Resp - COPD: Chronic Management Flashcards
Definition of COPD
- Disease associated with airflow obstruction, not fully reversible. Airflow obstruction is progressive and associated with an abnormal inflammatory response of lungs to noxious particles or gas.
- Chronic bronchitis: cough and sputum production on most days for 3months within 2 consecutive years
- Emphysema: histological Dx of enlarged spaces distal to terminal bronchial with destruction to alveolar walls
Pathophysiology
- Loss of elasticity and alveolar attachments of airways leads to loss of elastic recoil and the airways collapse during expiration.
- Inflammation and scarring lead to narrowing of small airways
- Mucus secretion (due to goblet cell hyperplasia) blocks airways
- All of these lead to hyperinflation of the lungs and SOB
Causes
- Smoking: increased number of neutrophil granulocytes, which secrete proteases and elastases (de-activate alpha 1 anti-trypsin) + negatively affect surfactant = Increased lung distension, inflammation and loss of terminal alveoli
- Infections/pollution
- Alpha 1 antitrypsin deficiency
Symptoms
- cough + sputum
- dyspnea
- wheeze
- wt loss
Signs
- tachypnea
- prolonged exploratory phase
- hyperinflation of lungs
- Wheeze +/- early inspiratory crackles
- cyanosis
- cor pulmonale: Raised JVP, peripheral oedema
Outline the MRC dyspnea score
- Dyspnea on vigorous exertion
- SOB on hurrying/walking up stairs
- Walks slowly/has to stop for breath
- Stops for breath after <100m/few mins
- Too breathless to leave house/SOB while dressing
Complications of COPD
- Acute exacerbation +/- infection
- polycythaemia
- pneumothorax (ruptured bullae)
- cor pulmonale
- lung carcinoma (long standing inflammation)
Ix
- BMI (could be cause of type 1 Resp failure)
- Bloods: FBC (polycythaemia), alpha 1-AT levels, ABG
- CXR: hyperinflation (>6ribs anteriorly), bullae
- ECG: r atrial hypertrophy, cor pulmonale
- Spirometry: FEV <80%, FEV1:FVC <0.7, raised TLC, raised RV
- Echo: pulmonary HTN, RV hypertrophy
How do you assess severity?
- Mild: FEV1>80% (but FEV1:FVC <0.7 and symptomatic)
- Mod: FEV1 50-79%
- Severe: FEV1 30-49%
- V severe: FEV1 <30%
Rx: general methods
- Stop smoking
- Pulmonary rehab
- Rx for poor nutrition/obesity
- influenza and pneumococcal vaccine
- review 2x/y with regular assessment of lung function tests
Step 1 in COPD treatment:
-Short acting beta 2 agonist (SABA - salbutamol) or short acting muscarinic antagonist (SAMA - Ipratropium)
What is the next step in treatment for COPD? How do you determine which stem of treatment is appropriate?
-Pts who remain breathless or have exacerbations despite SABA/SAMA - next step is determined by whether they have ‘asthmatic features’ and features suggestive of steroid responsiveness or not.
Features indicative of asthma/steroid responsiveness
- Any previous secure diagnosis of asthma or atopy
- A higher blood eosinophil count (do FBC as work up)
- Substantial variation in FEV1 over time (at least 400ml)
- Substantial diurnal variation in PEF (at least 20%)
What treatment to you give for pts with asthmatic features/features suggestive of steroid responsiveness?
- LABA + ICS
- If pats remain breathless/have exacerbations over triple therapy: LAMA + LABA + ICS
What treatment to you give for pts with NO asthmatic features/ NO features suggestive of steroid responsiveness?
Add LABA (salmeterol) and LAMA (tiotropium bromide) to existing Tx (SABA or SAMA)
What additional treatments should you give to patients with Cor pulmonale?
- Pt with features including peripheral oedema, raised JVP, systolic parasternal heave, loud P2
- Loop diuretic for oedema
- Consider LTOT
- ACEi, CCB and alpha blockers NOT recommended by NICE
