Pediatric emergency medicine trisk 0232 0232

initiated Expansion of the lungs increases the neonate’s PaO2 and pH, which causes pulmonary vasodilation and a subsequent fall in pulmonary vascular resistance The initial breaths taken by the infant must inflate the lungs and effect a change in vascular pressures so that the lung water is absorbed into the pulmonary arterial system and cleared from the lung This inflation pressure is a powerful mechanism for the release of pulmonary surfactant, which increases compliance of the lung and establishes functional residual capacity Full alveolar development and sufficient surfactant production is not complete until 34 weeks’ gestation Prior to 23 to 24 weeks’ gestation, there is a lack of surfactant and terminal airways have not developed, therefore resuscitation prior to 23 to 24 weeks is rarely successful outside of a controlled neonatal intensive care environment