Use of hypoxic mixture in an infant with congenital heart disease with pulmonary hyperflow and moderate acute bronchiolitis: case report

Laura C. González-Hakspiel, Pediatric Cardiovascular Critical Care Unit, Cardiovascular Institute-Hospital Internacional de Colombia (HIC)–Fundación Cardiovascular de Colombia (FCV)–Fundación Universitaria FCV, Floridablanca, Colombia
Aylem N. Fonseca-Meneses, Pediatric Cardiovascular Critical Care Unit, Cardiovascular Institute-Hospital Internacional de Colombia (HIC)–Fundación Cardiovascular de Colombia (FCV)–Fundación Universitaria FCV, Floridablanca, Colombia
Andrés F. Rubio-Duarte, Congenital and Pediatric Heart Diseases Center. Cardiovascular Institute-Hospital Internacional de Colombia (HIC)–Fundación Cardiovascular de Colombia (FCV)–Fundación Universitaria FCV, Floridablanca, Colombia
Keyla M. Meneses-Silvera, Pediatric Cardiovascular Critical Care Unit, Cardiovascular Institute-Hospital Internacional de Colombia (HIC)–Fundación Cardiovascular de Colombia (FCV)–Fundación Universitaria FCV, Floridablanca, Colombia

Acute bronchiolitis is a major destabilizing factor in infants with congenital heart disease and left-to-right shunt lesions, as it exacerbates pulmonary overcirculation and compromises systemic perfusion. We report the case of a 5-month-old infant with a large ventricular septal defect, patent ductus arteriosus, and severe mitral regurgitation, all with significant hemodynamic repercussions, who developed moderate acute bronchiolitis caused by human metapneumovirus and parainfluenza virus type 3. Despite initial management with continuous positive airway pressure and intravenous vasodilators, the patient showed worsening respiratory distress and systemic hypoperfusion. A high-flow nasal cannula with a hypoxic gas mixture (FiO₂ 14.5%) Acute bronchiolitis is a major destabilizing factor in infants with congenital heart disease and left-to-right shunt lesions, as it exacerbates pulmonary overcirculation and compromises systemic perfusion. We report the case of a 5-month-old infant with a large ventricular septal defect, patent ductus arteriosus, and severe mitral regurgitation, all with significant hemodynamic repercussions, who developed moderate acute bronchiolitis caused by human metapneumovirus and parainfluenza virus type 3. Despite initial management with continuous positive airway pressure and intravenous vasodilators, the patient showed worsening respiratory distress and systemic hypoperfusion. A high-flow nasal cannula with a hypoxic gas mixture (FiO₂ 14.5%)

Keywords: Bronchiolitis. Continuous positive airway pressure. Vascular resistance. Pulmonary circulation. Congenital heart defects.