Respiratory Flashcards
How to treat pneumomediastinum?
Observe. Usually resolves spontaneously
____ is actively transported across pulmonary epithelial cells to air spaces to create fetal lung fluid. Changes to ____ secreting to move fluid out of alveolar air spaces.
Chloride / Sodium. 30% of FLF is absorbed PTD
Diaphragm paralysis, the affected side has ____ movements compared to unaffected side. The _____ side is more common (_____ sign)
LESS movement on affected side. R side more common. Kienbock’s sign.
Which stages of lung development have which pathologies?
Embryonic: TEF, tracheal stenosis, laryngeal cleft:
Pseudoglandular: CDH, bronchogenic cyst, CCAM/CPAM, congenital lobar emphysema
Canalicular: pulmonary hypoplasia
Saccular: pulmonary hypoplasia
Difference between CCAM and bronchopulmonary sequestration?
CCAM: congenital cystic adenomatoid malformation. Cystic lesion occurs in developing lung. Supplied by PULMONARY circulation and connected to tracheobronchial tree
Bronchopulmonary sequestration: non-functioning lung tissue. NOT connected to tree. receives blood from systemic circulation.
By what principles does HFOV work?
PAM TB
Pendelluft effect: differential movement of gas as result of diff time constraints
Asymmetric velocity of gas
Molecular diffusion: across alveolar gradients all factor in gas exchange
Taylor dispersion: parabolic movement of inspired gas that allows for increased area for diffusion
Bulk Convection: bulk axial gas flow
How many types of surfactant are there? Which is NOT in exogenous surfactant?
A, B, C, D. SP-A is NOT in exogenous surfactant No clinical dz in deficiency of D. A is most abundant. B is “better” for you.
Type I vs Type II pneumocytes? Which comes first?
Type II –> Type 1 pneumocytes
Type II: cuboidal, 10% of alveolar surface. Greater # of cells in alveolar lining. Important role in SURFACTANT metabolism and secretion
Type I: fried egg, tight junctions. 90% of alveolar surface. Important role in gas exchange, no gene material for surfactant.
Surfactant is mostly comprised mainly of _____
Lipids. Phosphatidylcholine desaturated (50%), monosaturated (20%)
Most common organisms associated with chorioamnionitis?
ureaplasma and mycoplasma
Prenatal corticosteroids help mature fetal lung by ______? Postnatal corticosteroids help by ______?
Antenatal: Decreasing amount of mesenchymal tissue and increasing potential airspace volume. Arrest alveolar septation.
Postnatal: arrest alveolar septation and microvascular development
BPD Definition (2000 NIH)
Mild: O2 for 28 days, RA at 36 weeks
Moderate: O2 x 28 days plus <30% O2 at 36 weeks
Severe: same, but >30% O2 and/or PPV
New BPD pulmonary changes?
Consistent with ALTERED lung development. Arrest of alveolarization with increased alveolar diameters and fewer alveoli. Hyperinflation, minimal cystic emphysema. Less airway reactivity compared to “classical” BPD. Less pulmonary HTN, minimal fibrosis.
Factors that help distribute surfactant admnistration
Gravity, higher volume, faster rate of administration, positive pressure to distribute, higher volumes of fetal lung fluid/edema helps distribute
Central chemoreceptors that respond to CO2 are located on ____. Mechanoreceptors are located on ____ and respond to TV. Oxygen peripheral chemoreceptors are located on _____.
ventrolateral surface of medulla; airway smooth muscle; carotid and aortic bodies
Bohr equation and measuring dead space?
Volume of CO2 in expired air = volume of CO2 from dead space + volume of CO2 from alveoli that are V/Q
What is physiologic, alveolar, and anatomic dead space?
Anatomic: conducting airways (bronchoconsriction decreases dead space)
Alveolar: alveoli that are not involved in gas exchange with vasculature
Physiologic = anatomic + alveolar
Fetal breathing is interrupted by?
Prostaglandin
A-a gradient equation?
[FiO2(760-PH2O) - PaCO2/R] - PaO2
R = 0.8
3 observations about apnea of prematurity
1) decreased ventilatory response to hypercarbia
2) irritation of laryngeal mucosa induces inhibition of breathing (superior laryngeal nerve)
3) Hypoxic ventilatory depression is reaction to sustained hypoxia (mediated centrally in pons by inhibitory NT like adenosine). Caffeine is competitive antagonist of adenosine
Locations and names of sodium pumps to get fluid out of lungs
Apical surface: amiloride sensitive ENaC - actively transports Na from alveolar lumen into respiratory cell (dev. expressed, increase also after endogenous steroids/catecholamines of labor)
Basolateral cell membrane: Na-K-ATPase, transports Na from the respiratory cell into interstitial
Water follows via aquaporins
How long before echo shows improvement of PH on sildenafil?
2 weeks
Boyle’s Law
Charles’ Law
Dalton’s Law
Fick’s Law
Henry’s Law
BL: at constant temp, given V of gas varies inversely to P to which subjected
CL: warm gas expands, cool gas shrinks
DL: Total + by mixture of gases = sum of partial pressure of each gas
FL: transfer of solute by diffusion directly proportional to XS area available for diffusion
HL: at constant temp, any gas physically dissolves in liquid proportion to PP
Choanal atresia has problem b/w which weeks of development?
Failure of bucconasal membrane to rupture b/w 5-6th weeks of development. Unilateral more common. Can be bony or membranous obstruction or both. Most are sporadic, most have associated malformations. More common in females.
How many alveoli does term infant have at birth?
50-150 million alveoli (adults have 200-600 million)
When have chylothorax, switch to enfaport bc
lymphatic vessels not required for absorption of MCT
Chylothorax: transudative effusion; pH > 7.4, WBC < 1K, LDH < 200. >80% lymphocytes, TG > 110
Corticosteroid effects prenatally can be seen on US?
No! Less fetal breathing and movements, HR less variability. Fetal blood flow NOT affected.
Describe classic BPD (Pre surfactant era)
structural damage of normal pulmonary structures from mechanical ventilation and oxygen toxicity - airway squamous metaplasia, alveolar septal fibrosis, airway smooth muscle hypertrophy, marked inflammation
Describe new BPD
disruption of normal alveolar/vascular development; diffuse alveolar/capillary hypoplasia. Significant loss of surface area for gas exchange. Airway injury, inflammation, fibrosis are milder