Hyperkalemia - Diagnosis and Management - GrepMed Handbook



S/Sx: Most pts asymptomatic. Weakness, cramping, nausea, paresthesias, palpitations, bradycardia, arrhythmias

Etiology: 

 • Medications: K+, ACEi/ARBs, NSAIDs, β-blockers, Antibiotics (Bactrim, PCN G-K), K-sparing diuretics, Saline infusion, Calcineurin inhibitors,  Digoxin, Succinylcholine

 • Redistribution: Acidosis, Cell Lysis (TLS, rhabdo/crush injury, ischemia, hemolysis, transfusions), ↓insulin (DM, DKA, octreotide), hyperK periodic paralysis, post-hypothermia

 • ↓ Renal K+ Excretion:

     - Renal Failure, esp w oliguria / GFR<15

     - ↓ Effective arterial volume (↓distal Na delivery): CHF, cirrhosis, hypovolemia

     - ↓ Renin/Aldosterone, RTA Type IV, AI

 • Ureterojejunostomy (reabsorption)  



Workup:

 • Assess for Pseudohyperkalemia - hemolysis, tourniquet / IVF line draw, ↑↑Plts or ↑↑WBC (use heparinized tube)

 • ECG (↓Sens but Δs indicate badness): Peak T, flat P, ST depress, ↑PR ↑QRS intervals, bradycardia → sine wave → PEA/VF

 • Labs: BMP (Assess GFR), ±VBG (acidosis), CK+LDH (lysis)

     ± Urine Lytes: UNa < 20 suggests ↓ distal Na delivery, UK:Cr < 15 suggests ↓ renal excretion

     ± Renin/Aldosterone levels, Cortisol+ACTH stim test (only if no clear cause)



Management:

 • Stabilization, Redistribution and Elimination (see Table below)

 • STOP offending medications (review MAR)

 • Optimize volume status to improve GFR 

     - Diuresis (hypervolemia)

     - IVF (hypovolemia) - Use LR/Plasmalyte (Bicarb≥22) or isotonic bicarbonate gtt (Bicarb<22) - avoid NS (→hyperchloremic acidosis) 

 • Low K diet



Stabilization Treatments:

 • Calcium 2-3g IV Ca-gluconate or 1g CaCl- (central line)

     - 1st line, stabilizes cardiac membrane. 

     - Transient, repeat dose PRN (ongoing arrhythmia).

Redistribution Treatments:

 • Insulin 5-10U reg IV + 1-2 amps D50W

     - Drives K+ into cells. Give D50 before insulin. Monitor hypoglycemia

 • Albuterol 10-20 mg neb or 0.5 mg IV, Terbutaline 7 µg/kg SC (~0.5 mg)

     - Give albuterol as a continuous neb. Monitor for tachycardia 

 • Epinephrine IV - Only if concurrent need for vasopressor or HyperK-induced bradycardia

 • Isotonic Bicarbonate gtt - Only in acidosis. Use gtt, NOT hypertonic Amp IVP

 • Diuretics (IV loop diuretic ± thiazide / acetazolamide) 

     - IV loop diuretic (lasix ≥ 60 mg) alone may be sufficient if intact GFR. 

     - IVF as needed to avoid hypovolemia 

Elimination Treatments:

 • K-Binding Resins - Exchanges K+ for cations in gut. Slow - don’t delay HD

     - Na-Zirconium (10g PO tid) - caution in HTN & edema

     - SPS (15-60g PO/PR) - avoid ileus/obstruction (ischemia/necrosis), limited evidence for effectiveness

     - Patiromer (8.4-25.2 g/d PO)

 • Hemodialysis - Definitive in ESRD or failure of other measures



Check out https://emcrit.org/ibcc/hyperkalemia/ for a definitive guide to diagnosis and management of hyperkalemia



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