Hypokalemia: Difference between revisions
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==Background== | ==Background== | ||
== Clinical Features | |||
==Clinical Features== | |||
*CNS | *CNS | ||
**[[Weakness]] | **[[Weakness]] | ||
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**Ileus | **Ileus | ||
*Renal | *Renal | ||
**[[Metabolic | **[[Metabolic alkalosis]] | ||
*CV | *CV | ||
**PACs/PVCs | **PACs/PVCs | ||
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**AV block | **AV block | ||
**[[V tach]], [[V fib]] | **[[V tach]], [[V fib]] | ||
==Differential Diagnosis== | ==Differential Diagnosis== | ||
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*Special diets or those low in potassium | *Special diets or those low in potassium | ||
===Increased loss=== | ===Increased loss=== | ||
*GI | *GI | ||
**Vomiting, diarrhea, fistula | |||
*Renal | *Renal | ||
**Diuretics | **Diuretics | ||
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*Theophyline | *Theophyline | ||
== | ==Diagnosis== | ||
* | *Serum potassium level is diagnostic | ||
* | **Normal = 3.5-5meq/L | ||
**Severe hypokalemia = <2.5meq/L | |||
*Oral | *Suggestive ECG findings: | ||
** | **[[ST segment depression]] | ||
**KCl elixir | **U wave (V4-V6) | ||
** | **[[QT prolongation]] | ||
*Intravenous | **[[PVC]] | ||
** | |||
** | [[Image:ECG Hypokalemia.jpg]] | ||
* | |||
==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, phelbitis, sclerosis | |||
*Also treat [[Hypomagnesemia]] if present | |||
==Disposition== | |||
*Based on underlying cause | |||
==See Also== | ==See Also== | ||
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*[[Hypokalemic periodic paralysis]] | *[[Hypokalemic periodic paralysis]] | ||
== | ==References== | ||
<references/> | |||
[[Category:FEN]] | [[Category:FEN]] | ||
Revision as of 11:18, 28 March 2016
Background
Clinical Features
- CNS
- Weakness
- Cramps
- Hyporeflexia
- GI
- Ileus
- Renal
- CV
- PACs/PVCs
- Bradycardia or atrial/junctional tachycardia
- AV block
- V tach, V fib
Differential Diagnosis
Shift
- Alkalosis (each 0.10 rise in pH causes 0.5 decrease)
- Insulin
- B-agonist
Decreased intake
- Special diets or those low in potassium
Increased loss
Drugs
- Penicillin
- Lithium
- L-dopa
- Theophyline
Diagnosis
- Serum potassium level is diagnostic
- Normal = 3.5-5meq/L
- Severe hypokalemia = <2.5meq/L
- Suggestive ECG findings:
- ST segment depression
- U wave (V4-V6)
- QT prolongation
- PVC
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, phelbitis, sclerosis
- Also treat Hypomagnesemia if present
Disposition
- Based on underlying cause