pulmonary function test Another name for pulmonary function tests is lung function tests. pptx

Pulmonary Function Testing
Pulmonary function tests (PFTs) determine how well your lungs work. They determine how much air goes into and out of your lungs, how much air goes from your lungs to your blood and how well your lungs work during exercise. Your healthcare provider will contact you a few days later with your results.
Pulmonary function testing is safe. But you may feel dizzy, lightheaded or tired from breathing so deeply. You may also cough from blowing into the mouthpiece or feel tired from exercising. These symptoms should go away shortly after you complete the PFT. Let the healthcare provider know if you need a break during testing.

1. Prsented by Seheli Sinha MPT 1st year student PULMONARY FUNCTION TEST

2. INTRODUCTION Pulmonary function testing is a complete evaluation of the respiratory system including patient history, physical examinations, and tests of pulmonary function. The primary purpose of pulmonary function testing is to identify the severity of pulmonary impairments.

3. INDICATION Diagnose lung disease. Monitor the effect of chronic diseases like asthma chronic obstructive lung disease or cystic fibrosis. Detect early changes in lung function. Identify narrowing in the airways. Evaluate airway bronchodilator reactivity. Preoperative testing To evaluate need and effectiveness of the treatment.

4. CONTRAINDICATION Myocardial Infarction Unstable Angina Recent thoracic and abdominal surgeries Recent Opthalmic surgery Abdominal, thoracic and cerebral Anureysms Active Hemoptysis Pneumothorax

5. Lung volumes and capacities

6. Techniques to measure lung volumes P lethysmography Helium dilution method Nitrogen washout method

7. Plethysmography The plethysmographic method is based on Boyle’s law. This law states that when gas volume and pressure changes occur, the initial volume (V 1 ) multiplied by the initial pressure (P 1 ) equals the final volume (V 2 ) multiplied by the final pressure (P 2 ): P 1 V 1  = P 2 V 2 . The body plethysmograph is an airtight chamber, or “body box,” in which the patient sits while breathing through a mouthpiece

8. Helium dilution method The helium dilution method requires the person to rebreathe a helium gas mixture through a closed circuit from a spirometer of known volume. Helium is a foreign gas to the lung and is inert and insoluble in the blood.

9. NITR0GEN WASHOUT METHOD The patient continues to breathe 100% oxygen until all of the nitrogen has been washed from the lungs. The amount of nitrogen exhaled is quantified by collecting the total volume of gas expired and measuring its nitrogen concentration . FRC can then be calculated by dividing the volume of nitrogen exhaled by the concentration of nitrogen in the lungs. 

10. HOW TO PREPARE THE PATIENT Stop taking your breathing medicines for a short period. Wear loose, comfortable clothing that doesn’t squeeze your chest. Avoid any heavy exercise before your test. Avoid using tobacco products before your test .

11. PROCEDURE spirometry is a physiological test that measures the ability to inhale and exhale air relative to time. Spirometry is a diagnostic test of several common respiratory disperses such as asthma   and chronic obstructive pulmonary disease. The main results of spirometry are forced vital capacity (FVC), forced expiratory volume exhaled .

12. 6MWT Six-minute walk test is a standard test to assess exercise capacity objectively and determine prognosis in many respiratory (such as COPD, idiopathic pulmonary fibrosis, and pulmonary hypertension) and non-respiratory conditions (such as heart failure). The minimal clinically important difference for change in the 6MWT distance of adults is approximately 30 meters. Performance of the test requires the presence of a flat, straight corridor 30 m (100 feet) in length, the ability to monitor heart rate and pulse oximetry  throughout the test, and if the patient uses supplemental oxygen, to record the flow rate and type of Oxygen device. 

13. Sit up straight Get a good seal around the mouth piece Rapid inhale maximally Without any delay blow out as hard as fast as possible Continue the exhale until the patient can't blow no more Expiration should continue at least 6sec (in adult) and 3 sec (children under 10yrs)Repeat at least 3 technically acceptable times (without cough, air leak and false start) Hold for atleast 30 sec

14. INTERPRETATION (GOLD Criteria for COPD) FEV1 80-100% predicted: Mild (Stage 1) FEV1 50- 80% predicted: Moderate (Stage 2) FEV1 30- <50% predicted: Severe (Stage 3) FEV1 <30% predicted: Very severe (Stage 4) FEV1 <50% with right side heart failure: Very severe (Stage 4)

15. In obstructive disease: Decreased in Emphysema Normal or increased in Asthma In restrictive disease: Decreased in parenchymal disease Normal in non- parenchymal restriction [9]

16. Thnak you