Early Abnormalities in Gas Exchange in Infants with Congenital Diaphragmatic Hernia

Abstract

To determine how blood gas exchange is altered during the transition in the first hour of life in infants with congenital diaphragmatic hernia (CDH). This was a prospective observational cohort study evaluating arterial blood gas (ABG) samples and ventilator support in 34 infants with CDH in the first hour of life. Infants were stratified into mild, moderate, and severe CDH. The first ABG was compared with the umbilical cord ABGs and response to intervention evaluated on subsequent ABGs among infants with different CDH severities. Infants were intubated at a median of 120seconds (range 50-240seconds) and ABGs obtained at a median of 6minutes (IQR 4, 8minutes), 16minutes (IQR 13.5, 22.5minutes), and 60minutes (IQR 56, 64minutes). Compared with the cord ABG, first ABG mean partial pressure of carbon dioxide (PaCO2) increased from 49.8mm Hg to 82.1mm Hg, mean base deficit decreased from -2.2 to -7.3, and mean pH from 7.298 to 7.060. With ventilator adjustments, second mean PaCO2 decreased to 76.7mm Hg and third mean PaCO2 48.5mm Hg. When stratified, with all CDH severities PaCO2 increased abruptly, remained elevated in moderate and severe CDH, and improved in all severities by 60minutes after delivery. Gas exchange is markedly altered in the first hour of life in infants with CDH with abrupt onset of acidemia and a mixed respiratory and metabolic acidosis. Early implementation of adequate cardiopulmonary support may contribute to more timely stabilization of gas exchange.