Dyspnea (includes pulmonary edema)

Question 1

What is dyspnea?

Answer 1

Subjective experience of breathing discomfort that consists of qualitatively distinct sensations that vary in intensity.

Question 2

Is dyspnea a sign or symptom?

Answer 2

It’s a symptom, and should be distinguished from signs of increased work of breathing.

Question 3

Increased airway resistance or stiffness is associated with…

Answer 3

a sense of increased effort to breathe.

Question 4

Chemoreceptors: where are they & what do they sense?

What sensation do they cause when activated?

Answer 4

Where: carotid bodies
What they sense: hypoxemia, acute hypercapnia, acidemia
Sensation: air hunger

Question 5

Mechanoreceptors: where are they & what do they sense?

What sensation do they cause when activated?

Answer 5

Where: lungs
What they sense: bronchospasm
Sensation: chest tightness

Question 6

J-receptors: where are they & what do they sense?

What sensation do they cause when activated?

Answer 6

Where: lungs
What they sense: interstitial edema
Sensation: air hunger

Question 7

Pulmonary vascular receptors: where are they & what do they sense?

What sensation do they cause when activated?

Answer 7

Where: lungs
What they sense: acute changes in pulmonary artery pressure
Sensation: Air hunger

Question 8

What sensation is associated with hyperinflation of the lungs?

Answer 8

An inability to get a deep breath; unsatisfying breaths

Question 9

Metaboreceptors: where are they & what do they sense?

What sensation do they cause when activated?

Answer 9

Where: skeletal muscle
What they sense: biochemical changes during exercise
Sensation: breathing discomfort

Question 10

How might anxiety contribute to dyspnea?

Answer 10

1) By altering the interpretation of sensory data

2) by leading to breathing patterns that heighten physiologic abnormalities

Question 11

What pathophysiology is often associated with chest tightness or constriction?

Answer 11

1) bronchoconstriction

2) interstitial edema (asthma, MI)

Question 12

What pathophysiology is often associated with increased effort to breathe?

Answer 12

1) airway obstruction

2) Neuromuscular disease (COPD, mod-to-severe asthma, myopathy, kyphoscoliosis)

Question 13

What pathophysiology is often associated with air hunger?

Answer 13

1) Increased drive to breathe (CHF, PE, airflow obstruction)

Question 14

What pathophysiology is often associated with the inability to get a deep breath?

Answer 14

1) Hyperinflation (asthma, COPD)

2) Restricted tidal volume (pulmonary fibrosis, chest wall restriction)

Question 15

What pathophysiology is often associated with heavy or rapid breathing?

Answer 15

Deconditioning

Question 16

Most diseases of the respiratory system produce dyspnea by…

Answer 16

…mechanical alterations of lungs or chest wall.

Question 17

Most diseases of the cardiovascular system produce dyspnea by…

Answer 17

…causing gas exchange abnormalities or stimulating pulmonary/vascular receptors.

Question 18

Asthma & COPD are what type of lung disease?

Answer 18

Obstructive

Question 19

What does chronic airway obstruction cause to happen to the lungs?

Answer 19

Air trapping & hyperinflation

Question 20

Which is more common: hypoxemia or hypercapnia?

Answer 20

Hypoxemia

Question 21

Diseases of lung parenchyma (AKA interstitial lung diseases) may be caused by:

Answer 21

1) Infection
2) Occupational exposure
3) Autoimmune disorders

Question 22

Disease of lung parenchyma result in:

Answer 22

1) increased stiffness (decreased compliance) of lungs & increased work of breathing
2) hypoxemia & increased drive (bc of V/Q mismatch & destruction of alveolar-capillary interface)

Question 23

Diseases of the left heart result in:

Answer 23

1) Greater LV end-diastolic volume & pressure, which
2) Increased pulmonary capillary pressures, which lead to
3) Interstitial edema, which
4) Stimulates pulmonary receptors, causing
5) Dyspnea!

Question 24

Examples of diseases of the pulmonary vasculature

Answer 24

1) PE
2) primary pulmonary hypertension
3) pulmonary vasculitis

Question 25

Diseases of pulmonary vasculature result in:

Answer 25

1) Increased pulmonary artery pressure
2) Stimulation of pulmonary receptors
3) Hyperventilation & hypoxemia are common & not affected by supplemental O2

Question 26

Diseases of the pericardium result in what effect on the lungs?

Answer 26

1) Increased intracardiac pressure leads to
2) Increased pulmonary vascular pressure, causing
3) Dyspnea! Surprise!

Question 27

What is a good way to distinguish cardiac dyspnea from respiratory-based dyspnea?

Answer 27

Exercise stress test.

Respiratory cause: patient achieves max ventilation, demonstrates increase in hypoxemia or dead space, or develops bronchospasm

Cardiac cause: HR > 85% of predicted max, anaerobic threshold occurs early, BP excessively high or low, O2 pulse falls, or ischemic changes on ECG

Question 28

Common Causes of Noncardiogenic Pulmonary Edema: Direct Injury to Lung Edition!

Answer 28

1) Chest trauma, pulmonary contusion
2) Aspiration
3) Smoke inhalation
4) Pneumonia
5) O2 toxicity
6) Pulmonary embolism/reperfusion

Question 29

Common Causes of Noncardiogenic Pulmonary Edema:

Hematogenous Injury to Lung Edition!

Answer 29

1) Sepsis
2) Pancreatitis
3) Non-thoracic trauma
4) Leukoagglutination reactions
5) Multiple transfusions
6) IV drug use (just say no, kids!)
7) Cardiopulmonary bypass

Question 30

Common Causes of Noncardiogenic Pulmonary Edema:

Possible Lung Injury Plus Elevated Hydrostatic Pressures Edition!

Answer 30

1) High-altitude pulmonary edema
2) Neurogenic pulmonary edema
3) Re-expansion pulmonary edema