Respiratory Diseases in the Newborn

Abstract

Respiratory diseases are frequently caused by immature respiratory and cardiovascular systems in the premature newborn and by adaptation mechanisms related to asphyxia and congenital malformations in the full-term newborn. Perinatal infections affect both premature and full-term newborns. Respiratory diseases can be classified as those caused by (a) perinatal asphyxia, (b) related to immaturity and lung liquid reabsorption, (c) related to lung circulation, (d) caused by infections in the newborn, and (e) caused by congenital alterations of the airway and lungs. The clinical picture is usually referred to as respiratory distress syndrome characterized by the presence of tachypnea, retraction, grunting, cyanosis, and apnea, whether of a respiratory or nonrespiratory source. A detailed perinatal anamnesis based on risk factors, an exhaustive physical examination, and complementary laboratory testing are essential for determining a precise diagnosis. Adequate management of each condition depends on the understanding of the underlying physiopathological mechanisms. Respiratory diseases increase mortality and morbidity rates in the newborn. The change from intrauterine breathing through the placenta to the external pulmonary breathing grants a unique feature to these problems, which are, to a great extent, caused by the alteration of the cardiopulmonary adaptation. In premature newborns, immature respiratory and cardiovascular systems are the most important cause of respiratory diseases. For the term newborn, adaptation mechanisms are mainly altered by asphyxia and congenital malformations. Perinatal infections affect both term and preterm newborns and are a frequent cause of respiratory problems.