Potassium, magnesium, and phosphate replacement
Dose ranges by serum level for adult IV or oral replacement, with infusion limits.
Inputs
1 of 3Actual (total) body weight
Electrolyte
K in mEq/L; Mg and phosphate in mg/dL.
as labeled
Patient values are shared with every calculator.
When to use
- Adults with normal kidney function needing electrolyte replacement.
Pearls and pitfalls
- Reduce doses by about 50% with eGFR below 30 and recheck sooner.
- IV potassium: usually 10 mEq/h peripheral, up to 20 mEq/h central with cardiac monitoring.
- Correct magnesium first in refractory hypokalemia.
- Use potassium phosphate only if potassium is below 4.
Why use
The common replacement bands in one place, with rate limits.
Dose band by serum level (Kraft 2005); phosphate in mmol/kg