Hyperkalemia: Difference between revisions
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==Background== | ==Background== | ||
*Defined as >5.5 mEq/L | *Defined as >5.5 mEq/L | ||
*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 | ||
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*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) | ||
Line 23: | Line 22: | ||
*[[Heparin]] | *[[Heparin]] | ||
*[[Antifungals]] ([[ketoconazole]], [[fluconazole]], [[itraconazole]]) | *[[Antifungals]] ([[ketoconazole]], [[fluconazole]], [[itraconazole]]) | ||
*[[ | *[[Cyclosporine]] | ||
*[[Tacrolimus]] | *[[Tacrolimus]] | ||
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*[[Drospirenone]] | *[[Drospirenone]] | ||
*Potassium sparing [[diuretics]] (amiloride, triamterene) | *Potassium sparing [[diuretics]] (amiloride, triamterene) | ||
*Trimethoprim | *[[Trimethoprim]] | ||
*Pentamidine | *[[Pentamidine]] | ||
==Clinical Features== | ==Clinical Features== | ||
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==Evaluation== | ==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]]=== | ===[[ECG]]=== | ||
''Changes NOT always predictable and sequential'' | ''Changes NOT always predictable and sequential'' | ||
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*7.5 - 8.0 mEq/L: widened QRS interval, flattened P waves | *7.5 - 8.0 mEq/L: widened QRS interval, flattened P waves | ||
*10 - 12 mEq/L: sine wave, ventricular fibrillation, heart block | *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== | ==Management== | ||
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**Peak effect: 30 minutes | **Peak effect: 30 minutes | ||
**Duration of effect: 2 hours | **Duration of effect: 2 hours | ||
* | *[[Sodium bicarbonate]] | ||
**Generally not considered unless pH <7.1 | |||
**Generally not | **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 | |||
===Remove K+ from body=== | ===Remove K+ from body=== | ||
*Intravenous [[furosemide]] (Lasix) 40 - 80mg | *Intravenous [[furosemide]] (Lasix) 40 - 80mg | ||
**Ensure adequate urine output first | **Ensure adequate urine output first | ||
*[[Sodium polystyrene sulfonate]] ( | **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]] | **'''Very Controversial, High Risk of Bowel Perforation''', see: [[EBQ: Use of Kayexylate in Hyperkalemia]] | ||
*[[Sodium zirconium cyclosilicate]] | *[[Sodium zirconium cyclosilicate]] | ||
**Potassium binder, similar to | **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) | *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> | **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]] | *[[Hydrocortisone]] if suspicious for [[adrenal insufficiency]] | ||
*Definitive treatment is [[hemodialysis]] | *Definitive treatment is [[hemodialysis]] | ||
===IV Fluid Choice=== | |||
*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> | |||
*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== | ==Disposition== |
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
- ACE inhibitors; Angiotensin II receptor blockers
- NSAIDs
- Heparin
- Antifungals (ketoconazole, fluconazole, itraconazole)
- Cyclosporine
- Tacrolimus
Block aldosterone binding to mineralocorticoid receptors
- Spironolactone
- Eplerenone
- Drospirenone
- Potassium sparing diuretics (amiloride, triamterene)
- Trimethoprim
- Pentamidine
Clinical Features
Typically non-specific
- Muscle weakness
- Lethargy, fatigue
- Paresthesias
- Nausea and Vomiting
- Difficulty breathing
- Palpitations, chest pain
Differential Diagnosis
Hyperkalemia
- Pseudohyperkalemia: hemolyzed specimen, prolonged tourniquet use prior to blood draw, thrombocytosis or leukocytosis
- Redistribution (shift from intracellular to extracellular space)
- Acidemia (see DKA)
- Cellular breakdown: see Rhabdomyolysis/Crush syndrome, electrical/thermal burn, 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
Peaked T-waves
- MI (hyperacute T waves)
- Hyperkalemia
- Benign Early Repolarization
- De Winter's T waves (acute LAD occlusion)
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)
- Regular
- Monomorphic ventricular tachycardia
- PSVT with aberrant conduction:
- PSVT with bundle branch block^
- PSVT with accessory pathway
- Atrial flutter with bundle branch block^
- Sinus tachycardia with bundle branch block^
- Accelerated idioventricular rhythm (consider if less than or ~120 bpm)
- Metabolic
- Irregular
- Atrial fibrillation/atrial flutter with variable AV conduction AND bundle branch block^
- Atrial fibrillation/atrial flutter with variable AV conduction AND accessory pathway (e.g. WPW)
- Atrial fibrillation + hyperkalemia
- Polymorphic ventricular tachycardia
^Fixed or rate-related
Evaluation
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
- Calcium gluconate: Give 10ml of a 10% solution over 10 mins
- 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]
- Give 10 units regular insulin intravenously with 25 to 50 grams (1 - 2 50 mL ampules) of 50% dextrose (D50)
- 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
- Very Controversial, High Risk of Bowel Perforation, see: EBQ: Use of Kayexylate in Hyperkalemia
- 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
- ↑ http://lifeinthefastlane.com/hyperkalemia/. Accessed 02/22/2016
- ↑ The Effect of Calcium on Severe Hyperkalemia http://hqmeded-ecg.blogspot.com/2015/04/the-effect-of-calcium-on-severe.html
- ↑ 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
- ↑ 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.
- ↑ IBCC Hyperkalemia Chapter
- ↑ IBCC Hyperkalemia Chapter
- ↑ 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
- ↑ https://emcrit.org/pulmcrit/fluid-selection-using-ph-guided-resuscitation
- ↑ 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.