**Core Concept**
A congenital diaphragmatic hernia (CDH) is a condition where there is a hole in the diaphragm, allowing abdominal organs to move into the chest cavity and compromise lung development. In neonates with CDH, respiratory distress is common due to pulmonary hypoplasia and the resulting shift of mediastinal structures towards the affected side.

**Why the Correct Answer is Right**
The correct answer involves recognizing the need for decompression of the abdominal contents to improve lung expansion and prevent further cardiac compromise. The maximal cardiac impulse shifting to the right side indicates that the heart is being pushed away from the left side, where the hernia is present. This can lead to decreased cardiac output and further compromise the neonate's respiratory status.

**Why Each Wrong Option is Incorrect**
**Option A:** Chest X-ray would be useful for diagnosis but not as an immediate next step in management. The immediate concern is to improve lung expansion and cardiac output.
**Option B:** Intubation and ventilation have already been performed, and the next step is to address the underlying cause of respiratory distress.
**Option C:** Surgical repair is the definitive treatment for CDH but not the immediate next step in management. Decompression of the abdominal contents is required before surgery.

**Clinical Pearl / High-Yield Fact**
In neonates with CDH, the presence of bowel loops in the chest cavity can be confirmed on X-ray by the presence of air-fluid levels and bowel gas. This is a critical finding that guides further management.

**Correct Answer:** D. Decompression of the hernia using a nasogastric tube or a balloon tamponade should be the next step in management to improve lung expansion and cardiac output.