What is the acute management of hyperkalemia (elevated potassium levels)?

Acute Management of Hyperkalemia

For severe hyperkalemia (≥6.5 mEq/L) or any hyperkalemia with ECG changes, immediately administer intravenous calcium gluconate 15-30 mL (or calcium chloride 5-10 mL) over 2-5 minutes to stabilize the cardiac membrane, followed by insulin/glucose and beta-agonists to shift potassium intracellularly, then implement potassium removal strategies. 1, 2

Initial Assessment

Before initiating treatment, verify true hyperkalemia by ruling out pseudohyperkalemia from hemolysis, repeated fist clenching, or poor phlebotomy technique—repeat the sample with proper technique or arterial sampling if possible 1, 2. Obtain an ECG immediately, looking for peaked T waves, flattened or absent P waves, prolonged PR interval, widened QRS complex, or sine-wave pattern, though these findings are highly variable and less sensitive than laboratory values 1, 2, 3.

Classification and Urgency

Classify hyperkalemia as:

• Mild: 5.0-5.9 mEq/L 1
• Moderate: 6.0-6.4 mEq/L 1
• Severe: ≥6.5 mEq/L 1

Any ECG changes indicate urgent treatment regardless of potassium level 1, 2.

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

Administer calcium first in all patients with ECG changes or severe hyperkalemia 1, 2:

• Calcium gluconate 10%: 15-30 mL IV over 2-5 minutes (preferred in most settings) 1, 2
• OR calcium chloride 10%: 5-10 mL (500-1000 mg) IV over 2-5 minutes 2, 4

The American Heart Association recommends calcium as first-line treatment because it directly antagonizes cardiac membrane effects within 1-3 minutes 1, 2. Critical caveat: Calcium does NOT lower serum potassium—it only protects the heart temporarily (30-60 minutes) while other treatments take effect 1, 2. If no ECG improvement occurs within 5-10 minutes, repeat the calcium dose 2. Do not administer calcium through the same IV line as sodium bicarbonate 2.

Special consideration: In malignant hyperthermia with hyperkalemia, use calcium only in extremis as it may contribute to myoplasmic calcium overload 1.

Step 2: Shift Potassium Intracellularly (15-30 Minutes Onset)

Administer multiple agents simultaneously for additive effect:

Insulin/Glucose (Primary Agent)

• Standard dose: 10 units regular insulin IV with 25g glucose (50 mL D50W) over 15-30 minutes 1, 2
• Alternative dosing: Some protocols use 0.1 units/kg (approximately 5-7 units in adults) to reduce hypoglycemia risk 1
• Onset: 15-30 minutes; Duration: 4-6 hours 1
• Monitoring: Check glucose and potassium every 2-4 hours 1
• Repeat dosing: Can repeat every 4-6 hours if hyperkalemia persists 1
• Critical safety check: Verify potassium is not below 3.3 mEq/L before administering insulin 1
• High-risk patients for hypoglycemia: Low baseline glucose, no diabetes history, female sex, altered renal function 1

Beta-2 Agonists (Adjunctive)

• Albuterol/Salbutamol: 10-20 mg nebulized over 15 minutes 1, 2, 5
• Onset: 15-30 minutes; Duration: 2-4 hours 1
• Use as adjunctive therapy to augment insulin/glucose effects 1, 6

Sodium Bicarbonate (Only if Metabolic Acidosis Present)

• Dose: 50 mEq IV over 5 minutes 1, 2
• Indication: Use ONLY in patients with concurrent metabolic acidosis (pH <7.35, bicarbonate <22 mEq/L) 1
• Mechanism: Promotes potassium excretion through increased distal sodium delivery and counters acidosis-induced potassium release 1
• Onset: 30-60 minutes (slower than other agents) 1
• Common pitfall: Do NOT use in patients without metabolic acidosis—it is ineffective and potentially harmful 1

Step 3: Remove Potassium from Body (Hours)

Loop Diuretics (If Adequate Renal Function)

• Furosemide: 40-80 mg IV 1, 2
• Increases renal potassium excretion by stimulating flow to collecting ducts 1
• Only effective if kidney function is adequate 1

Potassium Binders (Subacute Treatment)

• Sodium polystyrene sulfonate (Kayexalate): 15-50 g oral or rectal 2, 7
• FDA limitation: NOT for emergency treatment due to delayed onset of action 7
• Contraindications: Hypersensitivity, obstructive bowel disease, neonates with reduced gut motility 7
• Warning: Cases of intestinal necrosis reported; concomitant use with sorbitol not recommended 7
• Drug interaction: Take other oral medications at least 3 hours before or after 7

Newer Potassium Binders (Chronic Management)

• Patiromer and sodium zirconium cyclosilicate: FDA-approved for long-term management 1, 8
• Role in acute setting requires further investigation 8

Hemodialysis (Most Effective Method)

• Indications: Severe hyperkalemia unresponsive to medical management, oliguria, end-stage renal disease, or renal failure 1, 2, 9
• Most reliable and effective method for potassium removal 1, 9, 6

Monitoring During Treatment

• Continuous cardiac monitoring is essential throughout treatment 2
• Check potassium levels every 2-4 hours after initial treatment 1
• Monitor glucose closely to prevent hypoglycemia from insulin 1
• Reassess ECG for resolution of changes 2

Key Pitfalls to Avoid

• Do not rely solely on ECG findings—they are highly variable and less sensitive than laboratory tests 1
• Remember that calcium, insulin, and beta-agonists do not remove potassium—they only temporize while definitive removal strategies are implemented 1
• Always administer glucose with insulin to prevent life-threatening hypoglycemia 1
• Do not use sodium bicarbonate without metabolic acidosis—it is only indicated when acidosis is present 1
• Verify true hyperkalemia before aggressive treatment to avoid treating pseudohyperkalemia 1, 2
• Beware of rebound hyperkalemia after temporary measures wear off (calcium at 30-60 minutes, insulin/glucose at 4-6 hours) 1, 2

Chronic Management Considerations

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

• If potassium >5.0 mEq/L: Initiate potassium-lowering agent and maintain RAAS inhibitor unless alternative cause identified 1
• If potassium >6.5 mEq/L: Temporarily discontinue or reduce RAAS inhibitor, initiate potassium-lowering agent, monitor closely 1
• Reassess potassium 7-10 days after starting or increasing RAAS inhibitor doses 1