Intern Guide: Treatment of Hypokalemia and Hyperkalemia

Author: E. Chen, D.O.
Reviewer: V. Dimov, M.D.

A review of the treatment of hypokalemia and hyperkalemia in an inpatient setting.


- Check renal function
- Check magnesium levels
- Check for alkalosis or acidosis
- Also search for causes

Rule of thumb in patients with normal renal function: every 10 mEq KCL given will raise the serum potassium level by 0.1 mmol/dL.

If patient can receive PO, then give PO potassium.

When to give IV potassium?
We have searched many articles and did not find an evidence-based guideline. The consensus seems to be to give IV potassium along with PO when potassium level falls below 3.3 mEq/L. Of course, if patient is NPO, you should give IV potassium only.

Sliding scale for potassium replacement:

If potassium is:
3.8-3.9, give 20 mEq of KCL
3.6-3.7, give 40 mEq of KCL
3.4-3.5, give 60 mEq of KCL
3.2-3.3 , give 80 mEq of KCL
3.0-3.1 , give 100 mEq of KCL


This is a medical emergency. Please review the current AHA/CPR guidelines for treatment of hyperkalemia on

Evaluate with ECG, electrolytes, BUN, Cr, and glucose.

Transfer to telemetry if K is higher than 6.5 mmol/dL or if ECG abnormalities (peaked T waves, QRS widening).

If ECG abnormalities are present, give one ampule of calcium gluconate IV over 3 minutes. It may be repeated in 5 minutes, if ECG does not improve

Be very cautious if patient is on Digoxin, you may have to infuse calcium much slowly over an hour and watch for Digoxin toxicity.

In all patients with K higher than 5.5 mmol/dL consider:

- Low K diet
- D/C salt substitutes, KCL, potassium-sparing agents, beta blockers, ACEi/ARB, NSAIDs and look for suitable substitutes.

Treat hyperkalemia with one or more of the following:
- 10-15 U of regular insulin with one ampule of D50 IV Q2-3 hrs or 10 units of regular insulin in 500 ml of D20 infused over an hour
- 10-20 mg of albuterol by nebulizer (remember one amp of premixed albuterol is 2.5 mg)
- 1-2 amps (50-100 mmol NaHCO3) IV over 10-20 minutes (onset in 20 mins, lasts 2 hours). Do not give with calcium, or will precipitate. Give if the patient is in metabolic acidosis.

Kayexalate (sodium polystyrene sulfonate) 20-30 gms PO, or retention enema 50 gms in 200 cc water with 50 gms of sorbital or 200 cc of D20. PO works best. Avoid if bowel obstruction. Watch for sodium overload.


Treating Hyperkalemia (High Blood Potassium) According to the New 2005 CPR Guidelines -



Related Reading

How a Nephrologist Treats Acute Hyperkalemia. Renal Fellow Network, 02/2009.
Among patients with AMI, the lowest mortality was observed with potassium levels between 3.5 and 4.5 mEq/L. JAMA, 2012.

Published: 01/30/2006
Updated: 02/22/2010


  1. too good

    Dr pankaj budhiraja

  2. dude, hypokalemia occurs in alkalosis

  3. True.

    Hypokalemia in alkalosis.

    Hyperkalemia in acidosis.

    1. True, you'll see an extracellular hypokalemia with alkalosis and an extracellular hyperkalemia in acidosis. Don't forget the big picture though, acidosis can cause a serum hyperkalemia, but that's because it causes potassium to shift from its intracellular state. Therefore, acidosis causes someone to be intracellulary depleted of potassium. In DKA, the initial potassium is usually high --> this is due to the acidosis. Although the potassium is high, the acidosis caused the cells to lose potassium - making them intracellulary hypokalemic.