Ch. 5

Question 1

What is the equation for Ve?

Answer 1

Vt x F

Question 2

Definition of Ve?

Answer 2

Volume of air during normal RR inspired and expired over 1 min. OR rate of respirations per min.

Question 3

How long do you measure Ve?

Answer 3

15 secs

Question 4

Inc. rate usually reflects changes in ______ ?

Answer 4

Vent status

Question 5

Inc. rate =

Answer 5

Hypoxia
Hypercapnia
Inc. temp

Question 6

Dec. rate =

Answer 6

• CNS depression
• CO2 narcosis (hyper-oxygenation or O2 toxicity)
• Neuromuscular disease involving vent disorders

Question 7

What is the respiratory exchange ratio (RER)?

Answer 7

The ratio between the volume of CO2 produced (VCO2) divided by the volume of O2 consumed (VO2).

Question 8

Fun fact

Answer 8

The ratio of the body’s CO2 output to the uptake of CO2 indirectly shows the muscles oxidative capacity to get energy.

Question 9

RER must be calculated….?

Answer 9

If the inspiratory volumes are used (machine does this).

Question 10

What is the formula for RER?

Answer 10

VCO2/VO2

Question 11

What is the normal for RER?

Answer 11

80%

Question 12

RER ______ as CO2 production ______ ?

Answer 12

Increases ; increases

Question 13

How do you measure RER?

Answer 13

• RIP- uses transducers to measure pulmonary ventilation by measuring the movement of the chest and abdominal wall.
• Volume displacement spirometer (water seal spirometer).
• Flow sensing spirometer
• O2 & CO2 analyzer

Question 14

What are some calculations used for RER?

Answer 14

Vt = Ve/F
Ve = Vt x F

Question 15

What is the usual range for Vt?

Answer 15

400-700 mls in a healthy adult

Question 16

Ve must be calculated with _____ values to determine adequacy of the vent?

Answer 16

Blood gas (ABG)

Question 17

What is normal Ve?

Answer 17

5-10 L/min in healthy adult

Question 18

Hyperventilation means what?

Answer 18

Body is trying to compensate

Question 19

Ve does not determine ________ or ________?

Answer 19

Hypoventilation; hyperventilation

Question 20

Body will compensate for _______ ?

Answer 20

Decreased CO2

Question 21

What is hypoventilation?

Answer 21

PCO2 > 45 pH < 7.35

Question 22

What is hyperventilation?

Answer 22

PCO2 < 35 pH > 7.45

Question 23

What are the 2 types of dead space?

Answer 23

Anatomic & alevolar
together they add up to physiological dead space

Question 24

What is dead space usually dependent on?

Answer 24

BTPS or LPM

Question 25

What is anatomic dead space?

Answer 25

Air in the upper airways that do not participate in gas exchange.

Question 26

What is alveolar dead space?

Answer 26

Lung volumes that are ventilated but not perfused by capillary blood flow. Air is trapped in the small airways (alveoli) that cannot participate in gas exchange.

Question 27

How to measure Vd?

Answer 27

Exhaled gas is collected over specified interval and measured. Blood gases are taken at the same time to measure PaCO2. **info is added to Bohr equation**

Question 28

What is the formula for Vd?

Answer 28

PaCO2 -PeCo2 / PaCO2 **PaCO2 = arterial** **PeCO2 = end tidal**

Question 29

How can anatomic Vd be calculated?

Answer 29

By IBW 1mL/lb or 2mL/kg

Question 30

How to calculate alveolar dead space?

Answer 30

Calculated during measurements of volumes RV/TLC ratio.

Question 31

Physiological Vd can be important because it takes into account both _____ & ______ Vd?

Answer 31

Anatomic; alveolar

Question 32

What is alveolar ventilation?

Answer 32

Part of the ventilation that participates in gas exchange at the alveolar level.

Question 33

What is the formula for alveolar ventilation?

Answer 33

VA = F (Vt -Vd)

Question 34

Vd is considered equal to _______?

Answer 34

Anatomic Vd (1mL/lb or 2mL/kg of IBW)

Question 35

What are some techniques to measure ventilator response?

Answer 35

Open circuit and closed circuit

Question 36

What are some techniques used to measure CO2 & O2?

Answer 36

Open circuit Closed circuit CO2 scrubber

Question 37

What is P100?

Answer 37

The pressure generated at the mouth during first 100 milliseconds of an inspiratory effort against an occluded airway. **this is what drives ventilation**

Question 38

Changes in P100 are directly related to changes in ….?

Answer 38

Body position and contractile properties of the respiratory muscles.

Question 39

What is the normal range for P100?

Answer 39

1.5-5 cmH20

Question 40

P100 is increased in?

Answer 40

Hypercapnia and hypoxia

Question 41

P100 is helpful in?

Answer 41

Determining effects of tx in pts with abnormal ventilation responses measured with closed circuit.

Question 42

What does a pneumotachometer measure?

Answer 42

The volume of airflow in lungs