Lungs

Question 1

• Obstruction of upper fetal airway (CHAOS)
• Airways become dilated, lungs enlarge and fill with fluid; diaphragm flattened or inverted, fetal ascites and/ or hydrops
• Tx: dilation

Answer 1

Laryngeal atresia

Question 2

• Abnormal communication between trachea and esophagus 2/2 failure of foregut endoderm to proliferate quickly enough in relation to the rest of the embryo
• Associated with esophageal atresia and polyhydramnios
• Clinical features: excessive saliva or mucus accumulation in nose and mouth; gagging and cyanosis after swallowing milk; abdominal distension after crying; reflux of gastric contents into the lungs causing pneumonitis
• Dx: inability to pass a catheter into stomach and radiographs demonstrating air into infants stomach

Answer 2

Tracheoesophageal fistula

Question 3

Complete absence of UL lung or lobe and accompanying bronchi d/t failure of respiratory bud to split into R/L buds

Answer 3

Pulmonary agenesis

Question 4

• Insufficient amniotic fluid production (<500mL)
• Associated with renal agenesis or failure

Severe/ chronic conditions → pulmonary hypoplasia

• Restriction of fetal thorax 2/2 uterine pressure
• Decreased hydraulic pressure on the lungs affects stretch receptors
• Risk significantly increased with oligohydramnios <26 weeks
• Potters sequence (wide nasal bridge, limb hypoplasia, nasal flairing, renal failure)

Answer 4

Oligohydramnios

Question 5

• Rapid labored breathing shortly after birth 2/2 surfactant deficiency
• Type II alveolar cells incapable of producing surfactant
• Lungs are underinflated, alveoli contain fluid and resemble glassy membrane
• Clinical signs: tachypnea; nasal flaring; suprasternal, intercostal, or subcostal retractions, grunting; cyanosis

Answer 5

Respiratory distress syndrome

Question 6

• Fluid or air filled cysts thought to be formed by dilation of terminal bronchi
• Causes disturbance in bronchial development during late fetal life
• Clinical signs: wheezing, cyanosis, difficulty breathing

Answer 6

Congenital lung cysts