A 2.35 kg singleton female was born at 37-3/7 weeks gestation after in-vitro fertilization. The antenatal course was notable for intrauterine growth restriction and polyhydramnios. Fetal MRI evaluation demonstrated lung volumes of 46% to 59% of the mean for gestational age. Delivery was by repeated cesarean section, and she required airway intubation and mechanical ventilation within the first few minutes after birth because of respiratory distress. She was supported by high frequency oscillatory ventilation, and inhaled nitric oxide was added to her regimen because of persistent shunting.
Chest CT imaging with contrast on the second day of life demonstrated symmetric, diffuse bilateral pulmonary hypoplasia without focal lesions, vascular anomalies or other signs of alveolar growth disorders. The study also confirmed findings of pulmonary hypertension, with mild enlargement of the main pulmonary artery and mild right ventricular enlargement. Whole exome sequencing subsequently demonstrated a de novo missense mutation in the PBX1 gene as the likely cause of her pulmonary findings. Other diagnoses addressed and treated throughout her hospital stay included pulmonary hypertension by cardiac catheterization, severe gastroesophageal reflux s/p fundoplication, and eventration of the right hemidiaphragm.
The infant remained in the Newborn/Infant Intensive Care Unit (N/IICU) for the next eight months. She was supported by invasive mechanical ventilation for almost two months, and then by noninvasive bi-level positive airway pressure (BPAP) support. Attempts to wean to less support resulted in episodes of dyspnea, so the ventilatory strategy was changed to continuous BPAP support, but with daytime BPAP delivered via a RAM cannula to provide support less intrusively during awake hours, while a nasal mask was used overnight. The daytime BPAP settings were titrated to deliver an inspiratory pressure high enough not only to be able to unload inspiratory muscles and assist ventilation, but also to account for leak.
Once a stable ventilation regimen was established, the infant transferred to the Pulmonary floor at CHOP where she remained for an additional six months to refine her care plan and to ready her family for her discharge to home. Her parents were trained in all aspects of her care including her ventilator management, cardiorespiratory assessments, gastro-jejunostomy tube feedings, and administration of inhaled and enteral medications. Her growth and developmental milestones were monitored, and therapies were adjusted as needed. She was able to be discharged home with 16 hours/day of skilled nursing care just before she was 14 months old.
This patient’s ongoing pulmonary care was assumed by members of the Technology Dependence Center (TDC) of the Division of Pulmonary and Sleep Medicine following her discharge. Although she lives out of state, through weekly telephone calls and periodic office visits, she was gradually able to wean from all daytime respiratory support by 29 months of age. She continues to use BPAP with sleep to treat moderate obstructive sleep apnea. She was able to stop sildenafil use and no longer has evidence of pulmonary hypertension on echocardiogram. She is now 4 years old, attends regular preschool, and has weathered several acute respiratory illnesses without the need for rehospitalization.
This child’s successful outcome was the result of close collaboration among the teams that cared for her in the N/IICU, on the pulmonary floor and with the TDC after her return home, along with the attentive and thoughtful support of her family. The unconventional use of continuous noninvasive ventilation allowed this child to avoid placement of a tracheostomy while still providing her support for good growth and development.
This patient is one of approximately 900 children followed long term in the TDC at CHOP who require some form of technology for breathing assistance outside of the hospital. The TDC helps to provide a seamless transition from hospital to home. With the assistance of family and primary care providers, the TDC’s multidisciplinary team of physicians, nurses, social workers, nutritionist and respiratory therapist help keep children safely at home and, whenever possible, work to liberate children from respiratory technology as they grow and recover.
For more information about CHOP’s Pulmonary Hypoplasia Program or to make a referral, call 215-590-2733 or visit us online.