Hyperkalemia: Difference between revisions
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===Stabilize cardiac membranes===
===Stabilize cardiac membranes===
''Indicated if there are any ECG changes or evidence of arrhythmias. Consider if K >7 mEq/L''
''Indicated if there are any ECG changes or evidence of arrhythmias. Consider if K >7 mEq/L''
*[[Calcium gluconate]]: Give 10ml of a 10% solution over 10 mins
*Either one of the following:
**Only 1/3 the calcium compared to calcium chloride  
**[[Calcium gluconate]]: Give 10ml of a 10% solution over 10 mins
**Can cause hypotension due to osmotic shift
***Only 1/3 the calcium compared to calcium chloride  
*[[Calcium chloride]] 1 gram IV  
***Can cause hypotension due to osmotic shift
**Give over 1 - 2 minutes  
**[[Calcium chloride]] 1 gram IV  
**Extravasation is bad: use a good IV
***Give over 1 - 2 minutes  
**Usually given in code situations  
***Extravasation is bad: use a good IV
***Usually given in code situations  
*Duration of action: 30 - 60 minutes <ref> The Effect of Calcium on Severe Hyperkalemia http://hqmeded-ecg.blogspot.com/2015/04/the-effect-of-calcium-on-severe.html</ref>
*Duration of action: 30 - 60 minutes <ref> The Effect of Calcium on Severe Hyperkalemia http://hqmeded-ecg.blogspot.com/2015/04/the-effect-of-calcium-on-severe.html</ref>
*Use caution in patients taking [[Digitalis Toxicity|Digoxin]] although risk of [[Stone Heart]] may be unsubstantiated <ref>Erickson CP, Olson KR. Case files of the medical toxicology fellowship of the California poison control system-San Francisco: calcium plus digoxin-more taboo than toxic? J Med Toxicol. 2008 Mar;4(1):33-9</ref>
*Use caution in patients taking [[Digitalis Toxicity|Digoxin]] although risk of [[Stone Heart]] may be unsubstantiated <ref>Erickson CP, Olson KR. Case files of the medical toxicology fellowship of the California poison control system-San Francisco: calcium plus digoxin-more taboo than toxic? J Med Toxicol. 2008 Mar;4(1):33-9</ref>

Revision as of 07:34, 6 May 2015

Background

  • Defined as >6.0 mEq/L
  • Consider pseudohyperkalemia (e.g. from hemolysis)
  • Potassium secretion is proportional to flow rate and sodium delivery through distal nephron
    • Thus, loop & thiazide diuretics cause hypokalemia

Clinical Features

Differential Diagnosis

  • Pseudohyperkalemia: hemolyzed specimen, prolonged tourniquet use prior to blood draw, thrombocytosis or leukocytosis
  • Redistribution (shift from intracellular to extracellular space)
  • Increased total body potassium
    • Inadequate excretion: Acute/chronic renal failure, Addison's disease, type 4 RTA
    • Drug-induced: potassium-sparing diuretic (spironolactone), angiotensin converting enzyme inhibitors (ACE-I), nonsteroidal anti-inflammatory drugs (NSAIDs)
    • Excessive intake: diet, blood transfusion
  • Other causes: succinylcholine, digitalis, beta-blockers

Diagnosis

ECG

Changes NOT always predictable and sequential

  • 6.5 - 7.5 mEq/L: peaked T waves, prolonged PR interval, shortened QT interval
  • 7.5 - 8.0 mEq/L: widened QRS interval, flattened P waves
  • 10 - 12 mEq/L: sine wave, ventricular fibrillation, heart block

Treatment

C BIG K Die

  • Calcium
  • Bicarbonate, Beta agonist (albuterol)
  • Insulin, Glucose
  • Kayexylate, lasiX
  • Dialysis

Stabilize cardiac membranes

Indicated if there are any ECG changes or evidence of arrhythmias. Consider if K >7 mEq/L

  • Either one of the following:
    • Calcium gluconate: Give 10ml of a 10% solution over 10 mins
      • Only 1/3 the calcium compared to calcium chloride
      • Can cause hypotension due to osmotic shift
    • Calcium chloride 1 gram IV
      • Give over 1 - 2 minutes
      • Extravasation is bad: use a good IV
      • Usually given in code situations
  • Duration of action: 30 - 60 minutes [1]
  • Use caution in patients taking Digoxin although risk of Stone Heart may be unsubstantiated [2]
  • Do serial EKGs to track progress: may need to give multiple doses

Shift K+ intracellularly

  • Intravenous insulin + dextrose
    • Give 10 units regular insulin intravenously with 25 to 50 grams (1 - 2 50 mL ampules) of 50% dextrose (D50)
      • May withhold dextrose if blood sugar >300 mg/dl (>17 mmol/L)
      • Duration of effect: 4 - 6 hours
  • Nebulized albuterol 5 - 20 mg
    • Response is dose-dependent
    • Peak effect: 30 minutes
    • Duration of effect: 2 hours
  • Intravenous sodium bicarbonate 50 ml of 8.4% solution (1 ampoule) given over 5 minutes
    • Duration of effect: 1 - 2 hours
    • Generally not required, unless pH <7.1

Remove K+ from system

  • Intravenous furosemide (Lasix) 40 - 80 mg
    • Ensure adequate urine output first
  • Sodium polystyrene sulfonate (Kayexylate): 30 gm oral or per rectum
  • Intravenous normal saline solution for volume expansion if dehydrated, rhabdomyolysis, diabetic ketoacidosis or other acidosis
  • Definitive treatment is hemodialysis

See Also

External Links

References

  1. ↑ The Effect of Calcium on Severe Hyperkalemia http://hqmeded-ecg.blogspot.com/2015/04/the-effect-of-calcium-on-severe.html
  2. ↑ Erickson CP, Olson KR. Case files of the medical toxicology fellowship of the California poison control system-San Francisco: calcium plus digoxin-more taboo than toxic? J Med Toxicol. 2008 Mar;4(1):33-9
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