COPD Flashcards
What is the micro pathology of COPD?
- Hypertrophy and hyperplasia of mucus-secreting goblet cells of bronchial tree
- Fibrosis and thickening of bronchial walls
- Lymphocytic infiltrate
- Emphysema – Dilatation and destruction of lung tissue distal to terminal bronchiole leading to reduced elasticity and gas exchange surface
What are the main differentials of COPD?
Asthma
Bronchiectasis
Lung cancer
In acute exacerbations: Pneumothorax Pneumonia Pulmonary oedema Large pleural effusion PE
How would you manage an acute exacerbation of COOD?
ABCDE approach
- Monitoring, iv access, bloods (consider theophylline level)
- Early CXR and ABG
Oxygen
- Titrated to maintain sats within individualised target range
- Usually 88-92% if unsure
- ABG to ensure not retaining CO2
Bronchodilators - Salbutamol 5mg - Nebulised (or inhaled via spacer – equally effective) - Can run back to back Ipratropium 0.5mg - No evidence this is more effective than salbutamol but given anyway Prednisolone 30mg - 7-14 days
Antibiotics
- If febrile, sputum purulent or signs of consolidation
Treat as pneumonia if consolidation on CXR
Empirical treatment – aminopenicillin, macrolide or tetracycline – refer to local guidelines
IV Thephylline
-Only if no response to bronchodilator therapy
What would you do to manage COPSMD if these medical steps are failing?
Non-invasive ventilation (CPAP or BiPAP)
- In patients who are still hypercapnic and hypoxic despite medical therapy
- Has been shown to improve survival
- Must clearly document plan for what should happen if further deterioration and ceiling of treatment
Contraindications
- Confusion or agitation
- Unless this is due to high CO2
- Severe dementia
- Facial burns or trauma
- Vomiting
- Undrained pneumothorax
- Copious secretions
- Haemodynamically unstable, moribund or low GCS - Unless in HDU
- Upper GI surgery or obstruction
Can use doxapram if NIV not available or inappropriate
- Stimulant of chemoreceptors. CI in epilepsy.
Invasive ventilation
- Careful consideration regarding whether appropriate
- Close liaison with ITU team
What is the definition of COPD?
Airflow obstruction that is:
- Not fully reversible
- Progressive
- Does not change markedly over several months
What is the pathophysiology of COPD?
Combination of airway and parenchymal damage
This occurs as a result of chronic inflammation and encompasses chronic bronchitis and emphysema
An exacerbations of COPD is a rapid and sustained worsening of symptoms beyond normal day-to-day variations
What is the epidemiology of COPD?
Prevalence: an estimated 3 million people have COPD in the UK
Incidence: approximately 1% overall and 10% in over 75 year olds
What are the causes/risk factors for COPD?
Smoking
- In UK, 90% of COPD is caused by long-term smoking
smokers of >30/day have a 20x risk compared to non-smokers, although only 10-20% of heavy smokers get COPD
Air pollution
Biomass fuels
Alpha-1-antitrypsin deficiency
Serum protease inhibitor
Can present with lung disease (75%) or liver cirrhosis (25%) - Pan-acinar (lower lobes) as opposed to centri-lobular in smoking and environmental exposures
What are the causes of acute exacerbation of COPD?
Viral
- Rhinovirus, influenza, coronvirus, adenovirus, RSV
Bacteria
1. Common Strep. Pneumonia Haemophilus Moraxella - WCC may be normal with mild symptoms
2. Rare Staph aureus (during flu season) Pseudomonas
What is the presentation of COPD?
Exertional breathlessness Chronic cough Sputum production Wheeze Frequent winter bronchitis Fatigue Ankle Swelling Weight loss
What are the main differentials of COPD?
Asthma
Bronchiectasis
Lung cancer
In acute exacerbations: Pneumothorax Pneumonia Pulmonary oedema Large pleural effusion PE
What are the investigations of COPD?
Bedside Pulse oximetry Sputum MCS ECG - May show tall P-waves of cor pulmonare, RBBB and RVH (right axis deviation, prominent V1 R-wave and V6 S-wave) Calculate BMI
Bloods
FBC: Hb and Hct can be raised in response to chronic hypoxia
Blood cultures if pyrexial
Alpha-1-antitrypsin levels
Theophylline level if on maintenance therapy
ABG
Normal in mild disease
Hypoxia and hypercapnia in advanced disease
Respiratory acidosis +/- partial or full metabolic compensation
Imaging
CXR
- Classically shows bullae, hyperinflation and flattened diaphragms but can be normal
CT (high resolution CT – HRCT)
- Can do in expiration phase if looking for air trapping
Echo
Assess cardiac function (?cor pulmonare)
Lung function tests High RV and TLC Low VC FEV1/FVC reduced (i.e. obstructive) - FEV1/FVC < 0.7, FVC < 0.8 predicted Little reversibility with salbutamol: <15% Low KCO - Carbon Monoxide gas transfer coefficient reduced in proportion to severity
What is the mangement of acute and chronic copd?
See notes
What are the complications of COPD?
Progressive respiratory failure Cor Pulmonale Recurrent LRTIs Pneumothoraces Post-infective bronchiectasis Acute renal failure (likely pre-renal)
What is the prognosis of COPD?
Mortality is 70 per 100,000 per year (down from 200 25 years ago)
5 year survival approx. 75%
With acute exacerbations
- 1/3 will be re-admitted within 3 months and 14% will die within 3 months
