Secondary infection presenting as recurrent pulmonary hypertension

Primary infection in the neonate, especially group B streptococcal infection, has long been recognized as a cause of persistent pulmonary hypertension of the newborn (PPHN), sometimes requiring treatment with inhaled nitric oxide (iNO) and extracorporeal membrane oxygenation (ECMO). However, secondary nosocomial infections in the neonatal period have not been widely reported as a cause of severe recurrent pulmonary hypertension (PHTN). We now present two cases of secondary infection in the neonate leading to significant PHTN. In both cases, the infants presented with PPHN soon after birth, requiring transfer to a level 3 neonatal intensive care unit and treatment with high-frequency oscillatory ventilation and iNO. After successful resolution of the initial PPHN, including extubation to nasal cannula, both infants developed signs of severe recurrent PHTN, leading to reintubation, high-frequency oscillatory ventilation and iNO therapy, and consideration of ECMO. In both cases, blood cultures taken at the time of recurrence of PHTN returned positive, one for Staphylococcus epidermidis, the other for methicillin-resistant Staphylococcus aureus. These unusual cases present the possibility of severe recurrent PHTN requiring iNO or ECMO in the setting of secondary infection. We speculate that these infants, although extubated after their first episodes of PHTN, were at risk for recurrence of PHTN due to continued pulmonary vascular reactivity.