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Week 4: Asthma and COPDDr Felix Woodhead
Consultant Physician
Obstructive Lung Disease
• Reduced rate of airflow
• Wheeze
• Big lungs
• Asthma
• COPD
• Bronchiectasis
Delivery methods
• Nebulisers
• Inhalers– Aerosol
– Dry powder
– Proprietary types
DrugsBronchodilators
β2 agonists
• Short-acting– Salbutamol
– Terbutaline
• Long-acting– Salmeterol
– Formoterol
Antimuscarinics
• Short-acting– ipratropium
• Long-acting– tiotropium
Steroids
• Beclomethasone (BCZ)
• Budesonide
• Fluticasone
• Small- particle BCZ
Combined agents
• Seretide (Purple)– =serevent (salmeterol) + flixotide (fluticasone)
– Evohaler (MDI) or accuhaler (DPI)
• Symbicort– Oxis (formoterol) + pulmicort (budesonide)
– Turbohaler (DPI)
– SMART regime
COPD
Definition
• Airflow obstruction (FEV1/FVC < 0.7)
• Usually progressive
• Not fully reversible
• Doesn’t change markedly over few months
• Predominantly caused by cigarette smoking
• Differentiation from asthma
GLOBAL INITIATIVE FOR OBSTRUCTIVE LUNG DISEASE
• FEV1 ≥ 80% - GOLD stage 1
• FEV1 = 50-79% - GOLD stage 2
• FEV1 = 30-49% - GOLD stage 3
• FEV1 < 30% - GOLD stage 4
• Stage 1 needs symptoms (asymp not COPD)
• Relatively poor correlation between FEV1 & symptoms
BODY MASS INDEX OBSTRUCTION DYSPNOEA EXERCISE CAPACITY
• BMI : <21 or not
• Obstruction: broadly GOLD cutoffs
• Dyspnoea: MRC score
• Exercise tolerance: 6 minute walk test
• Composite score better than GOLD
Treatment of stable diseaseNICE 2010
Stop smoking!
• Assess every time
• Not asking is a dereliction of duty
• Only intervention that changes natural history of disease
• “If you think you’re breathless now, just you wait…”
• It is NEVER too late to stop smoking
• Do not diagnose asthma if you think they may have COPD
Inhaled treatment
• SOB/ex limitation: SABA/SAMA prn
• Exacs/SOB
– LAMA (tiotropium) regardless of FEV1
– Or
• LABA if FEV1 > 50%
• Combined LABA/ICS if FEV1 < 50%
• Still exacs/SOB– LAMA & Combined LABA/ICS
(Home) Nebulisers
• Consider in patients with distressing symptoms despite adequate inhaled Rx
• Only continue if beneficial
• Side effects can occur
• Takes up time
• Placebo effect common
Systemic treatment
• Corticosteroids – avoid
• Theophyllines– Only after inhaled Rx tried, or not tolerated
– Particular care in the elderly
– Levels increased by macrolide/fluoroquinolone
• Mucolytics– Consider in patients with chronic productive cough
– Continue only if beneficial
Oxygen therapy
• Role is to delay death from cor pulmonale
• The breathlessness paradox– SOB often good pO2
– Low sats, often not breathless
• LTOT– pO2 < 7.3 kPa when stable
– pO2 < 8 kPa and nocturnal hypoxaemia, polycythaemia or cor pulmonale
– Needs to be used for at least 15/24 hours
• Short burst use (cylinders) – little role
Acute exacerbation of COPD
Definition
• Sustained worsening of symptoms from usual state
• Beyond daily day-day variation
• Acute in onset
• Often associated with– ↑ SOB, ↑ cough, ↑ sputum volume, ↑ sputum purulence
• May require change in treatment
• Occur due to precarious V/Q in bad lungs caused by often minor stimuli
Exclude• Pneumothorax
• SVT
• Myocardial infarction
• Pulmonary oedema
• Lung cancer
• PE
• Pneumonia (NOT ‘infective exacerbation’)
• No role for ‘CURB’ score in IECOPD (it is not pneumonia)
Management
• ↑ frequency of inhaled treatment (often nebulised)
• Steroids for all (30 mg od 7-14/7)
• Antibiotics if sputum purulent
• O2 given
– With care, and control
– ALWAYS Venturi acutely
– Adjusted by SaO2 not patient/relative/nurse distress
– Guided later by ABGs
– With NIV if needed
Other issues
• Like ‘breathlessness’, fear ‘comfort’
• Keep calm
• Do not give opiates/benzos
• Get senior help if necessary
• Nebulise on air, using nasal specs for sup O2
• NIV - use early
• 2.5 mg salbutamol 2° better than 5 mg 4°
• IV aminophyline can be useful
Non-invasive ventilation
• For ACUTE ventilatory failure
• Treats ↓ pH
• Allows ↑ FiO2 without ↑ pCO2
• Only suitable if conscious and protecting airway
• ↑EPAP (PEEP) useful in pulm oedema and obesity
• NOT poor man’s ITU
• NO ROLE IN ACUTE ASTHMA/pneumonia
Asthma
Principles
• Variable airflow obstruction
• Cough and wheeze
• Nocturnal features
• Specific (allergic) triggers
• Non-specific triggers
• Eosinophils in airways
• Responds to steroids
Acute severe asthma
• PEFR 50-33%
• RR ≥ 25
• HR ≥ 110
• Unable to complete sentences
• But SpO2 >92%
• Worse = life-threatening (silent chest, cynanosis, low SpO2)
• Better = moderate asthma
Treatment
• Steroids
• O2
• Nebs driven with O2
• ABG if low sats or drowsy– Normal pCO2 is a sign of bad prognosis
• Senior review
• Increase inhaled treatment/start it. Educate. Inhaler technique
• Consider IV bronchodilators
Stable asthma
• Steroids– Inhaled best
– Systemic if admission on the cards
• Step 1: SABA only
• Step 2: SABA & ICS 200-800 mcg/day
• Step 3: add LABA (combined)
• Step 4: ↑ ICS dose (stop LABA if no benefit)
• Step 5: help! Montelukast etc, aminophylline
• Steroids – psychosocial issues?