Treatment-hypokalemia

(JAMA 2000;160:2429)

• If true potassium deficit: potassium repletion (↓ 1 mEq/L ≈ 200 mEq total body loss)

Dosage: 40 mEq PO q4h, 10 mEq/h (IV), 20 mEq/h (central line), 40 mEq in 1 L IVF

• Replete K+ to >3 or >4 mEq/L if high-risk (HTN, CHF, arrhythmias, MI, digoxin, cirrhosis)
• Beware of excessive potassium repletion if transcellular shift cause of hypokalemia
• Treat underlying cause (if ↓ vol: avoid dextrose as ↑ insulin → intracellular potassium shifts)
• Consider Rx that ↓ K loss: ACEI/ARB, K+-sparing diuretics, βB
• Replete Mg if <2 mEq/L: IV Mg-SO4 1–2 g q2h and oral Mg-oxide (limited by diarrhea).

Causes of low Mg