A patient with diabetic ketoacidosis often is potassium depleted. In addition, the serum potassium concentration tends to fall once insulin therapy is started.

Serum potassium should be monitored frequently during potassium replacement.


Urine output should be >= 1 mL per kg per hour before starting potassium replacement.


Serum Potassium

Potassium in IV Infusate


< 3 mmol/L

40 to 60 mmol/L

hold insulin until > 3.3

3 to 4 mmol/L

30 to 40 mmol/L


4 to 5.3 mmol/L

20 mmol/L


> 5.3 mmol/L

do not give

start potassium when below 5.3 mmol/L


The infusate is prepared by adding a potassium salt to 1 liter IV fluid to reach the final concentration.


Molecular weight of potassium: 39.1 grams

1 mmol potassium: 39.1 mg

Molecular weight of potassium chloride: 74.55grams

1 mmol potassium chloride: 74.55 mg


High intravenous doses of potassium may damage veins. Options to avoid this injury are to use a central line or to administer potassium by 2 separate peripheral IVs.


Alternatives to potassium chloride:

(1) oral potassium citrate (if the patient able to tolerate oral intake)

(2) IV potassium acetate

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