Pulmonary Function Testing

Question 1

Anatomic dead space volume (VD)

Answer 1

the volume of air that occupies the non-respiratory conducting airways

Question 2

expiratory reserve volume (ERV)

Answer 2

the max volume of air that can be exhaled after a normal tidal exhalation
- 15% of total lung volume

Question 3

forced expiratory volume (FEV)

Answer 3

the max volume of air exhaled in a specified period of time, usually the first, second, and third second of forced vital capacity maneuver

Question 4

forced vital capacity FVC

Answer 4

the volume of air expired during a forced max expiration after a forced max inspiration

Question 5

functional residual capacity FRC

Answer 5

the volume of air in the lungs after exhalation

• FRC = ERV + RV
• 40% of total lung volume

Question 6

inspiratory capacity (IC)

Answer 6

the maximal volume of air that can be inspired after a normal tidal exhalation

• IC = TV + IRV
• 60% of total lung volume

Question 7

inspiratory reserve volume IRV

Answer 7

max volume of air that can be inspired after normal tidal inspiration
50% of total lung volume

Question 8

minute volume ventilation VE

Answer 8

the volume of air expired in one minute

VE= TV x respiratory rate

Question 9

peak expiratory flow PEF

Answer 9

max flow of air during the beginning of a forced expiratory maneuver

Question 10

residual volume RV

Answer 10

volume of gas remaining in the lungs at the end of a max expiration
25% total lung volume

Question 11

tidal volume TV

Answer 11

total volume inspired and expired with each breath during quiet breathing
10% of lung volume

Question 12

total lung capacity TLC

Answer 12

the volume of air in the lungs after a max inspiration
TLC = RV + VC
TLC = FRC + IC

Question 13

vital capacity VC

Answer 13

volume change that occurs between max inspiration and max expiration
VC= TV + IRV + ERV
75% of lung volume

Question 14

pulmonary function testing

Answer 14

the measurements include FVC, PEF, and forced expiratory volume in the first second and mid expiratory flow

Question 15

obstructive ventilatory impairment

Answer 15

• characterized by decreased expiratory flows
• airway narrowing during exhalation causes a disproportionate reduction of max air flow compared to the max volume displace from the lungs
• FEV1/FVC <70% is the primary indicator of an obstructive impairment
• asthma, emphysema, chronic bronchitis

Question 16

restrictive ventilatory impairment

Answer 16

• characterized by reduced lung volumes and relative normal expiratory flow rates
• inferred from spirometry when FVC is reduced and FEV1/FVC is normal or >80%
• pathologies include interstitial lung disease, pleural diseases, chest wall deformities, obesity, pregnancy, neuromuscular disease, tumor