Blood Gas Analysis

Question 1

Which drugs have minimal CV effects?

Answer 1

Etomidate
Alfaxalone
Midazolam
Hydromorphone

Question 2

Normal pH

Answer 2

7.35-7.45

Question 3

Primary acid base disorder

Answer 3

defined by the initial change in HCO3 or PaCO2

Question 4

Compensation

Answer 4

secondary change in HCO3 or PaCO2 in order to attenuate the effect of the primary disorder on blood pH.

Question 5

Base Excess

Answer 5

to an excess or deficit in the amount of base present in the blood

Question 6

Positive Base Excess

Answer 6

metabolic alkalosis

Question 7

Negative Base Excess

Answer 7

metabolic acidosis

Question 8

PaCO2

Answer 8

alveolar ventilation

Question 9

Increased PaCO2 will…

Answer 9

Lower the PaO2
Lower the pH
Reflect respiratory acidosis
Reflect Respiratory compensation

Question 10

FiO2

Answer 10

Inspired O2 fraction

Question 11

PiO2

Answer 11

inspired O2 pressure

Question 12

V/Q mismatch

Answer 12

Lower than expected PaO2 values may indicate inadequate gas exchange resulting in pulmonary atelectasis

Question 13

A-a difference

Answer 13

PaO2 is always lower than PAO2

Question 14

Causes for high A-a difference

Answer 14

V/Q mismatch
Right to left shunt
Diffusion impairment

Question 15

Reasons for V/Q Mismatch

Answer 15

Atelectasis

Lung diseases

Question 16

A-a difference

Answer 16

used to distinguish lung diseases from hypoventilation as a cause of hypoxemia

Question 17

5 causes of hypoxemia

Answer 17

Low FiO2
Hypoventilation
Diffusion impairment 
V/Q mismatch 
Right to left shunt

Question 18

Hypoxia

Answer 18

insufficient oxygenation of the tissues

Question 19

Caused of Hypoxia

Answer 19

Hypoxemia
Insufficient tissue perfusion
insufficient O2 uptake

Question 20

What is PaO2 is mostly defined by?

Answer 20

Concentration of Hemoglobin

SaO2

Question 21

What is considered high for lactate?

Answer 21

> 2mmol/L

Indicates increased anaerobic metabolism

Question 22

Lactic acidosis

Answer 22

Tissue hypoxia leads to increased anaerobic metabolism and produces lactate and acids

Question 23

Low PaO2 /FiO2 ratio

Answer 23

V/Q mismatch caused by atelectasis due to anesthesia