Difference between revisions of "Hyperkalemia"

(Block aldosterone binding to mineralocorticoid receptors)
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== Background ==
+
==Background==
*Defined as >6.0 mEq/L  
+
*Defined as >5.5 mEq/L  
 
*Consider pseudohyperkalemia (e.g. from hemolysis)  
 
*Consider pseudohyperkalemia (e.g. from hemolysis)  
 
*Potassium secretion is proportional to flow rate and sodium delivery through distal nephron  
 
*Potassium secretion is proportional to flow rate and sodium delivery through distal nephron  
**Thus, loop & thiazide diuretics cause ''hypo''kalmia
+
**Thus, loop & thiazide [[diuretics]] cause ''hypo''kalmia
  
 
===Medication Causes===
 
===Medication Causes===
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*Potassium supplements
 
*Potassium supplements
 
*Salt substitutes
 
*Salt substitutes
*Hyperosmolar solutions (mannitol, glucose)
+
*Hyperosmolar solutions ([[mannitol]], [[dextrose|glucose]])
 
*Suxamethonium
 
*Suxamethonium
 
*Intravenous cationic amino acids
 
*Intravenous cationic amino acids
*Stored red blood cells (haemolysis releases potassium)
+
*Stored [[pRBCs|red blood cells]] (haemolysis releases potassium)
 
*Herbal medicines (such as alfalfa, dandelion, horsetail, milkweed, and nettle)
 
*Herbal medicines (such as alfalfa, dandelion, horsetail, milkweed, and nettle)
  
 
====Reduce aldosterone secretion====
 
====Reduce aldosterone secretion====
*ACE inhibitors; Angiotensin II receptor blockers
+
*[[ACE inhibitors]]; [[Angiotensin II receptor blockers]]
 
*[[NSAIDs]]
 
*[[NSAIDs]]
*[[Heparins]]
+
*[[Heparin]]
*Antifungals (ketoconazole, fluconazole, itraconazole)
+
*[[Antifungals]] ([[ketoconazole]], [[fluconazole]], [[itraconazole]])
*Ciclosporin
+
*[[Cyclosporine]]
*Tacrolimus
+
*[[Tacrolimus]]
  
 
====Block aldosterone binding to mineralocorticoid receptors====
 
====Block aldosterone binding to mineralocorticoid receptors====
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*[[Eplerenone]]
 
*[[Eplerenone]]
 
*[[Drospirenone]]
 
*[[Drospirenone]]
*Potassium sparing diuretics (amiloride, triamterene)
+
*Potassium sparing [[diuretics]] (amiloride, triamterene)
*Trimethoprim
+
*[[Trimethoprim]]
*Pentamidine
+
*[[Pentamidine]]
  
 
==Clinical Features==
 
==Clinical Features==
 +
''Typically non-specific''
 +
*[[Muscle weakness]]
 +
*[[Lethargy]], [[fatigue]]
 +
*[[Paresthesias]]
 +
*[[Nausea and Vomiting]]
 +
*[[Difficulty breathing]]
 +
*[[Palpitations]], [[chest pain]]
  
== Differential Diagnosis ==
+
==Differential Diagnosis==
*Pseudohyperkalemia: hemolyzed specimen, prolonged tourniquet use prior to blood draw, thrombocytosis or leukocytosis
+
{{Hyperkalemia DDX}}
*Redistribution (shift from intracellular to extracellular space)
+
{{Peaked T-waves DDX}}
**Acidemia (see [[Diabetic ketoacidosis|DKA]])
+
{{Tachycardia (wide) DDX}}
**Cellular breakdown: see [[Rhabdomyolysis]]/[[Crush syndrome]], hemolysis, see [[Tumor lysis syndrome]]
 
*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==
+
==Evaluation==
=== [[ECG]] ===
+
===[[ECG]]===
 
''Changes NOT always predictable and sequential''
 
''Changes NOT always predictable and sequential''
 
*6.5 - 7.5 mEq/L: peaked T waves, prolonged PR interval, shortened QT interval
 
*6.5 - 7.5 mEq/L: peaked T waves, prolonged PR interval, shortened QT interval
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*10 - 12 mEq/L: sine wave, ventricular fibrillation, heart block
 
*10 - 12 mEq/L: sine wave, ventricular fibrillation, heart block
  
==Treatment==
+
==Management==
 
===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''
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*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>
*Do serial [[EKG]]s to track progress: may need to give multiple doses
+
*Do serial [[ECG]]s to track progress: may need to give multiple doses
  
 
===Shift K+ intracellularly===
 
===Shift K+ intracellularly===
*Intravenous insulin + dextrose  
+
*Intravenous [[insulin]] + [[dextrose]]
 
**Give 10 units regular insulin intravenously with 25 to 50 grams (1 - 2 50 mL ampules) of 50% dextrose (D50)
 
**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)
+
***May withhold dextrose if blood sugar >300mg/dl (>17 mmol/L)
 
***Duration of effect: 4 - 6 hours  
 
***Duration of effect: 4 - 6 hours  
 
***Consider mixing in 10 cc NS syringe to ensure small volume of 10 units insulin fully administered via IV
 
***Consider mixing in 10 cc NS syringe to ensure small volume of 10 units insulin fully administered via IV
***insulin cleared renally, be careful about inducing hypoglycemia
+
***Insulin cleared renally, be careful about inducing hypoglycemia (ESRD patients).
*Nebulized albuterol 5 - 20 mg
+
****In a [https://onlinelibrary.wiley.com/doi/abs/10.1002/phar.2038 small 2017 retrospective cohort study], researchers found that giving 5 units of insulin instead of 10 units reduced serum potassium to the same extent as 10 units, with a lower rate of hypoglycemia.
 +
****Consider decreasing to 5 units or increasing dextrose dose to 50g with following risk factors: pretreatment blood glucose <150, acute kidney injury/chronic kidney disease, no history of DM, weight <60kg, female sex <ref> Moussavi K1, Fitter S2, Gabrielson SW3, Koyfman A4, Long B5. Management of Hyperkalemia With Insulin and Glucose: Pearls for the Emergency Clinician. J Emerg Med. 2019 Jul;57(1):36-42. </ref>
 +
*Nebulized [[albuterol]] 15 - 20mg
 
**Response is dose-dependent  
 
**Response is dose-dependent  
 
**Peak effect: 30 minutes
 
**Peak effect: 30 minutes
 
**Duration of effect: 2 hours  
 
**Duration of effect: 2 hours  
*Intravenous sodium bicarbonate 50 ml of 8.4% solution (1 ampoule) given over 5 minutes  
+
*Intravenous [[sodium bicarbonate]] 50ml of 8.4% solution (1 ampoule) given over 5 minutes  
 
**Duration of effect: 1 - 2 hours
 
**Duration of effect: 1 - 2 hours
 
**Generally not required, unless pH <7.1
 
**Generally not required, unless pH <7.1
  
 
===Remove K+ from body===
 
===Remove K+ from body===
*Intravenous furosemide (Lasix) 40 - 80 mg
+
*Intravenous [[furosemide]] (Lasix) 40 - 80mg
 
**Ensure adequate urine output first
 
**Ensure adequate urine output first
*[[Sodium polystyrene sulfonate]] (Kayexylate): 30 gm oral or per rectum
+
*[[Sodium polystyrene sulfonate]] (Kayexalate): 30 gm oral or per rectum
 
**'''Very Controversial, High Risk of Bowel Perforation''', see: [[EBQ: Use of Kayexylate in Hyperkalemia]]
 
**'''Very Controversial, High Risk of Bowel Perforation''', see: [[EBQ: Use of Kayexylate in Hyperkalemia]]
*Intravenous normal saline solution for volume expansion if dehydrated, rhabdomyolysis, diabetic ketoacidosis or other acidosis  
+
*[[Sodium zirconium cyclosilicate]]
*Definitive treatment is hemodialysis
+
**Potassium binder, similar to Kayexalate
 +
*Intravenous lactated ringers solution for volume expansion if dehydrated, rhabdomyolysis, diabetic ketoacidosis or other acidosis (avoid NS, causes hyperchloremic acidosis which shifts potassium out of cells increasing level)
 +
**consider isotonic bicarbonate if significant acidosis (D5W with 3 amps of bicarb per liter), can calculate bicarbonate deficit then divide by 150mEq/L to estimate number of liters of isotonic bicarbonate required) <ref> https://emcrit.org/pulmcrit/fluid-selection-using-ph-guided-resuscitation </ref>
 +
*[[Hydrocortisone]] if suspicious for [[adrenal insufficiency]]
 +
*Definitive treatment is [[hemodialysis]]
 +
 
 +
==Disposition==
 +
*Consideration for ICU for frequent electrolyte checks and close cardiac monitoring
  
 
==See Also==
 
==See Also==
 
*[[Electrolyte abnormalities]]
 
*[[Electrolyte abnormalities]]
 
*[[Acute kidney injury]]
 
*[[Acute kidney injury]]
 +
*[[Hemodialysis/Hemoperfusion]]
 
*[[Crush syndrome]]
 
*[[Crush syndrome]]
  
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*[https://ecgweekly.com/2015/01/case-of-the-week-january-12-2015/ ECG Weekly -Hyperkalemia]
 
*[https://ecgweekly.com/2015/01/case-of-the-week-january-12-2015/ ECG Weekly -Hyperkalemia]
  
==References ==
+
==References==
 
<references/>
 
<references/>
  
 
[[Category:FEN]]
 
[[Category:FEN]]
[[Category:Nephro]]
+
[[Category:Renal]]

Revision as of 16:59, 16 October 2019

Background

  • Defined as >5.5 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 hypokalmia

Medication Causes

Alter transmembrane potassium movement

  • β blockers
  • Digoxin
  • Potassium-containing drugs
  • Potassium supplements
  • Salt substitutes
  • Hyperosmolar solutions (mannitol, glucose)
  • Suxamethonium
  • Intravenous cationic amino acids
  • Stored red blood cells (haemolysis releases potassium)
  • Herbal medicines (such as alfalfa, dandelion, horsetail, milkweed, and nettle)

Reduce aldosterone secretion

Block aldosterone binding to mineralocorticoid receptors

Clinical Features

Typically non-specific

Differential Diagnosis

Hyperkalemia

  • 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

Peaked T-waves

Wide-complex tachycardia

Assume any wide-complex tachycardia is ventricular tachycardia until proven otherwise (it is safer to incorrectly assume a ventricular dysrhythmia than supraventricular tachycardia with abberancy)

^Fixed or rate-related

Evaluation

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

Management

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
  • Takes effect in 15-30 minutes[1]
    • (If given for hyperkalemic cardiac arrest, need to continue resuscitation for at least 30 minutes)
  • Duration of action: 30 - 60 minutes [2]
  • Use caution in patients taking Digoxin although risk of Stone heart may be unsubstantiated [3]
  • Do serial ECGs 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 >300mg/dl (>17 mmol/L)
      • Duration of effect: 4 - 6 hours
      • Consider mixing in 10 cc NS syringe to ensure small volume of 10 units insulin fully administered via IV
      • Insulin cleared renally, be careful about inducing hypoglycemia (ESRD patients).
        • In a small 2017 retrospective cohort study, researchers found that giving 5 units of insulin instead of 10 units reduced serum potassium to the same extent as 10 units, with a lower rate of hypoglycemia.
        • Consider decreasing to 5 units or increasing dextrose dose to 50g with following risk factors: pretreatment blood glucose <150, acute kidney injury/chronic kidney disease, no history of DM, weight <60kg, female sex [4]
  • Nebulized albuterol 15 - 20mg
    • Response is dose-dependent
    • Peak effect: 30 minutes
    • Duration of effect: 2 hours
  • Intravenous sodium bicarbonate 50ml 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 body

  • Intravenous furosemide (Lasix) 40 - 80mg
    • Ensure adequate urine output first
  • Sodium polystyrene sulfonate (Kayexalate): 30 gm oral or per rectum
  • Sodium zirconium cyclosilicate
    • Potassium binder, similar to Kayexalate
  • Intravenous lactated ringers solution for volume expansion if dehydrated, rhabdomyolysis, diabetic ketoacidosis or other acidosis (avoid NS, causes hyperchloremic acidosis which shifts potassium out of cells increasing level)
    • consider isotonic bicarbonate if significant acidosis (D5W with 3 amps of bicarb per liter), can calculate bicarbonate deficit then divide by 150mEq/L to estimate number of liters of isotonic bicarbonate required) [5]
  • Hydrocortisone if suspicious for adrenal insufficiency
  • Definitive treatment is hemodialysis

Disposition

  • Consideration for ICU for frequent electrolyte checks and close cardiac monitoring

See Also

External Links

References

  1. http://lifeinthefastlane.com/hyperkalemia/. Accessed 02/22/2016
  2. The Effect of Calcium on Severe Hyperkalemia http://hqmeded-ecg.blogspot.com/2015/04/the-effect-of-calcium-on-severe.html
  3. 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
  4. Moussavi K1, Fitter S2, Gabrielson SW3, Koyfman A4, Long B5. Management of Hyperkalemia With Insulin and Glucose: Pearls for the Emergency Clinician. J Emerg Med. 2019 Jul;57(1):36-42.
  5. https://emcrit.org/pulmcrit/fluid-selection-using-ph-guided-resuscitation