Physiological Umbilical Cord Clamping in Patients With Congenital Diaphragmatic Hernia. Clinical Trial

Congenital diaphragmatic hernia (CDH) is a malformation that affects 1 in every 3000 newborns. The diaphragm does not complete its closure during embryogenesis, which allows the abdominal organs to herniate into the thoracic cavity altering lung development. The lungs of patients with CDH are small, with a decreased surface area for gas exchange and developmental impair of the pulmonary vasculature, resulting in respiratory failure and pulmonary hypertension shortly after birth. When clamping the umbilical cord, a large part of the preload is abruptly excluded, generating an increase in vascular resistance, which in turn increase the afterload, resulting in a decrease in cardiac output. The output is restored by decreasing vascular resistance in pulmonary circuit after lung aeration upon receiving the preload of the right atrium, increasing pulmonary flow and thus sustaining the preload of the left ventricle. If pulmonary aeration occurs before clamping the umbilical cord, the pulmonary blood flow increases before placenta flow is lost, thus avoiding a decrease in cardiac output. This modality has been called physiological base cord clamping (PFC). The hypothesis is that PFC once ventilation has been established could prevent hypoxia and improve cardiac output in newborns with CDH and secondarily improve their hemodynamic parameters, stabilizing gas exchange and pulmonary hypertension during the first 24 hours of birth.