Chapter 3

Question 1

Tidal volume (Vt)

Answer 1

500 ml

air that normally moves in/out of lungs in one quiet breath

Question 2

Inspiratory reserve volume (IRV)

Answer 2

3100 ml

forcibly inhaled beyond normal resting Vt

Question 3

Expiratory reserve volume (ERV)

Answer 3

1200 ml

exhaled beyond normal resting Vt

Question 4

Residual volume (RV)

Answer 4

1200 ml

Air that remains in lungs after ERV

Question 5

Vital capacity (VC)

Answer 5

4800 ml

-maximum volume of air that can be exhaled after a maximal inspiration.

Question 6

Inspiratory capacity (IC)

Answer 6

3600 ml

-volume of air that can be inhaled after a normal exhalation

Question 7

Functional residual capacity (FRC)

Answer 7

2400 ml

-volume of air remaining in the lungs after a normal exhalation

Question 8

Total lung capacity (TLC)

Answer 8

6000ml

-maximum amount of air that the lungs can accommodate

Question 9

Calculate: IC

Answer 9

IC = Vt + IRV

Question 10

Calculate: FRC

Answer 10

FRC = ERV + RV

Question 11

Calculate: TLC

Answer 11

TLC = Vt + IRV + ERV + RV

Question 12

Calculate: Capacity Ratio

Answer 12

RV/TLC x 100

Question 13

Obstructive Disorders

Answer 13

• CBABE*
  1. Cystic fibrosis
  2. Bronchiectasis
  3. Asthma
  4. Bronchitis (Chronic)
  5. Emphysema

-Volumes are decreased
IRV, ERV, VC, IC

Question 14

Restrictive Disorders

Answer 14

-Everything is decreased

1. Pneumonia
2. Lung cancer
3. Fail chest
4. Pulmonary edema
5. Scoliosis/Kyphoscoliosis

Question 15

Ways to measure RV

Answer 15

1. Closed circuit helium dilution
   
   • 7 mins long
   • When He changes by <0.2% over 1 sec test terminated
2. Open circuit nitrogen washout
   
   • <3 mins is normal, >7min is bad
3. Body plethysmography (body box)
   
   • Most common/accurate
   • Boyle’s law

Question 16

Forced Vital Capacity (FVC)

Answer 16

• most common*
• normal TET to complete is 4-6 secs
• Obstructive = TET increase
• Restrictive = TET normal or lower than normal

Question 17

FEVt

Answer 17

• Restrictive = decrease
• Obstructive = decrease
• Decreases with age*

Question 18

FEV1 / FCV ratio

Answer 18

• How these values change in respect to obstructive disorders
• diagnoses patients with obstructive lung disease
• <83% is not normal
• <70% obstructive

Question 19

Factors that affect PFT values

Answer 19

1. Age
2. Height
3. Weight
4. Gender
5. Race

Question 20

Flow volume loop

Answer 20

• Restrictive: small/oval FVC

- Obstructive: large (L-shaped) FVC

Question 21

Diffusion capacity of carbon monoxide (DLco)

Answer 21

• Measures CO that moves across the AC membrane
• Avg. for resting male 25 ml/min/mmHG
• If higher, diffusion problem

Question 22

Pulmonary function test (PFT)

Answer 22

Dynamic compression

• 1st 30% of FVC = effort-dependent
• last 70% of FVC = effort-independent
  
  • still moving air, flow rate can’t increase

Question 23

Diseases of DLco

Answer 23

1. Pulmonary edema
2. Emphysema
3. Pulmonary hemorrhage

Question 24

Calculate: VC

Answer 24

VC = IRV + Vt + ERV