Lung Function Tests Flashcards

1
Q

How would you use lung function tests

A

Diagnosis and monitoring of

  • disease progression
  • risk stratification
  • treatment response
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the 4 routine LFTs

A

Spirometry
Lung volume
Gas transfer
Volitional resp muscle strength

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the 4 specialist LFTs

A

Exercise bronchial provocation
Exhaled biomarkers
Lung mech, forced oscillations
Non volitional resp muscle strength

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are some examples of

  • airway
  • chest wall
  • lung
  • muscle
  • thoracic cavity
  • pulmonary vasculature diseases
A

Airway

  • Asthma
  • CODP
  • Bronchiolitis

Chest wall

  • Scleroderma
  • Kyphoscoliosis
  • Pregnancy
  • Obesity

Lung

  • IPF
  • Tumour
  • Resection
  • Collapse

Muscle

  • Polio
  • NMD
  • Phrenic palsy

Thoracic cavity

  • Cardiomegaly
  • Effusion
  • Tumour

Pulmonary vascular diseases

  • PE
  • HF
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the characteristics of obstructive illnesses

What are some examples

A

Decreased airflow due to lumen obstruction
Airway wall changes
Airway support loss
Ext compression

Asthma
COPD
Bronchiectasis
Bronchiolitis
CF
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the characteristics of restrictive illnesses

What are some examples

A
Decreased lung volume
Abnormal lung parenchyma
Abnormal chest wall
Weak resp muscles
Abnormal pleura
Fibrosis
Kyphoscoliosis
DMD
Phrenic palsy
Obesity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the characteristics of mixed illnesses

A

Decreased airflow and lung volume

SCD
Idiopathic fibrosis + emphysema

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How would you differentiate between obstructive and restrictive lung disease on a flow volume loop

A

Obstructive
-concave shape on expiration as airways collapse

Restrictive
-similar shape to normal loop but smaller

Each disease has its own characteristic shape

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How would you differentiate between obstructive and restrictive lung disease on spirometry
What can you not diagnose via spirometry

A

Obstructive

  • FEV1 < 0.8
  • FRC reduced slightly
  • FEV1/FRC <0.7

Restrictive

  • FEV1, reduced
  • FRC, reduced
  • FEV1/FRC normal

Cannot diagnose restrictive diseases
-in obstructive diseases, airways collapse on themselves so FRC may be reduced. Can look restrictive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the reversibility test

How would you differentiate between asthma and COPD

A

Repeat spirometry after BD
-Increased FEV1 > 12% => significant reversibility

Asthma, significant reversal
COPD, relief due to some deflation but no significant reversal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the definitions of

  • RV
  • TLC
  • FRC

How would you measure lung volume

A
RV
-vol after max expiration
TLC
-vol after max inspiration
FRC
-vol after relaxed expiration

Gold standard
Body plethysmograph
Inert gas dilution

N2 washout
CXR planimetry
volume CT
USS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the causes of increased FRC, RV

  • intrapulmonary
  • extrapulmonary
A

Intrapulmonary
-airway obstruction

Extrapulmonary
-resp muscle weakness

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the causes of increased TLC

A

Emphysema

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the causes of decreased TLC

  • intrapulmonary
  • extrapulmonary
A

Intrapulmonary

  • Pneunectomy
  • Atlectasis
  • Consolidation
  • Edema
  • Fibrosis

Extrapulmonary

  • pleural disease
  • ribcage issues
  • resp muscle issues
  • obesity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the transfer coefficient
What is it a measure of

What factors does the TLCO depend on

  • alveolar mv
  • Hb binding
A

KCO=TLCO/Va
Gas uptake/litre of vent lung

gas transfer from lung to Hb
Alveolar mv
-SA
-conc change
-solubility
-MW

Hb binding

  • [Hb]
  • perfusion
  • PO2
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How would you judge if your LFT or SR reading is abnormal

What are the different stages or abnormality from SR

A

LFT
-% of predicted value

SR
-no of SDs from PV

Mild
+- 1.65 - 2.5

Moderate
+-2.51 - 3.5

Severe
+-3.51