What is a normal TTKG?
The transtubular potassium gradient in the cortical collecting duct is an index reflecting conservation of potassium. A normal TTKG in normal subjects on normal diets is 8-9. With a potassium load the TTKG may rise to 11. In the face of Hyperkalemia, a low TTKG (<7) may indicate hypoaldosteronism.
How do you read TTKG?
A TTKG greater than 8 indicates that aldosterone is present and the collecting duct is responsive to it. A TTKG less than 5 in the presence of hyperkalemia indicates aldosterone deficiency or resistance.
What is TTKG test?
The transtubular potassium gradient (TTKG) is used to gauge renal potassium secretion by the cortical collecting duct, indirectly assessing mineralocorticoid bioactivity in patients who have hypo- or hyperkalemia.
When to use TTKG?
What does high TTKG mean?
During hyperkalemia or high potassium intake, more potassium should be excreted in the urine and the TTKG should be above 10. Low levels (<7) during hyperkalemia may indicate mineralocorticoid deficiency, especially if accompanied by hyponatremia and high urine Na.
How do you test for Hypoaldosteronism?
ASSAYS
- Differentiating between the different causes of hypoaldosteronism is done by measurement of the plasma renin activity (PRA), serum aldosterone, and serum cortisol.
- The PRA is measured by radioimmunoassay (RIA) for angiotensin I after plasma incubation at 37 degrees Celsius.
What is normal urine potassium level?
For adults, normal urine potassium values are generally 20 mEq/L in a random urine sample and 25 to 125 mEq per day in a 24 hour collection. Lower or higher urinary level may occur depending on the amount of potassium in your diet and the amount of potassium in your body.
What is your patients TTKG value?
Typical TTKG in a normal person on a normal diet is 8-9. During hyperkalemia or high potassium intake, more potassium should be excreted in the urine and the TTKG should be above 10.
What is pseudo hypo aldosteronism?
Pseudohypoaldosteronism (PHA) comprises a heterogeneous group of disorders of electrolyte metabolism characterized by an apparent state of renal tubular unresponsiveness or resistance to the action of aldosterone. It is manifested by hyperkalemia, metabolic acidosis, and a normal glomerular filtration rate (GFR).
Can NSAIDs cause hypoaldosteronism?
NSAIDs induced hyporeninemic hypoaldosteronism may cause hyperkalemia/type 4 RTA in susceptible patients.
How does the transtubular potassium gradient ( TTKG ) calculator work?
The transtubular potassium gradient calculator evaluates the conservation of potassium in the collecting ducts of the kidney. By comparing the K concentration in the kidney ducts with that from the peritubular capillaries, TTKG can help with the differential diagnosis of hyperkalemia and hypokalemia.
What should be the normal TTKG for potassium?
Notes The transtubular potassium gradient in the cortical collecting duct is an index reflecting conservation of potassium. A normal TTKG in normal subjects on normal diets is 8-9. With a potassium load the TTKG may rise to 11.
When to use TTKG for plasma and urine?
TTKG = (Urine K x Plasma osm) / (Plasma K x Urine osm) In theory, there are some restrictions to the above formula and that should be used only when urine osmolarity is above 300 mOsm/kg and urine sodium is above 25 mEq/L because it doesn’t exclude the occurrence of a possible potassium wasting syndrome.
What does it mean when TTKG is under 3?
TTKG index interpretation. TTKGs under 3 are consistent with potassium depletion or hypokalemia only if the regulatory mechanisms of the body are in place and there is a reduced urinary excretion of K. Low TTKGs accompanied by hyperkalemia suggests a type IV renal tubular acidosis.