Acid base balance

Question 1

What can the anion gap help measure?

Answer 1

acid base balance specifically metabolic acidosis

Question 2

Anion Gap formula?

Answer 2

(Na+ + K+) - (Cl- + HCO3)

Question 3

Normal anion gap range

Answer 3

5-15 mEq/L

Question 4

HCO3 level range

Answer 4

22-29 mEq/L

Question 5

Winters formula

Answer 5

Expected PaCO2= (bicarb x 1.5) + 8

Question 6

What does Winters formula calculate?

Answer 6

Winter’s Formula is used to predict the PaCO2 which should result if there is appropriate respiratory compensation for a metabolic acidosis

Question 7

What does the Winters formula result tell us about pH balance?

Answer 7

If the actual measured PaCO2 is lower than predicted, there is a concomitant respiratory alkalosis; if it is higher than predicted there is a concomitant respiratory acidosis

Question 8

What is the THUMB rule?

Answer 8

Put your thumb over the first digit of the pH on the ABG. The PaCO2 should be the last two digits. For instance, if the pH is 7.30, then the PaCO2 should be about 30mmHg; if the pH is 7.15 then the PaCO2 should be about 15mmHg, etc

Question 9

What is the difference between Ve and Alvelolar Ve?

Answer 9

Dead space

Question 10

How is anatomical dead space estimated?

Answer 10

1ml/lb of IBW

Question 11

What is the f (CO2) correction formula?

Answer 11

current CO2 x current f / desired CO2 = corrected f

Question 12

How fast should you adjust the f to effect the CO2 level?

Answer 12

In increments of 2 breaths/min. to ensure there is no air trapping.

Question 13

How would you assess for air trapping?

Answer 13

The flow wave form does not return to baseline