How to Calculate TTKG

TTKG, or transtubular potassium gradient, reflects the collection of potassium in cortical collecting ducts, or CCD, of the kidneys. By calculating TTKG, you are measuring the kidney's renal processing of potassium. "K" is the symbol for potassium.



The formula basically states that you should take potassium of urine, divided by the potassium of plasma, and then divide that by the osmolality of urine, divided by the osmolality of plasma. Osmolality refers to the measurement of osmoles per kilogram.

Instructions

• 1

  Go to an online TTKG calculator, such as one created by MDcalc.com, MedCalc3000.com or Nephromatic.com.

• 2

  Enter the values for the urine's potassium and osmolality and plasma's potassium and osmolality, which you have collected from the patient or test subject.

• 3

  Read the value created by the online TTKG calculator.

• 4

  Write the formula (Urine K / Plasma K) / (Urine osmolality / Plasma osmolality) if you prefer to do the calculation by hand. Enter the values asked for by the equation.

• 5

  Multiply the outcome of the equation by 100 to obtain the percentage.