Respiratory Flashcards
Asthma
Chronic inflammatory condition characterised by reversible airflow obstruction, airway hyper-responsiveness, involvement of T cells, mast cells, eosinophils and smooth muscle hypertrophy.
Most common chronic condition in children
Asthma
Causes of Asthma
Atopy: triad with hayfever, eczema and asthma
Genetic
Environment: viral, bacterial infections, allergen exposure, occupational exposure, food additives and chemicals
Pathophysiology of Asthma
Type 1 IgE mediated hypersensitivity reaction causing:
- bronchoconstriction
- Inflammation caused by mast cells, eosinophils, dendritic cells and lymphocytes (Th2 response)
- Increased mucous production
- Airway remodelling
What happens in airway remodelling
Loss of ciliated cells
Increase in goblet cells and mucus
Smooth muscle hyperplasia due to contraction
Nerves contribute to irritability of airways
Symptoms of Asthma
Wheezing, coughing, sputum, SOB, chest tightness, triggered by cold air, exercise, pollution, allergens, nocturnal dyspnoea
Signs on examination of Asthma
Tachypnoea, wheeze, hyper inflated chest, hyper-resonant to percuss, decreased air entry,
Investigations for asthma
FEV1/ FVC ration, FEV1, PEFR, CXR, FBC, immunoassay for allergen specific IgE
Expected FEV1/FVC ratio for Asthma and COPD
<0.7
Airflow obstruction
A reduced FEV1 and a reduced FEV1/FVC ratio, such that FEV1 is less than 80% of that predicted, and FEV1/FVC is less than 0.7.
Differentials for asthma
CF, chronic rhino sinusitis, tracheomalacia, vascular ring, foreign body aspiration, vocal cord dysfunction, alpha-1 antitrypsin deficiency, COPD, bronchiectasis, PE, congestive heart failure
Vascular ring
Congenital lesion where normal vessels are in an abnormal location and may cause compressionof oesophagus or airway
Treatment for Asthma
- Short-acting beta agonist e.g salbutamol
- Inhaled corticosteroids e.g fluticacsone, budesonise, beclometasone.
Leukotrine-receptor antagonist e.g. montelukast and theophylline - Inhaled corticosteroids AND long-acting inhaled B2 agonist (LABA) e.g. salmetrol
- High dose inhaled corticosteroid and regular bronchodilators: add LABA and LRTA
- Regular oral corticosteroids: add prednisolone 40mg daily
Don’t give LABA without ICS to patients
Complications of Asthma
Treatment from inhaled corticosteroids can lead to: oral candidiasis, dysphonia, oesophageal candidiasis
Chronic Obstructive Pulmonary Disease (COPD)
Progressive disease characterised by airway obstruction with little or no reversibility and FEV1/FVC ratio <0.7.
Includes chronic bronchitis (blue bloaters) and emphysema (pink puffers)
Chronic bronchitis
Cough, sputum production on most days for 3 months of 2 consecutive years
Emphysema
Enlarged airspaces distal to terminal bronchioles with destruction of alveolar walls. Classified according to site of damaged: centri-acinar, pan-acinar, irregular.
How common is COPD
3rd most common cause of death
>40 yo, mostly men
90% of COPD patients are smokers
Causes of COPD
- Loss of elasticity and alveolar attachments
- Inflammation and scarring causing narrowing of airways
- Mucus secretion blocking airways
leading to hyperinflation of lungs and breathlessness
Risk factors for COPD
Smoking
Age
Alpha-1-antitrypsin deficiency
Air pollution, occupational dusts, fumes etc
Symptoms of COPD
chronic cough, sputum, SOB, recurrent chest infections, weight loss, barrel chest
Signs of COPD
Tachypnoea, accessory muscles used, pursed lip, cyanosis, CO2 flap, wheeze, decreased vesicular breath sounds, peripheral oedema
Pink Puffers (Emphysema)
Breathless but not cyanosed. Increased alveolar ventilation. Accessory muscle used, cachexia, barrel chest. May progress to type 1 respiratory failure
Blue Bloaters (Bronchitis)
Cyanosed but not breathless. Decreased alveolar ventilation. May progress to type 2 respiratory failure. Can develop cor pulmonale.
Difference between Asthma and COPD
Asthma presents earlier, has no sputum and is a reversible airway obstruction
Investigations for COPD
Chest Xray, spirometry can differentiate between obstructive and restrictive, FBC, ABG, ECG, sputum culture
Managing COPD
Smoking cessation, pulmonary rehabilitation, exercise, Diet advice and supplementation, vaccination and antiviral therapy, depression advice and treatment
Treating COPD
- Inhaled therapy
- Oral therapy
- Oxygen therapy
Inhaled therapy for COPD
- Short-acting beta agonist e.g. salbutamol, turbutaline
- Short-acting muscarinic antagonist e.g. ipratropoum
- Long-acting muscarinic antagonist e.g. tiotropium
- Inhaled corticosteroids
Oral therapy for COPD
Oral corticosteroids
Theophylline
Mucolytics e.g. carbocisteine
Antibiotics
Complications for COPD
Cor pulmonale Recurrent pneumonia Pneumothorax Depression Respiratory failure Anaemia Secondary Polycythaemia
Pulmonary fibrosis
A restrictive condition when interstitial lungs become damaged and scarred losing its elasticity
3 types of pulmonary fibrosis
Replacement fibrosis- secondary to lung damage
Focal fibrosis - in response to irritants
Diffuse lung parenchyma
5 main causes of Pulmonary fibrosis
Drug induced, radiation induced, environmental , autoimmune and occupational
Investigating Pulmonary fibrosis
CT
Bronchial Cancer
malignant neoplasm of the lung arising from the epithelium of the bronchus. 2 types: SCLC and NSCLC
Small Cell Lung Carcinoma
15% of cases, highly malignant, arise from Kulchitsky cells