What is the appropriate workup and management for a patient presenting with hyperkalemia?

Hyperkalemia Workup and Management

Initial Assessment and Classification

Immediately obtain an ECG and verify the potassium level is not pseudohyperkalemia from hemolysis, repeated fist clenching, or poor phlebotomy technique before initiating treatment. 1

Severity Classification

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

ECG changes (peaked T waves, flattened P waves, prolonged PR interval, widened QRS) indicate urgent treatment regardless of the absolute potassium level. 1 However, absent or atypical ECG changes do not exclude the necessity for immediate intervention. 3

Initial Laboratory Workup

• Complete metabolic panel (electrolytes, BUN, creatinine, glucose) 1
• Complete blood count 1
• Urinalysis 1
• Venous blood gas if metabolic acidosis suspected 1
• Magnesium level 1

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Acute Hyperkalemia Management

Step 1: Cardiac Membrane Stabilization (if K+ ≥6.5 mEq/L OR any ECG changes)

Administer IV calcium immediately—this is the first priority to prevent fatal arrhythmias. 1, 2

• Calcium gluconate 10%: 15-30 mL IV over 2-5 minutes 1
• OR Calcium chloride 10%: 5-10 mL IV over 2-5 minutes 1
• Onset: 1-3 minutes 1, 2
• Duration: 30-60 minutes (temporary only) 1, 2
• Repeat dose: If no ECG improvement within 5-10 minutes, give second dose 1
• Critical caveat: Calcium does NOT lower potassium—it only stabilizes cardiac membranes temporarily 1, 2

Continuous cardiac monitoring is mandatory during and after calcium administration. 1

Step 2: Shift Potassium Intracellularly

Administer all three agents together for maximum effect: 1

Insulin + Glucose (First-line)

• Insulin: 10 units regular insulin IV 1
• Glucose: 25g dextrose (50 mL of 50% dextrose) IV 1
• Onset: 15-30 minutes 1, 2
• Duration: 4-6 hours 1, 2
• Can be repeated every 4-6 hours as needed 1
• Monitor glucose closely to prevent hypoglycemia 1

Beta-2 Agonist

• Albuterol: 10-20 mg nebulized in 4 mL over 10 minutes 1, 3
• Onset: 15-30 minutes 1
• Duration: 2-4 hours 1
• Can be repeated as needed 1

Sodium Bicarbonate (ONLY if metabolic acidosis present)

• Indication: pH <7.35, bicarbonate <22 mEq/L 1
• Dose: 50 mEq IV over 5 minutes 1
• Onset: 30-60 minutes 1
• Do NOT use without metabolic acidosis—it is ineffective and wastes time 1, 2

Step 3: Remove Potassium from the Body

Loop Diuretics (if adequate renal function)

• Furosemide: 40-80 mg IV 1
• Only effective if GFR adequate 1, 2

Hemodialysis (most effective method)

• Indications: 1, 2
  • Severe hyperkalemia unresponsive to medical management
  • Oliguria or end-stage renal disease
  • Acute kidney injury with rising potassium
• Most reliable method for potassium removal 1, 4

Potassium Binders (for subacute/chronic management)

• Sodium zirconium cyclosilicate (SZC/Lokelma): 1
  • Acute: 10g three times daily for 48 hours
  • Maintenance: 5-15g once daily
  • Onset: ~1 hour
• Patiromer (Veltassa): 1
  • Starting dose: 8.4g once daily with food
  • Titrate up to 25.2g daily based on response
  • Onset: ~7 hours
  • Separate from other oral medications by 3 hours
• Avoid sodium polystyrene sulfonate (Kayexalate): Delayed onset, limited efficacy, risk of bowel necrosis 1, 2

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Chronic Hyperkalemia Management

Medication Review and Adjustment

Do NOT permanently discontinue RAAS inhibitors—these provide mortality benefit in cardiovascular and renal disease. 1, 2

Algorithm for RAAS Inhibitor Management:

• K+ 5.0-6.5 mEq/L: 1, 2
  • Initiate potassium binder (patiromer or SZC)
  • Maintain RAAS inhibitor therapy
  • Monitor closely
• K+ >6.5 mEq/L: 1, 2
  • Temporarily discontinue or reduce RAAS inhibitor
  • Initiate potassium binder
  • Restart RAAS inhibitor at lower dose once K+ <5.0 mEq/L

Medications to Review/Discontinue:

• NSAIDs 1, 2
• Potassium-sparing diuretics (spironolactone, amiloride, triamterene) 1
• Trimethoprim 1
• Heparin 1
• Beta-blockers 1
• Potassium supplements 1
• Salt substitutes (high potassium content) 1

Dietary Considerations

Evidence linking dietary potassium intake to serum levels is limited, and potassium-rich diets provide cardiovascular benefits. 1 Focus dietary restriction on:

• Processed foods (high bioavailable potassium) 1
• Salt substitutes containing potassium 1
• Herbal supplements (alfalfa, dandelion, horsetail, nettle) 1

Do NOT implement stringent dietary potassium restrictions in patients on potassium binders. 1

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Monitoring Protocol

High-Risk Patients Requiring Frequent Monitoring:

• Chronic kidney disease 1
• Heart failure 1
• Diabetes 1
• On RAAS inhibitors 1
• History of hyperkalemia 1

Monitoring Schedule:

• After starting/escalating RAAS inhibitors: Check K+ within 7-10 days 1, 2
• After initiating potassium binder: Check K+ within 1 week 1
• During acute treatment: Every 2-4 hours until stabilized 1
• After insulin/glucose or beta-agonist: Recheck within 1-2 hours 1
• Long-term: Individualize based on risk factors 1

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Special Populations

Chronic Kidney Disease

• Stage 4-5 CKD: Optimal K+ range 3.3-5.5 mEq/L (broader than normal) 1, 2
• Target K+ 4.0-5.0 mEq/L minimizes mortality risk 1
• Maintain RAAS inhibitors aggressively using potassium binders—these drugs slow CKD progression 1, 2

Heart Failure

• Both hypokalemia and hyperkalemia increase mortality 1
• Target K+ 4.0-5.0 mEq/L strictly 1
• Use potassium binders to enable continuation of RAAS inhibitors 1, 2

Hemodialysis Patients

• Target predialysis K+ 4.0-5.5 mEq/L 1
• Monitor for rebound hyperkalemia 4-6 hours post-dialysis 1
• Consider adjusting dialysate potassium concentration (typically 2.0-3.0 mEq/L) 1

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Critical Pitfalls to Avoid

1. Do NOT rely solely on ECG findings—they are highly variable and less sensitive than laboratory tests 1
2. Do NOT use sodium bicarbonate without metabolic acidosis—it is only indicated when acidosis is present 1, 2
3. Do NOT forget to administer glucose with insulin—hypoglycemia can be life-threatening 1
4. Remember that calcium, insulin, and beta-agonists do NOT remove potassium from the body—they only temporize 1, 2
5. Do NOT delay treatment while waiting for repeat lab confirmation if ECG changes are present 1
6. Do NOT permanently discontinue RAAS inhibitors—use potassium binders instead 1, 2
7. Do NOT give calcium through the same IV line as sodium bicarbonate—precipitation will occur 1

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Team Approach

Optimal chronic hyperkalemia management involves a multidisciplinary team: 1

• Cardiologists
• Nephrologists
• Primary care physicians
• Nurses
• Pharmacists
• Dietitians
• Social workers