- ACRONYMS AND DEFINITIONS
- ABG - Arterial blood gas
- ACCP - American College of Chest Physicians
- ACP - American College of Physicians
- ATS - American Thoracic Society
- CAT - COPD Assessment Test
- COPD - Chronic obstructive pulmonary disease
- ERS - European Respiratory Society
- GOLD - Global Initiative for Chronic Obstructive Lung Disease
- ICS - Inhaled corticosteroid
- LABA - Long-acting beta agonist
- LAMA - Long-acting muscarinic antagonist
- mMRC - British Medical Research Council questionnaire
- PFTs - Pulmonary function tests (spirometry)
- RCT - Randomized controlled trial
- SABA - Short-acting beta agonist
- SAMA - Short-acting muscarinic antagonist
- EPIDEMIOLOGY
- Chronic obstructive pulmonary disease (COPD) is a progressive lung disease that is marked by airflow obstruction
- Tobacco smoking is by far the largest risk factor for COPD. Inhalation of smoke from biomass fuels used in cooking is another important risk factor, particularly in underdeveloped countries.
- The prevalence of COPD is difficult to estimate because an official diagnosis requires pulmonary function testing, and these tests are not readily available in many countries. Studies have found that anywhere from 174 - 384 million people worldwide may have COPD.
- In the United States, COPD affects more than 5% of the adult population, and it is the third leading cause of death [1,2,6]
- PHYSIOLOGY
- Overview
- COPD is marked by pathological changes in four different compartments of the lungs: central airways, peripheral airways, lung parenchyma and pulmonary vasculature
- Central airways
- Bronchial gland hypertrophy and goblet cell metaplasia occurs. This results in excessive mucus production or chronic bronchitis. Cell infiltrates also occur in bronchial glands.
- Airway wall changes include squamous metaplasia of the airway epithelium, loss of cilia and ciliary dysfunction, and increased smooth muscle and connective tissue.
- Peripheral airways
- Bronchiolitis (swelling and mucus buildup) is present in the peripheral airways at an early stage of the disease
- Pathological extension of goblet cells and squamous metaplasia in the peripheral airways occurs
- Inflammatory cells in the airway wall and airspaces are similar to those in the larger airways
- As the disease progresses, there is fibrosis and increased deposition of collagen in the airway walls.
- Lung parenchyma
- Emphysema, defined as an abnormal enlargement of airspaces distal to the terminal bronchioles, occurs in the lung parenchyma in COPD. As a result of emphysema there is a significant loss of alveolar attachments which contributes to peripheral airway collapse.
- Two types of emphysema:
- Centrilobular - involves dilatation and destruction of the respiratory bronchioles. It is the most common type of emphysema in COPD and is more prominent in the upper zones.
- Panlobular - involves destruction of the whole of the acinus. It is predominantly seen in patients with α₁-antitrypsin deficiency and is more prominent in the lower zones
- Pulmonary vasculature
- Initially, there is thickening of the vessel wall and endothelial dysfunction. These changes are followed by increased vascular smooth muscle and infiltration of the vessel wall by inflammatory cells, including macrophages and CD8+ T lymphocytes
- In advanced stages of the disease, there is collagen deposition and emphysematous destruction of the capillary bed. Eventually, these structural changes lead to pulmonary hypertension and right ventricular dysfunction (cor pulmonale). [2]

- RISK FACTORS FOR COPD
- Overview
- Tobacco smoke is by far the most common risk factor for COPD
- Other risk factors exist and may play a larger role than once thought. In studies, 25 - 45% of patients with COPD have never smoked.
- Risk factors for COPD include the following:
- Tobacco smoke (active and passive) - most common
- Indoor air pollution - smoke from plant, wood, and coal burning
- Occupational exposures
- Crop farming - grain dust, organic dust, inorganic dust
- Animal farming - organic dust, ammonia, hydrogen sulphide
- Dust exposures - coal mining, hard-rock mining, tunneling, concrete manufacturing, construction, brick manufacturing, gold mining, iron and steel founding
- Chemical exposures - plastic, textile, rubber industries, leather manufacturing, manufacturing of food products
- Pollutant exposure - transportation and trucking, automotive repair
- Treated pulmonary tuberculosis
- Lower-respiratory-tract infections during childhood
- Outdoor air pollution
- Particulate matter (< 10 μm or < 2.5 μm diameter)
- Nitrogen dioxide
- Carbon monoxide
- Chronic asthma
- Hereditary deficiency of α₁-antitrypsin [2,3]
- DIAGNOSIS OF COPD
- Symptoms of COPD
- Chronic cough
- Chronic sputum production
- Shortness of breath - initially with exertion, then progressing (with minimal exercise and at rest)
- History of exposure to tobacco smoke or other pollutants [2]
- Physical exam findings in COPD include the following:
- Wheezing - predominant physical exam finding present in COPD. It may not always be present in early disease.
- Hyperresonance of the lungs on percussion - due to hyperinflation
- Barrel chest deformity (increased chest width - front to back)
- Signs of cor pulmonale - split second heart sound, pulmonary and tricuspid insufficiency murmurs, neck vein distension, liver enlargement, peripheral edema
- Loss of muscle mass [2]
- Diagnostic evaluation
- All patients
- Spirometry with bronchodilator reversibility testing - see spirometry below
- Chest X-ray
- Select patients
- α₁-antitrypsin - younger patients with COPD (40 - 50 year olds) and patients with a strong family history of COPD. A serum value of α₁-antitrypsin < 15–20% of the normal limits is highly suggestive of homozygous α₁-antitrypsin deficiency [2]
- Blood gas monitoring - if considering oxygen therapy (see oxygen measurements below)
- Heart ECHO or cath - to assess for pulmonary hypertension and cor pulmonale
- CT scan of the lungs - to rule out other lung diseases [2]
- Differential diagnosis
- Asthma - airflow obstruction that is largely reversible is more consistent with asthma
- Congestive Heart Failure (CHF) - pulmonary edema, fine crackles on exam, dilated heart, airflow restriction
- Bronchiectasis - large volume of purulent sputum, bronchial dilation and bronchial wall thickening on chest radiography/CT
- Tuberculosis
- Obliterative bronchiolitis - younger patients, nonsmokers, history of rheumatoid arthritis/fume exposure, hypodense areas on CT
- Diffuse panbronchiolitis - affects mostly male nonsmokers, almost all have chronic sinusitis, diffuse small centrilobular nodular opacities and hyperinflation on chest radiography and high-resolution CT [2]
- Spirometry definitions
- Spirometry - tests used to measure respiratory function. Also referred to as pulmonary function tests (PFTs).
- Forced expiratory volume in 1 second (FEV1) - volume of air exhaled during the first second of forced exhalation (after full inspiration)
- Forced expiratory volume in 6 seconds (FEV6) - volume of air exhaled during the first six seconds of forced exhalation (after full inspiration)
- Forced expiratory flow (FEF 25-75%) - speed of air (in L/s) coming out of lungs over 25 - 75% of the FVC
- Forced vital capacity (FVC) - volume of air that can be forcibly blown out after full inspiration
Spirometry findings in COPD | ||
---|---|---|
Severity | FEV1/FVC (post-bronchodilator) |
FEV1 (% predicted post-bronchodilator) |
Mild COPD (GOLD 1) |
≤ 0.7 | ≥ 80% |
Moderate COPD (GOLD 2) |
≤ 0.7 | 50 - 80% |
Severe COPD (GOLD 3) |
≤ 0.7 | 30 - 50% |
Very Severe COPD (GOLD 4) |
≤ 0.7 | < 30% |
- COPD TREATMENT
- Drug classes and abbreviations
- Short-acting beta agonist (SABA) - albuterol, levalbuterol
- Long-acting beta agonist (LABA) - salmeterol, formoterol, indacaterol
- Short-acting muscarinic antagonist (SAMA)✝ - ipratropium
- Long-acting muscarinic antagonist (LAMA)✝ - aclidinium, tiotropium, umeclidinium
- Inhaled corticosteroids (ICS) - fluticasone, beclomethasone, mometasone, budesonide, ciclesonide, flunisolide
- Corticosteroids - prednisone, prednisolone, methylprednisolone
- Phosphodiesterase 4 inhibitors - roflumilast (Daliresp®)
- ✝ Muscarinic antagonists are also referred to as anticholinergics
- COPD treatment goals
- Reduce long-term lung function decline
- Prevent and treat exacerbations
- Reduce hospitalizations and mortality
- Relieve disabling shortness of breath
- Improve exercise tolerance and health-related quality of life
- Maintenance therapy recommendations
- Two sets of recommendations for maintenance therapy in COPD are presented below: a joint recommendation from the ACP/ATS/ERS/ACCP published in 2011 and the 2017 GOLD recommendations
- For the GOLD recommendations, patients are classified into Groups A through D based on their symptoms and exacerbation history. The ACP/ATS/ERS/ACCP recommendations are mainly based on spirometry results.
2011 ACP / ATS / ACCP / ERS maintenance recommendations |
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All patients
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Stable patients with FEV1 60 - 80% of predicted
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Stable patients with FEV1 < 60% of predicted
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Stable patients with FEV1 < 50% of predicted
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2017 GOLD maintenance recommendations |
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Step 1 - Assign patient a group
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GROUP A: mMRC 0 - 1 or CAT < 10 and mild exacerbation history
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GROUP B: mMRC ≥ 2 or CAT ≥ 10 and mild exacerbation history
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GROUP C: mMRC 0 - 1 or CAT < 10 and moderate/severe exacerbation history
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GROUP D: mMRC ≥ 2 or CAT ≥ 10 and moderate/severe exacerbation history
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ATS / GOLD recommendations for acute exacerbations |
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Bronchodilators
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Corticosteroids
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Antibiotics
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Oxygen
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- Oxygen therapy
- Some patients with moderate-to-severe COPD are chronically hypoxic or develop hypoxia with exertion. Two small trials performed decades ago found that oxygen therapy improved outcomes in hypoxic patients. [PMID 6776858, PMID 6110912] Several more recent trials (see oxygen studies) have not found a beneficial effect of oxygen therapy in patients with moderate hypoxia. Recommendations from the ATS and GOLD are presented below along with a brief description of oxygen delivery systems.
- Oxygen devices
- Oxygen tanks - oxygen tanks are metal cylinders filled with compressed oxygen. Smaller tanks are portable and can be wheeled around. Some portable tanks can be refilled from stationary oxygen concentrators in the home. Tanks can deliver flow rates up to 6 L/min. The size of the tank and the flow rate of oxygen determine how long they will last. A larger portable tank will last about 5 hours at a flow rate of 2 L/min.
- Oxygen concentrators - oxygen concentrators draw in ambient air, remove nitrogen and other gasses from it, and then deliver concentrated oxygen to the user. Oxygen concentrators come in both stationary and portable versions. Oxygen concentrators require electricity to operate so they must be plugged in or use a rechargeable battery. Some stationary units can deliver up to 10 L/min, but most can only go up to 5 L/min. Portable units can only deliver up to 3 L/min.
- Liquid oxygen - liquid oxygen is oxygen that has been compressed and cooled (-297°F) to the point that it becomes frozen. The frozen oxygen is stored in a large stationary reservoir in the patient's home, and a small portable container is filled from it. Frozen oxygen containers can deliver oxygen at flow rates > 6 L/min. They also last longer than tanks and are lighter than both tanks and concentrators which makes them better suited for highly mobile patients. The main disadvantage of liquid oxygen systems is their high cost and maintenance.
- ATS 2020 home oxygen therapy recommendations
- COPD categories
- Severe resting hypoxemia (defined as one of the following):
- PaO2 ≤ 55 mmHg or SpO2 ≤ 88%
- PaO2 56 - 59 mmHg or SpO2 = 89% plus one of the following: edema, hematocrit ≥ 55%, or P pulmonale (right atrial enlargement) on an ECG
- Moderate hypoxemia: SpO2 89 - 93%
- Severe exertional room air hypoxemia: SpO2 ≤ 88% on exertion
- Recommendations
- Adults with severe resting hypoxemia should receive long-term oxygen therapy for ≥ 15 hours/day
- Adults with severe exertional hypoxemia should be prescribed ambulatory oxygen
- Adults with moderate hypoxemia should not be prescribed oxygen
- For adults who are mobile outside of the home and require flow rates > 3 L/min, liquid oxygen is preferred [8]
- GOLD 2017 oxygen therapy recommendations
- Oxygen therapy is recommended in patients who meet one of the following criteria:
- COPD patients with resting hypoxemia of PaO2 ≤ 55 mmHg or SpO2 ≤ 88% with or without hypercapnia confirmed twice over a 3-week period
- PaO2 between 55 mmHg and 60 mmHg or SpO2 of 88% if there is evidence of pulmonary hypertension, peripheral edema suggesting congestive heart failure, or polycythemia (hematocrit > 55%) [5]
- Other treatments
- Lung volume reduction surgery (LVRS) - LVRS involves surgically removing parts of the lung that have severe emphysema. The procedure is only beneficial in patients who have mostly upper lobe disease. Patients with low baseline exercise capacity tend to benefit the most. See PMID 12759479 for the pivotal randomized controlled trial of LVRS.
- Endobronchial valves - Endobronchial valves are one-way valves that are placed during bronchoscopy. The valves are placed in airways that lead to diseased tissue. The valves allow air to leave the diseased tissue, but they do not allow air to enter it. This causes the diseased tissue to collapse. Collapsing diseased tissue allows more air to reach healthier tissue. The pivotal studies on endobronchial valves are available here - PMID 20860505, PMID 26650153
- Endobronchial coils - Endobronchial coils are placed during bronchoscopy. The coils are placed in airways around diseased tissue. During placement, the wire coils are straightened in a device, and when they are released from the device, they recoil and compress the surrounding tissue. The compressed tissue blocks airflow to diseased lung and supplies traction to surrounding healthier tissue which helps open airways. The pivotal studies on endobronchial coils are available here - PMID 26757466, PMID 27179849
- Mucolytics - The mucolytics N-acetylcysteine and carbocysteine have been studied in the treatment of COPD. Results from trials are generally mixed, but there is some evidence they may help prevent exacerbations. [7]
- Vaccinations
- Influenza - all patients with COPD should receive yearly influenza vaccination
- Pneumonia vaccines
- Pneumovax (PPSV23) - all patients with COPD should receive PPSV23 regardless of age. At age 65 years or older, patients should receive PCV13 and another dose of PPSV23 at least 1 year after PCV13 and at least 5 years after the most recent dose of PPSV23.
- Prevnar 13 (PCV13) - At age 65, all patients should receive PCV13 [5]
- OXYGEN MEASUREMENTS
- Overview
- Oxygenation in COPD can be measured with an arterial blood gas (ABG) or with pulse oximetry
- ABG is preferred, but pulse oximetry is more convenient
- Arterial Blood Gas (ABG)
- The ABG measurement involves taking a sample of blood from an artery (as opposed to a vein where blood samples are typically drawn)
- The radial artery at the wrist is a common location for drawing blood in an ABG
- The ABG measures the partial pressure of oxygen and carbon dioxide in the blood. See acid-base disorders for more.
- These two parameters are useful in measuring the severity of COPD. They are also used to determine when oxygen therapy is indicated (see treatment above).
- The ABG measures the following parameters:
- Oxygen tension (PaO2)
- Carbon dioxide tension (PaCO2)
- Blood pH
- Oxyhemoglobin saturation (SaO2)
- Bicarbonate concentration (HCO3)
Normal ABG values | |
---|---|
Measure | Normal range |
pH | 7.3 - 7.5 |
PaO2 | ≥ 80 mmHg |
PaCO2 | 30 - 50 mmHg |
HCO3 | 21 - 27 mEq/L |
SaO2 | ≥ 95% |
- Pulse Oximetry (Pulse Ox)
- Pulse oximetry measures the percent of hemoglobin that is saturated with oxygen (SpO2)
- SpO2 and SaO2 (see ABG above) are both measures of hemoglobin oxygen saturation. The term SpO2 is used when the SaO2 is estimated by pulse oximetry.
- Hemoglobin oxygen saturation (SpO2) correlates with PaO2
- Pulse oximetry is measured by placing a probe over the fingertips or earlobe
- Pulse oximeters work on the principle that unsaturated hemoglobin and oxygenated hemoglobin absorb light of different wavelengths
- The probe emits two wavelengths of light. The absorption of each wavelength is measured in pulsatile blood, and the percent saturation is calculated.
- Factors that can affect pulse oximetry:
- Abnormal hemoglobin (carboxyhemoglobin, methemoglobin) - falsely high
- Hyperbilirubinemia - falsely low
- Nail polish - depends on the color. Turning probe sideways on finger will avoid interference.
- Poor circulation (dehydration) - unreliable results [4]
Relation between PaO2 and SaO2 | ||
---|---|---|
Degree of hypoxemia | PaO2 | SaO2 |
Normal | ≥ 80 mmHg | 95 - 100% |
Mild | 60 - 79 mmHg | 90 - 94% |
Moderate | 40 - 59 mmHg | 75 - 89% |
Severe | < 40 mmHg | < 75% |
- SPACERS, INHALERS, AND VALVED HOLDING CHAMBERS
- Spacers, nebulizers, and valved holding chambers are discussed in detail under asthma
- Some patients may prefer these delivery devices over standard inhaler devices
- In general, these devices have not been shown to improve outcomes when compared to standard inhalers [2]
- STUDIES
- STUDY
- Design: Randomized, placebo-controlled trial (N=841 | length = 24 months) in patients with mild-to-moderate COPD
- Treatment: Tiotropium 18 mcg once daily vs Placebo
- Primary outcome: Between-group difference in the change from baseline to 24 months in the forced expiratory volume in 1 second (FEV1) before bronchodilator use
- Results:
- The FEV1 in patients who received tiotropium was higher than in those who received placebo throughout the trial (ranges of mean differences, 127 to 169 ml before bronchodilator use and 71 to 133 ml after bronchodilator use; p<0.001 for all comparisons)
- Findings: Tiotropium resulted in a higher FEV1 than placebo at 24 months and ameliorated the annual decline in the FEV1 after bronchodilator use in patients with COPD of GOLD stage 1 or 2
- STUDY
- Design: Randomized, placebo-controlled trial (N=5993 | length = 4 years) in patients with moderate-to-severe COPD
- Treatment: Tiotropium 18 mcg once daily vs Placebo. All other respiratory meds except for other inhaled antimuscarinics were permitted.
- Primary outcome: Rate of decline in the mean FEV1 before and after bronchodilation beginning on day 30
- Results:
- Mean absolute improvements in FEV1 in the tiotropium group were maintained throughout the trial (ranging from 87 to 103 ml before bronchodilation and from 47 to 65 ml after bronchodilation), as compared with the placebo group (p<0.001).
- After day 30, the differences between the two groups in the rate of decline in the mean FEV1 before and after bronchodilation were not significant
- Findings: In patients with COPD, therapy with tiotropium was associated with improvements in lung function, quality of life, and exacerbations during a 4-year period but did not significantly reduce the rate of decline in FEV1
- The FLAME study enrolled 3362 patients with COPD
Main inclusion criteria
- COPD with ≥ 1 exacerbation in last year
- Smoking history of ≥ 10 pack-years
- Post-bronchodilator FEV₁ 25% - 60% of predicted value
- Post-bronchodilator FEV₁/FVC < 0.70
Main exclusion criteria
- Long QT syndrome or QTc > 450 ms
- Narrow-angle glaucoma
- Symptomatic benign prostatic hyperplasia
- Requiring O₂ therapy for > 12 hours a day
Baseline characteristics
- Average age 64 years
- Average duration of COPD - 7.3 years
- Using inhaled glucocorticoids - 56%
- Current smoker - 40%
- Average post-bronchodilator FEV₁ % of predicted - 44%
- Average post-bronchodilator FEV₁/FVC - 0.416
Randomized treatment groups
- Group 1 (1680 patients) - Indacaterol 110 μg + glycopyrronium 50 μg once daily for 52 weeks
- Group 2 (1682 patients) - Salmeterol 50 μg + fluticasone 500 μg twice daily for 52 weeks
- Before the treatment phase, patients were entered into a 4-week run-in period with tiotropium only. After the run-in phase, patients were randomized to study treatment and all other preventative inhalers were prohibited. Open-label salbutamol (100 μg) was provided as rescue medication.
- Treatment was given as double dummy inhalers
Primary outcome: Annual rate of all COPD exacerbations (mild, moderate, or severe). COPD exacerbations were defined as
mild (involving worsening of symptoms for > 2 consecutive days but not leading to treatment with systemic glucocorticoids or antibiotics), moderate (leading to treatment with systemic
glucocorticoids, antibiotics, or both), or severe (leading to hospital admission or a visit to the emergency department that lasted > 24 hours in addition to treatment with systemic glucocorticoids,
antibiotics, or both).
Results
Duration: 52 weeks | |||
Outcome | LABA/LAMA | LABA/ICS | Comparisons |
---|---|---|---|
Primary outcome (annual rate of exacerbations) | 3.59 | 4.09 | Rate ratio 0.88, 95%CI [0.82 - 0.94], p<0.001 |
Median time to first exacerbation | 71 days | 51 days | HR 0.84, 95%CI [0.78 - 0.91]. p<0.001 |
Annual rate of moderate or severe exacerbations | 0.98 | 1.19 | HR 0.83, 95%CI [0.75 - 0.91]. p<0.001 |
Pneumonia | 3.2% | 4.8% | p=0.02 |
Oral candidiasis | 1.2% | 4.2% | N/A |
|
Findings: Indacaterol-glycopyrronium was more effective than salmeterol-fluticasone in preventing COPD exacerbations in patients with a history of exacerbation
during the previous year
StraightHealthcare analysis
- The FLAME study found that the addition of an inhaled anticholinergic was more effective than an inhaled corticosteroid in patients with COPD who were receiving a long-acting beta agonist
- Anticholinergics were superior across a broad array of outcome measures. They also carried a significantly lower risk of pneumonia.
- STUDY
- Design: Randomized, placebo-controlled trial (N=6112 | length = 3 years) in patients with COPD
- Treatment: Salmeterol/Fluticasone 50/500 twice daily vs Salmeterol 50 twice daily vs Fluticasone 500 twice daily vs Placebo
- Primary outcome: The primary outcome was death from any cause over three years of follow-up
- Results:
- Primary outcome: Salmeterol/Fluticasone - 12.6%, Salmeterol - 13.5%, Fluticasone - 16%, Placebo - 15.2%
- All comparisons were nonsignificant except for Salmeterol/Fluticasone vs Fluticasone (p=0.007)
- Findings: The reduction in death from all causes among patients with COPD in the combination-therapy group did not reach the predetermined level of statistical significance. There were significant benefits in all other outcomes among these patients.
- A study published in the NEJM enrolled 738 patients with COPD and moderate desaturations at rest or during exercise
Main inclusion criteria
- Stable COPD
- Resting desaturation (SpO2 89 - 93%) or exercise-induced desaturation (during the 6-minute walk test, SpO2 ≥ 80% for ≥ 5 minutes and < 90% for ≥ 10 seconds)
- ≥ 10 pack-year smoking history
- Postbronchodilator FEV1/FVC < 0.70 and postbronchodilator FEV1 < 70% of predicted or > 70% of predicted and radiologic evidence of emphysema
Main exclusion criteria
- Hospitalization or COPD exacerbation within last 30 days
- Desaturation below 80% for at least 1 minute during the 6-minute walk
Baseline characteristics
- Average age 69 years
- Qualifying criteria: Resting desat - 18% | Exercise desat - 43% | Both - 39%
- Average resting SpO2 on room air - 93%
- Average postbronchodilator FEV1 (% predicted) - 46%
- Average postbronchodilator FEV1/FVC - 0.46
- Using home oxygen at enrollment - 16%
- Current smoker - 27%
Randomized treatment groups
- Group 1 (370 patients) - No supplemental oxygen
- Group 2 (368 patients) - Supplemental oxygen
- In the supplemental oxygen group, patients were prescribed 24-hour oxygen if their resting SpO2 was 89 - 93%. If patients only had desaturations during exercise, they were prescribed oxygen during sleep and exercise. Oxygen was prescribed at 2 L/min at rest and adjusted to keep sats ≥ 90% for at least 2 minutes during ambulation.
- In the no supplement group, oxygen was only given if resting sats decreased to ≤ 88% or if exercise-induced desats of < 80% occurred for ≥ 1 minute. Oxygen was prescribed for 1 month and then reassessed.
- Patients using oxygen at enrollment had to agree to stop if randomized to the no supplement group
Primary outcome: Composite of overall mortality or first hospitalization for any cause
Results
Duration: Median of 18.4 months | |||
Outcome | No oxygen | Oxygen | Comparisons |
---|---|---|---|
Primary outcome (annual rate) | 36.4% | 34.2% | HR 0.94, 95%CI [0.79 - 1.12], p=0.52 |
Overall mortality (annual rate) | 5.7% | 5.2% | HR 0.90, 95%CI [0.64 - 1.25], p=0.53 |
First hospitalization for any cause (annual rate) | 34.5% | 31.6% | HR 0.92, 95%CI [0.77 - 1.10], p=0.37 |
Average oxygen use per day | 1.8 hours | 13.6 hours | N/A |
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Findings: In patients with stable COPD and resting or exercise-induced moderate desaturation, the prescription of long-term supplemental oxygen did not result in a longer
time to death or first hospitalization than no long-term supplemental oxygen, nor did it provide sustained benefit with regard to any of the other measured outcomes
- STUDY
- Design: Randomized sham-controlled trial (N=243 | length = 3 years) in patients with COPD who had nocturnal desaturation (SpO2 < 90% for ≥ 30 minutes) but did not qualify for long-term oxygen therapy
- Treatment: Nocturnal oxygen to keep sats > 90% for > 90% of the time vs Sham oxygen concentrator
- Primary outcome: Composite of death from any cause or a requirement for long-term oxygen therapy in the intention-to-treat population
- Results:
- Primary outcome: Nocturnal oxygen - 39%, Sham - 42% (diff −3.0%; 95%CI [−15.1 to 9.1])
- The trial was stopped early due to recruitment and retention difficulties
- Findings: Our underpowered trial provides no indication that nocturnal oxygen has a positive or negative effect on survival or progression to long-term oxygen therapy in patients with COPD.
- STUDY
- Design: Randomized placebo-controlled trial (N=144 | length = 90 days) in patients with COPD who still had persistent symptoms and/or serum C-reactive protein ≥ 8 mg/L 14 days after an index COPD exacerbation
- Treatment: Ciprofloxacin 500 mg twice daily vs Placebo
- Primary outcome: Time to the next exacerbation within a 90-day period
- Results:
- Primary outcome (median days): Cipro - 34 days, Placebo 32.5 days (p=0.76)
- Exacerbation within 90 days: Cipro - 57%, Placebo 53%
- Findings: In patients with persistent symptoms and/or raised C-reactive protein 14 days after a COPD exacerbation, an additional course of ciprofloxacin resulted in no additional benefit compared with placebo. This suggests that nonrecovered exacerbations are not driven by ongoing bacterial infection and may potentially be targeted with antiinflammatory therapy
- A study in the NEJM enrolled 1142 patients with COPD
Main inclusion criteria
- Diagnosis of COPD
- ≥ 10 pack-years smoking history
- PFTs consistent with COPD
- Using oxygen or had received steroids within one year
- Been to ER or hospitalized for COPD
Main exclusion criteria
- Asthma
- Resting heart rate > 100 bpm
- A prolonged QT interval or using medications that prolong the QT interval
- Hearing impairment
Baseline characteristics
- Average age 65 years
- Average % of predicted FEV1 - 39
- Average pack-year smoking history - 58
- Current smoker - 22%
- Using ICS + LAMA + LABA - 48%
- Long-term oxygen therapy - 60%
Randomized treatment groups
- Group 1 (558 patients) - Azithromycin 250 mg once daily for 1 year
- Group 2 (559 patients) - Placebo once daily for 1 year
Primary outcome: time to the first acute exacerbation of COPD, defined as “a complex of respiratory symptoms (increased or new onset)
of more than one of the following: cough, sputum, wheezing, dyspnea, or chest tightness with a duration of at least 3 days requiring treatment with antibiotics or systemic steroids"
Results
Duration: 1 year | |||
Outcome | Azithromycin | Placebo | Comparisons |
---|---|---|---|
Primary outcome (median time to first exacerbation) | 266 days | 174 days | p<0.001 |
Frequency of exacerbations (# per patient-years | 1.48 | 1.83 | p=0.01 |
Decrease in hearing | 25% | 20% | p=0.04 |
Hospitalization related to COPD (mean events/patient-year) | 0.34 | 0.49 | p=0.14 |
Findings: Among selected subjects with COPD, azithromycin taken daily for 1 year, when added to usual treatment, decreased the frequency of exacerbations and improved
quality of life but caused hearing decrements in a small percentage of subjects. Although this intervention could change microbial resistance patterns, the effect of this change is not known.
- STUDY
- Design: Randomized, placebo-controlled trial (N=311, length=180 days)
- Treatment: Prednisone 40 mg once daily for 5 vs 14 days
- Primary outcome: time to next exacerbation within 180 days
- Results:
- Patients with reexacerbation within 180 days: 5 days - 36%, 14 days - 37% (p=0.006 for noninferiority)
- Median time to reexacerbation: 5 days - 43.5 days, 14 days - 29 days
- Findings: In patients presenting to the emergency department with acute exacerbations of COPD, 5-day treatment with systemic glucocorticoids was noninferior to 14-day treatment with regard to reexacerbation within 6 months of follow-up but significantly reduced glucocorticoid exposure. These findings support the use of a 5-day glucocorticoid treatment in acute exacerbations of COPD.
- BIBLIOGRAPHY
- 1 - PMID 21810710 ACP 2011 update
- 2 - 2004 ATS COPD GL
- 3 - PMID 19716966 Lancet review of COPD in non-smokers
- 4 - PMID 9794863 BMJ ABG review
- 5 - PMID 28150362 - Global Strategy for the Diagnosis, Management and Prevention of Chronic Obstructive Lung Disease 2017 Report, Respirology (2017)
- 6 - PMID 28513453 - Chronic obstructive pulmonary disease, Lancet (2017)
- 7 - PMID 26222376 - Mucolytic agents versus placebo for chronic bronchitis or chronic obstructive pulmonary disease, Cochrane Database Syst Rev (2015)
- 8 - PMID 33185464 - Home Oxygen Therapy for Adults with Chronic Lung Disease: An Official American Thoracic Society Clinical Practice Guideline, Am J Respir Crit Care Med (2020)