Week 4: Asthma and COPDDr Felix WoodheadConsultant 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?