Acid-Base Concepts & ABG Interpretation (Dall) Flashcards Preview

M2 Renal/Respiratory > Acid-Base Concepts & ABG Interpretation (Dall) > Flashcards

Flashcards in Acid-Base Concepts & ABG Interpretation (Dall) Deck (16)
Loading flashcards...
1
Q

What is the main enzyme involved in acid base balance?

What reactions does it catalyze?

A

Carbonic Anhydrase

CO2 + H2OH2CO3H + HCO3

2
Q

What equation can you to calculate hydrogen ion concentration?

A

Henderson Equation

[H]=24(pCO2/[HCO3])

3
Q

How much acid is produced daily? From what processes?

A

20,000 mmol

All cellular respiration

4
Q

What is the physiological pH range? What determines this range?

A

6.8-7.6 pH

This is the range at which enzymes are viable.

5
Q

What organs are responsible for acid base buffering? Which organ does most of the buffering?

A

Lung and Kidney

Lung buffers far more

6
Q

Where does buffering occur in the kidney?

A
Proximal tubule (HCO3 resorption) 
Collecting duct (H+ excretion)
7
Q

What tests are done when an acid/base disorder is suspected?

A

Arterial Blood Gases - pCO2, pH

Basic Chemistry- HCO3, Na, Cl, Urea,

8
Q

What is normal pH value? HCO3 values? pCO2 values?

A

pH- 7.40
HCO3- 24 mmol/L
pCO2- 40 mmHg

9
Q

What values denote acidosis or alkalosis?
pH
HCO3
pCO2

A

Acidosis
pH < 7.4
HCO3 < 24 mmol/L
pCO2 > 40 mmHg

Alkalosis
pH > 7.4
HCO3 > 24 mmol/L
pCO2 < 40 mmHg

10
Q

What is the condition where 2 or more acid/base values are abnormal?

A

Mixed acid-base disturbance

11
Q

What diseases are marked by an abnormal pCO2 value?

what diseases are marked by an abnormal HCO3 value?

A

Respiratory alkalosis or acidosis

Metabolic alkalosis or acidosis

12
Q

What formulas can you use to calculate the expected pCO2 compensation for metabolic acidosis?

A

pCO2= 1.5*[HCO3] +8
OR
pCO2=last two digits of pH (only works in narrow pH range)

13
Q

What formula can you use to calculate the expected pCO2 compensation for metabolic alkalosis?

A

pCO2= 0.9*[HCO3] +9

14
Q

What is the expected bicarbonate compensation in respiratory acidosis?

A

an increase of 1mmol/L HCO3/ 10 mmHg pCO2 acute

an increase of 4mmol/L HCO3/10 mmHg pCO2 chronic

15
Q

What is the expected bicarbonate compensation in respiratory alkalosis?

A

a decrease of 2mmol/L HCO3/ 10mmHg pCO2 acute

a decrease of 4mmol/L HCO3/ 10mmHg pCO2 chronic

16
Q

What is the anion gap? What is the accepted value for the anion gap?

A

A test that measures the difference between measured amounts of cations and anions in the blood.

Anion gap should be 10

Decks in M2 Renal/Respiratory Class (50):