COPD Flashcards
what is the NICE definition of COPD?
characterised by airflow obstruction, which is usually progressive, not fully reversible and does not change markedly over several months.
the disease is predominantly caused by smoking
what is the pathophysiology of COPD?
- mucous gland hyperplasia
- loss of cilia function
- In emphysema, alveolar wall destruction causes irreversible enlargement of air spaces distal to the terminal bronchiole.
- also get chronic inflammation (macrophages and neutrophils) and fibrosis of small airways)
what are the causes of COPD?
- smoking
- inherited a-1-antitrypsin deficiency
- industrial exposure e.g soot
what is the outpatient management of COPD?
- ‘COPD care bundle’
- smoking cessation
- pulmonary rehabilitation
- bronchodilators
- anti muscarinics
- steroids
- mucolytics
- diet
- long term oxygen therapy if appropriate
- lung volume reduction if appropriate
- multidisciplinary management
what is long term oxygen therapy?
- extended periods of hypoxia cause renal and cardiac damage, can be prevented by LTOT
- continuous oxygen therapy for most of the day - at least 16hrs/day for survival benefit
- offered if pO2 is below 7.3 kPa or below 8 kPa with cor pulmonale.
- o2 needs should be balanced with loss of independence and reduced activity which may occur
what is pulmonary rehabilitation?
- COPD patients will avoid exercise and physical activity because of breathlessness
- this may lead to a vicious cycle of increasing social isolation and inactivity leading to worsening of symptoms
- pulmonary rehabilitation aims to break this cycle, with an MDT 6-12 week programme of supervised exercise, unsupervised home activity, nutritional advice and disease education.
what are the causes of COPD exacerbations?
can be
- infective e.g change in sputum colour/volume, fever or raised WCC +/- CRP
or
- non infective e.g environmental pollutants
what is an acute exacerbation of COPD?
a respiratory emergency
a sudden worsening of COPD symptoms including (shortness of breath, quantity and color of phlegm) that typically lasts for several days.
how do you treat an acute exacerbation of COPD using an ABCDE approach?
ABCDE approach
A -
B - oxygen via fixed performance face mask due to risk of CO2 retention.
NEBs - salbutamol and ipatropium.
Steroids - prednisone 30mg STAT and OD for 7 days
CXR
C - antibiotics if raised CRP. WCC or purulent sputum
D
E
consider IV aminophylline
consider NIV if type 2 res failure and pH 7.25-7.35
if pH <7.25 consider ITU referral.
how would you treat type 2 respiratory failure?
- if not acidotic, oxygen
- if acidotic (probably will be due to CO2 retention) NIV via BiPAP.
how can you calculate how many litres of oxygen someone is on?
e.g if you give someone 8 litres of oxygen, whats their total oxygen %
every 1 litre of oxygen given per minute = 4%
normal breathing is 21% oxygen
so if you add 1 lite of oxygen = 25%
so 8 litres =. 4 x 8 = 32
32 +21 = 53%
