Hypokalemia

Background

Low = <3.5meq/L

Low! = <2.5meq/L

Diagnosis

Symptoms:

1) CNS (weakness, cramps, hyporeflexia)

2) GI (ileaus)

3) CV (dysrhythmia, dig tox, U waves, ST depression, prolonged QT)

4) Renal (met alkalosis)

DDX

A. Shift

    1) Increased pH

    2) B-agonist, inuslin

B. Reduced intake

C. Increased loss

    1) Renal

         i) Primary (hyperaldos, osmotic diuresis)

         ii) Secondary (*diuretics, malignant HTN, renal art stenosis)

         iii) Misc (licorice, hyperCa, Mg def, RTA, leukemia)

         iv) Drugs (PCN, lithium, L-dopa, theophyline)

    2) GI Loss (v/d/fistula)

Treatment

20meq/h KCl IV or PO

(every 10meq should inc serum by ~0.1meq/L)

• treat hypomag if present

Source

2/7/06 DONALDSON (adapted from Tintinalli)