Neonatal, developmental, vascular lung disease Flashcards
Describe how the design of the lung works to protect the organism from airborne toxins while still performing gas exchange
Upper airway filter that filters out particles over 10 microns in diameter.
Tracheobronchial mucociliary apparatus filters out particles that are over 5 microns
Intraalveolar phagocytic system traps other particles.
Normal histology of a bronchi from outter to inner
Pseudo-stratified ciliated columnar epithelium, thin Basement membrane, subepithelial layer, cartillaginous ring. (I think Heron says its a little more complicated. Check out his first pwrpt).
Right mainstream bronchus is more vertical than the left?
True…creates a greater risk for aspiration on the right
“Fetuses breathe with their placentas, newborns breathe with their lungs” What is the significance of this?
If a fetus has a lung problem we dont know it until its a newborn
Name two developmental anomalies involving the lung
- Pulmonary agenesis or hypoplasia
- Tracheobronchial anomalies
What is pulmonary agenesis or hypoplasia
multiple malformation syndromes such as a diaphragmatic hernia
Tracheobronchial anomalies
…see slide
Congenital emphysema?
What lobes does it tend to effect?
Accounts for half of congenital lung lesions in infancy. Tends to effect upper left lobe (50%) and right middle lobe (24%). Air traps due to a cartilage deficiency in bronchial tree
Congenital cyst?
When is it found?
Mucus filled bronchial epithelium cells….not found until 14-30 yrs of age. May occur anywhere in the lungs
Explain pulmonary sequestrations
It is pulmonary tissue that is within (intrlobar) or outside of (extralobar) normal lung. It does not connect to the tracheobronchial tree.
Intralobar sequestration usually present as
recurrent infection
Extralobar sequestration usually associated with
I dont know but they are usually recognized in kids as mass lesions
3 types of neonatal aspiration syndromes
Inhalation of amniotic fluid/MECONIUM in utero due to fetal distress…most likely to see this
Inhalation of bloody amniotic fluid peripartum
Inhalation of gastric contents postpartum
Hyaline membrane disease
Pulmonary edema, membrane formation, resorptive atelactisis, bronchiolar epithelium necrosis.
More common in males, prematures, twins, mild maternal diabetes, C-section, colder weather.
Due to the physiochemical shock of lung expansion
What is atelectasis
collapsing of a lung or incomplete lung expansion at birth
Three types of atelactasis
1) Resorption- intrabronchial obstruction in this one- it is reversible
2. ) compression- compression from outside- reversible
3. ) Contraction- Caused by parenchymal scarring, this is not reversible
Which type of atelectasis is not reversibel
Contraction- caused by parenchymal scarring
What is pulmonary edema
Intraalveolar pooling of proteinaceous fluid due to hemodynamic causes or microvascular injury.
Two categories of pulmonary edema causes
hemodynamic and microvascular
Hemodynamic causes of pulm edema are
increased hydrostatic pressure in the vasculature or decreased oncotic pressure
Increased hydrostatic pressure can be caused from>
Left sided heart failure. Mitral valve stenosis, volume overload, pulmonary vein obstruction
Decrease oncotic pressure causes
hypoalbuminemia, nephrotic syndrome, liver disease
Microovascular causes of pulm edema are
infectious gasses, irritant gasses, toxic drugs, sepsis, radiation
Proinflammatory cytokines
IL-1, IL-8, TNF….released by macrophages during acute lung injury and ARDS
What factors do neutrophils release in the alveolar space and what do these things do>
Leukotrienes, oxidants, proteases, Platelett Activating Factor
These contribute to local tissue damage, accumulation of fluid, surfactant inactivation and hyaline membrane formation.
What does MIF do?
MIF (macrophage inhibiting factor) sustains the local proinflammatory response.
TGF-Beta and PDGF stimulate what
Fibroblast growth and collagen deposition associated with healing
Two Pulmonary hemorrhagic syndromes
Goodpasture’s and Granulomatosis with polyangiitis
Goodpastures syndrome triad is
Glomerulonephritis, lung hemorrhage, and antibodies to the alpha 3 chan of type IV collagen
Typica goodpasture’s patient
Youbg adult male…20-30 yo
Left untreated….renal failure
Granulomatosis with Polyangiitis affects?
Lungs and upper resp tract, potentially the kidney
G w/ P is characterized by
necrotizing vasculitis and granulomas
G w/ P most commonly affects
middle aged men
Look for what with G w/ P
ELevated serum C-ANCA corresponding to ant PR# proteinase antibodies
What the hell are ANCAs
Anti- neutrophil cytoplasmic antibodies are a family of autoantibodies that react with myeloid specific proteins found in white blood cells
What is the most common tracheoesophageal fistulae?
One in which the trachea communicates with the distal portion of an esophagus that was atretic at the top.
Common causes of ARDS
Burns, Near drowning, mechanical trauma
Smoke or irritant gasses
