A 40yo male with pre-existing glumerulonephritis having proteinuria and hematuria suddenly
deteriorates and presents with oliguria and serum K+=7.8mmol/L, urea=13mmol/L,
creat=342mmol/L, GFR=19mL/h. The best management would be?
a. Calcium supplement
b. Calcium resonate enema 30g
c. 10units insulin with 50% dextrose
d. Nebulized salbutamol
e. 10ml of 10% calcium gluconate
f. Hemodialysis urgent
answer: E, first priority is to protect the heart, next step after that should be dialysis
Treatment of Hyperkalemia
• acute therapy is warranted if ECG changes are present, or if patient is symptomatic
• tailor therapy to severity of increase in [K+] and ECG changes
[K+] <6.5 and normal ECG
treat underlying cause, stop K+ intake, (increase the loss of K+ ) via urine and/or GI tract
[K+] between 6.5 and 7.0, no ECG changes:
(shift k+ into cells) add insulin to above regimen
[K+] >7.0 and/or ECG changes:
first priority is to(protect the heart), add calcium gluconate to above
- Protect the Heart
• calcium gluconate 1-2 amps (10 mL of 10% solution) IV
• antagonizes cardiac toxicity of hyperkalemia, protects cardiac conduction system, no effect on serum [K+]
• onset within minutes, lasts 30-60 min (may require repeat doses during treatment course of hyperkalemia) - Shift K+ into Cells
• regular insulin (Insulin R) 10-20 units IV, with 1-2 amp D50W (give D50W before insulin)
onset of action 15-30 min, lasts 1-2 h
monitor capillary blood glucose q1h because of risk of hypoglycemia
can repeat every 4-6 h
caution giving D50W before insulin if hyperkalemia is severe as it can cause a serious arrhythmia
• NaHCO3 1-3 ampules (given as 3 ampules of 7.5% or 8.4% NaHCO3 in 1L D5W) onset of action 15-30 min, transient effect, drives K+ into cells in exchange for H+, more effective if patient has metabolic acidosis
• B2-agonist in nebulized form (dose = 2 cc or 10 mg inhaled) or 0.5 mg IV
onset of action 30-90 min, stimulates Na+/K+ ATPase
caution if patient has heart disease as may result in tachycardia - Enhance K+ Removal from Body
• via urine (preferred approach)
furosemide (≥40 mg IV), may need IV NS to avoid hypovolemia
• via gastrointestinal tract
cation-exchange resins: calcium resonium or sodium polystyrene sulfonate : increasingly falling out of favor due to risk of colonic necrosis; works by binding Na+ in exchange for K+, and controversial how much K+ is actually removed
lactulose PO to avoid constipation (must ensure that patient has a bowel movement after resin is administered – main benefit may be the diarrhea caused by lactulose)
kayexalate enemas with water
• dialysis (renal failure, life threatening hyperkalemia unresponsive to therapy)