Chronic Obstructive Pulmonary Disease

Why COPD is Important ? COPD is the only chronic disease that is showing progressive upward trend in both mortality and morbidity It is expected to be the third leading cause of death by 2020 Approximately 14 million Indians are currently suffering form COPD* Currently there are 94 million smokers in India 10 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 Deterioration End of Life

“Despite this burden, COPD is a “Cindrella” conditions that receives limited recognition from both patients and physicians” Respiratory Medicine 2002; 96: S 1 -S 31

Obstructive Airway Disease Asthma Explosion in research Revolution in therapy COPD Little research (? neglect) Few advances in therapy

New Definition Chronic 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 Factors Smoke from home cooking and heating fuel Occupational dust and chemicals Gender: More common in men. M:F ratio is 5%:2.7% (in India) Increasing age Others: Infection, nutrition and deficiency of  1 antitrypsin

Pathophysiology of COPD Increased mucus production and reduced mucociliary clearance - cough and sputum production Loss of elastic recoil - airway collapse Increase smooth muscle tone Pulmonary hyperinflation Gas exchange abnormalities - hypoxemia and/or hypercapnia

Key Indicators for COPD Diagnosis Chronic coughPresent intermittently or every day often present throughout the day; seldom only nocturnal Chronic sputum productionPresent for many years, worst in winters. Initially mucoid – becomes purulent with exacerbation Dyspnoea that isProgressive (worsens over time) Persistent (present every day) Worse on exercise Worse during respiratory infections Acute bronchitisRepeated 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 respiration Low, flat diaphragm Diminished breath sound

Spirometry Diagnosis Assessing severity Assessing prognosis Monitoring progression

Spirometry FEV 1 – Forced expired volume in the first second FVC – Total volume of air that can be exhaled from maximal inhalation to maximal exhalation FEV 1 /FVC% - The ratio of FEV 1 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 FEV 1 /FVC Postbronchodilator FEV 1 % predicted At risk>0.7>80 Mild COPD<0.7>80 Moderate COPD< Severe COPD< Very severe COPD <0.7<30

Pharmacotherapy for Stable COPD Bronchodilators Short-acting  2 - agonist – Salbutamol Long-acting  2 - agonist - Salmeterol and Formoterol Anticholinergics – Ipratropium, Tiiotropium Methylxanthines - Theophylline Steroids Oral – 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 COPD Normal 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 (Resistance  1/radius 4 ) 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 PaO 2 Drugs of Today 2002; 38(9):

“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 assess with symptoms and spirometry