Chronic Obstructive Pulmonary Disease

Why COPD is Important ?

COPD is the only chronic disease that is showing progressive upward trend in both mortality and morbidityIt is expected to be the third leading cause of death by 2020Approximately 14 million Indians are currently suffering form COPD*Currently there are 94 million smokers in India10 lacs Indians die in a year due to smoking related diseases

*The Indian J Chest Dis & Allied Sciences 2001; 43:139-47

Disease Trajectory of a Patients with COPD

Symptoms

Exacerbations

Exacerbations

ExacerbationsDeterioration

End of Life

“Despite this burden, COPD is a “Cindrella” conditions that receives limited recognition from both patients and physicians”

Respiratory Medicine 2002; 96: S1-S31

Obstructive Airway Disease

Asthma

Explosion in

research

Revolution in

therapy

COPD

Little research

(? neglect)

Few advances in

therapy

New DefinitionChronic obstructive pulmonary disease (COPD) is a preventable and treatable disease state characterised by airflow limitation that is not fully reversible. The airflow limitation is usually progressive and is associated with an abnormal inflammatory response of the lungs to noxious particles or gases, primarily caused by cigarette smoking.Although COPD affects the lungs, it also produces significant systemic consequences.

ATS/ERS 2004

Risk FactorsSmoke from home cooking and heating fuelOccupational dust and chemicalsGender: More common in men. M:F ratio is 5%:2.7% (in India)Increasing ageOthers: Infection, nutrition and deficiency of 1 antitrypsin

Pathophysiology of COPD

Increased mucus production and reduced mucociliary clearance - cough and sputum productionLoss of elastic recoil - airway collapseIncrease smooth muscle tonePulmonary hyperinflationGas exchange abnormalities - hypoxemia and/or hypercapnia

Key Indicators for COPD DiagnosisChronic cough Present intermittently or every

day often present throughout the day; seldom only nocturnal

Chronic sputum production Present for many years, worst in winters. Initially mucoid – becomes purulent with exacerbation

Dyspnoea that is Progressive (worsens over time)Persistent (present every day)Worse on exerciseWorse during respiratory infections

Acute bronchitis Repeated episodes

History of exposure to risk factors

Tobacco smoke (including beedi) occupational dusts and chemical smoke from home cooking and heating fuel

Physical signs

Large barrel shaped chest (hyperinflation)Prominent accessory respiratory muscles in neck and use of accessory muscle in respirationLow, flat diaphragmDiminished breath sound

Algorithm for Diagnosis at Primary Care

Pt reporting with respiratory symptoms

Assess by

- H/o exposure to risk factors- Physical examination

Sputum for AFB

Treat as TB

+ve -ve

Provisional Diagnosis of COPD

Treat as COPD Poor response refer to secondary care

National Guidelines for Management of COPD at Primary Care Level

Spirometry

Diagnosis

Assessing

severity

Assessing

prognosis

Monitoring

progression

Spirometry

FEV1 – Forced expired volume in the first secondFVC – Total volume of air that can be exhaled from maximal inhalation to maximal exhalationFEV1/FVC% - The ratio of FEV1 to FVC, expressed as a percentage.

COPD classification based on spirometry GOLD 2003

SPIROMETRY is not to substitute for clinical judgment in the evaluation of the severity of disease in individual patients.

Severity Postbronchodilator FEV1/FVC

Postbronchodilator FEV1% predicted

At risk >0.7 >80

Mild COPD <0.7 >80

Moderate COPD

<0.7 50-80

Severe COPD <0.7 30-50

Very severe COPD

<0.7 <30

Pharmacotherapy for Stable COPD

BronchodilatorsShort-acting 2-agonist – Salbutamol

Long-acting 2-agonist - Salmeterol and Formoterol

Anticholinergics – Ipratropium, Tiiotropium

Methylxanthines - Theophylline

SteroidsOral – Prednisolone

Inhaled - Fluticasone, Budesonide

Post-bronchodilator

FEV1(% predicted)

Management based on GOLD

“Bronchodilator medications are central to the symptomatic

management of COPD”

GOLD Report 2003

How Do Bronchodilators Work?

Reverse the increased bronchomotor tone

Relax the smooth muscle

Reduce the hyperinflation

Improve breathlessness

“All guidelines recommend inhaled bronchodilator as first line therapy. The ATS suggest initial therapy with an anticholinergic drug if regular therapy is needed”

Chest 2000; 117: 23S-28S

Mode of Action

Cholinergic tone is the only reversible component of COPDNormal airway have small degree of vagal cholinergic tone (no perceptible effect due to patent airways)

Mode of Action (Contd.)

Airways are narrowed in COPD therefore vagal cholinergic tone has greater effect on airway resistance (Resistance1/radius4)Therefore, the need for anticholinergic drugs that will act as muscarinic receptor antagonist and block the acetylcholine induced bronchoconstriction

Mode of Action (Contd.)

Anticholinergics may also reduce mucus hypersecretion

Anticholinergic have no effect on pulmonary vessels, and therefore do not cause a fall in

PaO2

Drugs of Today 2002; 38(9): 585-600

“Patients with moderate to severe symptoms of COPD require combination

of bronchodilators”

“Combining bronchodilators with different mechanisms and durations of actions may increase the degree of bronchodilation for

equivalent or lesser side effects’’

GOLD Report 2003

Algorithm for the management of COPD

Short acting bronchodilator – as required

Tiotropium

Tiotropium+LABA

Long acting beta agonist

LABA + tiotropium

Add-Inhaled steroids-Theophylline

Mild

Severe

ass

ess

wit

h s

ym

pto

ms

and

spir

om

etr

y