Chapter 143: Bronchopulmonary Dysplasia and Chronic Lung Disease of Infancy

BACKGROUND

Bronchopulmonary dysplasia (BPD) is an iatrogenic, chronic lung disorder of infancy that results in persistent respiratory symptoms, medical fragility, and in most cases, the long-term need for supplemental oxygen. With continuing advances in the care of critically ill neonates, the nomenclature of BPD is evolving, as is its incidence and pathogenesis. Today, BPD is often referred to as chronic lung disease of infancy (CLDI).¹ Both BPD and CLDI are chronic pulmonary disorders that result from an acute and often critical respiratory illness in a newborn infant, and there is considerable overlap in their pathogenesis, risk factors, and manifestations. Thus, the two terms are generally considered to be interchangeable.

BPD and CLDI develop in premature infants or critically ill neonates as a consequence of therapeutic maneuvers (oxygen and positive-pressure ventilation) required for survival. The risk of an infant developing BPD is related to gestational age, the severity of the initial illness, the duration and intensity of oxygen and ventilator therapy, and other factors that are less well characterized. These prognostic factors include variables specific to the infant, such as gender, race, genetic predilection, nutritional status, presence of patent ductus arteriosus, and other complications of newborn intensive care as well as maternal variables such as cigarette smoking during pregnancy and the presence of amnionitis.¹ These factors often result in significantly different clinical courses and outcomes in infants despite apparently similar care.

Most children with BPD have multisystem disease rather than isolated pulmonary involvement. The medical fragility associated with BPD and CLDI results in an increased risk of re-hospitalization after discharge from the nursery. The pediatric hospitalist will therefore encounter infants with BPD and CLDI and will be called on to address the problems unique to this complex group of patients. Many infants with BPD or CLDI are readmitted to the hospital within the first 2 years of life, with the highest incidence of re-hospitalization being in those born most prematurely.² Respiratory illness, most notably due to respiratory syncytial virus (RSV) or other viruses, is the most common reason, causing up to two thirds of readmissions, followed by gastroenteritis, feeding difficulties, and seizures.² Further, BPD and CLDI often have systemic manifestations that may complicate the respiratory management of these infants. If the extra-pulmonary manifestations are not recognized and addressed, they can interfere with lung growth and healing, which are necessary for the resolution of BPD and CLDI. Often the goal of therapy is to re-establish the infant’s baseline state or to diagnose and treat a new problem rather than to provide a definitive cure. This requires both skilled medical management and attention to the details of discharge planning.

CLINICAL PRESENTATION

When originally described by Northway and colleagues,³ BPD occurred primarily in relatively mature infants with an average birth weight of nearly 2 kg and a gestational age of 32 weeks, who developed hyaline membrane disease ...