Lung Function Test

Front 1

Main function of respiratory system

Back 1

(lung tissue, airways, thorax, respiratory muscles, pleural cavity, respiratory center and motoric nerves innervating respiratory musles) – continual delivery of oxygen into the blood of lung capillaries and elimination of CO2 from lungs

Front 2

Efective ventilation

Back 2

● patency of airways
● normal elasticity of lung parenchyma and thorax
● efficient respiratory muscles 
● correct regulation in CNS

Front 3

Basic ventilatory disorders

Back 3

● obstructive respiratory disorders
- airways (increased resistance to airfow)
● restrictive respiratory disorders
- elastic properties of lung and thorax, respiratory muscles, pleural cavity and respiratory  center

Front 4

Measurements of ventilatory function

Back 4

●screening (basic) functional tests:
- measurement of FEV1
- monitoring PEF by peak flow meter
●complete functional measurements (complete spirometry and examination of blood gases)

Front 5

Tidal volume

Back 5

(Vt = VI + VE) (500 ml, 15% VC)

Front 6

Inspiratory reserve volume (IRV)

Back 6

( 2 500 ml, 60% VC) – gas volume that can be maximally inspired after normal inspiration

Front 7

Exspiratory reserve volume (ERV)

Back 7

(1 000 ml, 25% VC) – gas volume that can be maximally expired from the level of FRC

Front 8

Residual volume (RV)

Back 8

(1 000 – 2 000 ml) – volume after complete expiration

Front 9

Vital capacity

Back 9

VC = IRV + Vt + ERV

Front 10

Inspiratory capacity

Back 10

IC = Vt + IRV

Front 11

Exspiratory capacity

Back 11

EC = Vt + ERV

Front 12

Functional residual capacity

Back 12

FRC = RV + ERV - gas volume after normal expiration

Front 13

Total lung capacity

Back 13

TLC = IRV + Vt + ERV + RV

Front 14

Dynamic parameters
FEV1

Back 14

FEV1 is the volume expired in the first second of maximal expiration after a maximal inspiration and is a useful measure of how quickly full lungs can be emptied

Front 15

FVC

Back 15

FVC is the maximum volume of air which can be exhaled or inspired during forced manoeuvre

Front 16

FEV1/FVC

Back 16

FEV1/FVC is the FEV1 expressed as a percentage of the VC or FVC and gives a clinically useful index of airflow limitation

Front 17

FEF25-75%

Back 17

FEF25-75% is the average expired flow over the middle half of the FVC manoeuvre and is regarded as a more sensitive measure of small airways narrowing

Front 18

PEF

Back 18

PEF is the maximal expiratory flow rate achieved and this occurs very early in the forced expiratory manoeuvre

Front 19

Obstructive ventilatory disorders (OVD)

Back 19

reduction of airflow because of an increase resistance in airways (reduced ventilation of some regions of lungs)
( FEV1,   FEV1/FVC,  RV)

Front 20

Causes:

Back 20

► overproduction of (viscous) mucus in airways
► mucosal swelling
► contraction of smooth muscles of airways (bronchospasm)
► oedema of mucosa
► inflammatory infiltration of airway mucosa
► airway compression

Front 21

Example of diseases

Back 21

- bronchial asthma
- chronic bronchitis
- emphysema

Front 22

Degrees of OVD:

Back 22

- mild degree FEV1 in range of 60 - 80 % RV
- moderate degree FEV1 in range of 45 – 60 % RV
- severe degree FEV1 under 45 % RV

Front 23

Consequences of OVD depend on:

Back 23

- causes and character of obstruction
- duration and localization in airways

Front 24

Clinical features:

Back 24

dyspnea with thorax in inspiratory position, exhausting breathing (whistling).

Front 25

Characteristic:

Back 25

slow and deep breathing

Front 26

The most common patient-related problems when performing the FVC manoeuvre

Back 26

1. Submaximal effort

2. Leaks between the lips and mouthpiece

3. Incomplete inspiration or expiration (prior to or during the forced manoeuvre)

4. Hesitation at the start of the expiration

5. Cough (particularly within the first second of expiration)

6. Glottic closure

7. Obstruction of the mouthpiece by the tongue

8. Vocalisation during the forced manoeuvre

9. Poor posture

Front 27

Restrictive ventilatory disorders (RVD)

Back 27

-decreased ability to ventilate lungs because of reduced elasticity of lung parenchyma and thorax
- significant reduction of lung volumes (FVC under 80%, VC, TLC)
(limitation of maximum inspiration)

Front 28

Causes of RVD:

Back 28

► lung diseases: resection of lung tissue, atelectases, interstitial lung
diseases, pulmonary fibrosis, pulmonary oedema, tumors, pneumonia
► depression of respiratory center: drug overdose (sedative, narkotics)
► pleural cavity: pleural exudate, pneumotorax
► limitation of thorax movement: obesity, kyphoskoliosis, trauma, pain,gravidity, ascites
► neuromuscular diseases: paralysed diaphragm, muscular dystrophy, myasthenia gravis

Front 29

Degrees of RVD:

Back 29

- mild degree FVC till 60% RV and TLC till 65% RV
- moderate degree FVC 40 – 60% RV and TLC 50- 65% RV
severe degree FVC under 40% RV and TLC under 50% RV

Front 30

Characteristic

Back 30

rapid and shallow breathing

Front 31

Consequences of ventilatory disorders:

Back 31

>>alveolar hypoventilation>>hypoxemia >>hypercapnia >>disorder of acid base balance (MAC+RAC)

Front 32

Advantage of spirometry:

Back 32

• Detection of disease and its severity
• Identification of asthma triggers
• Progress/natural history monitoring
• Treatment response assessment