Flashcards in Acid-Base Concepts & ABG Interpretation (Dall) Deck (16):
What is the main enzyme involved in acid base balance?
What reactions does it catalyze?
CO2 + H2OH2CO3H + HCO3
What equation can you to calculate hydrogen ion concentration?
How much acid is produced daily? From what processes?
All cellular respiration
What is the physiological pH range? What determines this range?
This is the range at which enzymes are viable.
What organs are responsible for acid base buffering? Which organ does most of the buffering?
Lung and Kidney
Lung buffers far more
Where does buffering occur in the kidney?
Proximal tubule (HCO3 resorption)
Collecting duct (H+ excretion)
What tests are done when an acid/base disorder is suspected?
Arterial Blood Gases - pCO2, pH
Basic Chemistry- HCO3, Na, Cl, Urea,
What is normal pH value? HCO3 values? pCO2 values?
HCO3- 24 mmol/L
pCO2- 40 mmHg
What values denote acidosis or alkalosis?
pH < 7.4
HCO3 < 24 mmol/L
pCO2 > 40 mmHg
pH > 7.4
HCO3 > 24 mmol/L
pCO2 < 40 mmHg
What is the condition where 2 or more acid/base values are abnormal?
Mixed acid-base disturbance
What diseases are marked by an abnormal pCO2 value?
what diseases are marked by an abnormal HCO3 value?
Respiratory alkalosis or acidosis
Metabolic alkalosis or acidosis
What formulas can you use to calculate the expected pCO2 compensation for metabolic acidosis?
pCO2= 1.5*[HCO3] +8
pCO2=last two digits of pH (only works in narrow pH range)
What formula can you use to calculate the expected pCO2 compensation for metabolic alkalosis?
pCO2= 0.9*[HCO3] +9
What is the expected bicarbonate compensation in respiratory acidosis?
an increase of 1mmol/L HCO3/ 10 mmHg pCO2 acute
an increase of 4mmol/L HCO3/10 mmHg pCO2 chronic
What is the expected bicarbonate compensation in respiratory alkalosis?
a decrease of 2mmol/L HCO3/ 10mmHg pCO2 acute
a decrease of 4mmol/L HCO3/ 10mmHg pCO2 chronic