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. Acidosis drives potassium out of the cells

a. 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. Succs, dib, B-blockers

Treatment

• Calcium gluconate 1 amp IV (if ECG changes/hypotension/or >7; can give mult times)
• Caution in dig-toxic patients!
• Albuterol neb 2.5mg x 3
• 10 U reg insulin IV with 1 amp D50W IV now, and 1 amp in 15 min
• 1 amp NaBicarb IV (over 5 min)
• Kayexalate 30g PO (may cause volume overload; +/- 50mL sorbitol)
• Consider dialyisis & ?lasix

Source

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