Objective: Evolution of gas exchange during Intact Cord Resuscitation (ICR) remains unexplored. We aimed to investigate changes in placental hemodynamics and gas exchange during ICR in lambs with and without Congenital Diaphragmatic Hernia (CDH). Study Design: Eight CDH lambs (4.2 kg, 4 females) and nine controls (3.9 kg, 3 females) underwent ICR. At 80 days gestation (term=142 days), CDH was induced by diaphragmatic incision. After c-section at term, mean arterial pressure (MAP) was monitored via an aortic catheter. Umbilico-placental blood flow (Qup) was assessed with a flow transducer on the umbilical artery. Umbilical venous pressure was recorded, and blood gases from the aorta and umbilical vein were analyzed to evaluate placental oxygen transfer. ICR was performed for 60 min, followed by cord clamping (CC). Results: Qup and umbilical venous PO2 were similar and stable in both groups up to 50 min. MAP was 20% lower in normal lambs compared to CDH lambs (poxygen transfer was maintained during ICR (2.7 2.2-3.3ml/kg/min). PaCO2 was unchanged during ICR (53 50-58 mmHg) and abruptly increased after CC (83 60-101mmHg) (p2 (Minute 0= 16 12;18 mmHg; Minute 20= 50 48-105mmHg and 75 50;110mmHg after CC). Conclusions: ICR may support oxygenation and carbon dioxide removal in CDH newborns through placental gas exchange.
Duc et al. (Wed,) studied this question.