Electrolyte Repletion

Potassium

• Usual dose is 40meq IV or PO unless level is <2.5. If so, both forms should be given
• 10meq will raise serum level by 0.1
• Intravenous K+ typically runs at 10meq/hour, burns when infused, and may cause phelbitis/sclerosis if run faster
• Oral K+ more quickly absorbed and preferred
• KCl elixir easily swallowed, but tastes terrible, KDur oral tablet is large and hard to swallow
• Serum K+ will not respond if patient has concurrent hypomagnesmia

Magnesium

• Replete if serum level <1.7
• Usual dose is 2g over 1 hour
• If level <than 1.2, double the dose
• Oral repletion may done if level is >1.2 and pt is asymptomatic
• Magnesium oxide 400mg is approximately equal to 2g of MgSO4

Phosphorus

• If <2.4:
  • Neutra-Phos 2 packets PO Q6hr x 48hr OR sodium phosphate 30mmol IV
• If <1:
  • IV Sodium Phosphate 45mmol should be used