Pulmonary Terminology

Question 1

75-year-old male presents to establish care. He has a 40-pack-year history of smoking and notes that he has had a cough productive of thick sputum for many years (what he describes as a “smokers cough”). You suspect he has chronic bronchitis. What type of disease is this?

a. Airways disease
b. Alveolar filling disease
c. Interstitial lung disease
d. Pneumonic disease

Answer 1

a.	Airways disease *** 
Chronic bronchitis is a subtype of chronic obstructive pulmonary disease (COPD) characterized by obstructive physiology on pulmonary function testing (will discuss in subsequent lectures, not something you should know now) and a cough productive of sputum that lasts for 3 months and recurs for at least two consecutive years. The important point here is that chronic bronchitis is an example of an airways disease as the pathology is centered on the larger airways. Emphysema, the other COPD subtype, is not an airways disease as it is characterized by destruction of alveolar-capillary units (distal to the large airways). Other examples of airways diseases include asthma, bronchiectasis (both bronchiectasis caused by cystic fibrosis and non-CF bronchiectasis) and acute bronchitis.
b.	Alveolar filling disease
c.	Interstitial lung disease
d.	Pneumonic disease

Question 2

A 68-year-old female with acute pancreatitis is admitted to the Medical Intensive Care Unit with severe hypoxemic respiratory failure requiring initiation of mechanical ventilation. She has flat neck veins and no lower extremity edema on examination. Her chest x-ray shows diffuse fluffy opacities suggestive of extensive pulmonary edema. She has no history of heart disease and an echocardiogram demonstrates an EF of 75% with normal valves. She has no fever and a normal white blood cell count. Which of the following best describes the cause of her respiratory failure?

a. Airways disease
b. Cardiogenic pulmonary edema
c. Non-cardiogenic pulmonary
d. Interstitial lung disease
e. Lobar pneumonia

Answer 2

a. Airways disease
b. Cardiogenic pulmonary edema
c. Non-cardiogenic pulmonary
d. Interstitial lung disease
e. Lobar pneumonia

Answer: C
This patient has a diffuse alveolar filling problem caused by extensive pulmonary edema (there is no fever or laboratory evidence provided to suggest an infectious pneumonia). Pulmonary edema can be divided into high-pressure/cardiogenic and low-pressure/non-cardiogenic edema. The flat neck veins, lack of lower extremity edema, and normal echocardiogram do not suggest pulmonary venous hypertension as a driver of edema formation. As a result, this is likely non-cardiogenic pulmonary edema caused by injury to the alveolar-capillary interface. (As an aside, severe pancreatitis is a common cause of indirect injury to the alveolar-capillary interface through release of intravascular inflammatory mediators. This can lead to severe non-cardiogenic pulmonary edema also termed ARDS).

Question 3

Describe the forces which govern fluid flux between a microvessel and its surrounding interstitium

Answer 3

The factors which determine fluid flux between a microvessel and its surrounding interstitium are described in the Starling Equation (abbreviations defined above):
.
QE = KF [(Pmv - Pis) - mv - is

Broadly, increased intravascular hydrostatic pressure, decreased intravascular oncotic pressure, and increased endothelial permeability to proteins (the variable in the above equation) all lead to fluid accumulation in the interstitium.

Question 4

Name 3 airways diseases

Answer 4

asthma
COPD - specifically chronic bronchitis
Bronchiectasis

Question 5

Define Bronchiectasis

Answer 5

Bronchiectasis refers to dilation and scarring of the larger airways. Bronchiectasis is often broadly divided into two categories - CF and Non CF

Question 6

What is the filtration coefficient of the starling equation?

Answer 6

KF increases with increasing permeability or surface area.

Question 7

What does a high Pmy favor in the starling equation?

Answer 7

Flow of edema from vessel to interstitium

Question 8

What does a high Pis favor in the starling equation?

Answer 8

IMpedes the flow of edema from vessel to interstitium

Question 9

A reflection coefficient of 0 in the starling equation reflects what level of permeability?

Answer 9

complete permeability

Question 10

What does a low oncotic pressure in the microvasculature favor?

Answer 10

flow from vessel to interstitium

Question 11

What does a high interstitial oncotic pressure favor?

Answer 11

flow from vessel to interstitium

Question 12

What are the two types of pulmonary edema?

Answer 12

high pressure (cardiogenic) 
low pressure (non cardiogenic)

Question 13

What is the pathophysiology of the cardiogenic pulmonary edema?

Answer 13

intravascular hydrostatic pressure (Pmy) is too high, pushing fluid into the microvasculature. Typically left heart pathology

Question 14

What is low protein pulmonary edema?

Answer 14

cardiogenic pulmonary edema

Question 15

What causes low pressure or non cardiogenic pulmonary edema?

Answer 15

compromised alveolar capillary barrier

Question 16

What are some direct causes of low pressure edema?

Answer 16

pneumonia
aspiration
inhalational exposure

Question 17

What are some indirect causes of low pressure edema?

Answer 17

sepsis
pancreatitis
trauma

Question 18

What is high protein pulmonary edema?

Answer 18

non cardiogenic low pressure edema

Question 19

Acute respiratory distress syndrome (ARDS) is the prototypical example of what kind of pulmonary edema?

Answer 19

low pressure, non cardiogenic, high protein edema

Question 20

What pulmonary edema would be caused by malnutrition, nephrotic syndrome or cirrhosis?

Answer 20

fluid leakage from the microvascular space into the interstitium due to very low oncotic pressure

Question 21

What type of organisms are generally associated with HAP and VAP pneumonias?

Answer 21

gram negative resistant