Diaphragmatic hernia

Causes of respiratory distress at birth

Congenital anomalies

Diaphragmatic hernia
Cystadenomatoid malformations
Pulmonary hypoplasia
Tracheo-oesophageal fistula
Choanal atresia
Congenital heart disease

Congenital infection

Group B streptococci
Listeria

Neurological

Asphyxia
Haemorrhage

Miscellaneous

Meconium aspiration syndrome
Neonatal respiratory distress syndrome
Persistent fetal circulation
Pneumothorax

Congenital diaphragmatic hernia

Occurs in 1 in 4000 live births
Results from failure of closure of the pleuro-peritoneal canals
95% occur through the posterior foreman of Bachdalek
Less than 5% occur through the anterior foreman of Morgagni
90% occur on the left
The midgut herniates into the chest impairing lung development
Abnormalities of the pulmonary vasculature also result in pulmonary hypertension
Usually associated with gastrointestinal malrotation

Clinical features

May be diagnosed on antenatal ultrasound
Often presents with cyanosis and respiratory distress soon after birth
Prognosis is related to the time of onset and degree of respiratory impairment
Examination shows the abdomen to flat
Air entry is reduced on the affected side
Heart sounds are often displaced
Chest x-ray will confirm the presence of gastrointestinal loops in the chest
Occasionally presents with respiratory distress of intestinal obstruction later in life

Management

Respiratory support with intubation and ventilation is usually required
A nasogastric tube should be passed
Gas exchange and acid-base status should be assessed
Acidosis may need correction with bicarbonate infusion
Inhaled nitric oxide (NO) may reduce pulmonary hypertension
Surgery should be considered early after resuscitation
Hernial content are usually reduced via and abdominal approach
Hernial sac is excised and diaphragm repaired with nonabsorbable suture or a Gortex patch
A Ladd's procedure may be required for malrotation
A chest drain is usually not required
Early respiratory failure is associated with a poor prognosis

Bibliography

Schumpolick V, Steinau G, Schluper I, Prescher A. Surgical embryology and anatomy of the diaphragm with surgical applications. Surg Clin North Am 2000; 80: 213-239

Skarsgard E D, Harrison M R. Congenital diaphragmatic hernia: the surgeon's perspective. Pediatr Rev 1999; 20: 71-75.