What treatment should be given for hyperkalemia?

Treatment of Hyperkalemia

For elevated potassium, immediately assess severity and ECG changes, then proceed with a three-step approach: (1) stabilize cardiac membranes with IV calcium, (2) shift potassium into cells with insulin/glucose and beta-agonists, and (3) eliminate potassium from the body with diuretics, potassium binders, or hemodialysis. 1

Severity Classification and Initial Assessment

• Mild hyperkalemia: 5.0-5.9 mEq/L 1, 2
• Moderate hyperkalemia: 6.0-6.4 mEq/L 1, 2
• Severe hyperkalemia: ≥6.5 mEq/L (life-threatening) 1, 2

ECG changes (peaked T waves, flattened P waves, prolonged PR interval, widened QRS) mandate urgent treatment regardless of the potassium level. 1, 2 These cardiac manifestations indicate imminent risk of fatal arrhythmias and take priority over laboratory values alone. 3

Before initiating aggressive treatment, exclude pseudo-hyperkalemia from hemolysis or improper blood sampling by repeating the measurement with appropriate technique or arterial sampling. 4, 2

Step 1: Cardiac Membrane Stabilization (Immediate - Within 1-3 Minutes)

Administer IV calcium first in any patient with ECG changes or severe hyperkalemia (≥6.5 mEq/L). 1

Preferred option:

• Calcium chloride 10%: 5-10 mL (500-1000 mg) IV over 2-5 minutes 1, 2
• Provides more rapid increase in ionized calcium than calcium gluconate, making it more effective in critically ill patients 2
• Must be given through central venous catheter when possible, as extravasation through peripheral IV causes severe tissue injury 2

Alternative option:

• Calcium gluconate 10%: 15-30 mL IV over 2-5 minutes 1, 2
• Safer for peripheral IV administration 2

Critical caveat: Calcium does NOT lower serum potassium—it only protects against arrhythmias by stabilizing cardiac membranes. 1, 2 Effects begin within 1-3 minutes but last only 30-60 minutes, so you must proceed immediately to Steps 2 and 3. 1, 2 Monitor heart rate during administration and stop if symptomatic bradycardia occurs. 2

Step 2: Shift Potassium Into Cells (Onset 15-30 Minutes, Duration 4-6 Hours)

Use multiple agents simultaneously for additive effect:

Insulin with glucose (most effective):

• 10 units regular insulin IV with 25g glucose (50 mL of D50W) over 15-30 minutes 1, 2
• Verify potassium is not below 3.3 mEq/L before administering insulin 2
• Monitor glucose every 2-4 hours to prevent hypoglycemia, especially in patients with low baseline glucose, no diabetes, female sex, or renal dysfunction 2
• Can be repeated every 4-6 hours if hyperkalemia persists, with careful monitoring of potassium and glucose 2

Nebulized beta-2 agonists:

• Albuterol 10-20 mg nebulized over 15 minutes 1, 2
• Reduces serum potassium by approximately 0.5-1.0 mEq/L 1
• Use concurrently with insulin/glucose for additive effect 1

Sodium bicarbonate (only if metabolic acidosis present):

• 50 mEq IV over 5 minutes 1, 2
• Most effective when pH < 7.35 and bicarbonate < 22 mEq/L 2
• Works by countering acidosis-induced potassium release and increasing distal sodium delivery to promote renal potassium excretion 2
• Effects take 30-60 minutes to manifest 2

Important warning: These are temporary measures lasting only 1-4 hours, and rebound hyperkalemia can occur after 2 hours. 1 You must initiate potassium elimination strategies (Step 3) immediately to prevent rebound. 1

Step 3: Eliminate Potassium From Body (Definitive Treatment)

Loop diuretics (if adequate renal function):

• Furosemide 40-80 mg IV 1, 2
• Only effective in patients with functioning kidneys 1
• Can be combined with sodium bicarbonate to enhance potassium excretion through increased distal sodium delivery 2

Potassium binders:

• Sodium polystyrene sulfonate (Kayexalate): 15-50 g orally or rectally with sorbitol 1
• FDA indication: Treatment of hyperkalemia, but NOT for emergency use due to delayed onset of action 5
• Critical warning: Concomitant sorbitol use is NOT recommended due to risk of intestinal necrosis, which can be fatal 5
• Contraindicated in obstructive bowel disease, neonates with reduced gut motility, and patients without normal bowel function 5
• Administer at least 3 hours before or after other oral medications (6 hours in gastroparesis) 5
• Average adult dose: 15-60 g daily orally in divided doses, or 30-50 g rectally every 6 hours 5

Newer potassium binders (preferred for chronic management):

• Patiromer and sodium zirconium cyclosilicate are safer alternatives to traditional cation exchange resins 1, 2
• Better safety profile without the intestinal necrosis risk associated with sorbitol 1

Hemodialysis:

• Most effective method for severe hyperkalemia, especially in renal failure 1, 2
• Indicated for refractory cases not responding to medical treatment 3, 6
• Should be initiated urgently in patients with potassium >6.5 mEq/L who have inadequate renal function 3

Chronic and Recurrent Hyperkalemia Management

For patients on RAAS inhibitors (ACE inhibitors, ARBs, mineralocorticoid antagonists):

• When potassium >5.0 mEq/L: Initiate approved potassium-lowering agent, monitor levels closely, and MAINTAIN RAAS inhibitor therapy unless alternative treatable cause is identified 1, 2
• When potassium >6.5 mEq/L: Discontinue or reduce RAAS inhibitor temporarily, initiate potassium-lowering agent, monitor closely 1

The rationale is that RAAS inhibitors reduce mortality and morbidity in cardiovascular disease, so maintaining these life-saving medications with potassium binders is preferable to discontinuation. 4, 2 A substantial proportion of patients have RAAS therapy inappropriately discontinued after a single hyperkalemia episode, which increases their mortality risk. 4

Additional chronic management strategies:

• Review and adjust medications contributing to hyperkalemia: ACE inhibitors, ARBs, MRAs, NSAIDs, beta-blockers 2
• Dietary potassium restriction with close adherence monitoring 7
• Loop or thiazide diuretics to promote urinary potassium excretion 2
• Monitor potassium levels 7-10 days after starting or increasing RAAS inhibitor doses 2
• Higher-risk populations (CKD, heart failure, diabetes) require more frequent monitoring 2, 7

Common Pitfalls to Avoid

• Never rely on calcium alone—it does not lower potassium and lasts only 30-60 minutes 1, 2
• Never use sorbitol with sodium polystyrene sulfonate due to fatal intestinal necrosis risk 5
• Never forget to monitor for rebound hyperkalemia after temporary shifting agents wear off (2-4 hours) 1
• Never discontinue RAAS inhibitors prematurely in cardiovascular disease patients—use potassium binders instead 4, 1
• Never use sodium polystyrene sulfonate as emergency treatment—it has delayed onset and is not FDA-approved for acute management 5
• Never administer insulin without checking baseline potassium is >3.3 mEq/L to avoid dangerous hypokalemia 2