1. Lung Function Tests
Sema Umut

2. Lung Factors Affecting Function
Mechanical properties
Resistive elements

3. Mechanical Properties
Compliance
Describes the stiffness of the lungs
Change in volume over the change in pressure
Elastic recoil
The tendency of the lung to return to it’s resting state

4. Resistive Properties Determined by airway caliber Affected by
Lung volume
Bronchial smooth muscles
Airway collapsibility

5. A TEST SHOULD BE Acceptabile,easy Noninvasive Cost effective
Informative
Reproducible

6. Spirometry Acceptabile,easy Noninvasive Cost effective Inexpensive
Informative
Reproducible

7. Spirometry It is the most commonly used lung function screening study
It should be the clinician's first option

8. When can spirometry help us?
- Diagnosing disease
- Monitoring disease
- Prognosis
Directing therapy
Lung Age for prognostication

9. Indications for Spirometry
Diagnostic
To evaluate symptoms, signs, or abnormal laboratory tests
Dyspnea
Wheezing
Cough
Abnormal breath sounds
Overinflation
Expiratory slowing
Cyanosis

10. Abnormal laboratory tests
Hypoxemia
Hypercapnia
Polycythemia
Abnormal chest radiographs

11. To screen individuals at risk of having pulmonary diseases
Smokers
Individuals in
occupations with
exposures to
injurious substances

12. Indications for Spirometry
To assess preoperative risk
To assess health status before physical activity programs
To evaluate therapy

13. Disability/Impairment Evaluations
To assess individuals for legal reasons

14. FEV1/ht2 best index Prognosis Survival predictor of general population
Copenhagen City Heart Study
13,900 subjects for 25 yrs
Lange P. J Clin Epidemiol
1990; 43:
Cox proportional hazards
FEV1/ht2 best index
Framingham study
No experts in lung function. Self appointed group of chums. Not affiliated to American Thoracic or European Resp Societies

15. Spirometry Requirements
1. Good equipment
2. Good technicians (efor dependent)
3. Good clinicians
- correct indication
- correct use / presentation of the data
- correct decision making
No experts in lung function. Self appointed group of chums. Not affiliated to American Thoracic or European Resp Societies

16. Pulmonary Function Testing relates
Age : Smaller lung volumes as we age
Gender : The lung volumes of males are larger than females
Height
Race

17. Perform manoeuvre Attach nose clip, place mouthpiece in mouth
Inhale completely and rapidly
Exhale maximally until no more air can be expelled
Repeat for a minimum of 3 manoeuvres

19. Forced Vital Capacity FVC
Total volume of air expired forcefully after a full inspiration
Patients with restrictive lung disease have a decreased vital capacity

20. Slow Vital Capacity (SVC)
This is the total volume of air expired slowly after a full inspiration
If the SVC is greater than FVC,it indicates the presence of obstructive disease

21. FEV1 Forced Expiratory Volume in 1 Second
Volume of air expired in the first second during maximal expiratory effort

22. FEV1/FVC
Percentage of the forced vital capacity which is expired in the first second of maximal expiration to forced vital capacity
In health the FEV1/FVC is usually around 80%
Decrease in FEV1/FVC means obstruction

23. Tidal volume TV
The volume of air moved during normal quiet breathing (about 0.5 L)

24. RESIDUEL VOLUME (RV)
The volume of air remaining in the lungs after a forceful expiration (about 1.0 L).

25. FUNCTIONAL RESIDUEL CAPACITY(FRC)
The amount of air remaining in the lungs after a normal quiet expiration

26. TOTAL LUNG CAPACITY (TLC)
It is the volume of air in the lungs when the person has taken a full inspiration
TLC = RV + VC

27. TLC,RV,FRC Can not be measured by spirometry Helium dilution
Nitrogenmetry
Body plethysmography

28. INTERPRETATION OF SPIROMETRY
Compare the measured values of the patient with normal values derived from population studies
The percent predicted normal is used to define normal and abnormal and to grade the severity of the abnormality

29. Categories of Disease
Obstructive
Restrictive
Mixed

30. Spirogram measures two components - air flow and volume If flow is reduced, the defect is obstructive If volume is reduced the defect is restrictive

31. Interpretation FVC and FEV1 are normal – NORMAL
FVC is low but FEV1/FVC is >80 RESTRICTIVE
FEV1/FVC < 70% OBSTRUCTIVE

33. Spirometry
Obstruction (FEVı /FVC) < %70

34. Obstructive Lung Diseases
Asthma
Chronic obstructive pulmonary disease

35. COPD
-COPD is characterized by airflow limitation that is not fully reversible
-The airflow limitation is usually progressive and associated with an abnormal inflammatory response of the lung to noxious particles or gases

36. indoor/outdoor pollution
Diagnosis of COPD
EXPOSURE TO RISK
FACTORS
SYMPTOMS
cough
tobacco
sputum
occupation
shortness of breath
indoor/outdoor pollution
A diagnosis of COPD should be considered in any patient who has cough, sputum production, or dyspnea and/or a history of exposure to risk factors. The diagnosis is confirmed by spirometry.
To help identify individuals earlier in the course of disease, spirometry should be performed for patients who have chronic cough and sputum production even if they do not have dyspnea.
Spirometry is the best way to diagnose COPD and to monitor its progression and health care workers to care for COPD patients should have assess to spirometry. è è è
SPIROMETRY

37. Asthma Asthma is a chronic inflammatory disease of the airways
Inflammation causes the airways to narrow periodically
This produces wheezing and breathlessness
Obstruction to air flow is reversible

38. Bronchodilator Test
Evaluates how responsive the patient is to a bronchodilator medication
Spirometry is repeated about 15 minutes after giving a bronchodilator (400 mg salbutamol)

39. WHY TEST FOR REVERSIBILITY?
To determine best function
To follow rate of change in PFTs over time
To exclude asthma
To determine response to therapy

40. REVERSIBILITY Increase of 200 ml or 12-15% of the baseline FEV1 shows
REVERSIBLE
OBSTRUCTION 40
Both drugs combined 30 20 10 2 4 6 8

41. Restriction
Restriction means a decrease in lung volumes

43. Extrinsic Restrictive Lung Disorders
. Neuromuscular Disorders . Scoliosis, Kyphosis . Rib fractures . Pleural Effusion . Pregnancy . Gross Obesity . Tumors . Ascites

44. Intrinsic Restrictive Lung Disorders
Pnuemonectomy
Pneumonia
Lung tumors
Interstitial lung diseases
Sarcoidosis
Lung oedema

45. Flow – Volume Loop
is a measure of how much air can be inspired and expired from the lungs
It is a flow rate measurement

48. Restrictive Lung Disease
Characterized by diminished lung volume
Decreased TLC, FVC
Normal FEV1/FVC ratio

49. Large Airway Obstruction can be detected by Flow – Volume Loop
Characterized by a truncated inspiratory or expiratory loop

52. Extra-thoracic Upper Airway Obstruction

53. Peak Expiratory Flow Rate PEFR
The maximum flow rate during the forced vital capacity maneuver
Useful to monitor asthma

54. Measuring PEF
PEF must be achieved as rapidly as possible and at a high lung volume as possible
The subject must be encouraged to blow as vigorously as possible

55. PEF can be very useful in diagnosing occupational asthma
When is PEF useful?
PEF can be very useful in diagnosing occupational asthma

56. ARTERIAL BLOOD GASES INDICATION
Oxygenation
Ventilation
Acid-Base Status
There are 3 reasones why one should obtain a blood gas:

57. ARTERIAL BLOOD GASES
Blood gases is a measurement of how much oxygen and carbon dioxide is in the blood
Determines the acidity (pH) of the blood

58. ARTERIAL BLOOD GASES Blood is taken from an artery
The blood may be collected from the radial artery, the femoral artery , or the brachial artery

59. ARTERIAL BLOOD GASES
After the blood is taken, pressure is applied to the site for a few minutes to stop the bleeding
The sample must be quickly sent to a laboratory

60. Blood Gas Report pH 7.4 PaCO2 (mm Hg) 40 PaO2 (mm Hg) 110 - 0.5(age)
HCO3- (mmol/L)
B.E. (mmol/L)
O2 saturation >90%
This is a typical printout from a blood gas report:

61. Causes of a low PaO2 V/Q mismatch Dead space ventilation Shunt
Diffusion Impairment
Alveolar Hypoventilation
Altitude

62. Alveolar Hypoventilation
Reduced Respiratory Drive
Pump failure

63. ANALYSIS OF VENTILATON
Hypercapnea > 45 mm Hg Hypoventilation
Respiratory Acidosis
Hypocapnea < 35 mm Hg Hyperventilation
Respiratory Alkalosis

64. Respiratory alkalosis
Low levels of carbon dioxide in the blood due to alveolar hypervetilation (breathing excessively)

65. Respiratory acidosis
The kidneys and lungs maintain the body's acid/base (pH) balance
Respiratory acidosis develops when carbon dioxide is elevated
Primarily caused by alveoler hypoventilation ( decreased breathing)

66. Pitfalls Venous Sample _PaO2 = 40, PaCO2 = 45 Air-bubble in syringe
Free flow into syringe
Air-bubble in syringe
Falsely elevated PaO2
Arterial blood sample should be transported on ice under anaerobic conditions

67. Spirometry is essential in respiratory evaluation as tension arterial measurement is essential in cardiovascular evaluation