Hyperkalemia: Difference between revisions
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== Differential Diagnosis == | == Differential Diagnosis == | ||
*Pseudohyperkalemia: hemolyzed specimen, prolonged tourniquet use prior to blood draw, thrombocytosis or leukocytosis | |||
*Redistribution (shift from intracellular to extracellular space) | |||
**Acidemia (see [[Diabetic Ketoacidosis (DKA)|DKA]]) | |||
**Cellular breakdown: see [[Rhabdomyolysis]]/[[Crush Injury]], 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 | |||
== Treatment == | == Treatment == | ||
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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 | |||
*Intravenous calcium only if QRS interval is prolonged | |||
*Can give as calcium gluconate or calcium chloride | |||
**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 <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> | |||
**Do serial [[EKG]]s to track progress: may need to give multiple doses | |||
===Shift K+ intracellularly=== | ===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=== | ===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 | |||
**'''Controversial''', see: [[EBQ: Use of Kayexylate in Hyperkalemia]] | |||
*Intravenous normal saline solution for volume expansion if dehydrated, rhabdomyolysis, diabetic ketoacidosis or other acidosis | |||
*Definitive treatment is hemodialysis | |||
== See Also == | == See Also == | ||
Revision as of 07:31, 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
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
Differential Diagnosis
- 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 Injury, 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
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
- Intravenous calcium only if QRS interval is prolonged
- Can give as calcium gluconate or calcium chloride
- 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
- Calcium gluconate: Give 10ml of a 10% solution over 10 mins
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
- Give 10 units regular insulin intravenously with 25 to 50 grams (1 - 2 50 mL ampules) of 50% dextrose (D50)
- 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
- Controversial, see: EBQ: Use of Kayexylate in Hyperkalemia
- Intravenous normal saline solution for volume expansion if dehydrated, rhabdomyolysis, diabetic ketoacidosis or other acidosis
- Definitive treatment is hemodialysis
See Also
External Links
References
- ↑ 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