Management of Severe Hyperkalemia in a 71-Year-Old Female with Pyelonephritis and AKI
This patient requires immediate treatment for life-threatening hyperkalemia (K+ 6.7 mEq/L) with a three-step approach: cardiac membrane stabilization with IV calcium, intracellular potassium shift with insulin/glucose and nebulized beta-agonist, followed by potassium elimination strategies while treating the underlying pyelonephritis. 1
Immediate Emergency Management (Within Minutes)
Step 1: Cardiac Membrane Stabilization
- Administer IV calcium chloride 10% (5-10 mL) or calcium gluconate 10% (15-30 mL) over 2-5 minutes immediately 1, 2
- This protects against fatal arrhythmias within 1-3 minutes but does not lower potassium levels 1, 2
- Effects are temporary (30-60 minutes), so repeat if ECG changes persist 2
- Obtain ECG immediately to assess for peaked T waves, flattened P waves, prolonged PR interval, or widened QRS complex 1, 2
Step 2: Shift Potassium Intracellularly (15-30 Minutes)
- Give 10 units regular insulin IV with 50 mL of D50W (25g glucose) over 15-30 minutes 1, 3
- Administer nebulized albuterol 10-20 mg over 15 minutes 1, 2
- Consider IV sodium bicarbonate 50 mEq over 5 minutes only if metabolic acidosis is present 1, 2
Step 3: Eliminate Potassium from Body
- Administer furosemide 40-80 mg IV given eGFR 67 indicates adequate renal function for diuretic response 1, 3
- Initiate potassium binder therapy: 1
- Hemodialysis is reserved for refractory cases or if oliguria develops 1, 4
Treatment of Underlying Pyelonephritis
Antibiotic Selection with Renal Adjustment
- Start empiric broad-spectrum antibacterial therapy appropriate for pyelonephritis
- Dose adjustments are critical with eGFR 67: review all antibiotic dosing for renal impairment 5
- Avoid nephrotoxic agents (NSAIDs, aminoglycosides) that could worsen AKI and hyperkalemia 1, 6
Fluid Management
- Administer 0.9% NaCl IV initially to address volume depletion from infection and improve renal perfusion 3
- Do NOT add potassium to IV fluids until K+ confirmed <5.0 mEq/L 7, 3
- Monitor for hypervolemia given reduced renal function 1
Medication Review and Discontinuation
Immediate Medication Changes
- Stop all potassium-sparing diuretics, NSAIDs, and potassium supplements immediately 1, 6
- Review and hold ACE inhibitors/ARBs temporarily until K+ <5.0 mEq/L 1
- Per ACC/AHA guidelines, reinitiate RAASi therapy once concurrent conditions (pyelonephritis, AKI) are controlled AND K+ <5.0 mEq/L 1
- Discontinue trimethoprim-containing antibacterials if prescribed, as they impair renal potassium excretion 7
Monitoring Protocol
Intensive Monitoring Phase
- Check serum potassium every 2-4 hours initially until stable below 5.5 mEq/L 3, 6
- Continuous cardiac monitoring for at least 6 hours or until K+ <6.0 mEq/L 4, 6
- Reassess renal function (creatinine, eGFR) within 24 hours 3
- Monitor glucose hourly if insulin administered 3
Important Caveats
- Beware of rebound hyperkalemia after 2-4 hours as insulin/glucose and beta-agonist effects wear off 1, 2
- Exclude pseudohyperkalemia from hemolysis or improper sampling before aggressive treatment 2, 6
- Plasma potassium is 0.1-0.4 mEq/L lower than serum levels 1
Prevention of Recurrence
Dietary and Long-Term Management
- Initiate low-potassium diet education: restrict high-potassium foods and salt substitutes 7, 2
- Consider long-term potassium binder therapy if chronic hyperkalemia develops 1
- Monitor K+ within 1 week after restarting any RAASi therapy 1