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?