clinical features of COPD Flashcards
define COPD
a lung disease characterised by chronic obstruction of lung airflow that interferes with normal breathing and is not full reversible breathlessness, cough +/- sputum
COPD is characterised by…
persistent respiratory symptoms and airflow limitation due to airway +/- alveolar abnormalities usually caused by significant exposure to noxious particles or gases
what is the most common cause of copd
smoking
who is at higher risk of copd, males or females
females genetic predisposition
name 3 occupational causes of COPD
agriculture brick making cadmium mining dock workers construction flour and grain foundry workers petroleum pottery/ceramic quarries rubber plastics stonemasonry textiles welders
name 2 other causes of COPD
occupational biomass burning air pollution contributing factors: lower socioeconomic status asthma/hyper-reactive airway chronic bronchitis childhood infection
progression of COPD to clinical disease
- smoking and pollutants, host factors 2. impaired lung growth, accelerated decline, lung injury, lung and systemic inflammation 3. small airway disorders, emphysema, systemic effects 4. airflow limitation and clinical manifestation (symptoms, exacerbations, co-morbidities)
alpha-1 antitrypsin deficiency and COPD
rare inherited disease presents with early onset COPD <45y/o when absent/low –> alveolar damage and emphysema can also result in liver fibrosis or cirrhosis
what is alpha-1 antitrypsin
protease inhibitor made in the liver limits damage caused by activated neutrophils releasing elastase in response to infection/cigarette smoke
what % of smokers will develop COPD
<50% after 25yrs of smoking, at least 25% w/o any initial disease will have clinically significant COPD (stage 2 or worse) and 30-40% will have any COPD passive smoking also has an effect
impact of smoking on lung function
more resp symptoms and lung function abnormalities greater annual rate of decline in FEV1 (Fletcher-Peto curve) greater COPD mortality rate than non-smokers
smoking in pregnancy
may affect foetal lung growth and priming of the immune system
initial presentation of COPD
varies
some typical symptoms:
SOB
cough
sputum production
wheeze
recurrent chest infections
less common symptoms:
weight loss
fatigue
decreased exercise tolerance
ankle swelling (if causing heart failure)
cor pulmonale
clinical features of COPD on examination
if undiagnosed: little findings unless acute flare/chest infection
diagnosed: cyanosis, raised JVP, cacheaxia, hyperinflated chest, pursed lip breathing, use of accessory muscles, audible wheeze, peripheral oedema
investigations for COPD
no single diagnostic test
hx and spirometry
making a diagnosis of COPD
have to meet all of the following criteria:
35y/o
presence of risk factor (smoking, occupational exposure)
presence of typical sx
abscence of clinical features of asthma
AND
airflow obstruction confirmed by post-bronchodilator spirometry
spirometry in COPD
demonstrates lack of reversibility
FEV1/FVC <0.7 post bronchodilator
stages of COPD
- mild: FEV1 80% of predicted or higher, diagnosis made on respiratory symptoms
- moderate: FEV1 50-79% of predicted
- severe: FEV1 30-49% of predicted
- very severe: FEV1 <30% predicted
obstructive pattern in spirometry
large reduction in FEV1: <80% predicted normal
FVC reduced by not by as much: <80% predicted normal
FEV1/FVC <0.7
Features of COPD on CXR
vascular hila (bulky)
hyperinflation (can see >6 anterior ribs/10 posterior ribs, measured in mid-clavicular line)
bulla (large areas with no lung markings)
small heart
flat diaphragm
why would a CXR be carried out with COPD
excludes alternate pathology rather than diagnostic
screen for malignancy
prevalence of COPD
2% population
at least 50% underdiagnosed
increasing prevalance
decreasing incidence
M>F
differentiating between COPD and asthma
COPD: nearly all smoker/ex smoker, >35y/o , chronic productive cough, persistent and progressive SOB, night time waking (due to SOB +/- wheeze) uncommon, little diurnal variation in sx
asthma: can be smoker/ex smoker, often <35y/o, chronic productive cough uncommon, variable SOB, night time wakening common, diurnal variability of sx
pulmonary function tests for COPD
lung volumes: increased residual volume, increased total lung capacity, RV/TLC >30%
transfer factor: reduced gas transfer, reduced DLco, reduced Kco
signs of acute exacerbation of COPD
SOB
wheeze
chest tightness
cough
sputum - purulence, volume (different to normal)
unable to smoke
systemic upset, temperature, fatigue
features of COPD on HRCT - high resolution CT
signet ring sign
honeycombing
traction bronchiectasis
lung cysts
centrilobular emphysema
signs of severe exacerbation of COPD
SOB (RR >25/min)
accessory muscle use at rest purse lip breathing
cyanosis (<92% o/a)
significant decrease in exercise tolerance
signs of sepsis
fluid retention
confusion
differential diagnosis for COPD acute exacerbation
pnuemonia
PE
MI
LVF
lung cancer
pleural effusion
pneumothorax
management of acute exacerbation of COPD
change inhalers (technique, device, add bronchodilator, increase or add inhaled steroid)
nebulisers
oral steroids (prednisolone)
abx
self-management for selected patients
when to admit a patient to hospital for acute COPD exacerbation
unable to cope at home, living alone
severe SOB
poor/deteriorating general condition
poor level of activity/confined to bed
cyanosis, worsening peripheral oedema
impaired level of consciousness
already recieving LTOT
rapid rate of onset, acute confusion
significant co-morbidity
SaO2 <90%
changes on CXR
acute exacerbation of COPD 2y care management
determine trigger - viral/bacterial infection (most common), sedative drugs, pneumothorax, trauma
confusion, cyanosis, severe SOB, flapping tremor, drowsy, pyrexial, wheeze, tripod position
investigations
treatment
2y care investigations for acute exacerbation of COPD
CXR
blood gases
FBC
U+E
sputum culture
viral
2y care treatment of acute exacerbation of COPD
oxygen
nebulised bronchodilator (beta 2 and antimuscarinic)
oral/IV corticosteroid +/- abx
treat other co-existing conditions
severe COPD
respiratory failure (ABG)
flapping tremor (high co2 - hypercapnia)
Cor pulmonale: tachycardic, oedematous, congested liver
2y polycythaemia - increased Hb, increased haematocrit (body produces increased erythropoetin, increased blood viscosity)
ECG and ECHO features of cor pulmonale
ECG: right axis deviation, P pulmonale, T wave inversion V1-V4
echo: pulmonary hypertension, tricuspid regurgitation
measuring severity of COPD
spirometry
nature and magnitude of sx
hx of moderate and severe exacerbations and furture risk - number per year, hospitalisation
presence of co-morbidity
features of severe COPD
chronic bronchitis (blue bloater): overweight and cyanotic, elevated Hb, peripheral oedema, rhonci and wheezing
emphysema (pink puffer): older and thin, severe dyspnoea, quiet chest, CXR - hyperinflation, flattened diaphragm
MRC DYSPNOEA SCALE
- not troubled by SOB except during strenuous exercise
- SOB when hurrying/walking up a slight hill
- walks slower than others on level ground due to SOB or has to stop for breath when walking at own pace
- stops for breath after walking about 100m or after a few minutes on the level
- too breathless to leave the house or breathless when dressing/undressing
end stage COPD
terminal illness
unpredictable decline, acute decline
palliation of symptoms - SOB and anxiety
social aspects - care, housebound, oxygen at home
what is the most important thing that patients can do to slow progression of the disease
stop smoking
