Chronic obstructive pulmonary disease (COPD) causes a significant amount of morbidity and mortality. It’s the fourth leading cause of death in the world.
COPD produces anatomical changes in the lungs that lead to narrowing of small airways, destruction of lung tissue, overproduction of mucous, reduced ciliary function, and airflow limitation.
Smoking is the most common cause. Other risk factors include pollution, second-hand smoke, occupational exposure, and lead poisoning. Other factors include age, frequent respiratory infections as a child, and genetic factors.
Asthma is a disease of inflammation. COPD is a disease of obstruction. Goblet cells make mucus to get particles out of the lungs, but cilia are paralyzed and can’t move it out. The mucus obstructs the airway. That’s why we use steroids in asthma as the first line to reduce inflammation, but not in COPD. Patients with COPD tend to get worse as the disease progresses.
Diagnosis by pulmonary function testing. The Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines are the accepted guidelines.
- Comorbidities: pneumonia, stroke, lung cancer, heart disease
- Chronic bronchitis usually degrades to emphysema with age.
- Use Beta-blockers with caution (carvedilol is preferred)
- Vaccinate for the flu and pneumonia, consider things like Tamiflu (oseltamivir) in this population
- Consider smoking cessation.
Severity Scale:
A post-bronchodilator Fev1/FVC ratio of less than 0.7 (70%) confirms COPD. Patients are then classified as below.
- Gold 1 (mild): Fev1 >=80% of predicted
- Gold 2 (moderate): Fev1 between 50% and 79% of predicted
- Gold 3 (severe): Fev1 between 30% and 49% of predicted
- Gold 4 (very severe): Fev1 less than 30% of predicted
Remember, these are post-bronchodilator.
Assessment Tools:
- CAT (COPD Assessment Test) is the best test to assess medications.
- mMRC (Modified Medical Research Council dyspnea scale) is simple and not usually enough information. The scale is from 0 to 4 and assesses breathlessness
- St George’s Respiratory Questionnaire (SGRQ) is too complex and not feasible in most clinical settings.
- After assessment, use the ABCD tool to determine treatment
- History of exacerbations is the most important factor in determining care.
ABCD Assessment:
| Exacerbation History | Patient Symptoms mMRC 0-1 or CAT <10 | Patient Symptoms mMRC 2 or CAT >=10 |
| <=1 moderate exacerbation (no hospitalization) | A | B |
| >= 2 moderate exacerbations or >- 1 leading to hospitalization | C | D |
| COPD Gold Score | Initial Treatment Choices |
| A | Short-acting bronchodilator (SABA – short-acting beta-agonist or SAMA – short-acting muscarinic-agonist or combo) |
| B | LABA (long-acting beta-agonist) or LAMA (long-acting muscarinic-agonist) |
| C | LAMA or LAMA plus LABA or ICS (inhaled corticosteroid) plus LABA (LAMA is preferred: See POET trial) |
| D | LAMA or LABA (LAMA is preferred here too) *If CAT score is super high (~20) can start with LAMA + LABA, if eosinophil count is above 300 um, consider LABA + ICS (eosinophils mean inflammatory processes involved) |
Long-acting bronchodilators should be used in anyone in B or above because they are superior to short-acting bronchodilators. You can use two different classes if you need more control. LAMAs are superior to LABAs in some groups See POET trial. ICS have very little to no benefit in patients without eosinophilia. If blood eosinophilias are less than 100 cells/um, don’t use them.
Unlike asthma, patients need a SABA and/or SAMA for rescue therapy. COPD is obstructive, so you don’t really need to reduce inflammation as you do in asthma (that recommends an ICS + formoterol for rescue). You need to dry secretions and dilate airways. A combo like Combivent is better than either alone.
If the response to initial treatment is appropriate, maintain it. If initial treatment is not appropriate, you need to consider the treatable trait to target. GOLD has two: dyspnea and exacerbations. They are very similar.
Gold considers LABA + LAMA the best combo in most cases. See FLAME trial. LAMA + LABA was superior to LABA + ICS.
Escalation for Dyspnea:
- If on single long-acting bronchodilator (LABA or LAMA) add second from the other class OR consider changing to a more appropriate inhaler type (here is a good article on assessing what inhaler is right for which patient).
- If on LABA + ICS, add LAMA or change to LABA + LAMA (especially if no indication for ICS)
- If on LABA + LAMA + ICS, consider changing to a more appropriate inhaler type (here is a good article on assessing what inhaler is right for which patient) and/or removing ICS (especially if no indication for ICS)
Escalation for Exacerbations:
- If on single long-acting bronchodilator (LABA or LAMA) and blood eosinophils are >300 cells/um or >100 cells/um and the patient has had at least 2 exacerbations or one hospitalization can change to LABA + ICS OR change to LABA + LAMA if they don’t meet the guidelines for ICS.
- If on LABA + ICS, add LAMA or change to LABA + LAMA (especially if no indication for ICS)
- If on LABA + LAMA, consider adding ICS if eosinophil count is >100 OR add roflumilast** if the patient has chronic bronchitis and FEVz <50% and eosinophil count <100 OR consider adding azithromycin if the patient is a former smoker* and eosinophil count <100
- If on LABA + LAMA + ICS, consider removing ICS (especially if no indication for ICS) OR add roflumilast** if the patient has chronic bronchitis and FEVz <50% or R consider adding azithromycin if the patient is a former smoker*
*Benefit is the greatest in patients who don’t currently smoke. Former smokers can be colonized with h.influenza, azithromycin has some anti-inflammatory effects too
**Patients with a history of hospitalizations benefit most from roflumilast. Phosphodiesterase 4 inhibitor. COPD increases cyclic AMP levels. Decreases exacerbations, but no mortality benefit.
Corticosteroids in acute exacerbations only (not long term, bursts or acute).
Acute bronchitis:
- Usually caused by virus: rhinovirus, coronavirus, influenza virus, RSV
- Can be caused by bacteria: mycoplasma pneumonia, chlamydia, pneumonia, bordetella, pertussis
- Treatment:
- Bedrest, increase fluids
- APAP, NSAIDS, use cautions with antihistamines and decongestants (they increase the viscosity of secretions), dextromethorphan, codeine, Tessalon, and Tussionex
- If flu, can give Tamiflu or Relenza (Relenza causes bronchospasm) within 48 hours of symptoms.