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/hyperkalemi for a definitive guide to diagnosis and management of hyperkalemia
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