Lung Volumes DSA

Question 1

Can residual volume be determined by spirometry?

Answer 1

No

Question 2

What is Vital Capacity?

Answer 2

IRV + Vt + ERV

Question 3

What is VC influenced by?

Answer 3

• posture
• ability of diaphragm to contract/relax
• strength of the respiratory muscles
• thoracic wall expansibility
• resistance to air flow
• lung elasticity

Question 4

Can functional residual capacity (FRC) be determined by spirometry?

Answer 4

No

Question 5

What three things cannot be determined by spirometry?

Answer 5

RV, FRC, and TLC

Question 6

Can TLC be determined by spirometry?

Answer 6

No

Question 7

Normal IRV

Answer 7

3000 mL

Question 8

Normal ERV

Answer 8

1100-1200 mL

Question 9

Normal RV

Answer 9

1200 mL

Question 10

Normal IC

Answer 10

3500 mL

Question 11

Normal FRC

Answer 11

2300-2400 mL

Question 12

Normal VC

Answer 12

4600-4700 mL

Question 13

Normal TLC

Answer 13

5800-6000 mL

Question 14

Nitrogen washout technique

Answer 14

Determines the FRC.

Individual breaths 100% O2 through one-way valve, all expired gas is collected, monitored until N2 reaches zero.

Total volume of all gas expired is determined, and multiplied by % of N2 in mixed expired air.

Question 15

Helium dilution

Answer 15

Inhalation of a known concentration of Helium (C1) from a known volume (V1)

Change in concentration (C2) allows for determination of V2 = FRC

Question 16

Body plethysmography

Answer 16

Enclosed rigid box

Breath against shutter

Pressure in lungs change

Pressure in box changes proportionally in opposite direction