Hypoventilation

Question 1

Ventilation

Answer 1

the volume of air moved per unit of time

Question 2

Tidal volume

Answer 2

the volume of air inhaled in a single breath at rest

Question 3

Total lung capacity(TLC)

Answer 3

Total amount of air the lung can hold

Question 4

Residual volume

Answer 4

The amount of air left in the lungs after maximum expiration

Question 5

Vital capacity

Answer 5

the difference between the lung capacity and residual volume(so the amt. of air that can be moved during breathing)

Question 6

Functional Residual Capacity (FRC)

Answer 6

-volume at end of passive expiration

-Balance point of the elastic recoil of lung and chest wall

-Mechanical equilibrium

Question 7

Details of conducting airways

Answer 7

-Transport
-Filter inhaled particles (>10um)
-Warm such as in the sub epithelial vascular plexus
-Humidify through serous secretions

Question 8

Details of Gas exchange airways

Answer 8

Airways containing alveoli
-Respiratory bronchiole, alveolar
duct, alveolar sac, alveolus
* O2 and CO2 exchange

Question 9

True/False; Not all inspired air reaches alveoli

Answer 9

cc

Question 10

Alveolar ventilation (VA)

Answer 10

volume of air participating in gas exchange/minute

Question 11

What represents the relationship between CO2 production & VA(alveolar ventilation)?

Answer 11

PCO2

Question 12

Deadspace ventilation (Vd)

Answer 12

volume of air breathed/minute not participating in gas exchange

Question 13

Anatomic VD

Answer 13

Air in conducting airways, is constant and only effected by disease

Question 14

Alveolar VD

Answer 14

Air ventilating unperfused alveoli, constantly changing
-Contributes to V/Q mismatch

Question 15

Equipment VD

Answer 15

Air in a breathing circuit where both inspired and expired air go through a common path

Question 16

Deadspace/Tidal volume ratio (VD/VT)

Answer 16

Fraction of “wa

Question 17

What does breathing pattern affect?

Answer 17

The relative amounts of deadspace and alveolar ventilation depends
on pattern of breathin

Question 18

How does the VD/VT ratio change during panting?

Answer 18

the ratio is increased

Question 19

Alveolar hypoventilation always ____ PaCO2

Answer 19

increases

Question 20

A-aDO2

Answer 20

Alveolar-arterial oxygen difference

Question 21

A-aDO2 is normal in

Answer 21

low PiO2 and alveolar hypoventilation

Question 22

A-aDO2 increased by

Answer 22

• V/Q mismatch
• R to L Shunt
• Diffusion impairment

Question 23

PiO2 formula

Answer 23

PiO2 = (Patm – PH2O) x FiO2

Question 24

PAO2 formula

Answer 24

PAO2 = PiO2 – O2 consumed

Question 25

A-aDO2 Formula

Answer 25

A-aDO2 = PAO2 – PaO2

Question 26

O2 consumed formula

Answer 26

O2 consumed = PaCO2/RQ

Question 27

Causes of hypoxemia (decreased PaO2)

Answer 27

1) Low PiO2 2) Alveolar hypoventilation 3) V/Q mismatch 4) Right-to-left shunts 5) Diffusion impairment

Question 28

True/False; Alveolar hypoventilation always increases PaCO2

Answer 28

True

Question 29

What is the determinant of alveolar ventilation?

Answer 29

CO2

Question 30

Does a normal respiration rate meant normal ventilation?

Answer 30

No

Question 31

Does increased respiration rate = hyperventilation?

Answer 31

No

Question 32

Does decreased respiration rate = hypoventilation?

Answer 32

No

Question 33

What blood gas value is indicative of the ventilation status?

Answer 33

PCO2

Question 34

What factors determine ventilation adequacy and how is it acheived?

Answer 34

Vt, f and Vd(Deadspace ventilation) in relation to metabolism, achieved by adjusting VT and f

Question 35

During exercise, what changes occur in terms of O2 needs and CO2 production?

Answer 35

Both increase

Question 36

How does the exercising animal manage the increase in O2 needs and CO2 production?

Answer 36

↑ minute ventilation ↑ cardiac output (HR and stroke volume)

Question 37

Minute ventilation VE formula

Answer 37

Minute ventilation VE = tidal volume x frequency Ex: Resting horse: VE = (5 L/breath) x (10 breath/min) = 50 L/minute Galloping horse: VE = (15 L/breath) x (110 breath/min) = 1,650 L/minute

Question 38

Determinants of alveolar ventilation

Answer 38

Deadspace volume (Vd), along with Vt and f, determine alveolar ventilation

Question 39

True/ False; The less the deadspace ventilation, the less the alveolar ventilation

Answer 39

FALSE; The GREATER the deadspace ventilation the less the alveolar ventilation

Question 40

What does it mean that Vd is "static"?

Answer 40

It is not directly able to respond to a need for increased alveolar ventilation

Question 41

Relationship of O2 consumed to CO2 produced

Answer 41

O2 consumed is porportional to CO2 produced

Question 42

Elevated PaCO2 means what for alveolar hypoventilation?

Answer 42

Elevated PaCO2 is pathognomonic (specifically characteristic or indicative of a particular disease or condition) for alveolar hypoventilation

Question 43

Supplemental O2 typically relieves hypoxemia of hypoventilation but what would not be relieved?

Answer 43

hypercapnia(a condition marked by excessively high carbon dioxide levels in the bloodstream, typically resulting from hypoventilation) will not be relieved until ventilation is restored

Question 44

Is Hypoventilation a reliable indicator of lung disease?

Answer 44

No