J Vis Exp. 2026 May 8;(231). doi: 10.3791/70620.
ABSTRACT
Bronchopulmonary dysplasia with pulmonary hypertension (BPD-PH) is a devastating complication of preterm birth that is associated with increased morbidity and mortality. Preterm birth disrupts normal lung and vascular development, and postnatal exposures such as mechanical ventilation and oxygen therapy can further impair lung and pulmonary vascular growth, contributing to the development of BPD-PH. In the preterm lamb model of evolving BPD, lambs are delivered preterm and mechanically ventilated for up to 21 days, incorporating interrupted lung development along with injury from mechanical ventilation and oxidative stress to recapitulate key features of evolving BPD-PH. The goal of the cardiac catheterization protocol is to directly assess pulmonary hemodynamics in preterm and term neonatal lambs. Lambs are intubated, mechanically ventilated, and sedated throughout the study. At the time of cardiac catheterization, a Swan-Ganz catheter is advanced through the external jugular vein to the superior vena cava and then through the right atrium, right ventricle, and main pulmonary artery. Cather position is confirmed by identification of characteristic pressure waveforms obtained during advancement through the right-sided cardiac chambers. Mean pulmonary artery pressure and pulmonary capillary wedge pressure are measured via pressure transduction, and cardiac output is determined by thermodilution to enable calculation of pulmonary vascular resistance. The protocol provides reproducible measurements of pulmonary hemodynamics that parallel those obtained during clinical cardiac catheterization in human neonates. By enabling direct assessment of pulmonary vascular pressures and resistance, this method enhances the translational utility of the preterm lamb model for mechanistic evaluation of potential therapies for BPD-PH.
PMID:42184224 | DOI:10.3791/70620