Acid Base Values Exam 1 Flashcards
units of pCO2
mmHg
units of HCO3
mEq/L
units of total CO2
mEq/L
units of base excess
mEq/L (?)
Which equation defines the relationship between pH, pCO2 and bicarbonate?
Henderson Hasselbalch
pH = 6.1 + log( HCO3 / (pCO2 x 0.03))
HCO3 stays the same. Associate rate of breathing with pCO2 and pH
- hyperventilate = pCO2 decreases = pH increases = respiratory alkalosis
- hold your breath = pCO2 increases = pH decreases = respiratory acidosis
pCO2 stays the same. Associate HCO3 level to pH
- decreased HCO3 = pH decreases = metabolic acidosis
- increased HCO3 = pH increases = metabolic alkalosis
What can cause low HCO3?
- lactate knocks down bicarb
- hypoperfusion can cause this
What is base excess?
- tells you how far from normal you are (normal = 23)
- BE of -3 => bicarb = 20
- BE of 3 => bicarb = 26
associate base excess values with metabolic assessment
- Below normal (-base excess)=metabolic acidosis.
- Above normal(+ base excess)=metabolic alkalosis
Describe the impact of salicylate on blood gases.
pH is within normal values but the HCO3 indicate metabolic acidosis and pCO2 indicate resp alkalosis (HCO3 and pCO2 are opposites essentially)