Flashcards in Resp. path Deck (385)
COPD w/ permanently enlarged air sacs distal to terminal bronchioles w/ destruction of their walls and w/o obvious fibrosis
What is the main enzyme implicated in emphysema?
5 morphological subtypes of emphysema
1. centrilobular - esp. w/ cigarettes
2. panlobular / panacinar - a1-antitrypsin and end-stage centrilobular
3. paraseptal - assoc. w/ pulmonary fibrosis. may -> spontaneous pneumothorax
4. irregular - associated w/ pulmonary scars
5. interstitial - subcutaneous. due to trauma or elevated intraalveolar pressure
What type of emphysema is cigarette smoking usually associated with?
Anthracosis often present
What part of respiratory tree is involved in centrilobular emphysema?
Primarily respiratory bronchioles due to high conc. of inhaled irritants
More prominant in upper lung fields
Chronic Bronchitis Definition
Productive cough w/o discernible cause for at least 3 months in 2 consecutive years
Ratio of thickness of mucous glands to total thickness of airway wall.
Elevated in chronic bronchitis
most severe subtype of asthma - prolonged interval of continual symptoms, unresponsive to treatment
May be life-threatening
Common effector pathway of asthma
Stimulus in susceptible host -> release of inflammatory mediators -> increased vascular permeability, edema, neural and cytokine mediated bronchoconstriction, mucus hypersecretion, chemotaxis of additional inflamm. cells -> amplification
Major chemical mediators of acute phase of asthma
LTC4, D4, E4
PGD2 - mucus prod
Parasympathetic neural reflexes
What happens in late phase of asthma?
Infiltration of white cells (esp. eosinophils) in response to locally released chemotactic factors
Prolongation and augmentation of disease process
2 common drugs that can contribute to asthma
aspirin: decreased prostaglandin production and relative increase in leukotriene
B-antagonists: may precipitate bronchospasm
What respiratory disease is assoc. w/ mucus plugs?
Curschmann Spirals and Charcot-Leyden Crystals - what are they and what are they associated with?
Curschmann Spirals: mucoid swirls of epithelial cells
Charcot-Leyden Crystals: extruded eosinophil granules - needle-like crystals
What is bronchiectasis
Permanent airway dilation due to recurrent infections w/ necrosis
Incomplete expansion of lungs at birth
What happens to the mediastinum in obstructive atelactasis?
Mediastinal shift toward atelactic lung
What happens to the mediastinum in compression atelactasis?
Mediastinal shift away from atelactic lung
Effects of alpha, B1, and B2 agonists
alpha: vasoconstriction and vasopressor -> decongestion
B1: increased myocardial conductivity, increased HR and contractile force
B2: relax bronchial sm. muscle, inhibit inflamm. mediator release, stimulate mucocilliary clearance
What receptors do epinepherine, ephederine, and isoproterenol work at?
epinepherine: B1, B2, alpha
ephedrine: B1, B2, alpha
isoproterenol: B1, B2
How do selective B2 agonists work?
increase AC -> increased cAMP -> sm. muscle relaxation
3 short acting B2 agonists
What is the difference between albuterol and levalbuterol?
Albuterol is a racemix mix of R and S enantiomers
Levalbuterol is only R (active)
considered equal, but levalbuterol is expensive.
What is the difference between salmeterol and formoterol?
Both last 12+ hrs
Formoterol is a full B2 agonist and has faster onset
Salmeterol is a partial B2 agonist
2 long acting B2 agonists available in 1x daily dosing?
Both available as DPI
What genetic factor has been associated with increased susceptibility to B2 agonist tolerance?
Gly16 polymorphism of B2 receptor.
-> reduced responsiveness to agonists
What is the recommendation regarding use of long acting B2 agonists in treating asthma?
Black box warning: should not be used as monotherapy. increased risk of death
What is the primary mechanism of action of anticholinergics in treatment of obstructive respiratory disease?
Reduction of intrinsic vagal tone
In what patient population is ipratropium contraindicated?
Those w/ soy lecithin or peanut allergy.
Propellant contains lecithin