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Flashcards in pulmonary: restrictive, obstructive diseases and PE Deck (71)
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1

what is the primary purpose of the pulmonary system?

supplying necessary O2 to the tissues and excreting CO2
*don't need 100% O2 to fulfill purpose

2

what is the difference in how the respiratory system delivers O2 and CO2 molecules opposed to the circulatory system?

respiratory system delivers gas and the circulatory system delivers liquid

3

describe obstructive disease

-more common than restrictive
-airway resistance increased
-air trapping and obstruction impedes air flow out (extended expiration times)
-lung volumes increase (RV and TLC)
-turbulent air flow leading to wheezing
-impaired gas exchange leading to VQ mismatch
-more amendable to treatment than restrictive

4

describe restrictive disease

-decreased lung compliance
-lung expansion restricted, impeding air flow in
-lung volumes reduced
-air resistance NOT increased

5

with obstructive disease, what 3 mechanisms cause an increase in airway resistance that leads to obstructed air flow?

-excessive secretions partly blocking bronchial lumen
-airway thickening by edema, hypertrophy of mucous glands, bronchitis, or asthma
-destruction of lung parenchyma (loss of airway radial traction narrows airway)

6

what are pulmonary function tests?

spirometry and flow volume loops to distinguish between obstructive and restrictive conditions

7

describe pulmonary function tests

-FEV1: volume forcefully exhaled in one second
-FVC: total volume that can be forcefully exhaled
-FEV1/FVC: ratio used to distinguish obstructive vs. restrictive

8

describe pulmonary function test results with obstructive diseases

-both FEV1 and FVC are low and ratio is less than 0.7
0.6-0.7: mild
0.4-0.6: moderate
less than 0.4: severe
ex: FEV: 1.3, FVC: 3.1, ratio 42%

9

describe PFT results with restrictive diseases

both FEV1 and FVC are low and ratio is greater than or equal to 0.7
ex: FEV: 2.8, FVC: 3.1, ratio 90%

10

describe normal PFT results

-FEV: 4.0
-FVC: 5.0
-ratio: 80%

11

describe characteristics of asthma

-chronic airway inflammation with periodic acute severe exacerbations
-bronchial airways are hyper-reactive to stimuli
-airway narrowing at all levels with varying severity
-expiratory airflow becomes obstructed (obstructive disease)
-reversible with bronchodilators

12

describe extrinsic asthma

*allergic asthma
-family hx of allergic/immunologic disease
-allergic related (allergen identified)
-immune system activation
*elevation of IgE levels and serum eosinophils

13

describe intrinsic asthma

*non-allergic asthma
-idiosyncratic (specific to the individual)
-exacerbations with triggers
-non-immune related (no allergen identified)
*normal IgE levels

14

what are signs and symptoms of asthma?

-periodic acute exacerbations: mild to severe attacks; bronchospasm; mucosal edema/secretions
-mild airway obstruction lasting for weeks
-increased airway resistance to gas flow: wheezing
-productive cough, dyspnea

15

describe pathology of asthma

-hypertrophied airway smooth muscle contracts during an attack causing bronchoconstriction
-mucous gland hypertrophy causes increased secretions, usu. white and scant (thick, slow moving; mucous plugs leads to obstruction)
-bronchial wall edema
-infiltration of eosinophils and lymphocytes
-remodeling leads to subepithelial fibrosis

16

what are common etiologies of asthma attacks?

-allergy induced
-respiratory viruses (children)
-occupational and environmental irritants (adults): airborne pollens, animal danders, dust, pollutants, chemicals
-drugs: aspirin, beta2blockers, NSAIDS, drugs causing histamine release
-exertional exercise
-stress, emotional, psychological

17

what are inflammatory mediators associated with asthma?

-cytokines associated with Th-2 and helper T cells: IL 4, 5, 9, 13
-arachidonic acid metabolites: leukotrienes, prostaglandins
-platelet-activating factor (PAF)
-neuropeptides
-reactive oxygen species (ROS)
-kinins (bradykinin)
-histamine
-adenosine
-serotonin
-chemotactic factors

18

describe the immune mediated process of asthma

-allergen binds to IgE on mast cell causing degranulation
-release of inflammatory mediators from mast cell
-bronchoconstriction via multiple mechanisms: decreased cAMP, increased cGMP increases PNS activity increasing cholinergic sensitivity causing vagal afferents sensitivity to histamine, noxious stimuli, cold air, irritants, and ET intubation

19

describe PNS role in bronchoconstriction

-balance between PNS and SNS regulates bronchial tone
-PNS stimulation via vagal activation causes activation of muscarinic receptors in bronchial smooth muscle
-muscarinic receptors cause increase in intracellular levels of cyclic guanosine monophosphate (cGMP)
-increased intracellular cGMP increases protein kinases that cause bronchoconstriction
*antimuscarinics promote dilation

20

what are the goals of asthma treatment?

-prevent bronchial inflammation
-maintain patent airways

21

what type of therapy is used for asthma treatment?

-long term control of airway narrowing
-rescue for acute bronchospasm attacks

22

what anti inflammatory drugs are used for asthma?

-glucocorticoids
-leukotriene blockers
-mast cell-stabilizing agents

23

what bronchodilator drugs are used for asthma?

-beta2 agonists (rescue)
-methylxanthines
-anticholinergics (antimuscarinics)

24

describe glucocorticoids for asthma treatment

-not rapid acting, usu. 1-3 hours onset
-admin. IV or inhaler
-decreased bronchial hypersensitivity, inflammatory response
-membrane-stabilizing
*most effective anti-inflammatory drugs
*effective as prophylactic pre-op drugs

25

what are common glucocorticoids used in asthma treatment?

-IV hydrocortisone, methylprednisolone
-fluticasone (Flovent)
-salmeterol (Advair)
-budesonide (Pulmicort)
-triamicinolone (Azmacort)
-beclomethasone (Beclovent)

26

describe leukotriene blockers for asthma treatment

-leukotrienes mediate inflammation in asthma
-blocker inhibit the 5-lipoxygenase enzymatic pathway (5-LO inhibitors)
-reduce the synthesis of leukotrienes
-only 50% of patients with beneficial response
*effective for aspirin-induced asthma

27

what are common leukotriene blockers used in asthma treatment?

-monotelukast (Singulair)
-zafirlukast (Accolate)
-pranlukast (Zyflo)
-zileuton (Ultair)

28

describe mast cell stabilizers for asthma treatment

*effective only with extrinisic (allergic) asthma
-block airway inflammation
-inhibits mediator release from mast cells
-stabilizes membranes inhibiting mast cell degranulation

29

what is a common mast cell stabilizer used in asthma treatment?

cromolyn

30

describe beta adrenergic agonists for asthma treatment

-most potent bronchodilators
-stimulation of beta 2 receptors in the lungs cause increased cyclase leading to increased cAMP which increases Ca++ promoting tracheobronchial smooth muscle relaxation
-inhibits inflammatory cell function