in conjunction with clinical history, serum/urine electrolytes, aldosterone/renin levels, and medication review.

Clinical Pearl

In unexplained hyperkalemia with low TTKG, always check: ACEi/ARBs, NSAIDs, K+-sparing diuretics, TMP-SMX, heparin, and aldosterone/renin levels.

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