COPD Flashcards
What is COPD?
COPD is an obstructive respiratory disease that is progressive. It includes bronchitis and emphysema.
What is emphysema?
Is the abnormal enlargement of alveolar airspaces distal to the terminal bronchiole and loss of alveolar walls —–> SOB due to reduced gas exchange.
What are bullae?
In emphysema the airspaces become dilated. If they become larger than 10mm they are termed bullous. emphysemous bulla can rupture causing spontaneous pneumothorax if on the surface of the lung.
What is bronchitis?
bronchitis is an obstructive lung disease that is defined as:
a cough and sputum for 3 months in 2 consecutive years.
- hypersecretion of mucus and bronchila mucous gland hypertrophy.
(mostly caused by smoking)
What are the clinical features of COPD?
Cough with sputum
SOB
(some pt have resp failure and cor pulmonale)
What is cor pulmonale?
Pulmonary hypertension causes right ventricular hypertrophy. This leads to heart failure caused primarily by respiratory disease.
** Oedema , raised JVP
Causes of pulmonary hypertension:
- multiple PE
- chronic hypoxaemia
- capillary defects e.g. emphysema
- left ventricular failure
Patients with COPD can develop Type 1 respiratory failure or Type 2 - what is the difference between them?
Type 1 = hypoxia and low level of CO2 secondary to HYPERventilation.
Type 2 = Hypoxia and high level of CO2 (hypercapnia) due to HYPOventilation and impaired CO2 clearance.
Type 2 –> respiratory acidosis.
Type 2 have risk of developing cor pulmonale.
What is the FEV1 and FEV1/FVC ratio in COPD?
FEV1 = < 80%
FEV1/FVC ratio = <0.7
What is the prevalence of COPD?
10-20% of over 40 yrs
What is a “pink puffer” in COPD?
pink puffers have : - increased alveolar ventilation - normal PaO2 - normal / Low PaCO2 - SOB - not cyanosed - **may develop Type 1 resp failure.
What is a blue bloater in COPD?
Blue bloaters have:
- decreased alveolar ventilation
- Low PaO2
- High PaCO2
- cyanosed
- no SOB
** Type 2 resp failure, may develop cor pulmonale
** O2 should be given with care as they have a lower requirement.
What are the signs of COPD?
- Tachypnoea
- Use of accessory muscles of respiration
- hyperinflation
- decreased cricosternal distance
- decreased chest expansion
- hyperresonant percussion note
- quiet breath sounds
- wheeze
- cyanosis
- cor pulmonale
What are the complications of COPD?
- acute exacerbation +/- infection
- Polycthaemia (raised Hb due to chronic hypoxaemia)
- respiratory failure
- Cor pulmonale (raised JVP, oedema)
- pneumothorax due to ruptured bullae
- lung carcinoma
how may a pneumothorax occur as a complication of COPD?
Emphysema can cause bullae on the surface of the lung. If one of these ruptures it can cause a spontaneous pneumothorax.
What investigations should be done for COPD?
1 ) Bloods:
- FBC (raised WCC for infective exacerbation, raised Hb indicated polycythaemia)
- CRP
- U & E
2 ) Chest Xray (hyperinflation, flattened diaphragm, large central pulmonary arteries, decreased peripheral lung markings, bullae)
3) ECG (right atrial and ventricular hypertrophy as a sign of Cor pulmonary)
4) ABG ( Low PaO2 +/- hypercapnia indicates resp failure)
5) Spirometry (FEV1 <80% , FEV1/FVC <0.7)
6) Total Lung capacity (TLC) raised—-Residual volume raised
