Anesthetic Considerations in Gastroschisis & Omphalocele

GASTROSCHISIS & OMPHALOCELE

Pathophysiology

Gastroschisis and omphalocele are congenital disorders characterized by defects in the abdomi-nal wall that allow external herniation of viscera. Omphaloceles occur at the base of the umbili-cus, have a hernia sac, and are often associated with other congenital anomalies such as trisomy 21, diaphragmatic hernia, and cardiac and blad-der malformations. In contrast, the gastroschisis defect is usually lateral to the umbilicus, does not have a hernia sac, and is often an isolated finding. Antenatal diagnosis by ultrasound can be followed by elective cesarean section at 38 weeks and imme-diate surgical repair. Perioperative management centers around preventing hypothermia, infection, and dehydration. These problems are usually more serious in gastroschisis, as the protective hernial sac is absent.

Anesthetic Considerations

The stomach is decompressed with a nasogastric tube before induction. Intubation can be accom-plished with the patient awake or asleep and with or without muscle relaxation. Nitrous oxide should be avoided to prevent further bowel distention. Muscle relaxation is required for replacing the bowel into the abdominal cavity. A one-stage closure (primary repair) is often not advisable, as it can cause an abdominal compartment syndrome. A staged clo-sure with a temporary Silastic “silo” may be neces-sary, followed by a second procedure a few days later for complete closure. Suggested criteria for a staged closure include intragastric or intravesical pressure greater than 20 cm H₂O, peak inspiratory pres-sure greater than 35 cm H₂O, or an end-tidal CO₂ greater than 50 mm Hg. Third-space fluid lossesare replaced with a balanced salt solution and 5% albumin. The neonate remains intubated after theprocedure and is weaned from the ventilator over the next 1–2 days in the ICU.