bicarb and lactate

Q: All of the following occurs with rapid intravenous bolus of sodium bicarbonate except? 

A) increase PCO2 
B) decrease production of lactate 
C) lower ionized calcium 
D) expand extracellular space 
E) raise the serum sodium concentration 


 Answer: B

This question is designed to point out the dangers associated with overuse of "bicarb" boluses in ICU. 

Sodium bicarbonate should be used very judiciously to raise PH only when it goes below 7.1.

An IV bolus of bicarbonate does exactly the opposite for which it is used! - it accelerates the production of lactate! Acidemia is a naturally occurring body protection. It acts as a "brake" on lactic acid generation by inhibiting glycolysis, largely mediated by a reduction in the activity of the enzyme, phosphofructokinase. Resolving acidemia too fast accelerates the production of lactate. 


#acid-base


Reference:

Hood VL, Tannen RL. Protection of acid-base balance by pH regulation of acid production. N Engl J Med 1998; 339:819.