Obstructive Lung Disease - COPD

Question 1

3 disorders that can occur in COPD?

Answer 1

Chronic bronchitis.
Emphysema.
Asthma. (note that asthma alone =/= COPD)

Question 2

Is asthma a disease of children?

Answer 2

No. It’s a disease that often has its onset in childhood, but it’s a lifelong disease.

Question 3

Is COPD preventable?

Answer 3

Yes - it’s an “enhanced chronic inflammatory response… to noxious particles or gases” - esp. smoking.

(…usually. I don’t know if we would call alpha-1 antitrypsin deficiency preventable, though it is treatable)

Question 4

3 cardinal symptoms of COPD?

Answer 4

Dyspnea, (esp. with exertion).
Cough.
Sputum production.

Question 5

If you suspect COPD, what’s the most illustrative test to do?

Answer 5

Spirometry.

Question 6

What does spirometry testing of someone with COPD yield?

Answer 6

Low FEV1/FVC.

Question 7

FEV1 declines with age, but when you smoke…

Answer 7

it declines much more rapidly (if one is susceptible to the smoke).

Question 8

How do measure the severity of COPD?

Answer 8

FEV1/FVC

Question 9

Is oxygen requirement a good measure of the severity of COPD?

Answer 9

No…

he really hit this point hard… though I’m not sure I fully understand the reasoning here

Question 10

How does BMI relate to prognosis for COPD?

Answer 10

Surprisingly, the people with higher BMIs live longer.

Cachexia is predicts poor prognosis for COPD.

Question 11

Characteristic inflammatory cells of COPD?

Answer 11

Macrophages, PMNs, lymphocytes (CD8s).

to be contrasted with those of asthma

Question 12

Is small airways disease all about the mucus?

Answer 12

No, there’s a lot of mucus, but the lumen is also constructed by mucosal and peribronchial inflammation/fibrosis. (obliterative bronchiolitis)

Question 13

What’s the deal with the “pink puffer” and the “blue bloater”?

Answer 13

These are supposed to represent the extremes of emphysema vs. chronic bronchitis predominate COPD, but the current thinking is that people have some mix of both.

Question 14

Reversibility of COPD vs. asthma?

Answer 14

COPD - the loss of lung function is irreversible.

Asthma - the loss of lung function is largely reversible (but fibrotic changes can happen after exacerbation…)

Question 15

When you think about emphysema having in decreased elasticity / increased compliance, what part of the lung actually has that decreased elasticity?

Answer 15

Think about a reduction in the elasticity of the interstitium. This means there’s less force pulling the airways open, and less force preventing a “barrel chest” from happening.

Question 16

Why do people with obstructive lung disease hyperventilate (e.g. with exertion)?

Answer 16

Because of air-trapping (can’t exhale quickly enough), tidal volume can’t be increased -> hyperventilation is necessary to achieve adequate respiration. (but this doesn’t work very well)

Question 17

How is CXR used in the diagnosis of COPD? (important)

Answer 17

It’s not.

CXR / HRCT can show you emphysema, but one can have COPD without having emphysema.

Question 18

How is diagnosis of COPD made?

Answer 18

Spirometry, history, and physical exam findings that make sense.
Eg. obstructive disease not relieved by albuterol, onset in middle age, Hx of smoking, etc.

Question 19

Role of vaccines in COPD treatment?

Answer 19

Influenza and pneumococcal vaccines are recommended for most. -prevents exacerbations.

Question 20

Pharmacologic therapies for COPD include…
(not necessary to know all the things, but you know roughly the order in which therapies are added when severity increases)

Answer 20

(smoking cessation, vaccines, and exercise first!)
Short-acting beta-agonists/muscarinic-antagonists.
Long-acting beta-agonists/mucarinic-antagonist.
Inhaled corticosteroids?
Ttheophylline, prophylactic ABx (azithromycin)?
Surgery?
BIPAP

With oxygen throughout.
(More on this in the pharmacology lecture.)

Question 21

Hard cutoff for when bronchodilator therapy (both short-acting and long-acting) should be started?

Answer 21

When FEV1 < 60% predicted, should treat.

Treatment between 60-80% is a judgment call.

Question 22

Do bronchodilators cause acute improvement in COPD?

Answer 22

No, but they actually appear to be beneficial when used longer term.

Question 23

Problem with using methylxanthines (theophyllline) for COPD?

Answer 23

Very narrow therapeutic index -with bad side effects. (including arrhythmias and seizures!)

Question 24

Downsides of chronic azithromycin for COPD?

Answer 24

Adverse effects: Hearing loss, arrhythmias.

While helpful after 1 year, quite possible that ABx resistance could develop.

Question 25

Does exercise help people with COPD?

Answer 25

Yes - as part of “Pulmonary Rehabilitation,” it’s quite effective at improving dyspnea, quality of life, and reducing health care utilization.

Question 26

Which treatment for COPD has the most impact on survival?

Answer 26

Oxygen therapy, best if 24 hr, continuous.

not sure if this statement is 100% accurate, but he did emphasize how good it is for improving survival

Question 27

Downside of giving too much O2? How does this work?

Answer 27

CO2 retention.

• Reverses hypoxic vasoconstriction for capillaries of poorly ventilated alveoli -> blood flow is shunted away from well-ventilated alveoli -> less CO2 release.
• Haldane effect (oxyhemoglobin carries less CO2 vs. deoxyHb).
• Reduce minute ventilation -reduced hypoxic drive to breathe.

(The first reason is probably most important.)

Question 28

Rationale behind lung volume reduction for emphysema?

Answer 28

If the emphysema is relatively focal and apical, resecting the damaged area allows the healthy parts of the lung to expand and function better - and can restore diaphragm architecture for better function.
(Dr. Cooper revived this surgery by carefully selecting patients who were likely to benefit from it.)

Question 29

BIPAP is nice.

Answer 29

Yeah. If you can avoid intubation, it’s a good thing.

BIPAP = bilevel positive air pressure… maintains positive pressure during expiration