obstructive lung diseases

Question 1

What is the underlying pathophysiology of an obstructive lung disease?

Answer 1

obstruction of flow causes air trapping. airways close prematurely at high lung volumes. this causes an increased residual volume and decreased forced vital capacity. function testing will show markedly decreased FEV1. decreased FVC (forced vital capacity). Decr. FEV1/FVC, V/Q mismatch
total lung capacity will increase (air trapping)

Question 2

common sequelae of obstructive lung disease

Answer 2

chronic hypoxic pulmonary vasoconstriction can lead to cor pulmonale

Question 3

What is chronic bronchitis? Pathology

Answer 3

one form of COPD. it causes hyperplasia of mucus-secreting glands in the bronchi. the reid index (thickenss of the gland layer/total thickness of the bronchial wall) > 50%. highly associated with smoking (basically we have mucinous hyperplasia - mucinous glands to try to protect the lung from toxins/pollutants).

Question 4

What are some clinical characteristics in chronic bronchitis? What airways are most effected?

Answer 4

this is a disease of the small airways. (pathoma says large airways).
productive cough for > 3 months/year for >2 yrs.
may see cyanosis (incr. PaCO2 and decr. PaO2) and late-onset dyspnea

Question 5

What are the pathological features of emphysemia? Pathophysiology?

Answer 5

enlarged airspaces. see decreased recoil and increaesd compliance. decreased diffusion (DLCO). all from destruction of alveolar walls.
you can have bronchiole collapse- they have no cartilage, so they need to stay open based on recoil of alveolar air sacs. as you loose the alveolar air sacs, the bronchioles may collapse.

Question 6

What are the 2 types of emphysema?

Answer 6

centriacinar: associated with smoking. they have too much protease activity becasue they have toxins in their lungs, which causes inflammation and requires protease clearance. Centriacinar: central part of the acinus most affected (this is where smoke hits first). also worse in the upper lobes.
panacinar: assoicated with an alpha-1-antitrypsin deficiency. not enough anti-protease activity.
increased elastase activity causes a loss of elastic fibers, which increases compliance. more common in the lower lobes. they may also develop liver cirrhosis (build up of alpha-1 antitrypsin in the ER of hepatocytes). pink- PAS positive globules in the liver. This is

Question 7

clinical features of emphysema.

Answer 7

exhalation through pursed lips to increase airway pressure and prevent airway collapse
often have weight loss
minimal sputum production
incr. AP diameter of the chest (normally meet at the functional residual capacity)- barrel chested people will have increased functional residual capacity of the lung.

Question 8

What are the pathologic features of asthma?

Answer 8

bronchial hyperresponsiveness. smooth muscle hypertrophy, curschman spirals (shed epithelium forms a mucus plug), and Charcot-Leyden crystals (breakdown of eosinophils in sputum)

Question 9

What are some clinical features of asthma?

Answer 9

many. but pulsus paradoxus and mucus plugging may be especially relevant

Question 10

What are the pathologic features of bronchiectasis?

Answer 10

chronic necrotizing infection of bronchi causes permanently dilated airways, purulent sputum, recurrent infections, and hemoptysis
dilatation results in loss of tone- can’t get air out appropriately

Question 11

What conditions are associated with bronchiectasis?

Answer 11

bronchial obstruction, poor ciliary motility (smoking), kartagener syndrome, CF, allergic bronchopulmonary aspergillosis (seen in CF pts and asthmatics)

Question 12

genetics of alpha 1 antitrypsin

Answer 12

PiZ allele causes misfolding of the protein. heteros are usually asymptomatic but they have a very high risk of emphysema with smoking. homozygous ppl have disease.
PiM is normal.

Question 13

What are the inflammatory response in allergic asthma?

Answer 13

TH2 T-cells are stimulated to make IL-4, IL-5, and IL-10.  IL-4 allows for class switching to IgE.  IL-5 calls in eosinophils.  IL-10 inhibits the production of TH1, and induces TH2- promotes this whole cascade.  
then, mast cells dump preformed histamine granules.  second phase: production of leukotrienes.  they casue vasoconstriction, incr. permeability, and bronchoconstriction.

Question 14

aspirin intolerant asthma

Answer 14

asthma, bronchospasm, nasal polyps

Question 15

clinical features of bronchiectasis

Answer 15

foul smelling sputum

secondary amyloidosis with deposition of AA. due to chronic inflammation