Case 2-4 - Chronic Obstructive Pulmonary Disease - Concepts

Front 1

Obstructive lung disease is characterized by loss of _________ or increased _______.

Back 1

loss of lung elasticity; increased airway resistance

Front 2

The hallmark of obstructive lung disease is _______________, as a result __________ occurs, causing an __________.

Back 2

Reduction of expiratory flow rate; air trapping; increase in resting lung volume and end-expiratory volume.

Front 3

Draw a graphical output of a spirometer during normal ventilation. Include volumes and capacities.

Back 3

Front 4

FEV1 is normally ____________ of the FVC.

Back 4

80% (FEV1/FVC = 0.8)

Front 5

________ and _________ are the two pathologic entities that comprise COPD.

Back 5

Emphysema; chronic bronchitis

Front 6

Emphysema and chronic bronchitis can often coexist, what does this mean?

Back 6

The patient exhibit features of both. There is clinical overlap.

Front 7

Emphysema is caused by ________________________________.

Back 7

Alveolar wall destruction as a result of excessive protease activity.

Front 8

The present hypothesis in emphysema is that activated neutrophils ___________________.

Back 8

Release proteases that destroy interstitial elastin and collagen type IV.

Front 9

In emphysema, alveolar wall destruction leads to a loss of pulmonary capillaries and a reduction in ___________.

Back 9

capillaries; oxygen diffusing capacity

Front 10

In emphysema, loss of pulmonary capillaries lead to a secondary increase in ____________ and ________.

Back 10

pulmonary artery pressure; right heart failure

Front 11

Interstitial elasticity help remain patency of _________ and __________.

Back 11

terminal bronchioles; respiratory bronchioles

Front 12

In emphysema, when patients exhales, many of their _______ has a tendency to ________, creating a _______ to air outflow.

Back 12

bronchioles; collapse; obstruction

Front 13

Chronic bronchitis is defined clinically as ___________.

Back 13

productive cough for ≥ 3 months in at least 2 consecutive years, in the absence of any other identifiable cause.

Front 14

Chronic bronchitis is characterized by __________ in the bronchial tree.

Back 14

excessive mucus

Front 15

Airway obstruction seen with chronic bronchitis is primarily due to ___________ and __________, both of which are triggered by inhaled __________ or ___________.

Back 15

bronchiolar inflammation; bronchospasm; irritants; acute respiratory infection.

Front 16

In cases of exacerbations in chronic bronchitis, it is helpful to employ ______ (3).

Back 16

1. Systemic corticosteroids
2. Inhaled beta-2 agonists
3. Inhaled anticholinergics

This is because bronchiolar inflammation is a cardinal feature.

Front 17

What is the pathogenetic background of chronic bronchitis?

Back 17

Long-standing inhalation of toxins and irritants → Submucosal hypertrophy in trachea & bronchi (early) → Increased # of goblet cells in small airways (small bronchi & bronchioles) (late).

Front 18

Compliance is [...]

Back 18

The amount of change in volume achieved by a certain pressure change (ΔV/ΔP).

Front 19

In interstitial fibrosis, the lungs are ______, and expand _____ for a given amount of pressure change; therefore, they have a ____ compliance.

Back 19

stiff; less; low

Front 20

As lung volume increases, interstitial elastin becomes ______, and compliance ________.

Back 20

taut; decreases

Front 21

In COPD, as FRC _______, lung expansion becomes more difficult because of ________ compliance at _______ resting volumes. This leads to ______ work of breathing.

Back 21

increases; lower; higher; increased

Front 22

What is the compliance of alveoli at the base of the lung?

Back 22

They are MORE compliant because the intrapleural pressure being more POSITIVE there due to effects of gravity on the lungs. They are less distended and more compliant.

Front 23

Emphysema is defined _______ and chronic bronchitis is defined ________.

Back 23

morphologically; clinically

Front 24

There is a difference in distribution of pure chronic bronchitis and pure emphysema. How is the distribution?

Back 24

Front 25

The collapse of alveoli and airways occurs preferentially at the ________ because of their _________.

Back 25

bases; relatively higher compliance than at the apices.

Front 26

Similar to the regional variation in ventilation, pulmonary capillary perfusion is _________ at the lung base compared with the apex.

Back 26

greater

Front 27

At the apex of the lung, where the _______ exceeds _______, described as zone __, there is ___________ flow.

Back 27

alveolar pressure; pulmonary arterial and venous pressure; 1; practically no flow

Front 28

In lung zone 2, the capillary flow is proportional to the difference in ___________.

Back 28

Pulmonary arterial pressure minus alveolar pressure. In zone 2, we do have capillary flow beceause Pa exceeds PA.

Front 29

At the base, in zone 3, ____________ exceeds ___________ and flow is proportional to ____________.

Back 29

pulmonary venous pressure; alveolar pressure (it's like a column of fluid); difference of pulmonary arterial and venous pressures.

Front 30

How is the V/Q ratio at the apex?

Back 30

High. Perfusion is lower than ventilation at the apex.

Front 31

The apex contributes ______ to the total
pulmonary capillary gas exchange because of _________.

Back 31

little; low perfusion

Front 32

Why do we see a pathologic V/Q mismatch with hypoxemia in COPD (emphysema)?

Back 32

The bases are more compliant, because at FRC they are stretched less. This is why we see a preferential collapse of alveoli in the base, and not (so much?) the apices. Ventilation is SHIFTED to the apex, which actually does not contribute a whole lot to total pulmonary capillary gas exchange due to its LOW PERFUSION. Gas exchange is therefore impaired and patients get hypoxemia.

Front 33

In COPD, the inability to effectively _____________ results in _____ retention, increased _______, and respiratory _______.

Back 33

expire alveolar CO2; CO2; arterial PaCO2; acidosis

Front 34

What is the compensation for the acid-bace imbalance in long-standing COPD?

Back 34

Compensation is renal. It consists of increased excretion of H+ as titratable acid (filtered HPO42- forms H2PO4-) and NH4+ (from glutamine), and increased reabsorption of "new" HCO3-.

Front 35

What would be seen on a chest X-ray of a patient with COPD?

Back 35

hyperinflated lungs, diaphragm flattening, and narrow cardiac silhouette.

Front 36

Describe two important patterns of emphysema.

Back 36

• Centriacinar (Centrilobular) emphysema:
- Seen in cigarette smokers.
- The proximal parts ("central") of the acini, formed by respiratory bronchioles, are affected, while distal alveoli are spared (but in severe cases, distal become affected).
- More common in upper lobes (particularly apical segments)

• Panacinar (Panlobular) emphysema
- Occurs in alpha1-antitrypsin deficiency
- Acini are uniformly enlarged from the level of the respiratory bronchiole to the terminal blind alveoli.
- Occurs more commonly in the lower lung zone

Front 37

In obstructive lung disease, such as asthma, FEV1 is ________ than FVC so the FEV1/FVC is ________.

Back 37

reduced MORE than FVC; decreased

Front 38

In COPD, in which airway R is increased, patients learn to expire ________________ to prevent the ______ that may occur with a forced expiration.

Back 38

slowly with "pursed lips"; airway collapse

Front 39

Why are people with a COPD primarily of emphysema, sometimes said to be "pink puffers"?

Back 39

Pink because of absence of cyanosis.
Puffers because they puff air out with pursed lips to produce a positive end-expiratory pressure, allowing some alveoli/small airways to remain patent when expiring and not collapsing.

Front 40

Why are people with a COPD primarily of chronic bronchitis, sometimes said to be "blue bloaters"?

Back 40

Blue because of cyanosis.
Bloaters because of systemic edema secondary to right ventricular failure.

Front 41

What pulmonary function abnormalities are expected in a patient with COPD?

Back 41

Increased lung resting volume (FRC)
Increased RV
Decreased FEV1 (collapse)
Decreased VC

"Loss of elasticity results in greater lung compliance, or distensibility. This hinders the ability for normal passive exhalation to occur, resulting in increased FRC and RV. Without the normal recoil mechanism, the thoracic cage expands, which increases TLC and results in the characteristic barrel chest."

Front 42

In COPD, air trapping occurs:
A. more in the upper lobes
B. more in the lower lobes
C. centrally greater than peripherally
D. equally throughout
E. Cannot be determined

Back 42

In COPD, air trapping occurs mostly at the bases, which results in shunting of ventilation to the apices where little perfusion occurs. This results in a ventilation/perfusion mismatch, which has a deleterious effect on gas exchange.

Front 43

As lung volume increases, lung compliance ________?

Back 43

Increasing lung volume results in stretching of alveoli and interstitial elastin, causing greater stiffness and recoil; therefore, compliance diminishes as lung volume increases