Calculating Base Excess
Q: Usually all new machines provide Base Excess/deficit automatically along with ABG. Supposedly you have a situation where ABG (arterial blood gas) is not available and due to some reason (like severe coagulopathy), you are not willing to do arterial punture, what is the formula to calculate Base Excess or Base Deficit?
A: Obtain HCO3 and PH from venous blood and apply following formula
B.E. = 0.9287 (HCO3 - 24.4 + 14.83 (pH - 7.4))
Or to roundup
B.E. = (HCO3 - 24 + 15 (PH - 7.4)
Base Excess is defined as the negative value of the concentration of titratable hydrogen ion in blood or plasma. The endpoint of titration is pH = 7.40. It also helps in determining the amount of bicarbonate immediately required for replacement with following formula
mEq of NaHCO3 needed = 0.1 or 0.2 × (BW in Kg) × (BE)
1 amp of bicarb. carries 50 mEq of NaHCO3
No comments:
Post a Comment