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

1. Redistribution

• Acidosis drives potassium out of the cells (e.g. DKA)

2. Cellular breakdown

• Rhabdomyolysis
• Hemolysis
• Tumor lysis syndrome
• 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.  Succs, dib, 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