We discussed a case about a middle aged man with uncontrolled HTN and T2DM, presenting with subacute bilateral lower extremity edema and sacral edema, found to have Hyperkalemia likely due to CKD from uncontrolled HTN and T2DM. Teaching points focused on going over a framework to organize causes of hyperkalemia, EKG features of hyperkalemia, and treatment options for hyperkalemia.

EKG features of hyperkalemia

• Tall peaked T waves, loss of P waves, widening QRS, sine wave / ventricular arrhythmia / asystole

Hyperkalemia tx (Check out the hyperkalemia order set!)

• Calcium
  • Stabilize cardiac membrane action potential
  • Rapid onset (minutes); short duration (30-60 min)
  • Contraindicated in digoxin toxicity
• Insulin + Dextrose
  • Intracellular shift of K via ↑ Na-K-ATPase
  • Rapid onset (10-20 min); lasts hours
• NaHCO3-
  • Intracellular shifts of K
  • Rapid onset (minutes); short duration
• Beta-2-adrenergic agonists
  • Intracellular shifts of K
  • Rapid onset (minutes)
  • Watch for tachycardia and angina
• Loop diuretics
  • Excretion of K, prevention of K absorption
  • IV Lasix peak effect (30 min); IV Lasix duration (2hrs)
• GI cation exchangers
  • Bind K in GI lumen -> excretion
  • Slow onset (many hrs); long duration (many hrs to days)
  • SPS (Kayexalate) associated w/ intestinal ischemia
• Dialysis