Respiratory Disorders

COPD

Clinical overview and exam mastery guide for GOLD treatment groups, maintenance inhaler logic, exacerbation management, and oxygen criteria.

Core Disease
Progressive airflow limitation
Major Cause
Smoking exposure
Maintenance Base
LAMA and/or LABA
Oxygen Target
SpO2 88-92%

COPD Structural Disease Model

Chronic irritation smoke / biomass / pollutants Airway disease mucus + narrowing Parenchymal loss emphysema + recoil loss Result: persistent airflow obstruction (not fully reversible) Therapy focus: bronchodilation + exacerbation prevention + smoking cessation

1. Definition

COPD is a progressive, largely irreversible airflow limitation syndrome driven by chronic bronchitis, emphysema, or both. Smoking is the main cause.

Chronic bronchitis Emphysema Not fully reversible

2. Pathophysiology

Step 1: Chronic airway inflammation develops.
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Step 2: Airway narrowing and mucus hypersecretion increase resistance.
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Step 3: Alveolar wall destruction causes air trapping and reduced recoil.
Unlike asthma, airflow obstruction in COPD is not fully reversible.

3. GOLD Classification (Treatment-Based)

Classify by symptom burden (mMRC/CAT) and exacerbation history.

Group A Group B Group E

GOLD Grouping and Initial Treatment

Group A Low symptoms / low exacerbation risk Single bronchodilator Group B More symptoms / lower exacerbation risk LABA or LAMA Group E Exacerbation-prone LABA + LAMA (consider ICS)

4. Short-Acting Bronchodilators (Rescue)

Albuterol (SABA)

  • Dose: 2 puffs every 4 to 6 hours as needed or 2.5 mg neb as needed
  • MOA: beta-2 agonist bronchodilation

Ipratropium (SAMA)

  • Dose: 2 puffs (17 mcg per puff) four times daily
  • MOA: muscarinic blockade to reduce bronchoconstriction
  • Side effect: dry mouth

5. Long-Acting Muscarinic Antagonists (LAMA)

Tiotropium (first-line maintenance)

  • MOA: M3 receptor blockade with long-acting bronchodilation
  • Dose: 18 mcg inhaled once daily (HandiHaler) or 2.5 mcg (2 inhalations) daily (Respimat)
  • Side effects: dry mouth, urinary retention
  • Caution: narrow-angle glaucoma

6. LABA (Long-Acting Beta Agonists)

  • Salmeterol dose: 50 mcg twice daily
  • MOA: sustained bronchodilation
  • Maintenance use is appropriate in COPD
High-yield distinction: LABA can be used alone in COPD (unlike asthma).

7. LABA + LAMA Combination

  • Preferred in moderate to severe symptomatic COPD
  • Example: umeclidinium/vilanterol, 1 inhalation once daily

8. Inhaled Corticosteroids (ICS) Role

  • Use in frequent exacerbations and/or high eosinophils
  • Example (in combination): fluticasone 250 to 500 mcg twice daily
  • Risk: increased pneumonia incidence
  • Not first-line as monotherapy in COPD

9. Triple Therapy (ICS + LABA + LAMA)

  • For severe disease or frequent exacerbations
  • Example: fluticasone/umeclidinium/vilanterol, 1 inhalation once daily

10. Phosphodiesterase-4 Inhibitor

Roflumilast

  • Use: severe COPD with chronic bronchitis and frequent exacerbations
  • MOA: PDE-4 inhibition reduces inflammation
  • Dose: 500 mcg orally once daily
  • Side effects: weight loss, diarrhea, insomnia
  • Contraindication: moderate to severe liver impairment

11. Acute COPD Exacerbation

Bronchodilator + Steroid Core

  • Frequent SABA plus or minus SAMA dosing
  • Prednisone 40 mg orally daily for 5 days

Antibiotic Trigger Criteria

  • Increased sputum purulence
  • Increased sputum volume
  • Increased dyspnea

Common 5-7 day regimens if infection suspected

Amoxicillin/clavulanate Azithromycin Doxycycline

12. Oxygen Therapy

  • Indicated when PaO2 <= 55 mmHg or oxygen saturation <= 88%
  • Long-term oxygen therapy improves survival in qualifying patients
  • Target saturation: 88-92%
  • Avoid over-oxygenation due to CO2 retention risk

Management Recap Drill

Group A: single bronchodilator.
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Group B: LABA or LAMA.
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Group E: LABA + LAMA, then consider ICS for frequent exacerbations.
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Exacerbation: SABA + steroid plus or minus antibiotics.

Guideline References (Management)

GOLD Guidelines

https://goldcopd.org

Guideline Scope

  • Group A/B/E classification
  • Inhaler selection and escalation
  • Exacerbation and oxygen criteria

13. Common Exam Traps

LABA monotherapy is allowed in COPD (unlike asthma).
ICS can increase pneumonia risk in COPD.
A 5-day prednisone course is usually sufficient in exacerbation.
Oxygen target is 88-92%, not normal-range saturation.
LAMA is a strong first-line maintenance option.

14. Quick Revision Summary

Must Remember

  • Smoking is the major COPD cause
  • LAMA or LABA is baseline maintenance
  • LABA/LAMA combination is preferred in symptomatic disease
  • Add ICS for frequent exacerbators or high eosinophils
  • Exacerbation core: bronchodilator + steroid

High-Yield Subtopics

  • GOLD A/B/E treatment logic
  • LAMA/LABA dosing and role
  • ICS limitations in COPD
  • Oxygen criteria and target range

Practice Questions

1) Which maintenance class is a strong first-line option in COPD?

Answer: LAMA (for example, tiotropium).

2) Is LABA monotherapy acceptable in COPD?

Answer: Yes. Unlike asthma, LABA alone can be used in COPD maintenance.

3) Typical systemic steroid duration in acute COPD exacerbation?

Answer: Prednisone 40 mg daily for 5 days.

4) When should long-term oxygen be considered?

Answer: PaO2 <= 55 mmHg or oxygen saturation <= 88%.

5) What oxygen saturation target is usually used in COPD exacerbation?

Answer: 88-92% to avoid over-oxygenation and CO2 retention.