Hyperkalemia: Difference between revisions

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A. Redistribution
A. Increased potassium release from cells


* 1. Metabolic Acidosis (drives potassium out of the cells (e.g. DKA))
* 1. Pseudohyperkalemia
* 2. Cellular breakdown
** a. Hemolysis of specimen
** b. Leukocytosis and thrombocytosis
*** 1. K+ increases by 0.15 meq for every 100,000 elevation in plt count
* 2. Metabolic Acidosis (drives potassium out of the cells (e.g. DKA))
* 3. Cellular breakdown
** a. Rhabdomyolysis
** a. Rhabdomyolysis
** b. Hemolysis
** b. Hemolysis

Revision as of 21:31, 1 March 2011

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. Increased potassium release from cells

  • 1. Pseudohyperkalemia
    • a. Hemolysis of specimen
    • b. Leukocytosis and thrombocytosis
      • 1. K+ increases by 0.15 meq for every 100,000 elevation in plt count
  • 2. Metabolic Acidosis (drives potassium out of the cells (e.g. DKA))
  • 3. 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
    • a. Give only if ECG changes/hypotension/or >7
    • b. Can give multiple times
    • c. Can also give CaCl 1 amp (but can lead to calcium toxicity)
    • d. Caution in dig-toxic patients!
    • e. Effect begins within minutes, lasts 30-60 minutes
  • 2. Albuterol neb 10mg in 4mL saline over 10 min
    • a. Peak effect within 90 min
    • b. Lowers K ~ 0.5-1.5
  • 3. Reg insulin 10 U IV with 1 amp D50W IV now, and 1 amp in 15 min
    • a. Effect begins in 10-20 min, peaks at 30-60 min, lasts 4-6 hours
    • b. Lowers K ~ 0.5 - 1.2
  • 4. Bicarbonate
    • a. Controversial
    • b. NaBicarb 1 amp IV (over 5 min)
  • 5. Kayexalate 30g PO or 50g PR (may cause hypernatremia and volume overload)
  • 6. Dialyisis


Source

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