Hyperkalemia: Difference between revisions

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==Background==
==Background==
High = >5.5meq/L
*Defined as >5.5 mEq/L  
*Potassium secretion is proportional to flow rate and sodium delivery through distal nephron
**Thus, loop & thiazide [[diuretics]] cause ''hypo''kalmia


High! = >6.5meq/L
===Medication Causes===
====Alter transmembrane potassium movement====
*[[β blockers]]
*[[Digoxin]]
*Potassium-containing drugs
*Potassium supplements
*Salt substitutes
*Hyperosmolar solutions ([[mannitol]], [[dextrose|glucose]])
*Suxamethonium
*Intravenous cationic amino acids
*Stored [[pRBCs|red blood cells]] (haemolysis releases potassium)
*Herbal medicines (such as alfalfa, dandelion, horsetail, milkweed, and nettle)


==Diagnosis==
====Reduce aldosterone secretion====
*Always consider pseudohyperkalemia (e.g. from hemolysis)
*[[ACE inhibitors]]; [[Angiotensin II receptor blockers]]
*[[NSAIDs]]
*[[Heparin]]
*[[Antifungals]] ([[ketoconazole]], [[fluconazole]], [[itraconazole]])
*[[Cyclosporine]]
*[[Tacrolimus]]


===ECG===
====Block aldosterone binding to mineralocorticoid receptors====
*[[Spironolactone]]
*[[Eplerenone]]
*[[Drospirenone]]
*Potassium sparing [[diuretics]] (amiloride, triamterene)
*[[Trimethoprim]]
*[[Pentamidine]]


6.5-7.5 - peaked Ts, inc PR, dec QT
==Clinical Features==
''Typically non-specific''
*[[Muscle weakness]]
*[[Lethargy]], [[fatigue]]
*[[Paresthesias]]
*[[Nausea and Vomiting]]
*[[Difficulty breathing]]
*[[Palpitations]], [[chest pain]]


7.5-8.0 - QRS widening, P flattening
==Differential Diagnosis==
{{Hyperkalemia DDX}}
{{Peaked T-waves DDX}}
{{Tachycardia (wide) DDX}}
 
==Evaluation==
[[File:PMC4475259 JCHIMP-5-27993-g003.png|thumb|Diagrammatic representation of ECG changes with increasing hyperkalemia]]
[[File:HyperK2014.jpg|thumb|ECG in hyperkalemia with peaked T waves and small P waves]]
[[File:PMC4475259 JCHIMP-5-27993-g001.png|thumb|ECG with widened QRS complex and tall broad T waves]]
[[File:PMC4475259 JCHIMP-5-27993-g005.png|thumb|ECG showing sine wave pattern]]
===Workup===
*[[ECG]]
*Chem 10 (including potassium, magnesium, and phosphorus)
**Consider point-of-care lab testing for more rapid result
*Consider [[ABG]]/[[VBG]] to evaluate pH
 
===[[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


10-12 - sine wave, v-fib, heart block
===Diagnosis===
*Based on lab testing (>5.5 mEq/L), although ECG may provide earlier information
*Consider pseudohyperkalemia (e.g. from hemolysis)


==Differential Diagnosis==
==Management==
#Pseudohyperkalemia
===Stabilize cardiac membranes===
##Hemolysis of specimen
''Indicated if there are any ECG changes or evidence of arrhythmias. Consider if K >7 mEq/L''
##Pronged tourniquet use prior to blood draw
*Either one of the following:
##Thrombocytosis/leukocytosis
**[[Calcium gluconate]]: Give 10ml of a 10% solution over 10 mins
#Redistribution
***Only 1/3 the calcium compared to calcium chloride
##Acidemia (DKA)
***Can cause hypotension due to osmotic shift
##Cellular breakdown
**[[Calcium chloride]] 1 gram IV
###Rhabdomyolysis/crush injury
***Give over 1 - 2 minutes
###Hemolysis
***Extravasation is bad: use a good IV
###Tumor lysis syndrome
***Usually given in code situations
#Increased total body potassium
*Takes effect in 15-30 minutes<ref>http://lifeinthefastlane.com/hyperkalemia/. Accessed 02/22/2016</ref>
##Inadequate excretion
**(If given for hyperkalemic cardiac arrest, need to continue resuscitation for at least 30 minutes)
###Renal caused (acute or chronic renal failure-must have GFR<10)
*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>
###Hypoaldo
*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>
###Drug-induced
*Do serial [[ECG]]s to track progress: may need to give multiple doses
####K sparing diuretics (spironolactone), ACEI, NSAIDs
##Excessive intake
###Diet
###Blood transfusion
#Misc
##Sux, Dig, B-blockers


<span class="Apple-style-span" style="font-size: 18px;">Treatment</span>
===Shift K+ intracellularly===
<div style="font-family: Arial, Verdana, sans-serif; color: rgb(34, 34, 34); background-color: rgb(255, 255, 255);">
*Intravenous [[insulin]] + [[dextrose]]
*1. Membrane Stabilization
**Give 10 units regular insulin intravenously with 25 to 50 grams (1 - 2 50 mL ampules) of 50% dextrose (D50)
**Calcium gluconate 1-3 amp IV or chloride 1amp IV
***May withhold dextrose if blood sugar >300mg/dl (>17 mmol/L)
***<span style="font-family:arial,helvetica,sans-serif;">Give if ECG changes/hypotension or >7</span>
***Duration of effect: 4 - 6 hours
***<span style="font-family:arial,helvetica,sans-serif;">Gluconate requires hepatic metabolism to free Ca moiety</span>
***Consider mixing in 10 cc NS syringe to ensure small volume of 10 units insulin fully administered via IV
***<span style="font-family:arial,helvetica,sans-serif;">Gluconate slower onset than Ca-chloride</span>
***Insulin cleared renally, be careful about inducing hypoglycemia (ESRD patients).
***<span style="font-family:arial,helvetica,sans-serif;">Chloride extravasation is very bad - use a good IV</span>
****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.
***<span style="font-family:arial,helvetica,sans-serif;">Duration of effect = 30-50min</span>
****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>
***<span style="font-family:arial,helvetica,sans-serif;">Caution in dig-toxic pts</span>
*Nebulized [[albuterol]] 15 - 20mg
***<span style="font-family:arial,helvetica,sans-serif;">May take more than one round of calcium</span>
**Response is dose-dependent
***<span style="font-family:arial,helvetica,sans-serif;">May require repeat dosing as effects are transient</span>
**Peak effect: 30 minutes
**Duration of effect: 2 hours
*[[Sodium bicarbonate]]
**Generally not considered unless pH <7.1
**Pushing "ampules of hypertonic bicarbonate have been proven to be ineffective in RCTs"<ref>[https://emcrit.org/ibcc/hyperkalemia/ IBCC Hyperkalemia Chapter]</ref>
**For '''normovolemic or hypovolemic''' patients with '''metabolic acidosis''':
***Give three amps of bicarbonate in a liter of D5W or sterile water


&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;
===Remove K+ from body===
*Intravenous [[furosemide]] (Lasix) 40 - 80mg
**Ensure adequate urine output first
**Decreases the potassium in three ways: dilution, shifting of potassium into muscle cells, and promotion of renal potassium excretion by alkalosis<ref>[https://emcrit.org/ibcc/hyperkalemia/ IBCC Hyperkalemia Chapter]</ref>
**More on how to use Lasix: [https://emcrit.org/ibcc/hyperkalemia/ IBCC Hyperkalemia Chapter]
*[[Sodium polystyrene sulfonate]] (Kayexalate): 30 gm oral or per rectum
**'''Very Controversial, High Risk of Bowel Perforation''', see: [[EBQ: Use of Kayexylate in Hyperkalemia]]
*[[Sodium zirconium cyclosilicate]]
**Potassium binder, similar to [[Sodium polystyrene sulfonate|Kayexalate]] but without risk of bowel perforation<ref>Beccari, Mario V, and Calvin J Meaney. “Clinical utility of patiromer, sodium zirconium cyclosilicate, and sodium polystyrene sulfonate for the treatment of hyperkalemia: an evidence-based review.” Core evidence vol. 12 11-24. 23 Mar. 2017, doi:10.2147/CE.S129555</ref>
*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]]


*2. Intracellular shift
===IV Fluid Choice===
**10 U insulin IV w/ 1 amp D50 IV now and 1 amp in 15 min
*LR is preferred over NS, even in renal failure<ref>O'Malley CM, Frumento RJ, Hardy MA, Benvenisty AI, Brentjens TE, Mercer JS, Bennett-Guerrero E. A randomized, double-blind comparison of lactated Ringer's solution and 0.9% NaCl during renal transplantation. Anesth. Analg. 2005 May;100(5):1518-24.</ref>
***Duration of effect = 4-6h
*The small amount of 4 mEq/L of potassium in lactated ringers does not contribute to worsening hyperkalemia
**Albuterol neb 2.5mg x 3 or 20mg over 1hour
*Hyperkalemia worsens with metabolic acidosis, and large volume normal saline administration increases risk of hyperchloremic non-anion gap metabolic acidosis
***Duration of effect = 2-4hr
***Higher doses more effective
***Dose 20mg over 1 hour dropped K by 0.6mEq
***Prior Bet-agonist use makes pts resistant to effects
**NaBicarb 1 amp IV (over 5 min)&nbsp;
**Duration of effect = 1-2hr


3. Removal
==Disposition==
*Consideration for ICU for frequent electrolyte checks and close cardiac monitoring


*Dialysis
==See Also==
*Lasix 40-80mg IV
*[[Electrolyte abnormalities]]
*Volume expansion with NS if dehydrated, TLS, rhabdomyolysis, DKA, acidosis
*[[Acute kidney injury]]
*Kayexylate 30-60gms PO - unreliable and slow to work
*[[Hemodialysis/Hemoperfusion]]
</div>
*[[Crush syndrome]]


==Source==
==External Links==
*[https://ecgweekly.com/2015/01/case-of-the-week-january-12-2015/ ECG Weekly -Hyperkalemia]


Tintinalli
==References==
<references/>


[[Category:FEN]]
[[Category:FEN]]
[[Category:Renal]]

Revision as of 18:04, 1 July 2020

Background

  • Defined as >5.5 mEq/L
  • 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

Diagrammatic representation of ECG changes with increasing hyperkalemia
ECG in hyperkalemia with peaked T waves and small P waves
ECG with widened QRS complex and tall broad T waves
ECG showing sine wave pattern

Workup

  • ECG
  • Chem 10 (including potassium, magnesium, and phosphorus)
    • Consider point-of-care lab testing for more rapid result
  • Consider ABG/VBG to evaluate pH

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

Diagnosis

  • Based on lab testing (>5.5 mEq/L), although ECG may provide earlier information
  • Consider pseudohyperkalemia (e.g. from hemolysis)

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
  • Sodium bicarbonate
    • Generally not considered unless pH <7.1
    • Pushing "ampules of hypertonic bicarbonate have been proven to be ineffective in RCTs"[5]
    • For normovolemic or hypovolemic patients with metabolic acidosis:
      • Give three amps of bicarbonate in a liter of D5W or sterile water

Remove K+ from body

  • Intravenous furosemide (Lasix) 40 - 80mg
    • Ensure adequate urine output first
    • Decreases the potassium in three ways: dilution, shifting of potassium into muscle cells, and promotion of renal potassium excretion by alkalosis[6]
    • More on how to use Lasix: IBCC Hyperkalemia Chapter
  • Sodium polystyrene sulfonate (Kayexalate): 30 gm oral or per rectum
  • Sodium zirconium cyclosilicate
    • Potassium binder, similar to Kayexalate but without risk of bowel perforation[7]
  • 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) [8]
  • Hydrocortisone if suspicious for adrenal insufficiency
  • Definitive treatment is hemodialysis

IV Fluid Choice

  • LR is preferred over NS, even in renal failure[9]
  • The small amount of 4 mEq/L of potassium in lactated ringers does not contribute to worsening hyperkalemia
  • Hyperkalemia worsens with metabolic acidosis, and large volume normal saline administration increases risk of hyperchloremic non-anion gap metabolic acidosis

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. ↑ IBCC Hyperkalemia Chapter
  6. ↑ IBCC Hyperkalemia Chapter
  7. ↑ Beccari, Mario V, and Calvin J Meaney. “Clinical utility of patiromer, sodium zirconium cyclosilicate, and sodium polystyrene sulfonate for the treatment of hyperkalemia: an evidence-based review.” Core evidence vol. 12 11-24. 23 Mar. 2017, doi:10.2147/CE.S129555
  8. ↑ https://emcrit.org/pulmcrit/fluid-selection-using-ph-guided-resuscitation
  9. ↑ O'Malley CM, Frumento RJ, Hardy MA, Benvenisty AI, Brentjens TE, Mercer JS, Bennett-Guerrero E. A randomized, double-blind comparison of lactated Ringer's solution and 0.9% NaCl during renal transplantation. Anesth. Analg. 2005 May;100(5):1518-24.
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