COPD

• Progressive disorder of airway obstruction with little or no reversibility
• Usually patients have either COPD or asthma not both
• Diagnosis of COPD is favoured by;
• Age of onset >35
• Smoking related
• Chronic dyspnoea
• Sputum production
• No marked diurnal or day to day variation

• Chronic bronchitis is defined clinically as having a productive cough on most days for 3 months of 2 successive years
• Emphysema is a histological diagnosis with enlarged airspaces distal to the terminal bronchioles with destruction of the alveolar walls

Pink puffers

• Have increased alveolar ventilation, a near normal PaO2 and a normal or low PaCO2
• They are breathless but not cyanosed
• They may progress to type I respiratory failure

Blue Bloaters

• Have decreased alveolar ventilation with a low PaO2 and a high PaCO2
• They are cyanosed but not breathless and may go on to develop cor pulmonale
• Rely on hypoxic drive to maintain respiratory effort

Clinical features

• Symptoms
  • Cough, sputum, dyspnoea, wheeze
• Signs
  • Tachypnoea, use of accessory muscles of respiration, hyperinflation, decreased cricosternal distance (<3cm), decreased expansion, resonant or hyperresonant percussion note, quite breath sounds (over bullae), wheeze, cyanosis, cor pulmonale
• Complications
  • Acute exacerbations
  • Polycythaemia
  • Respiratory failure
  • Cor pulmonale (raised JVP, oedema)
  • Pneumothorax (rupture of bullae)
  • Lung carcinoma

Tests

• FBC – increased PCV
• CXR – hyperinflation (greater than 6 anterior ribs seen above diaphragm in the midclavicular line), flat hemidiaphrams, large central pulmonary arteries, decreased vascular markings, bullae
• ECG – RA and RV hypertrophy
• ABG
• Lung function – FEV1 <80% of predicted, FEV1/FVC <70%

Severity of COPD

• Mild – FEV1 50-80% predicted
• Moderate – FEV1 30-49% predicted
• Severe – FEV1 <30% predicted

Treatment

• Chronic stable
• Non pharmacological
  • Stop smoking, exercise, treat poor nutrition or obesity, influenza and pneumococcal vaccination, pulmonary rehabilitation, palliative care
• Pharmacological;
  • Mild – antimuscarinic e.g. ipratropium or ?2 agonist PRN
  • Moderate – regular ipratropium or long acting ?2 agonist plus inhaled steroid (Seretide provides these)
  • Severe – combination therapy with regular short acting ?2 agonist and anticholinergic. Refer to specialist, consider steroid trial, assess for home nebulisers
• Mucolytics may help chronic productive cough
• Treat any depression

Long term O2 therapy

• An MRC trial showed that if a PaO2 was maintained > or equal to 8kPa for 15hr a day, 3yr survival improved by 50%
• UK guidelines suggest LTOT showed be given for;
• Clinically stable non-smokers with a PaO2 <7.3kPA despite maximum therapy (these values should be taken on 2 separate occasions 3wk apart
• If PaO2 is 7.3-8 kPa and pulmonary hypertension

Management of acute exacerbation of COPD

• History – ask about usually/recent treatments (home oxygen?), smoking, exercise capacity

DDX

• Asthma
• PE
• URT obstruction
• Pulmonary oedema
• Anaphylaxis

Investigations

• PEF
• ABG
• CXR – exclude pneumothorax and infection
• FBC, U&Es, CRP
• ECG
• Blood cultures is pyrexial
• Sputum culture

Management

• Oxygen start at 24-28% vary according to ABG. Aim for a PaO2 >8kPA with a rise in PaCO2 <1.5kPa
• Give nebulised bronchodilators – salbutamol 5mg/24hr and ipratropium 500?g/6hr
• Steroids – IV hydrocortisone 200mg and oral prednisolone 30-40mg
• Antibiotics if evidence of infection e.g. amoxicillin 500mg/8hr
• Physiotherapy to aid sputum expectoration
• If no response repeat nebulisers and considered IV aminophylline
• If no response consider nasal intermittent positive pressure ventilation if RR >30 or pH <7.35
• Consider intubation and ventilation if pH <7.26 and PaCO2 is rising
• Consider a respiratory stimulant drug e.g. doxapram 1.5 – 4mg (SE agitation, confusion, tachycardia, nausea). Only for patients not suitable for mechanical ventilation – use short term

Prior to discharge

• Liaise with GP regarding steroid reduction, home oxygen, smoking and pneumoccal and flu vaccinations

Surgery can be considered if;

• Recurrent pneumothoracese
• Isolated bullous disease
• Lung volume reduction (selected patients only)

• Air travel may be hazardous if PaO2 is <6.7kPa