Respiratory: Chornic obstructive Flashcards
What characterizes chronic obstructive disease
lung does not empty
-air is trapped
what values are changed in spirometry for obstructive lung disease
decrease FEV and FEV1 ( FEV1 is decreased more)
Increase TLC
Define chronic bronchitis
productive cough lasting at least 3 months over a minimum of 2 years
chronic bronchitis is highly associated with what habit
smoking
what characterizes chronic bronchitis
hypertrophy of bronchial mucinous glands
- increased thickness of mucus glands relative to bronchial wall thickness
- Reid index increases to greater 50%
what are 3 clinical features of chronic bronchitis
- productive cough with excessive mucus production
- cyanosis ‘blue bloaters’
- increase risk for infection and cor pulmonale
why does cyanosis ‘blue bloaters’ occur in chronic bronchitis
mucus plugs trap carbon dioxide
increase PaCO2 and decrease PaO2
Define emphysema
destruction of alveolar air sacs
what happens during exhalation in emphysema
loss of elastic recoil and collapse of airways
- results in obstruction and air trapping
In emphysema why do the alveolar air sacs collapse
imbalance of proteases and antiproteases
who and what gets released during normal inflammation of the lung
neutrophils and macrophages release proteases
what neutralizes porteases
alpha1-antitrypsin
how is the protease and antiprotease imbalanced in emphysema
excessive inflammation - increase protease
lack of alpha1-antitrypsin
what is the most common cause of emphysema
smoking
how does smoking cause emphysema
- excessive inflammation
- protease mediated damage
what does emphysema from smoking result in
centriacinar emphysema
upper lobe
what is a rare cause of emphysema
A1At deficiency
how does A1AT cause emphysema
- lack of antiprotease
what results from A1At emphysema
panacinar emphysema
lower lobes
what other clinical findings would you find for someone who has A1AT emphysema? why?
liver cirrhosis
- A1AT deficiency due to misfolding of mutated protein
- mutant A1At accumulates in endoplasmic reticulum of hepatocytes,
- liver damage
what does biopsy of liver cirrhosis show in an A1AT deficient person
reveals pink, PAS-positive globules in hepatocytes
what is the severity of A1AT based on
degree of A1AT deficiency
what is the normal allele for A1AT
PiM
what is the most common clinically relevant mutation in A1AT
PiZ
What alleles are usually asymptomatic with decreased circulating levels of A1AT
PiMZ heterozygotes
PiMZ heterozygotes have a significant risk for emphysema if they do what
smoke!
what allele are at significant risk for panacinar emphysema and cirrhosis
PiZZ homozygotes
what are 5 clinical features of emphysema
- dyspnea and cough with minimal sputum
- prolonged expiration and pursed lips
- weight loss
- increase A/P diameter of chest ( ‘barrel-chest’)
- hypoxemia and cor pulmonale ( both late complications)
why would hypoxemia occur in emphysema
destruction of capillaries in alveolar sac
What asthma and is the most likely cause
reversible airway bronchoconstriction
- allergic stimuli ( atopic asthma)
when does asthma usually present and what is asthma associated with
- in childhood
- allergic rhinitis, eczema, family history of atopy
Asthma is what type of hypersensitivity
type I hypersensitivity
In asthma, allergens induces what response and in what type of individuals
Th2 phenotype in CD4+ T cells
- genetically susceptible individuals
in Asthma, Th2 cells secrete what
IL4
IL5
IL10
role of IL4
mediates class switch to IgE
role of IL5
attracts eosinophils
role of IL10
stimulates Th2 cells and inhibits Th1
in asthma, re-exposure to allergen leads to what
IgE-mediated activation of mast cells
When mast cells are activated by IgE what do they release
- preformed histamine granules
- generation of leukotrienes C4, D4, E4
Leukotirienes C4, D4 and E4 causes what
bronchocontriction, inflammation, and edema ( early-phase reaction)
What is the late-phase reaction to mast cells that are activated by IgE in asthma
inflammation
-especially major basic protein derived from eosinophils, damaged cells and perpetuates bornchocontraction
When do clinical features present for asthma
episodic,
related to allergen exposure
what are clinical features of asthma
dyspnea
wheezing
productive cough
status asthmaticus
describe the productive cough in asthma
spiral-shaped mucus plugs (Curschmann spirals)
eosinophil-derived crystals ( charcot-Leyden crystals)
what is status asthmaticus and what can it lead to
severe, unrelenting attack
can lead to death
what are some non-allergic causes of asthma
exercise
viral infection
aspirin (aspirin-intolerant asthma)
occupational exposures
What is bronchiectasis
permanent dilatation of bronchioles and bronchi
- loss of airway tone results in air trapping
what is the common pathological cause for bronchiectasis
necrotizing inflammation with damage to airway
what are specific causes of bronchiectasis
cystic fibrosis Kartagener syndrome tumor or foreign body necrotizing infection allergic bronchopulmonary aspergillosis
what is Kartagener syndrome
inherited defect of dynein arm, necessary for cilliary movement
Kartagener syndrome is associated with what other complications
sinusitis
infertility (poor motility of sperm)
situs inversus (position of major organs is reversed ex. heart is on right side of thorax)
What is allergic bronchopulomary aspergillosis
hypersensitivity reaction to Aspergillus
what does bronchopulmonary aspergillosis lead to
chronic inflammatory damage
who is bronchopulomary aspergillosis usually seen in
asthma or cystic fibrosis
what are clinical features of Bronchiectasis
cough
dyspnea
foul-smelling sputum
what are complications of Bronchiectasis
hypoxemia with cor pulmonale
secondary amyloidosis
