Potassium Correction Based on Changes in pH
Potassium related content
The relationship between serum potassium levels and changes in blood pH
varies widely depending on several factors.
declines in pH leads to increases in serum potassium, while increases in pH
leads to declining potassium levels. Several sources promote the use of
an older equation:
Old Rule of
K+ corrected = K+ level - [0.6 x (pH initial - pH current)/0.1]
K+ corrected: what the serum potassium would be in the absense
of the acid-base disorder.
The equation above was considered a rough estimate and further studies found
that there could be considerable variance between changes in blood pH and
the final impact on serum potassium levels. For example, declines in pH from
organic acidosis such as ketoacidosis (diabetes, starvation, ethanol) or
lactic acidosis (circulatory or respiratory failure, liver failure, sepsis,
cancer, other) leads to little or no effect on potassium levels.
Conversely, inorganic (mineral acidosis) from chronic renal failure for
example can cause major shifts out of cells leading to significant increases
in plasma potassium levels
mmol/L or mEq/L
Select any that apply
Organic acidosis present e.g. lactic acidosis or
Non-organic (mineral acidosis) present e.g. chronic renal failure,
Type I (distal renal tubular acidosis), other
Respiratory or metabolic alkalosis present?
Respiratory acidosis present?
Androgue HJ, Madias NE. Changes in plasma potassium
concentration during acute acid-base disturbances. Am J
Aronson PS, and Giebisch G. Effects of pH on Potassium: New Explanations for
Old Observations. JASN November 2011, 22 (11) 1981-1989; DOI:
- Burnell JM, Scribner BH, Uyeno BT, Villamil MF.
The effect in humans of extracellular pH change on the relationship between
serum potassium concentration and intracellular potassium.
J Clin Invest. 1956;35(9):935.
- Fulop M. Serum potassium in lactic and keto acidosis. N
Engl J Med 1979; 300:1087–90.
- Rastergar A, Soleimani M.
Hypokalaemia and hyperkalaemia.
Postgrad Med J 2001;77:759–764.