Pulmonary Diseases and Conditions

Question 1

Emphysema

Answer 1

Obstructive lung disease (within COPD)

Destruction of the alveolar-capillary membranes distal to terminal bronchioles, resulting in dilatation of terminal air spaces, and this reduces surface area of the lung

Lose elasticity/recoil of lungs, taking you to higher FVC

EPP moves farther along airways to alveoli, causing ariway collapse

Tau (R x C) is increased so can’t count on passive exhalation anymore and have to use accessory muscles

Barrel chest, difficulty breathing out, increasing expiratory flow does NOT prevent airways from collapsing

Emphysema worse in upper lobes than in lower lobes

Question 2

Examples of obstructive lung disease

Answer 2

Asthma

Bronchitis

Upper airway?

Question 3

Examples of restrictive lung disease

Answer 3

Pulmonary fibrosis

Chest wall deformity

Neuromuscular weakness

Question 4

Lung volumes in obstructive lung disease

Answer 4

TLC, FRC, RV increased

FEV1/FVC ratio is decreased (normal is 80%)

Remember: hyperinflation, air trapping

Question 5

Lung volumes in restrictive lung disease

Answer 5

TLC, FRC, RV decreased because lungs are smaller

FEV1/FVC same or larger

Lungs are less compliant and thus more elastic

Question 6

Polio

Answer 6

Viral disease that causes muscle weakness that leads to restrictive lung disease

Iron lung was a negative pressure ventilator to aid patients in breathing

Question 7

Interstitial fibrosis

Answer 7

Stiff lungs

Can result in mechanical problems (alveolar hypoventilation) but also thickening can cause diffusion abnormality because of thickening of alveolar walls

On exercise PaO2 falls because of inadequate time for oxygen diffusion (this doesn’t happen very commonly)

Question 8

High altitude

Answer 8

Lower barometric pressure, so therefore 21% O2 concentration is lower O2 pressure, so you get lower PAO2 because of altitude

Also at high altitude, CO will increase (widening pulse pressure)

Also pulmonary arteries will constrict (hypoxic pulmonary vasoconstriction)

Question 9

Pulmonary embolism

Answer 9

Happens in people who are immobile for a long time, previously healthy, estrogen therapy, “bad cold” at onset of symptoms is actually PE, causes rapid deterioration

Pulmonary vascular resistance is increased

If no pulmonary infarction, PE can even be asymptomatic, or difficult to diagnose

Question 10

Bronchiectasis

Answer 10

Necrotizing infection of bronchi

Dilated bronchi that have destruction of muscle and elastic tissue

Green/yellow sputum

Smokers, CF, congenital, poor ciliary motility, breathing in food particles

Obstructive lung disease

Question 11

Honeycomb change

Answer 11

Multiple abnormal airspaces surrounded by dense collagen (pink)

Thick wall spaces

Seen in end stage pulmonary fibrosis, life expectancy only 3 years once you see honeycomb change

Question 12

COPD

Answer 12

Chronic Obstructive Pulmonary Disease

Two components: emphysema and airway inflammation

Lungs and chest get big–barrel chest

Lungs very gray/black because of anthrocrotic pigment

Destruction of alveoli

Emphysema worse in upper lobes than lower lobes

Question 13

Diseases caused by smoking

Answer 13

Emphysema

Chronic bronchitis

Respiratory bronchiolitis

Desquamative interstitial pneumonia

Eosinophilic granuloma

Cancer

Question 14

Chronic bronchitis

Answer 14

Airway inflammation causes increased glands and secretions (mucous in the airway)

Question 15

Interstitial lung disease (ILD)

Answer 15

200 different diseases with different causes but similar symptoms (inflammation and fibrosis)

Not that common

Most important is Usual Interstitial Pneumonia, usually affects lower lobe (spatially and temporally heterogeneous)

Question 16

Acute Lung Injury

Answer 16

Adult Respiratory Distress Syndrome (see hyaline membranes: pink lining that represents necrotic epithelial cells in alveolar septae and plasma proteins deposited from leakage of capillaries)

or

Diffuse Alveolar Damage (first see edema on x-ray, then hyaline membranes 24 hours later)

Question 17

Consolidation

Answer 17

Exudate, inflammatory cells that eventually turn white and harden

Seen in pneumonia

Question 18

Virchow’s triad of things that increase the probability of thromboemboli

Answer 18

1) Vascular injury
2) Stasis
3) Hypercoagulable state

Note: people who have just had surgery more at risk for PE because of these 3 things

Question 19

Major types of lung cancer

Answer 19

1) Adenocarcinoma
2) Squamous cell carcinoma
3) Small cell carcinoma (neuroendocrine/Kulchitsky cell)
4) Large cell undifferentiated carcinoma

Question 20

Mesothelioma

Answer 20

Tumor encasing/surrounding lung

Associated with asbestos exposure (can even have secondary asbestos exposure via clothes etc as a cause)

Question 21

Mechanism of damage caused by smoking

Answer 21

Activation of leukocytes that induce chronic inflammation and structural injury by release of enzymes and ROS’s

Inactivates anti-proteases, causing tissue destruction

Question 22

D-dimer test

Answer 22

D-dimer is a fibrin degradation product

Used to diagnose PE

High sensitivity (people who have PE WILL have high D-dimer) but low specificity (many false positives, so people with no PE may easily still have high D-dimer)

Question 23

Chronic hypercapnia/Chronic lung disease

Answer 23

Chronic respiratory failure causes increased PaCO2, low PaO2, acidic pH –> CO2 goes into CSF, H+ gets into kidney tubule, causes excretion of H+ and retention of HCO3- –> HCO3- actively transported out of BBB to try to reduce pH changes –> reduces H+ in CSF –> reduced stimulus for chemoreceptors to increase ventilation (bad!)

Compensated respiratory acidosis with chronic hypoxemia, hypercapnia, renal HCO3- retention, normal blood pH

Patients insensitive to chronically elevated PaCO2, so ventilation stimulated by hypoxia!

Dejor effect says: Don’t give 100% O2 to person with chronic hypercapnia because that decreases ventilation more (peripheral carotid bodies turned off!) and increases PCO2 even more

Patient develops pulmonary hypertension, edema, in response to hypoxemia which can lead to right side heart failure

Question 24

Sleep apnea

Answer 24

Cessation of breathing for more than 10 seconds

Caused by obstruction of hypopharyngeal airway or disturbance of ventilatory control during sleep

Leads to sleep disruption, nocturnal hypoxemia, early morning hypercapnia, sleepiness during day

Question 25

How can you tell if someone has diaphragm paralysis?

Answer 25

When they breathe in, their abdomen will be sucked INWARD

Thoraco-abdominal paradox

Have to use their accessory muscles to expand ribcage due to floppy diaphragm and this causes abdomen to be sucked in

Question 26

Why is emphysema considered obstructive?

Answer 26

Airways collapse because less elastic recoil moves EPP closer to alveoli, so can’t get air out