Congenital Diaphragmatic Hernia

Question 1

What sequelae of CDH are typically responsible for its lethality?

Answer 1

pHTN

pulmonary hypoplasia

cardiac dysfunction associated with the above

Question 2

What is the typical EBL of repair of CDH?

Answer 2

5 - 10 mL/kg

Question 3

What is the incidence of CDH?

Answer 3

1 in 4000

Question 4

What conditions are associated with CDH?

Answer 4

Malrotation (40 - 100%)

Congenital heart disease (23%)

Chromosomal (5 - 16%)

hypospadias (rare)

Renal anomalies (rare)

esophageal atresia (rare)

CNS abnormalities (rare)

Question 5

What congenital heart abnormalities are associated with CDH?

Answer 5

23% of CDH have CHD.

• VSD
• ASD
• PDA
• TOF

Question 6

What is the mortality of repair of congenital diaphragmatic hernia?

Answer 6

15 - 50% without ECMO

25 - 30% with ECMO

Question 7

What is the main factor that determines the severity of pulmonary hypoplasia in children with congenital diaphragmatic hernia?

Answer 7

The timing of the herniation (and the amount of abdominal contents in the chest).

Pulmonary hypoplasia is most severe with early herniation and may be minimal in cases of late (even postnatal) herniation.

The prognosis is correlated with magnitude of pulmonary hypoplasia and pulmonary muscular abnormalities on the contralateral side.

Question 8

What preoperative respiratory concerns in a child with congenital diaphragmatic hernia?

Answer 8

Decreased compliance increases risk of hypoventilation

Increased peak inspiratory pressures increases risk for pneumothorax.

Persistent pulmonary HTN and progressive hypoxemia may be present.

Question 9

Repeated bouts of hypoxemia predispose a preterm infant to what neurological event?

Answer 9

Intraventricular hemorrhage.

These areas of hemorrhage have loss of cerebral autoregulation and BP increases are directly transmitted to the microvasculature with increased risk of recurrent hemorrhage and edema.

Question 10

What hematologic goals should be met for a neonate presenting for repair of congenital diaphragmatic hernia?

Answer 10

Hct should be 35%.

Vit K should have been administered at birth.

Question 11

What intraoperative monitors should be used for repair of CDH?

Answer 11

Pre and post ductal pulse oximetry

arterial line (preductal if possible)

contralateral side precordial stethoscope

standard monitors otherwise

Question 12

What is the most likely cause of acute fall in SpO2 intraoperatively in a patient with congenital diaphragmatic hernia?

Answer 12

Pneumothorax on the unaffected side.

Do not attempt to expand lungs vigorously. Keep PIP < 30 cmH20 if possible.

Question 14

What is the location of the herniation of congenital diaphragmatic hernias?

Answer 14

Usually left sided (90%) via left foramen of Bochdalek (more common in boys)

Morgagni hernias (2 - 5%)are anterior or “retrosternal” and are more common in girls.

Remainder through esophageal hiatus.

Question 16

What is the implication of location of the herniation in congenital diaphragmatic hernias?

Answer 16

Bochdalek (posterolateral) defects are associated with significant lung hypoplasia and early - if not immediate - respiratory distress.

Morgagni and parasternal herniations are rarer and less symptomatic and present later.

Question 17

What is the effect of congenital diaphragmatic hernia on the physiology of the lung?

Answer 17

Although the ipsilateral lung is most affected, BOTH lungs are abnormal and result in decreased number and function of alveoli.

Lung hypoplasia often has smaller pulmonary arteries and decreased arterial branching resulting in higher PVR.

Question 18

To what extent does repair of posterolateral congenital diaphragmatic hernias resolve the pulmonary dysfunction?

Answer 18

It does note resolve the pulmonary dysfunction.

Question 20

What are the perioperative goal values on ABG and for temperature for patients with congenital diaphragmatic hernia?

Answer 20

normal or elevated pH

normothermia (because hypothermia increases O₂ consumption)

PaO₂ > 80 mmHg

PaCO₂ 25 - 30

Question 21

What postoperative sequelae are seen in patients who undergo repair of congenital diaphragmatic hernia?

Answer 21

High incidence of neurologic problems (20 - 30%):

• Developmental delay
• seizures
• hearing loss

Pulmonary outcomes are usually good.