Hypokalemia: Difference between revisions
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*Central nervous system | *Central nervous system | ||
**[[Weakness]] | **[[Weakness]] | ||
**[[Cramps]] | **[[myalgia|Cramps]] | ||
** | **Hyporeflexia | ||
*Gastrointestinal | *Gastrointestinal | ||
**[[Ileus]] | **[[Ileus]] | ||
| Line 11: | Line 11: | ||
**[[Metabolic alkalosis]] | **[[Metabolic alkalosis]] | ||
*Cardiovascular | *Cardiovascular | ||
**PACs/PVCs | **[[PACs]]/[[PVCs]] | ||
**[[ACLS: Bradycardia|Bradycardia]] or atrial/junctional tachycardia | **[[ACLS: Bradycardia|Bradycardia]] or [[atrial tachycardia|atrial]]/[[junctional tachycardia]] | ||
**[[AV block]] | **[[AV block]] | ||
**[[Tachycardia (wide)|Ventricular tachycardia]], [[Adult pulseless arrest|Ventricular fibrillation]] | **[[Tachycardia (wide)|Ventricular tachycardia]], [[Adult pulseless arrest|Ventricular fibrillation]] | ||
| Line 21: | Line 21: | ||
*Alkalosis (each 0.10 rise in pH causes 0.5 decrease) | *Alkalosis (each 0.10 rise in pH causes 0.5 decrease) | ||
*[[Insulin]] | *[[Insulin]] | ||
* | *[[Beta agonists]] | ||
*[[Hypokalemic periodic paralysis]] | *[[Hypokalemic periodic paralysis]] | ||
===Decreased intake=== | ===Decreased intake=== | ||
*Special diets or those low in potassium | *Special diets or those low in potassium | ||
*Chronic alcohol abuse | *Chronic [[alcohol Abuse|alcohol abuse]] | ||
===Increased loss=== | ===Increased loss=== | ||
*GI | *GI | ||
**Vomiting, diarrhea, fistula | **[[Vomiting]], [[diarrhea]], fistula | ||
*Renal | *Renal | ||
**Diuretics | **[[Diuretics]] | ||
** | **Hyperaldosteronism | ||
**Exercise | **Exercise | ||
**[[Hypercalcemia]] | **[[Hypercalcemia]] | ||
**[[Hypomagnesemia]] | **[[Hypomagnesemia]] | ||
===Drugs=== | ===Drugs=== | ||
*[[Penicillins]] | *[[Penicillins]] | ||
*[[Lithium toxicity|Lithium]] | *[[Lithium toxicity|Lithium]] | ||
*L-dopa | *L-dopa | ||
*[[Theophylline]], methylxanthines | *[[Theophylline]], methylxanthines (e.g. [[caffeine]] | ||
*[[Insulin]] | *[[Insulin]] | ||
*Barium | *Barium | ||
| Line 70: | Line 72: | ||
**Must be given in dilute solutions at slow rate (10meq/hour) to minimize side effects and cardiac toxicity | **Must be given in dilute solutions at slow rate (10meq/hour) to minimize side effects and cardiac toxicity | ||
**Generally should not give more than 40mEq via IV | **Generally should not give more than 40mEq via IV | ||
**Side effects: Local tissue burning, | **Side effects: Local tissue burning, phlebitis, sclerosis | ||
*Also treat [[Hypomagnesemia]] if present | *Also treat [[Hypomagnesemia]] if present | ||
*Re-check ECG after treatment <ref>Slovis, Corey. "Electrolyte Emergencies". Presentation.</ref> | *Re-check ECG after treatment <ref>Slovis, Corey. "Electrolyte Emergencies". Presentation.</ref> | ||
Revision as of 16:10, 29 September 2019
Background
Clinical Features
- Central nervous system
- Gastrointestinal
- Renal
- Cardiovascular
Differential Diagnosis
Intracellular Shift
- Alkalosis (each 0.10 rise in pH causes 0.5 decrease)
- Insulin
- Beta agonists
- Hypokalemic periodic paralysis
Decreased intake
- Special diets or those low in potassium
- Chronic alcohol abuse
Increased loss
- GI
- Renal
- Diuretics
- Hyperaldosteronism
- Exercise
- Hypercalcemia
- Hypomagnesemia
Drugs
- Penicillins
- Lithium
- L-dopa
- Theophylline, methylxanthines (e.g. caffeine
- Insulin
- Barium
- Quinine
- Catecholamines
Evaluation
- Serum potassium level is diagnostic
- Normal = 3.5-5meq/L
- Severe hypokalemia = <2.5meq/L
- Always check magnesium
- Suggestive ECG findings:
Management
- Potassium repletion (PO or IV)
- Every 10mEq KCl → serum K ↑ ~0.1mEq/L
- PO preferred (if symptomatic or level is <2.5, both oral and IV should be given)
- Oral potassium
- Inexpensive and rapidly absorbed
- KCl tablet (elixir form available but has poor taste)
- K-Dur (extended release tablet) is large and may be difficult to swallow
- Intravenous potassium
- Must be given in dilute solutions at slow rate (10meq/hour) to minimize side effects and cardiac toxicity
- Generally should not give more than 40mEq via IV
- Side effects: Local tissue burning, phlebitis, sclerosis
- Also treat Hypomagnesemia if present
- Re-check ECG after treatment [1]
- Hypokalemia in acute or recent myocardial infarction places patients at much higher risk for ventricular fibrillation[2]
- Previous studies and many professional organizations recommend maintaining K between 4.0 - 5.0 mEq/L in MI patients
- However, more recent studies suggest 3.5 - 4.5 mEq/L results in the lowest mortality
Disposition
- Based on underlying cause