Hyperkalemia

Background

High = >5.5meq/L

High! = >6.5meq/L

Always consider pseudohyperkalemia (e.g. from hemolysis)!

changes are not always predictable and may progress quickly on ECG

Pseudohyperkalemia
1. Hemolysis of specimen
2. Pronged tourniquet use prior to blood draw
3. Thrombocytosis/leukocytosis
Redistribution
1. Acidemia (DKA)
2. Cellular breakdown
  1. Rhabdomyolysis/crush injury
  2. Hemolysis
  3. Tumor lysis syndrome
Increased total body potassium
1. Inadequate excretion
  1. Renal caused (acute or chronic renal failure-must have GFR<10)
  2. Hypoaldo
  3. Drug-induced
    1. K sparing diuretics (spironolactone), ACEI, NSAIDs
2. Excessive intake
  1. Diet
  2. Blood transfusion
Misc
1. Sux, Dig, B-blockers

Membrane Stabilization
1. Calcium gluconate 1-3 amp IV or chloride 1amp IV
  1. Give if ECG changes/hypotension or >7
  2. Gluconate requires hepatic metabolism to free Ca moiety
  3. Gluconate slower onset than Ca-chloride
  4. Chloride extravasation is very bad - use a good IV
  5. Duration of effect = 30-50min
  6. Caution in dig-toxic pts
  7. May take more than one round of calcium
  8. May require repeat dosing as effects are transient
Intracellular shift
1. 10 U insulin IV w/ 1 amp D50 IV now and 1 amp in 15 min
  1. Duration of effect = 4-6h
2. Albuterol neb 2.5mg x 3 or 20mg over 1hour
  1. Duration of effect = 2-4hr
  2. Higher doses more effective
  3. Dose 20mg over 1 hour dropped K by 0.6mEq
  4. Prior Bet-agonist use makes pts resistant to effects
3. NaBicarb 1 amp IV (over 5 min)
4. Duration of effect = 1-2hr
Removal
1. Dialysis
2. Lasix 40-80mg IV
3. Volume expansion with NS if dehydrated, TLS, rhabdomyolysis, DKA, acidosis
4. Kayexylate 30-60gms PO - unreliable and slow to work

Tintinalli

Management Severe Hyperkalemia. Crit Care Med, 2008, 36:12