PFTs

Question 1

Indications for performing PFTs

Answer 1

Lung disease
Extent of impairment
Confirm other findings
Monitor interventions

Question 2

Contraindications for PFT

Answer 2

pneumothorax

Unknown origin haemoptysis

Unstable CV status

Thoracic, abdominal, cerebral aneurysms

Question 3

Things that determine predicted results

Answer 3

Age
Height
Sex
Ethnicity

Question 4

What is measured in spirometry

Answer 4

FEV1
VC
FVC

Shown on volume time trace

Question 5

Common spiro performance errors

Answer 5

Slow start
Mouth leak
Coughing
Variable effort
Glottis closure

Question 6

Acceptability criteria spirometry

Answer 6

X3 acceptable max forced expiratory manoeuvres

FVC and FEV1values within 150mL of next best values

If FVC <1L values should be within 100mL

Question 7

Obstructive LFT?

Answer 7

FEV1/FVC ratio <70%

Question 8

How to tell severity of obstructive disease?

Answer 8

%predicted FEV1

80% Mild
80-50% Moderate
50-30% Severe
<30% Very severe

Question 9

Restrictive disease pattern

Answer 9

FEV1/FVC ratio >70% with %pred VC <85%

Question 10

Restrictive disease severity

Answer 10

% predicted VC

85-75% borderline restrictive
<75% probable restrictive

Question 11

What does a flow volume loop show?

Answer 11

Flow vs volume

Question 12

How to perform spirometry with flow volume loop

Answer 12

Tidal breathing
Max insp
Max exp
Max insp

Question 13

What is measured for flow volume loop?

Answer 13

TLC
PEF
RV
PIF
MIF
FEF

Question 14

Describe obstructive flow volume loop

Answer 14

Concave limb (smaller) on expiration
Gas trapping

Question 15

Describe restrictive flow volume loop

Answer 15

Squashed appearance to x axis