Hyperkalemia

Background

High = >5.5meq/L

High! = >6.5meq/L

Diagnosis

Always consider pseudohyperkalemia (e.g. from hemolysis)

ECG

6.5 - peaked Ts, inc PR, dec QT

7.5 - QRS widening, P flattening

8 - sine wave, v-fib, heart block

Differential Diagnosis

A. Redistribution

• 1. Metabolic Acidosis (drives potassium out of the cells (e.g. DKA))
• 2. Cellular breakdown
  • a. Rhabdomyolysis
  • b. Hemolysis
  • c. Tumor lysis syndrome
  • d. Crush

B. Increased total body potassium

• 1. Inadequate excretion
  • a. Renal caused (acute or chronic renal failure-must have GFR<10)
  • b. Mineralocorticoid deficiency or Addison's disease
  • c. Drug-induced (potassium sparing diuretics [e.g., spironolactone] and ACE-inhibitors)
• 2. Excessive intake
  • a. Diet, meds
  • b. Blood transfusion

C. Pseudohyperkalemia

• 1. Hemolysis of the specimen
• 2. Prolonged period of tourniquets occlusion prior to blood draw
• 3. Thrombocytosis/leukocytosis

D. Misc

• 1. Sux, dig, B-blockers

Treatment

1) Calcium gluconate 1 amp IV (if ECG changes/hypotension/or >7; can give mult times)

Can also give Ca Gluconate 1 amp (but dissociates more slowly and must give more volume)

• Caution in dig-toxic patients!*

2) Albuterol neb 2.5mg x 3

3) 10 U reg insulin IV with 1 amp D50W IV now, and 1 amp in 15 min

4) 1 amp NaBicarb IV (over 5 min)

5) Kayexalate 30g PO (may cause volume overload; +/- 50mL sorbitol)

    -or rectal 50g enema

• 6) Consider dialyisis (& ?lasix 20-40mg IVP)

Source

7/2/09 Adapted from Tintinalli, Donaldson, Pani