COPD Flashcards
Main pathological features of COPD
- Obstructive bronchiolitis, fibrosis: Narrowing of small airways; release of profibrotic mediators stimulate fibroblast to produce matrix proteins, resulting in peribronchiolar fibrosis
- Emphysema (alveolar wall destruction): Permanent enlargement of alveoli & disrupted alveolar attachments (imbalance b/w protease and anti-protease antivity)
- Chronic bronchitis, mucus hypersecretion: Increased inflammation associated with chronic productive cough (goblet cell hyperplasia, mucosal edema, hypersecretion)
3 cardinal symptoms of COPD & other symptoms?
Dyspnea, Chronic cough, Sputum production
- Wheezing, chest tightness, fatigue, weight loss, muscle loss, anorexia
How to diagnose COPD
Forced spirometry is mandatory for diagnosis
- FEV1/FBC < 0.7 confirms presence of persistent airflow limitation
Risk factors for COPD
- Smoking (major risk factor)
- Indoor/outdoor air pollution
- Occupational exposure
- Abnormal lung growth & development
- Genetic factors (severe hereditary alpha-1 antitrypsin deficiency [AATD])
- Asthma
- Low socioeconomic status
- Infections (e.g. HIV, TB, severe childhood resp infection)
- Chronic bronchitis
Difference between GOLD, mMRC Grade, and CAT Score
GOLD 1-4 is a measure of airflow limitation using FEV1.
mMRC Grade measures nature and magnitude (severity) of SOB from 0-4. Used to determine initial pharmacological treatment.
CAT assesses the impact of the disease on the patient (higher score = more severe disease)
<10 = low impact
>30 = high impact on life; can barely leave house
10 and above = consider regular treatment
Change of 2 and above suggests clinically significant change in health status
Definition of high and low risk of COPD exacerbation
Exacerbation = Acute worsening of respiratory symptoms (dyspnea and/or cough & sputum)
- High risk: 2 or more exacerbation in the past 1 year / 1 or more exacerbation leading to hospital admission
- Low risk: 0 or 1 exacerbation (but not leading to hospital admission)
How to determine initial treatment?
Using symptoms score (mMRC or CAT) & risk of exacerbation.
Group A = mMRC 0-1, CAT <10 + Low risk (0 or 1 exacerbation in last 1 year not leading to hospital admission)
Group B = mMRC ≥ 2, CAT ≥ 10 + Low risk of exacerbation
Group E = ≥2 moderate exacerbations or ≥1 leading to hospitalization, regardless of symptoms
Recommended pharmacotherapy for Group A?
Group A: Bronchodilator (either short/long acting)
SABA = Salbutamol / LABA = Formoterol, Salmeterol, Indacaterol
or
SAMA = Ipratropium / LAMA = Tiotropium, Umeclidinium, Glycopyrronium
Recommended pharmacotherapy for Group B?
LABA + LAMA (single inhaler may be more convenient and effective than multiple)
Recommended pharmacotherapy for Group E?
LABA + LAMA (+ ICS if blood eosinophil > 300)
Example of LABA/LAMA (Group B/E)
- Umeclidinium + Vilanterol (62.5mcg/25mcg) Inhaler
- Tiotropium + Olodaterol (2.5mcg/2.5mcg) Inhaler
- Glycopyrronium + Indacaterol + (50mcg/110mcg capsule)
Combination more effective to increase FEV1, reduce symptoms & exacerbations compared to monotherapy. If combi not appropriate, can use LAMA or LABA
Example of Triple Therapy for Group E
[LAMA + LABA + ICS (if eos ≥ 300)]
- Glycopyrronium + Formoterol + Beclomethasone
- Umeclidinium + Vilanterol + Fluticasone.
Improves lung function, patient reported outcomes and reduces exacerbations compared to dual combination or LAMA alone.
Role of bronchodilators in COPD?
- SABA/LABA for all Group A pts to manage breathlessness. LABA preferred except in pts with very occasional breathlessness
- Rescue SABD should be prescribed to all patients for immediate symptom relief
- LABA and LAMA significantly improve lung function, dyspnea, health status and reduce exacerbation rates
- LAMAs have greater effect on exacerbation reduction compared to LABAs
- LABA+ICS not encouraged, should use LABA+LAMA+ICS if ICS is indicated
Follow-up Pharmacological Treatment Algorithm for Dyspnea
Follow-up Management based on whether pt experiences dyspnea or exacerbation.
Dypsnea:
Step up from LABA/LAMA
»> LABA + LAMA
»> Consider switching inhaler, implement non-pharm, investigate other causes
Follow-up Pharmacological Treatment Algorithm for Exacerbation
Follow-up Management based on whether pt experiences dyspnea or exacerbation.
LABA or LAMA
==> LABA + LAMA (if blood eos < 300) OR LABA+LAMA+ICS (if blood eos ≥ 300)
From LABA+LAMA
==> Add ICS if eos ≥ 100 ; if not, consider Roflumilast (FEV1 < 50% & chronic bronchitis) or Azithromycin (preferred in former/non-smokers)
From LABA+LAMA+ICS
==> Add Roflumilast (FEV1 < 50% & chronic bronchitis) or Azithromycin (preferred in former smokers).
==> Consider de-escalation if pneumonia or other side effects (exacerbation more likely if blood eos ≥300)
