Management of pulmonary hypertension in infants with congenital diaphragmatic hernia.

In infants with congenital diaphragmatic hernia (CDH), a posterolateral diaphragmatic defect results in herniation of abdominal contents into the chest and compression of the intrathoracic structures. In the most severe cases, hypoplasia of the ipsilateral and contralateral lungs, severe pulmonary hypertension (PH) and left ventricular (LV) hypoplasia/dysfunction all contribute to increased mortality. The management of PH in CDH is complicated by structural and functional changes in the heart, pulmonary vasculature, airways and lung parenchyma; consequently, determining optimal management strategies is challenging. Treatment of PH in patients with CDH changes as the underlying pathophysiology evolves in the days and weeks after birth. During the early transition, the use of pulmonary vasodilators is limited by LV structural and functional abnormalities, and pulmonary vasodilators such as inhaled nitric oxide (iNO) may have a limited role (for example, stabilization for extracorporeal membrane oxygenation (ECMO), treatment of marked preductal desaturation and treatment of PH as LV performance improves). In contrast, subacute treatment of PH in CDH with iNO has an important role in recurrent or persistent PH and potentially improves survival. Chronic PH and vascular abnormalities may persist into childhood in patients with CDH, contributing to late mortality. It is unclear how pulmonary vasodilator therapies, such as iNO, sildenafil and bosentan, will modulate late outcomes in CDH with late/chronic PH.

Challenges, priorities and novel therapies for hypoxemic respiratory failure and pulmonary hypertension in the neonate.

Future priorities for the management of hypoxemic respiratory failure (HRF) and pulmonary hypertension include primary prevention of neonatal lung diseases, 'precision medicine' and translating promising clinical and preclinical research into novel therapies. Promising areas of investigation include noninvasive ventilation strategies, emerging pulmonary vasodilators (for example, cinaciguat, intravenous bosentan, rho-kinase inhibitors, peroxisome proliferator-activated receptor-γ agonists) and hemodynamic support (arginine vasopressin). Research challenges include the optimal timing for primary prevention interventions and development of validated biomarkers that predict later disease or serve as surrogates for long-term respiratory outcomes. Differentiating respiratory disease endotypes using biomarkers and experimental therapies tailored to the underlying pathobiology are central to the concept of 'precision medicine' (that is, prevention and treatment strategies that take individual variability into account). The ideal biomarker should be expressed early in the neonatal course to offer an opportunity for effective and targeted interventions to modify outcomes. The feasibility of this approach will depend on the identification and validation of accurate, rapid and affordable point-of-care biomarker tests. Trials targeting patient-specific pathobiology may involve less risk than traditional randomized controlled trials that enroll all at-risk neonates. Such approaches would reduce trial costs, potentially with fewer negative trials and improved health outcomes. Initiatives such as the Prematurity and Respiratory Outcomes Program, supported by the National Heart, Lung, and Blood Institute, provide a framework to develop refined outcome measures and early biomarkers that will enhance our understanding of novel, mechanistic therapeutic targets that can be tested in clinical trials in neonates with HRF.

Predicting death or extended length of stay in infants with congenital diaphragmatic hernia.

OBJECTIVE: To predict mortality or length of stay (LOS) >109 days (90th percentile) among infants with congenital diaphragmatic hernia (CDH). STUDY DESIGN: We conducted a retrospective analysis using the Children's Hospital Neonatal Database during 2010 to 2014. Infants born >34 weeks gestation with CDH admitted at 22 participating regional neonatal intensive care units were included; patients who were repaired or were at home before admission were excluded. The primary outcome was death before discharge or LOS >109 days. Factors associated with this outcome were used to develop a multivariable equation using 80% of the cohort. Validation was performed in the remaining 20% of infants. RESULTS: The median gestation and age at referral in this cohort (n=677) were 38 weeks and 6 h, respectively. The primary outcome occurred in 242 (35.7%) infants, and was distributed between mortality (n=180, 27%) and LOS >109 days (n=66, 10%). Regression analyses showed that small for gestational age (odds ratio (OR) 2.5, P=0.008), presence of major birth anomalies (OR 5.9, P<0.0001), 5- min Apgar score ⩽3 (OR 7.0, P=0.0002), gradient of acidosis at the time of referral (P<0.001), the receipt of extracorporeal support (OR 8.4, P<0.0001) and bloodstream infections (OR 2.2, P=0.004) were independently associated with death or LOS >109 days. This model performed well in the validation cohort (area under curve (AUC)=0.856, goodness-of-fit (GF) χ(2), P=0.16) and acted similarly even after omitting extracorporeal support (AUC=0.82, GF χ(2), P=0.05). CONCLUSIONS: Six variables predicted death or LOS ⩾109 days in this large, contemporary cohort with CDH. These results can assist in risk adjustment for comparative benchmarking and for counseling affected families.