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

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.

• Type of study: Randomized clinical trial
• Primary objective: To establish the effectiveness of PFC in reducing hypoxia and improving cardiac output compared to immediate postintubation clamping in newborns with CDH. To establish the safety and feasibility of PFC after pulmonary recruitment achieved post intubation.
• Secondary objectives: describe the evolution of patients with CDH 24 hours after birth under pre-established conditions. Relate prenatal indices to the subsequent evolution of these patients. Describe maternal evolution and postpartum complications.
• Population: Patients who attend the Fetal Diagnosis and Treatment program of Garrahan Children's Hospital and undergo prenatal diagnosis of CDH are possible candidates. The study will be carried out in the Neonatal Intensive Care Unit of said hospital.
• Scope of the study: Garrahan Children's Hospital is a level 3 B pediatric hospital and national referral center located in Autonomous City of Buenos Aires, Argentina. Center that receives neonates with CDH referred from all over the country as well as from other countries in the region and carries out the relevant training for equal reception.
• Block randomization: will be carried out on the same day, 2 hours before entering the delivery room
• Intervention: Immediately after birth, the newborn will be placed on a mobile table, made to received these patients in the delivery room, at the level of the mother's womb, leaving the umbilical cord intact, intubated and gently ventilated (positive inspiration pressure (PIM) 15/25 - positive end expiratory pressure (PEEP)4 - fraction of inspired oxygen inspired oxygen fraction (FiO2) 50%), until saturation >85% and heart rate (HR) >100 or 10 timed minutes pass, whichever occurs first, the umbilical cord will be clamped and continued with the usual reception steps in accordance with the unit´s CDH reception protocol.
• Sample size: To calculate the sample size, a prevalence of hemodynamic alterations of 60% was considered in the first 24 hours of life of patients with CDH, following unit statistics and the aforementioned bibliography. The estimated sample size with a relative reduction of 50%: reduction from 60% to 30% of hemodynamic alterations - Power of 80% - Two-tailed test - alpha 5%. 40 patients required in each branch.

Inclusion Criteria:

• Prenatal diagnosis of congenital diaphragmatic hernia
• gestational age >34 weeks
• Informed consent signed by the patient's parents

Exclusion Criteria:

• Multiple gestation
• Major malformation or fetal genetic anomaly diagnosed in the prenatal stage
• Emergency cesarean section or maternal condition that prevents the approach
• Lack of informed consent