positive-pressure ventilation (and various ventilation strategies), and inadequate nutrition The disease process is thought to begin after inflammation and injury to the lung, with resultant arrest of alveolar septation and impaired microvascular development This occurs most commonly in infants with hyaline membrane disease or other acute perinatal lung disease Infants with apnea, congenital heart disease, or other illnesses requiring prolonged ventilation in the first weeks of life are also at risk Utilization of improved ventilation strategies, as well as antenatal glucocorticoids, surfactant, and improvement in nutrition, has improved outcomes in children with BPD In the emergency setting, patients with BPD may present with acute exacerbations of their chronic lung disease Furthermore, BPD is a risk factor for increased severity of other respiratory illnesses Goals of Treatment Treatment of BPD exacerbations involves supportive care with focused attention on the need for supplemental oxygenation and ventilation support, as well as the hydration status Bronchodilators, inhaled corticosteroids (ICSs), and diuretics may also be helpful Clinical Considerations Clinical Recognition BPD should be suspected among premature infants, as well as in children previously requiring either assisted ventilation and/or prolonged supplemental oxygen therapy Emergency providers most often will evaluate children with BPD when their underlying disease is worsened by intercurrent acute respiratory infections More than 50% of infants with BPD require admission for respiratory illness within a year of their diagnosis Of particular importance is respiratory syncytial virus (RSV) infection, which typically causes bronchiolitis with fever, tachypnea, crackles, and wheezing Patients with BPD who develop RSV bronchiolitis are prone to more severe courses, including higher rates of ICU admission, need for mechanical ventilation, and mortality Triage Children with BPD exacerbations may present with significant distress and may require prompt evaluation and treatment