Lesson 3

Congenital Diaphragmatic Hernia (CDH)

  • Definition: Diaphragmatic defect allowing abdominal contents into thoracic cavity.

  • Common Herniation Site: Foramen of Bochdalek (usually left side).

  • Other Sites: Foramen of Morgagni, paraesophageal areas.

Pathophysiology

  • Effects on Lungs:

    • Impairs lung development, leading to pulmonary hypoplasia.

    • Consequences: Poor pulmonary vascular development, increased pulmonary vascular resistance (PVR), pulmonary hypertension, airway impairment.

Anesthetic Management

  • Ventilation Strategy:

    • Keep peak inspiratory pressure (PIP) < 25-30 cm H2O to minimize barotrauma.

    • Maintain permissive hypercapnia despite increasing PVR.

    • Use one-lung ventilation if needed (advance ETT into mainstem bronchus of "good" lung).

  • Monitoring:

    • Preductal oxygen saturation (right upper extremity).

    • Should maintain SpO2 > 90%.

    • Monitor for increased intra-abdominal pressure using lower extremity pulse oximeter.

  • Delayed Surgery:

    • Wait 5-15 days for stabilization of pulmonary, cardiac, and metabolic status.

    • Surgery can be open or thoracoscopic; thoracoscopy may negatively affect acid-base balance.

  • Avoid: Conditions that increase PVR: hypoxia, acidosis, hypothermia.