Respiratory - Level 1 Flashcards
Pathology of asthma?
o Usually reversible either spontaneously or treatment
o 1. Airway narrowing
Smooth muscle contraction, thickening of airway wall by cellular infiltration and inflammation
Secretions within the airway
o 2. Inflammation
Mast cells, eosinophils, T cells, dendritic cells cause IgE production and release of histamine, prostaglandin D2, leukotriene C4
o 3. Remodelling
Hypertrophy and hyperplasia leading to more mucous secreting goblet cells
Epidemiology of asthma?
- 10-15% of people develop asthma in 2nd decade of life
- More common in developed world
- 15% of asthma induced at work
Risk factors of asthma?
- FHx of atopic disease
- Respiratory infections in infancy
- Tobacco smoke
- Low birth weight
- Social deprivation
- Inhaled particulates
Precipitating factors of asthma?
- House dust mite and its faeces
- Viral infections
- Cold air
- Exercise
- Irritant dust, vapours, fumes (cigarettes, perfume, exhaust)
- Emotion
- Drugs (Aspirin, beta-blockers)
Symptoms of asthma exacerbation?
o Acute SOB and wheeze
o May have chest tightness and cough
Assessment of asthma exacerbation?
o PEFR
o Symptoms and response to treatment
o HR and RR
o O2 sats
Severity assessment of asthma exacerbation - moderate?
PEFR 50-75% best or predicted
Increasing symptoms
No features of acute severe asthma
Severity assessment of asthma exacerbation - severe?
Any 1 of: • PEFR 33-50% best or predicted • Unable to complete sentences in 1 breath • RR ≥25 • HR ≥110
Severity assessment of asthma exacerbation - life-threatening?
Patient with severe asthma with any 1 of: • Altered consciousness • Cyanosis • Hypotension • Exhaustion, poor respiratory effort • Silent Chest • Threatening - SpO2<92% (PaO2<8kPa), PEFR <33% • Bradycardia • Normal pCO2 (4.6-6)
Severity assessment of asthma exacerbation - near-fatal asthma?
Raised PaCO2 and/or requiring mechanical ventilation with raised inflation pressures
DDX of acute asthma exacerbation?
Exacerbation of COPD
Infection
Management of asthma exacerbations - initial assessment?
o Clinical features
o PEFR
o HR, RR, Pulse Oximetry
o Assess Severity
Management of asthma exacerbations - further investigations?
ABG (if O2 <92% or life-threatening)
CXR (if suspected pneumothorax, consolidation, life-threatening asthma)
Management of asthma exacerbations - moderate asthma attack?
o Treat at home or in surgery and assess response to treatment
o Salbutamol via spacer every 60 seconds up to 10 puffs
o If no improvement – via salbutamol 5mg nebuliser
o Prednisolone 40-50mg for 5 days
o Admit if features of severe, life-threatening asthma or recent nocturnal symptoms/hospital admission
Management of asthma exacerbations -acute severe or life-threatening - initial management?
Make sure patient is sitting up
15L/min Oxygen via NRB mask if hypoxic (aim 94-98%)
IV access (FBC, U&E, glucose, CRP, cultures (if septic))
ABG
Salbutamol 5mg (or terbutaline 10mg) nebulised with oxygen
• If does not respond – every 15 mins or continuous nebuliser
Ipratropium Bromide 500mcg (0.5mg) added to nebulisers if poor initial response
• 4-6 hourly
Hydrocortisone IV 100mg every 6 hours (or prednisolone PO 40-50mg for 5 days if can take orally)
Magnesium Sulphate 1.2g-2g IV over 20 mins
Management of asthma exacerbations -acute severe or life-threatening - further treatment?
o Senior review if not improving – consider ITU
IV aminophylline IVI 5mg/kg over 20 mins
IV salbutamol
Management of asthma exacerbations -acute severe or life-threatening - when to refer to ITU?
Drowsiness, confusion, exhaustion, coma, worsening hypoxia, normo/hypercapnoea, ABG showing decreased pH
Management of asthma exacerbations -acute severe or life-threatening - if symptoms improving?
Nebulised salbutamol every 4 hours
Prednisolone 40-50mg OD PO for 5-7 days
Aim for O2 at 94-98%
Monitoring of asthma exacerbations?
HR, RR, O2 sats, ECG
Discharge advice given after acute severe asthma attack?
PEFR >75% best or predicted 1 hour after treatment
Oral Prednisolone OD 40-50mg for 5 days
Review inhaler technique and PEFR by asthma liason nurse
Advise GP follow-up within 2 days
Respiratory clinic appointment within 4 weeks
Return to hospital if symptoms worsen/recur
Classes of COPD patient?
Type 1 Respiratory Failure (Pink puffers)
Low paO2, normal PaCO2
Emphysema predominantly, breathless not cyanosed
Type 2 Respiratory Failure (blue bloaters)
Low PaO2, High PaCO2
Chronic bronchitis – cyanosed develop cor pulmonale and rely on hypoxic drive
Symptoms of COPD?
o Exertional dyspnoea o Cough o Sputum o Wheeze o Ask about present treatment, past medical history, exercise tolerance, recent history
Signs of COPD?
o Dyspnoea, tachypnoea, accessory use muscles, lip pursing
o Hyperinflation (barrel chest)
o Wheeze/Coarse crackles
o Cyanosis, right heart failure (severe disease)
o Tremor, bounding pulse, peripheral vasodilatation, drowsiness
DDx of exacerbation of COPD?
- Asthma
- Pulmonary Oedema
- Pneumothorax
- PE
- URTI