FLUID AND ELECTROLYTES

See also "Pediatric Fluid Management"

Fluid Management

Sodium Homeostasis

Potassium Homeostasis

Calcium Homeostasis

Phosphate Homeostasis

Basic info:

• Extracellular fluid = roughly 20% of body weight (5% plasma; 15% interstitium)
• Intracellular fluid = roughly 40% of body weight
• Normal plasma osmolarity = 280-300 mOsm/kg
• Serum osmolarity estimation = 2(Na + K) + Glu/18 + BUN/2.8
• Anion gap (in mEq/l) = Na - (Cl + HCO3); nl = 8-16mEq/l