Respiratory medicine Flashcards
Definition of COPD
A disease state characterised by airflow limitation that is not full reversible, is progressive and associated with an abnormal inflammatory response of the lungs to noxious particles or gases
Definition of emphysema
Abnormal permanent enlargement of the air spaces distal to the terminal bronchioles with destruction of alveolar walls without fibrosis
Definition of chronic bronchitis
Persistent cough with sputum production for at least 3 months in at least 2 consecutive years
Pathophysiology of COPD
Smoking - inc. neutrophils - elastases and proteases released - emphysema (breakdown of alveolar wall etc.)
a1-antitrypsin inactivated by cigarette smoke - imbalance between protease and antiprotease activity
Emphysema classifications
According to site of damage:
CENTRI-ACINAR emphysema:
- destruction concentrated around respiratory bronchioles
- distal alveolar ducts and alveoli tend to be preserved
- extremely common form, not always associated with disability
PAN-ACINAR emphysema:
- less common
- distension and destruction of WHOLE acinus (area supplied by terminal bronchiole)
- associated with a1-antitrypsin deficiency
IRREGULAR emphsema:
- patchy scarring and damage of lung parenchyma
Cause of airflow limitation in COPD
Reduced elasticity due to emphysema - red. recoil - collapse of airway during expiration
Inflammation and scarring - narrow airway
Mucus plugging of smaller airways
ALL CAUSE V/Q MISMATCH
Clinical features of COPD
Productive cough Wheeze SOB Frequent infective exacerbations If severe: - cyanosis - pursed lip breathing, accessory muscles - tachypnoea with prolonged expiration - intercostal recession - hyperinflated chest - reduced chest expansion - loss of normal cardiac and liver dullness to percussion
Investigations in COPD
FEV1:FVC less than 0.8 Reduced PEF May be partly reversible (less than 12%) CXR: - often normal - overinflation of lungs, low flattened diaphragms - sometimes large bullae - large proximal blood vessels, relatively little blood visible in peripheries
Management of COPD
COPD-X guidelines: C: confirm diagnosis and severity O: optimise function P: prevent deterioration D: Develop support (therapeutic relationship, MultiD care, action plans, support group) X: manage exacerbations
Assessing severity in COPD
FEV1/FVC less than 70% in all, class according to % predicted Mild: over 80% predicted Moderate: less than 80% predicted Severe: less than 50% predicted Very severe: less than 30% predicted
(Mod: breathlessness on walking, cough and sputum, Severe: SOB on minimal exertion, daily activities severely curtailed, chronic cough)
Optimising function in COPD
Goals: active therapy v palliative v terminal
Relievers: SABA, SAMA (ipratropium bromide)
Preventers: LAMA (tiotropium) LABA (indacterol - OD, salmeterol - BD)
ICS: consider if mod-sev and frequent exacerbations
Non-pharm: physical activity, pulmonary rehab, chest physio, smoking cessation, nutrition
Management of co-morbidities
Preventing deterioration in COPD
Smoking cessation
Immunisations: annual influenza, pneumococcal
+/- Mucolytic agents (N-acetylsysteine)
Oxygen therapy if hyopxaemia
Management of COPD exacerbations
Early diagnosis
Inhaled bronchodilators
Systemic corticosteroids
Antibiotic therapy (if clinical signs of infection)
Controlled O2 delivery
NIPPV for acute hypercapnie venitlator failure
Complications of COPD
Respiratory failure
Cor pulmonale (Pulmonary HTN)
Fluid retention and peripheral oedema secondary to renal hypoxia
Definition of asthma
A chronic inflammatory condition of the airways characterised by reversible airflow limitation, airway hyper-responsiveness to a wide range of stimuli and bronchial inflammation
Epidemiology of asthma
Peak age of 1st presentation = 3y
M:F 2:1 in childhood, 1:1 by adulthood
affects up to 15% children, 10% adults
More common in developed countries
Assessing severity of asthma
Intermittent:
- less than weekly daytime sx
- less than 2 night-time sx per month
- infrequent, brief exacerbations
- FEV1 80% predicted, variability less than 20%
Mild persistent:
- more than weekly, not daily daytime sx
- less than weekly night-tin sx
- occasional exacerbations, may affect activity or sleep
- FEV1 80% predicted, 20-30% variability
Moderate persistent:
- daily symptoms
- night-time sx weekly or more
- occassional exacerbations may affect sleep or activity
- FEV1 60-80% predicted, variability over 30%
Severe persistent:
- daily symptoms, restricting physical activity
- frequent night-time symptoms
- frequent exacerbations
- FEV1 60% predicted or less, variability over 30%
Conditions suggestive of CF in adults
BRANIAC Bronchiectasis Recurrent pancreatitis Allergic bronchopulmonary mycosis Infertility (Male) Nasal polyposis Infection with non-tuberculous mycobacterium Adult (there isn't' actually another A) - could be osteoporosis Chronic sinusitis
Definition of bronchiectasis
The congenital or acquired irreversible abnormal dilation and destruction of bronchial walls
Types of bronchiectasis
Cylindrical:
- dilated bronchi with straight, regular outlines
- tram-track lines (parallel to each other)
- Signet ring
Saccular/cystic:
- most severe form
- ballooned appearance of bronchi +/- air-fluid levels
- large, cystic areas with honeycomb appearance
- thicker bullae of emphysema
Varicose:
- bronchi with dilated segments and other areas of constriction - “string of pearls”
Follicular:
- extensive lymphoid nodules in bronchial walls
Clinical features of bronchiectasis
Chronic cough w purulent sputum Haemoptysis dyspnoea and wheezing Chest pain Postnasal drip Chronic fatigue Bilateral basal crackles Wheeze Ronchi Clubbing (in long-standing, severe bronchiectasis)
Investigations in bronchiectasis
High resolution CT:
- signet ring (end-on dilated bronchi are larger than accompanying pulmonary artery)
- Tramlines (non-tapering bronchi)
- cysts with air-fluid levels
- mucus plugging of dilated bronchi (flame and blob sign/tree-in-bud pattern)
Sweat chloride test Electron microscopic evaluation of ciliary structure (primary ciliary dyskinesia) Genetic tests (CFTR, a1 antitrypisin genotypes)
Management of bronchiectasis
Prolonged Abx for infective exacerbations (10-14d Augmentin)
Bronchodilators - if airflow obstruction
Inhaled corticosteroids
Pulmonary rehab
Bronchial hygiene therapy (inc. removal of secretions)
Surgery (if obstructing tumour, removal of severely damaged segments etc.)
CXR findings in PE
Often normal in small/medium PE
May show small effusion (blunting of costophrenic angle)
Massive PE:
- oligaemic lung fields
- dilation of pulmonary arthery in hilum
- is often normal
ECG findings in PE
Sinus tachycardia
Sometimes AF
In massive:
Peaked P waves lead II (RA dilatation)
R axis deviation (RV dilatation)
RBBB, T wave inversion on R precordial leads
Classic S1Q3T3 is rare
Wells criteria for PE
Clinical sx of DVT = 3 PE more likely than other diagnoses = 3 Prior DVT/PR = 1.5 Tachycardia = 1.5 Immobilised 3d or surgery in last 4w = 1.5 Haemoptysis = 1 Malignancy = 1
5 or more, likely - perform CTPA
If less than 5, low risk, perform D-dimer to exclude
Management of PE
Parenteral anticoagulant - LMWH is agent of choice for initial treatment (unfractionated if significant renal disease) Oral warfarin or rivaroxaban Target INR 2-3 Minimum 3 months anticoagulation
Thrombolytics are indicated in patients with haemodynamic instability (systolic BP under 90)
+/- patients with poor prognostic markers (inc. troponin, RV dilatation)
Assessing severity of pneumonia
SMART-COP Systolic BP less than 90 = 2 Multilobar involvement on CXR = 1 Albumin less than 35 = 1 Respiratory rate over 25 (30 if 50 or older) = 1 Tachycardia over 125 = 1 Confusion = 1 Oxygen low (93%, 90% if 50) = 2 pH - acidaemic = 2
Severe if over 5 points - high risk of needing intensive respiratory or vasopressor support
