ROLE IN COPD

Smokers, bio fuel users and people exposed to air pollution are at highest risk of developing COPD. Since COPD is potentially progressive and fatal disease, early diagnosis and treatment is very important.

Early symptoms are cough and sputum production. Unfortunately most smokers take these as normal phenomenon of smoker’s cough and do not seek medical attention. They usually consult doctors only when they feel dyspnea which is a late symptom of COPD.

The best indicator of COPD is spirometry. Ideally Spirometry test should be done in all smokers and repeated annually in abnormal reports and repeated every three yearly in normal reports.

Spirometry assisted counselling is an excellent tool in COPD patients for smoking cessation.

ROLE IN ASTHMA

Spirometry is carried out at initial diagnosis of asthma, after treatment started and stabilized symptoms to document attainment of near normal airway function and every 1 to 2 yearly to assess maintenance of airway function.

Detect sub-clinical abnormalities in high risk individuals like smokers, occupational exposures, chest wall deformity, etc.

To assess the post-operative complications in high risk patients those who are about to undergo a thoracic or abdominal surgery.

It is a test that measures how fast a person can exhale (breathe out).

It checks lung functioning, and is often used by patients who have asthma.

The flow of exhaled air from the lungs may be restricted due to inflammation or congestion from excess mucous.

PEFR is measured by peak flow meter.

INDICATIONS

 Bronchial asthma : 20% increase in PEFR after bronchodilator is diagnostic.

Indentification of trigger factors in asthma

Monitoring severity of asthma

Therapy and self management of asthma

Evaluation of dyspnoea and as a bedside pulmonary function test

ADVANTAGES

• Inexpensive
• Easy to use in all age groups except in ≤ 6 years of age.
• Portable handheld device – so, useful in industrial workers for diagnosis of occupational asthma.
• Non-invasive method for lung function assessment- so, can be used in PHCs along with anthropometric measurements (i.e. height, weight, etc.)

Spirometry is currently the most commonly performed lung function test in clinical practice and is considered to be the gold standard diagnostic test for asthma and COPD.

However, spirometry is not an easy test to perform because the forceful expi­ratory and inspiratory manoeuvres require good patient co-operation.

Children aged <5 years, elderly people and those with physical and cognitive limitations cannot perform spirometry easily.

ADVANTAGES OF IOS (IMPULSE OSCILLOMETRY)

• Patient needs to perform simple tidal breathing manoeuvres that require less effort and co-operation than spirometry, meaning that children and the elderly can therefore perform this test easily.
• It can be performed in patients on ventilators and also during sleep.
• One of the most remarkable fea­tures of IOS in relation to spirometry is that it has much greater sensitivity to detect peripheral airways obstruction.
• IOS are more sensitive instru­ments to detect small airways obstruction in patients with asthma and chronic obstructive pulmonary disease (COPD)
• IOS parameters seem to be able to pick up early changes in lung function such that they are superior to spirometry in predicting loss of control in asthmatic patients and possibly in identifying early airway disease in smokers.