Hypokalemia: Difference between revisions

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[[Image:ECG Hypokalemia.jpg]]
[[Image:ECG Hypokalemia.jpg]]


== DDX ==
==Differential Diagnosis==
===Shift===
===Shift===
#Alkalosis (each 0.10 rise in pH causes 0.5 decrease)
*Alkalosis (each 0.10 rise in pH causes 0.5 decrease)
#[[Insulin]]
*[[Insulin]]
#B-agonist
*B-agonist
===Decreased intake===
===Decreased intake===
*Special diets or those low in potassium
*Special diets or those low in potassium
===Increased loss===
===Increased loss===
#GI (v/d/fistula)
*GI (v/d/fistula)
#Renal
*Renal
#*Diuretics
**Diuretics
#*Hyperaldo
**Hyperaldo
#*Exercise
**Exercise
#*[[HyperCa]]
**[[HyperCa]]
#*[[HypoMg]]
**[[HypoMg]]
===Drugs===
===Drugs===
#[[Penicillin]]
*[[Penicillin]]
#[[Lithium]]
*[[Lithium]]
#L-dopa
*L-dopa
#Theophyline
*Theophyline


==Treatment==
==Treatment==

Revision as of 06:29, 19 January 2015

Background

  • Low = <3.5meq/L
  • Low! = <2.5meq/L

Clinical Features

Diagnosis

  • ECG findings:
    • ST seg depression
    • U wave (V4-V6)
    • QT prolongation

ECG Hypokalemia.jpg

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

  • GI (v/d/fistula)
  • Renal

Drugs

Treatment

  • every 10meq should inc serum by ~0.1meq/L
  • If level is <2.5, both oral and IV should be given
  • Typically 20meq/hr KCl IV or PO
  • Oral K+
    • more quickly absorbed and preferred
    • KCl elixir easily swallowed, but tastes terrible
    • KDur oral tablet is large and hard to swallow
  • Intravenous K+
    • typically runs at 10meq/hour (peripheral line)
    • burns when infused, and may cause phelbitis/sclerosis if run faster
  • Treat Hypomagnesemia if present

See Also

Source

  • Tintinalli