For a patient with a serum potassium of 6.5 mmol/L, what immediate medications and their dosages should be administered?

Emergency Management of Severe Hyperkalemia (Potassium 6.5 mEq/L)

For a patient with serum potassium of 6.5 mEq/L, you must immediately administer IV calcium gluconate 10% (15-30 mL over 2-5 minutes) to stabilize the cardiac membrane, followed simultaneously by insulin 10 units IV with 25 grams of dextrose (50 mL D50W) and nebulized albuterol 10-20 mg to shift potassium intracellularly, while arranging urgent hemodialysis if the patient has renal failure or ECG changes persist. 1, 2, 3

Immediate Assessment (Within 5 Minutes)

Obtain a 12-lead ECG immediately to assess for life-threatening cardiac manifestations of hyperkalemia, including peaked T waves, flattened P waves, prolonged PR interval, widened QRS complex, or sine-wave pattern. 1, 2 The presence of any ECG abnormality indicates a medical emergency requiring immediate treatment, even if the potassium level is being repeated to confirm the result. 1, 2

Do not delay treatment while waiting for repeat laboratory confirmation if ECG changes are present—ECG abnormalities indicate urgent need for cardiac membrane stabilization regardless of the exact potassium value. 1, 2

Verify the patient is on continuous cardiac telemetry monitoring, as severe hyperkalemia (≥6.5 mEq/L) carries extreme risk of ventricular fibrillation and cardiac arrest. 1, 2

Step 1: Cardiac Membrane Stabilization (Onset 1-3 Minutes)

Administer IV calcium gluconate 10% (15-30 mL) over 2-5 minutes as the first medication. 1, 2, 3 This provides immediate protection against fatal arrhythmias by stabilizing the cardiac membrane. 1, 2

• Calcium chloride 10% (5-10 mL, 500-1000 mg) IV over 2-5 minutes may be used instead if central venous access is available, as it is more potent than calcium gluconate. 1, 2
• Critical caveat: Calcium does NOT lower serum potassium—it only temporarily stabilizes the cardiac membrane for 30-60 minutes. 1, 2, 3
• Repeat the calcium dose if no ECG improvement is observed within 5-10 minutes. 1, 2
• Never administer calcium through the same IV line as sodium bicarbonate, as precipitation will occur. 4

Step 2: Intracellular Potassium Shift (Administer Simultaneously)

Insulin-Glucose Therapy (Onset 15-30 Minutes, Duration 4-6 Hours)

Give 10 units of regular insulin IV push together with 25 grams of dextrose (50 mL D50W). 1, 2, 3 This lowers serum potassium by approximately 0.5-1.2 mEq/L within 30-60 minutes. 1, 2

• Glucose must always accompany insulin to prevent life-threatening hypoglycemia. 1, 2
• Never give insulin without glucose—hypoglycemia can be fatal. 1, 2
• Monitor blood glucose closely, especially in patients with low baseline glucose, no history of diabetes, female sex, or altered renal function, as these factors increase hypoglycemia risk. 5

Beta-Agonist Therapy (Onset ~30 Minutes, Duration 2-4 Hours)

Administer nebulized albuterol 10-20 mg in 4 mL over 10-15 minutes. 1, 2, 3 This reduces potassium by 0.5-1.0 mEq/L and augments the insulin-glucose effect. 1, 2

• The dose may be repeated every 2 hours if needed. 1, 2
• The combined insulin-glucose plus nebulized beta-agonist regimen is more effective than either modality alone. 1, 2

Sodium Bicarbonate (ONLY with Metabolic Acidosis)

Administer sodium bicarbonate 50 mEq IV over 5 minutes ONLY if metabolic acidosis is documented (pH <7.35 and bicarbonate <22 mEq/L). 1, 2, 3

• Do NOT use sodium bicarbonate without documented metabolic acidosis—it is ineffective as monotherapy for hyperkalemia and wastes time. 1, 2, 3
• The onset of action is slower (30-60 minutes) compared with insulin or beta-agonists. 1, 2

Step 3: Definitive Potassium Removal (Within Hours)

Loop Diuretics (If Adequate Renal Function)

Administer IV furosemide 40-80 mg to enhance renal potassium excretion in patients with eGFR >30 mL/min who are non-oliguric. 1, 2, 3

• Loop diuretics are effective only when estimated GFR >30 mL/min and urine output is adequate. 1, 2
• Diuretics should be titrated to maintain euvolemia, not primarily for potassium management. 1, 2

Hemodialysis (Most Reliable Method)

Hemodialysis is the gold-standard for rapid potassium removal and should be arranged urgently. 1, 2, 3 Absolute indications include:

• Serum potassium >6.5 mEq/L unresponsive to medical therapy 1, 2
• Oliguria or anuria 1, 2
• End-stage renal disease 1, 2
• Ongoing potassium release (tumor lysis syndrome, rhabdomyolysis) 1, 2
• Severe renal impairment (eGFR <15 mL/min) 1, 2
• Persistent ECG changes despite medical management 1, 2

In hemodynamically unstable patients (hypotensive, requiring vasopressor support), continuous renal replacement therapy (CRRT) is preferred over intermittent hemodialysis because it minimizes rapid fluid shifts and reduces the risk of intradialytic hypotension. 1, 2

Potassium Binders (Sub-Acute Management)

Sodium zirconium cyclosilicate (SZC/Lokelma): 10 g three times daily for 48 hours, then 5-15 g once daily for maintenance. 1, 2 Onset of action ~1 hour, suitable for urgent scenarios. 1, 2

Patiromer (Veltassa): 8.4 g once daily with food, titrated up to 25.2 g daily. 1, 2 Onset of action ~7 hours, reserved for sub-acute or chronic management. 1, 2 Must be separated from other oral medications by at least 3 hours. 1, 2

Avoid sodium polystyrene sulfonate (Kayexalate) due to risk of bowel necrosis, colonic ischemia, and limited efficacy data. 1, 2, 3

Step 4: Medication Management During Acute Episode

Hold the following medications immediately when potassium >6.5 mEq/L: 1, 2

• RAAS inhibitors (ACE inhibitors, ARBs, mineralocorticoid receptor antagonists) 1, 2
• NSAIDs 1, 2
• Potassium-sparing diuretics (spironolactone, amiloride, triamterene) 1, 2
• Trimethoprim-containing agents 1, 2
• Heparin 1, 2
• Beta-blockers 1, 2
• Potassium supplements and salt substitutes 1, 2

After acute resolution: Restart RAAS inhibitors at a lower dose once potassium <5.0 mEq/L, using a concurrent potassium binder (SZC or patiromer) to enable continuation of life-saving RAAS therapy. 1, 2 These agents provide mortality benefit in cardiovascular and renal disease. 1, 2

Monitoring Protocol

Acute Phase

• Recheck serum potassium 1-2 hours after insulin/glucose or beta-agonist therapy. 1, 2
• Continue potassium checks every 2-4 hours until stable. 1, 2
• Obtain repeat ECG to confirm resolution of prior cardiac changes. 1, 2
• Monitor blood glucose closely to detect hypoglycemia from insulin therapy. 5

Post-Acute Phase

• Check potassium within 1 week after initiating or escalating RAAS inhibitors. 1, 2
• Reassess 7-10 days after starting a potassium binder. 1, 2
• Individualize monitoring frequency based on renal function (eGFR), heart failure status, diabetes, or history of recurrent hyperkalemia. 1, 2

Critical Pitfalls to Avoid

Do not delay calcium administration while awaiting repeat potassium levels when ECG changes are present—ECG abnormalities indicate urgent need for membrane protection. 1, 2

Never give insulin without glucose—hypoglycemia can be fatal. 1, 2

Recognize that calcium, insulin, and beta-agonists are temporizing measures only—they do NOT remove potassium from the body. 1, 2, 3

Do not use sodium bicarbonate without documented metabolic acidosis—it is ineffective and wastes time. 1, 2, 3

Do not permanently discontinue RAAS inhibitors—use potassium binders to maintain these life-saving medications that provide mortality benefit in cardiovascular and renal disease. 1, 2

Remember that rebound hyperkalemia can occur 2-4 hours after temporary measures (insulin, albuterol, bicarbonate) wear off, requiring continued monitoring and definitive potassium removal strategies. 1, 2