1. What is a Potassium Deficiency Calculator?

Definition: This calculator estimates the potassium deficiency in millimoles based on target and current potassium levels, and the distribution volume.

Purpose: It helps medical professionals determine the amount of potassium supplementation needed to correct hypokalemia.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( D \) — Potassium deficiency (mmol)
• \( K_t \) — Target potassium level (mmol/L)
• \( K_c \) — Current potassium level (mmol/L)
• \( V \) — Distribution volume (L)

Explanation: The difference between target and current potassium levels is multiplied by the distribution volume to calculate the total deficiency.

3. Importance of Potassium Deficiency Calculation

Details: Accurate potassium deficiency estimation ensures proper correction of hypokalemia while avoiding overcorrection which can lead to hyperkalemia.

4. Using the Calculator

Tips: Enter the target potassium level (default 4.0 mmol/L), current potassium level, and distribution volume (default 40L). All values must be > 0 (except current which can be 0).

5. Frequently Asked Questions (FAQ)

Q1: What is a typical target potassium level?
A: The normal range is 3.5-5.0 mmol/L, with 4.0 mmol/L often used as a target for mild-moderate deficiency.

Q2: How is distribution volume determined?
A: For adults, 40L is commonly used (total body water). Adjust based on patient size (e.g., 30L for small adults, 50L for large adults).

Q3: Why is potassium replacement calculated in mmol?
A: Potassium supplements are dosed in mmol, making this the most clinically relevant unit for replacement calculations.

Q4: How should the calculated deficiency be administered?
A: Typically given IV (maximum 20mmol/hr in peripheral line) or orally, divided over several doses with monitoring.

Q5: Does this account for ongoing losses?
A: No, additional potassium may be needed for ongoing losses (e.g., diarrhea, diuretics). Monitor serum levels closely.