Presurgical pulmonary function tests in the first few days of life in neonates with congenital heart disease, a pilot study

Objective: To compare early pulmonary function tests (PFTs) in neonates with critical congenital heart disease (CHD) compared to a historical reference group. Design: Infants ≥ 37 weeks gestation with critical CHD were studied within the first few days of life, prior to cardiac surgery, and compared to data from a published reference group of healthy term neonates without CHD, studied at the same institution. Passive respiratory resistance (Rrs) and compliance (Crs) were measured with the single breath occlusion technique following specific acceptance criteria. The study was powered for a 30% difference in Rrs. Results: PFTs in 24 infants with CHD were compared to 31 historical reference infants. There was no difference in the Rrs between the groups. The infants with CHD had a significantly decreased Crs (1.02 ± 0.26 mL/cmH2O/kg versus 1.32 ± 0.36; (p < 0.05; mean ± SD)). Conclusions: Further prospective studies are required to quantify early PFTs in infants with CHD of different phenotypes.