1. HYPOKALEMIA

2. Etiology Definition serum potassium concentration < 3.5 mEq/L
total body potassium deficit
Poor intake
Excessive renal & GI loss
serum potassium is shifted into the intracellular compartment
drug

3. Drug induce hypo K

4. Category & Clinical presentation
State
Serum K level
Clinical presenttation
mild
3-3.5 mEq/L
asymptomatic
moderate
2.5-3 mEq/L
cramping, weakness, malaise, and myalgias
severe
< 2.5 mEq/L
ECG changes
arrhythmias
ECG changes: ST-segment depression or flattening,T-wave inversion, and U-wave elevation

5. Treatment K supplement  3 salt (Chloride, phosphate, carbonate)
PO  mild to moderate (should be divided into 3-4 doses to minimize the developement of GI side effects)
IV  severe (K < 2.5 mEq/L)
 exhibiting signs symptoms of hypokalemia
 patients unable to tolerate oral therapy

6. KCl oral 10% KCl elixir (20 mEq/15 ml) Ped KCl 2% (4 mEq/15ml)
serum K
60 ml
120 ml
180 ml

7. KCl IV infusion NaCl D5W  advoided
10 to 20 mEq of potassium is diluted in 100 mL 0.9% NaCl
administered through a peripheral vein over 1 hour
Mutiple dose: can be repeated as needed until the serum potassium concentration normalizes (equilibium time 30 min)

8. KCl IV infusion (Conc.) Severe K depletion KCl 300 to 400 mEq/day
dilute 40 to 60 mEq in 1,000 mL 0.45% NaCl
Rate of infusion: not exceeding 40 mEq/h
Central intravenous line into a large vein
(e.g., superior vena cava)

9. Alternative therapy Potassium-sparing diuretics
Spironolactone : 25-mg, 50-mg, and 100-mg tablets
Start 25 to 50 mg daily  titrated to a maximum dose of 400 mg/day.
side effects: hyperkalemia, gynecomastia, breast tenderness, and impotence

10. Alternative therapy Triamterene: 50-mg and 100-mg capsules
Start 50 mg twice daily titrated to 100 mg twice daily
side effects: hyperkalemia, sodium depletion, and metabolic acidosis
Amiloride: 5-mg tablet
Start 5 mg daily; however, 10 mg can be given in those with severe hypokalemia

11. Alternative therapy
Generally, concomitant use of potassium supplementation with potassium-sparing diuretics is not necessary.
There is a significant risk of hyperkalemia during combination therapy, especially in patients with underlying renal insufficiency or diabetes mellitus.

12. The end