How to manage severe hyperkalemia?

Management of Severe Hyperkalemia (Potassium 7.1 mEq/L)

A potassium level of 7.1 mEq/L is a medical emergency requiring immediate treatment with intravenous calcium to stabilize the cardiac membrane, followed by therapies to shift potassium intracellularly and remove it from the body. 1

Immediate Assessment (First 5 Minutes)

• Obtain an ECG immediately to assess for life-threatening cardiac toxicity including peaked T waves, flattened/absent P waves, prolonged PR interval, widened QRS complex, or sine-wave pattern 1, 2
• Verify the result is not pseudohyperkalemia by checking for hemolysis on the sample, though treatment should not be delayed if clinical suspicion is high 3
• Place patient on continuous cardiac monitoring 1

Step 1: Cardiac Membrane Stabilization (Acts in 1-3 Minutes)

Administer calcium immediately regardless of ECG findings at this potassium level:

• Calcium gluconate 10%: 15-30 mL IV over 2-5 minutes OR calcium chloride 10%: 5-10 mL (500-1000 mg) IV over 2-5 minutes 4, 1
• Calcium antagonizes the cardiac membrane effects of hyperkalemia within 1-3 minutes but does NOT lower serum potassium 4, 1
• If no effect observed within 5-10 minutes, repeat the dose 4
• Effect is temporary (30-60 minutes), so additional potassium-lowering measures must follow immediately 1

Step 2: Shift Potassium Intracellularly (Acts in 30-60 Minutes)

Administer all three therapies simultaneously for maximum effect:

• Insulin with glucose: 10 units regular insulin with 25g glucose (50 mL of D50) IV over 15-30 minutes 4, 1, 2
• Nebulized albuterol: 10-20 mg nebulized over 15 minutes 4, 1, 2
• Sodium bicarbonate: 50 mEq IV over 5 minutes (especially if metabolic acidosis present, though can be used regardless) 4, 1

These therapies redistribute potassium into cells but do not remove it from the body, so total body potassium remains elevated 4

Step 3: Remove Potassium from Body (Acts in Hours)

• Furosemide 40-80 mg IV if patient has adequate renal function and is not oliguric 4, 1
• Sodium polystyrene sulfonate (Kayexalate) 15-50g with sorbitol orally or rectally 1, 5
  • Note: This is NOT for emergency treatment due to delayed onset of action 5
  • Avoid concomitant sorbitol due to risk of intestinal necrosis 5
• Hemodialysis for patients with oliguria, end-stage renal disease, or refractory hyperkalemia 4, 1

Identify and Address Underlying Causes

• Review medications immediately: Stop or reduce RAAS inhibitors (ACE inhibitors, ARBs), potassium-sparing diuretics, NSAIDs, and beta-blockers 2, 3
• Assess renal function with creatinine and eGFR 4
• Check for metabolic acidosis which promotes potassium shift out of cells 4
• Consider adrenal insufficiency in appropriate clinical context 3

Critical Pitfalls to Avoid

• Do NOT delay calcium administration while waiting for ECG or repeat potassium levels - at 7.1 mEq/L, cardiac arrest risk is immediate 1, 6
• Do NOT administer calcium through the same IV line as sodium bicarbonate (will precipitate) 1
• Do NOT rely on sodium polystyrene sulfonate alone for acute management - it takes hours to work 5
• Do NOT give insulin without glucose - severe hypoglycemia can occur 4
• Monitor glucose closely after insulin/glucose administration to prevent rebound hypoglycemia 7

Monitoring During Treatment

• Continuous cardiac monitoring throughout treatment 1
• Recheck potassium within 1-2 hours after initial treatment to assess response 3
• Monitor for hypoglycemia 1-2 hours after insulin administration 7
• Check calcium and magnesium levels as sodium polystyrene sulfonate can cause depletion 5

Disposition

• Hospital admission is mandatory for potassium >6.0 mEq/L, regardless of symptoms or ECG changes 3
• At 7.1 mEq/L, this patient requires intensive monitoring until potassium is consistently below 6.0 mEq/L 3