Bicarb and ECF volume

Q: A 50 mL ampule of 50 mEq of sodium bicarbonate (popularly known as "1 amp of bicarb") expands the Extra Cellular Fluid (ECF) volume by approximately 

A) 50 mL 
B) 100 mL
C) 250 mL.
D) 500 mL
E) unpredictable


Answer: C

"one amp of bicarb" expands the ECF volume by approximately 250 mL, which is approximately equivalent to one IVF bolus!

#acidbase


Reference: 

Alpern RJ, Cogan MG, Rector FC. Effects of extracellular fluid volume and plasma bicarbonate concentration on proximal acidification in the rat. Journal of Clinical Investigation. 1983;71(3):736-746.