COPD And Breathlessness

11.9.06

NICE definition of COPD
• Characterised by airflow obstruction.
• Usually progressive.
• Not fully reversible.
• Does not change markedly over several months.
• Predominantly caused by smoking.

COPD
• Includes chronic bronchitis and emphysema.
• Characterised by airflow obstruction and little bronchodilator reversibility.
• Normal spirometry excludes diagnosis.
• Prevalence in UK ≈ 1.7% men, 1.4% women.
• 30,000 deaths annually in UK = 6% of all male and 4% of all female deaths.
• By 2020, projected to rank 5th as burden of disease worldwide (12th in 1990).

Impact on services
• >90,000 admissions to UK hospitals per year.
• 10% of all medical admissions.
• Nearly half of all COPD costs are hospital admissions.

Risk factors
1. EXPOSURE TO TOBACCO SMOKE.
2. Others:
• Occupational dusts and chemicals eg. coal dust.
• Specific genetic factors eg. alpha-1-antitrypsin deficiency.
• Indoor and outdoor pollution.
3. Predisposition:
• Recurrent bronchopulmonary infections.
• Socioeconomic status.
• Allergy and airway hyper-responsiveness.
• Lung growth - low birth weight and wheezy bronchitis.

How common?
• 10% females and 11% males have low FEV1 - Health and Lifestyle Survey (1987).
• 9% adult primary care population have abnormal FEV1 and respiratory symptoms - Primary Care Respiratory Journal (2001).
• 27% smokers aged 35-70 with chronic cough have FEV1 <80% predicted - BMJ (2002).
• 37% middle-aged adults who smoked continuously have FEV1 <80% predicted - Locke (2005).

Diagnosis
• Suggested by symptoms/history:
-chronic and progressive cough and/or wheeze and/or shortness of breath (usually exertional);
-impaired ability to exercise;
-significant smoking history.
• Confirmed by spirometry, not peak expiratory flow.
• Spirometry potentially differentiates asthma from COPD.
• If spirometry normal, not COPD.

Respiratory symptoms
• Dyspnoea - all diagnoses, but pattern important in asthma and IHV - episodic and at rest.
• Cough - asthma, ILD - dry; COPD, bronchiectesis - productive.
• Phlegm - COPD and bronchiectesis; frothy, pink with pulmonary oedema.
• Wheeze - any airway disease - asthma, COPD and bronchiectesis.
• Exercise limitation - all diagnoses - consequence of dyspnoea; deconditioning, obesity.
• Haemoptysis.
• Chest pain.

COPD/asthma - history
COPD Asthma
Smoker/ex-smoker Nearly all Possibly
Symptoms under 45 Uncommon Often
Chronic productive cough Common Uncommon
Breathlessness Persistent and progressive Variable

Importance of FEV1/PVC ratio
• Obstructive: ratio <0.7 - asthma/COPD/bronchiectesis.
• Normal: ratio >0.7, <0.8/0.85-ish - asthma/IHV/cardiac disease.
• Restrictive: ratio >0.8/0.85-ish - ILD/obesity.

Other invesetigations
• FBC - Hb and PCV.
• Alpha-1-antitrypsin level.
• ECG - R heart strain, P pulmonale.
• CXR.
• Full pulmonary function, +/- reversibility.
Plus maybe…
• Serial PEF +/- histamine challenge (asthma).
• HRCT (bronchiectesis and emphysema).
• ECHO (heart failure and R heart pressures).

Physiology
• Airflow obstruction.
• Dynamic airway collapse.
• Diffusion abnormality.
• VQ mismatch.
• Shunting.
• Dynamic hyperinflation.

Aims of treatment
• Relief of breathlessness and other symptoms.
• Improve exercise capacity.
• Improve sleep capacity.
• Reduce exacerbations.
• Hence, improve quality of life.

Current COPD treatment
1. All patients:
• Smoking cessation.
• Influenza and pneumococcal vaccinations.
• Short-acting bronchodilators as required.
• Pulmonary rehabilitation if exercise limited.
2. FEV1 <80% predicted:
• All of above, and if symptomatic…
• Long-acting bronchodilators.
• Theopyllines.
3. FEV1 <50% predicted:
• All of above, and if symptomatic…
• Inhaled corticosteroids/combination inhaled steroid/long-acting bronchodilator inhalers.
4. FEV1 30% predicted:
• All of above, and if symptomatic…
• Long-term oxygen therapy.
• Lung transplant.

Exacerbations
• Major cause of mortality and morbidity in hospital admissions.
• UK Audit - ≈ 15% COPD patients dead within 3 months of admission with COPD exacerbation.

Management of exacerbations
• Antibiotics:
-as local protocols;
-culture if failure to respond.
• Oral corticosteroids.

Acute management
• Bronchodilators.
• Corticosteroids.
• Antibiotics.
• Controlled oxygen.
• Ventilations - IPPV/NIV.
• Exercise.
• Home care.