Small Group: Pathophysiology Cases 1 - 7

Question 1

Differentiate anatomic and physiologic dead space.

Answer 1

Anatomic dead space is the part of the lung that does not participate in gas exchange (the conducting airways), while physiologic dead space is the sum of alveolar dead space and anatomic dead space.

Question 2

What percent change in a bronchodilator challenge shows success?

Answer 2

12% change

Question 3

Draw PV curves for normal individuals and those with obstructive and restrictive diseases.

Answer 3

Done

Question 4

What variables determine TGV/FRC?

Answer 4

Lung compliance and chest wall compliance, because FRC is the point at which these forces are equal and opposite

Question 5

What variables determine TLC?

Answer 5

Lung compliance, chest wall compliance, inspiratory muscles

Question 6

Kussmaul breathing is ____________.

Answer 6

fast and deep breathing

Question 7

Normal anion gap is __________.

Answer 7

8 - 10 mEq/L

Question 8

Why does increasing tidal volume decrease dead space?

Answer 8

Percent dead space = V(d) / V(t). In a normal person V(d) is constant at about 150 mL. Increasing tidal volume thus decreases percent dead space with each breath.

Question 9

What is the mnemonic for obstructive lung diseases?

Answer 9

BABE B (bronchitis, asthma, bronchiolitis, emphysema, and bronchiectasis)

Question 10

Again, a bronchodilator challenge is positive if ____________.

Answer 10

either the FEV or FVC increase by greater than 12%

Question 11

Provide a differential diagnosis for restrictive lung disease PFTs.

Answer 11

Decreased compliance due to interstitial lung disease or fibrosis; skeletal abnormalities such as scoliosis; neuromuscular disorders; pleural disorders

Question 12

What environmental exposures lead to restrictive lung disease?

Answer 12

Asbestos, coal, and birds

Question 13

What is the equation for arterial oxygen content?

Answer 13

(1.34 x Hgb x SpO2) + 0.003 x P(a[O2])