Respiratory Flashcards
All infants <30wks should automatically be started on CPAP in the DR
Benefits of CPAP
-deters alveolar collapse
-increases end-expiratory lung volumes
-maintains functional residual capacity (FRC).
Indications for nitric oxide
> 34wks, PaO2<100 on 100% O2 and OI >20
Literature suggests there is no difference in oxygenation response between 20 ppm and 5-6 ppm, though 20ppm is associated with an improved pulmonary-systemic blood flow ratio
Response to nitric oxide
-PaO2 increase by >20mmHg or 20% from baseline
-increase O2 sats by 10%
**assess after 30mins
20/20/20 rule
concerning methemoglobin level
If >5%
Can begin weaning FiO2 after 4 hours of iNO by 5% per hour
fetal absorption of fluid
- 1/3 absorbed prenatally during labor
- 1/3 absorbed during vaginal delivery
- 1/3 absorbed after delivery
Mechanism of fluid absorption
-Onset of labor, maternal epinephrine, and glucocorticoids activate the ENaC on the apical membranes of type II pneumocytes.
-Sodium in the alveolus is transported passively across the ENaC proteins which in turn is actively transported back to the interstitium by the Na+/K+-ATPase pump
-An osmotic gradient is created which allows chloride and water to follow and be absorbed into pulmonary circulation and lymphatics.
if placenta undergoes stress might increase innate steroid release for baby and result less severe RDS vs chorioamnioitis results in diffuse inflammation response and worsening RDS
Diabetes and surfactant
hyperglycemia and hyperinsulinemia can disrupt surfactant lipid and protein synthesis, causing delayed maturation in surfactant in IDM
TTN time frame
symptomatic for 12 to 24 hours, but signs may persist as long as 72 hours
RDS peak time
48-72hrs
hyperoxia does not enhance pulmonary vasodilation-> increased free radius that increase pulmonary arterial contractility and impairs vasodilation effects of iNO
Atelectotrauma
repeated alveoli deflation and decreased lung volumes
-look at flow volume loop should see immediate increase upon a breath
volutrauma
inflation of lungs to volumes that approach the total lung capacity
barotrauma
overinflation and shearing stressed due to high PIPs
Minimal tidal volume: <1kg: 5ml/kg, >1kg: 4.5ml/kg
causes of pulmonary edema
-too much blood/fluid going to the lungs
-increase leaking at capillary (sepsis, hypoxemia, hypoxia, RDS)
-increase resistance to blood leaving lungs (TAPVR, tamponade)
Avoid caffeine in preterm infants likely to remain mechanically ventilated beyond 10 post natal days
CAP trial
The use of caffeine was associated with decreased risk of bronchopulmonary dysplasia (anti-inflammatory effect) and cerebral palsy at 2 years
VitA criteria
<28wks, >28wks + <1kg +needs for mechanical ventilation or supplemental oxygen at 24hrs of life
-outborn qualifies if first dose given by 96hrs of life