Lung Function Tests

Question 1

FEV1

Answer 1

Forced expiratory volume in 1 second

Question 2

FVC

Answer 2

Forced Vital Capacity

Question 3

TLC

Answer 3

Total lung capacity

Question 4

FRC

Answer 4

Functional residual capacity

Question 5

AWR

Answer 5

Airway resistance

Question 6

C

Answer 6

Lung compliance

Question 7

TLco

Answer 7

Single breath carbon monoxide transfer factor

Question 8

PaCO2

Answer 8

Partial pressure of oxygen in systemic arterial blood

Question 9

SpO2

Answer 9

Oxygen saturation in arterial blood by pulse oximetry

Question 10

PetCO2

Answer 10

End tidal partial pressure of CO2

Question 11

What is the equation for minute volume?

Answer 11

Tidal volume x respiratory frequency

Question 12

Equation for measuring FRC by He dilution

Answer 12

He(initial) v Vol(spir) x FHe(initial)

Question 13

What does F stand for in He dilution equation

Answer 13

Fractional concentration of helium

Question 14

How is human lung compliance measured

Answer 14

Nano-oesophageal tube - oesophageal balloon

Question 15

Compliance =

Answer 15

Delta V / Delta P

Question 16

Airway resistance measured by

Answer 16

Constant volume whole body plethysmography

Question 17

AWR equation, shutter open

Answer 17

AWR= (deltaPalveolar/F)
deltaPalv = deltaPbox x (Volbox/Valv)

Question 18

Shutter closed equation

Answer 18

Valv =Palm x (delta V / delta P alv )

Question 19

Equation for airway resistance slope

Answer 19

Slope = GAW = 1/raw

Question 20

Carbon Monoxide Transfer Factor

Answer 20

TLco = mmol CO transferred . Min-1. KPa-1

Question 21

Residual volume

Answer 21

RV = vol in x (%He in / % He out) - vol

Question 22

Normal Pa02

Answer 22

95

Question 23

Normal PaCO2

Answer 23

40

Question 24

Normal HCO3

Answer 24

25

Question 25

Normal pH

Answer 25

7.4

Question 26

low pa02, normal or low PaCO2 and HCO3, normal or high pH

Answer 26

Ventilation:perfusion mismatch

Question 27

Low pao2, high Pac02, normal hco3, low pH

Answer 27

Acute hypo ventilation, acute respiratory acidosis

Question 28

Low pa02, high, high, low

Answer 28

Chronic hypoventilation, chronic respiratory alkalosis

Question 29

Normal pa02, low paco2, normal hco3, high pH

Answer 29

Acute hyperventilation, acute respiratory alkalosis

Question 30

Normal pa02, low PaCO2, low hco3, high pH

Answer 30

Chronic hyperventilation, chronic respiratory alkalosis

Question 31

Test for reversibility of airway obstruction

Answer 31

Beta 2 agonist (salbutamol) inhalation
15% incr in FEV1 in 15 mins
Usually increases in FVC
FEV1/FVC ration useful
Diagnosis = asthma

Question 32

Test for bronchial hyper-responsiveness

Answer 32

Methacholine or histamine
PC20 ie dose which causes a 20% fall in FEV1
Normal = >16mg/mL

Question 33

Test for allergy

Answer 33

Any suspect allergen
Increased diurnal variation in PEF occupational asthma

Question 34

Predicted VE

Answer 34

= 70% of (40xFEV1)

Question 35

Predicted peak HR

Answer 35

220-age