Core Content: COPD

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If you're primarily an ICU provider, I know what you're probably thinking: COPD is easy. Bronchodilators, steroids, antibiotics, BiPAP and the tincture of time. But it's actually a legitimately serious disease, and the devil is in the detail

COPD is the THIRD leading cause of death in the United States;

  • costs 50 billion annually
  • is the cause of 8 million physician office visits
  • 1.5 million ED visits; hospitalizations for acute exacerbations account for 14 billion dollars annually
  • 1/5 of patients hospitalized with an acute exacerbation of COPD will be readmitted within 30 days
  • And most patients with COPD report some level of limitation in performing activities of daily living due to breathlessness

Physiology of COPD

COPD is a common, preventable and treatable disease that is characterized by persistent respiratory symptoms and airflow limitations (due to airway/alveolar abnormalities) usually caused by exposure to noxious particles or gases

Environmental Factors that predispose to COPD:

  1. Tobacco smoke
  2. Cooking fuel used indoors
  3. Organic dusts, chemical fumes
  4. Asthma
  5. Severe childhood respiratory infections

And socioeconomic factors:

  1. Older individuals
  2. Females
  3. Low SES

All these factors combined lead to chronic inflammation, increased mucous production and often some element of bronchospasm. Over time this causes inflammation and narrowing of small airways (key feature in chronic bronchitis) and destruction of lung parenchyma (key feature in emphysema). Often these two phenotypes (chronic bronchitis/emphysema) coexist

Of note, there is a significant amount of extra-pulmonary inflammation in COPD - still somewhat a mystery but thought to be the reason COPD coexists with other conditions (CV disease, osteoporosis, weight loss)

Persistent airflow limitation is the OBSTRUCTION

Diagnosis of COPD

Should be considered in those with risk factors + SOB, chronic cough, hx of wheezing; may have peripheral cyanosis, decreased number of word dyspnea, increased AP diameter. These are all supporitve findings

The gold standard for diagnosis is to use pulmonary function tests

  • Airflow limitation as proven by post-bronchodilator FEV1/FVC ratio<70%
  • FEV1/FVC: what percentage of your vital capacity (so the big breath you take) can you blow out in the first second of a forced expiration?

Once you establish the presence of persistent airflow limitation, you must characterize their disease using GOLD guidelines.

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For all patients with established airflow limitation (FEV1/FVC < 70%), you should:

  1. Step 1 - assess severity using FEV1
    1. Mild FEV1 >/= 80% - GOLD Grade 1
    2. Moderate FEV1 50-80% - GOLD Grade 2
    3. Severe FEV1 30-50% - GOLD Grade 3
    4. Very severe FEV1<30 - GOLD Grade 4
  2. Step 2 - assess symptoms
    1. Modified British Medical Research Council Questionnaire (mMRC) - primarily questions about dyspnea
      • 2 or greater - severe
        • Do you get short of breath while getting dressed? (mMRC of 4)
        • (if no..)
        • Do you get short of breath when walking down the block? (mMRC of 3)
        • (if no...)
        • Can you keep up with other people your age without getting short of breath? (mMRC of 2)
    2. COPD Assessment Test (CAT)
      • 10 or greater - severe
  3. Step 3 - Obtain an exacerbation history
    • How many exacerbations have they had in the past year and how many have led to hospital admission?
    • This used to STAGE them with GOLD grades

Treatment of COPD

  • Grade A: Any bronchodilator, pick your poison
  • Grade B: LAMA or LABA, or both
  • Grace C: LAMA or LAMA + LABA or LABA + ICS
  • Grade D: Just like grade C, you can do LAMA, LABA/LAMA, LABA/ICS or triple therapy with the option of adding roflumilast or chronic macrolide therapy in select patients

What is an exacerbation?

Acute worsening of respiratory symptoms (dyspnea, cough, bronchospasm, sputum production) usually precipitated by SOMETHING - not taking inhalers, a respiratory infection etc.

  • Somewhat subjective - but generally anyone who requires hospitalization or a visit to the ED categorically have a severe exacerbation
    • Over 80% of COPD exacerbation are treated outpatient

How to approach acute exacerbations:

  • Increase dose/frequent of short acting bronchodilators; combine SABA/SAMA
  • Oral corticosteroids per GOLD guidelines
  • Antibiotics if there are signs of bacterial infection
    • In southeast, macrolide resistance is increasing - doxy is a good choice and levaquin is another option
  • Avoid hyperoxemia - can worsen hypercapnia. Target O2 sat between 88-92%
  • BiPAP for work of breathing - start early and use often

Little things make a big difference

  • Smoking Cessation Counseling
    • Greatest capacity to influence natural history of COPD
    • Literature on smoking cessation coming soon
  • Flu shot
  • Pulmonary rehab
  • Consider long term oxygen in those with severe resting hypoxemia (PaO2 <55mmHg)
  • Early palliative care - not necessarily for end of life but for symptomatic control

 

 

Attributes

"Past Catching Up" by Lee Rosevere is licensed under CC BY-NC 4.0 / Song has been cropped in length from original form

"Encirchment", "Vanagon", "Clay" and "Raw Umber" by Podington Bear is licensed under CC BY-NC 3.0 / Songs have been cropped in length from original form

Coughing by Rachel

Apple ringtone by Apple

John HeislerComment