Roberta L. Keller

Observed to expected lung area to head circumference ratio in the prediction of survival in fetuses with isolated diaphragmatic hernia.

To assess the value of antenatally determined observed to expected fetal lung area to head circumference ratio (LHR) in the prediction of postnatal survival in isolated, congenital diaphragmatic hernia (CDH).

Prenatal prediction of survival in isolated left-sided diaphragmatic hernia

To investigate the potential value of antenatally determined intrathoracic herniation of the liver and the ratio of fetal lung area to head circumference (LHR) in the prediction of postnatal survival in isolated, left‐sided congenital diaphragmatic hernia (CDH).

Pediatric Pulmonary Hypertension Guidelines From the American Heart Association and American Thoracic Society

Pulmonary hypertension is associated with diverse cardiac, pulmonary, and systemic diseases in neonates, infants, and older children and contributes to significant morbidity and mortality. However, current approaches to caring for pediatric patients with pulmonary hypertension have been limited by the lack of consensus guidelines from experts in the field. In a joint effort from the American Heart Association and American Thoracic Society, a panel of experienced clinicians and clinician-scientists was assembled to review the current literature and to make recommendations on the diagnosis, evaluation, and treatment of pediatric pulmonary hypertension. This publication presents the results of extensive literature reviews, discussions, and formal scoring of recommendations for the care of children with pulmonary hypertension.

Congenital diaphragmatic hernia: endothelin-1, pulmonary hypertension, and disease severity.

RATIONALE Endothelin-1 (ET1) is dysregulated in pulmonary hypertension (PH). It may be important in the pathobiology of congenital diaphragmatic hernia (CDH). OBJECTIVES We hypothesized that ET1 levels in the first month would be higher in infants with CDH who subsequently expired or were discharged on oxygen (poor outcome). We further hypothesized that ET1 levels would be associated with concurrent severity of PH. METHODS We sampled plasma at 24 to 48 hours, and 1, 2, and 4 weeks of age in 40 prospectively enrolled newborns with CDH. We performed echocardiograms to estimate pulmonary artery pressure at less than 48 hours of age and weekly to 4 weeks. PH was classified in relationship to systemic blood pressure (SBP): less than 2/3 SBP, 2/3 SBP-systemic is related to pressure, or systemic-to-suprasystemic pressure. MEASUREMENTS AND MAIN RESULTS ET1 levels at 1 and 2 weeks were higher in infants with poor outcome compared with infants discharged on room air (median and interquartile range: 27.2 [22.6, 33.7] vs. 19.1 [16.1, 29.5] pg/ml, P = 0.03; and 24.9 [17.6, 39.5] vs. 17.4 [13.7, 21.8] pg/ml, P = 0.01 at 1 and 2 weeks, respectively). Severity of PH was significantly associated with increasing ET1 levels at 2 weeks (16.1 [13.7, 21.8], 21.0 [17.4, 31.1], and 23.6 [21.9, 39.5] pg/ml for increasing PH class, P = 0.03). Increasing severity of PH was also associated with poor outcome at that time (P = 0.001). CONCLUSIONS Infants with CDH and poor outcome have higher plasma ET1 levels and severity of PH than infants discharged on room air. Severity of PH is associated with ET1 levels.

Long-term surgical outcomes in congenital diaphragmatic hernia: observations from a single institution

BACKGROUND/PURPOSE Surgical complications are common in survivors of congenital diaphragmatic hernia (CDH), but little is known about long-term incidence patterns and associated predictors. METHODS A cohort of 99 CDH survivors was prospectively followed at a single-institution multidisciplinary clinic. Data were gathered regarding the adverse surgical outcomes of hernia recurrence, chest and spinal deformity, and operative small bowel obstruction (SBO), and then were retrospectively analyzed in relation to perinatal and perioperative markers of disease severity to determine significant predictors. Statistical methods used included univariate and multivariate regression analysis, hazard modeling, and Kaplan-Meier analysis. RESULTS At a median cohort age of 4.7 (range, 0.2-10.6) years, 46% of patients with patch repairs and 10% of those with primary repairs had a hernia recurrence at a median time of 0.9 (range, 0.1-7.3) years after repair. Chest deformity was detected in 47%. Small bowel obstruction and scoliosis occurred in 13%. Recurrence and chest deformity were significantly more common with patch repair, liver herniation, age at neonatal extubation greater than 16 days, oxygen requirement at discharge, and prematurity. The strongest predictor of SBO was patch repair. Multivariate analysis showed that patch repair was independently predictive of recurrence and early chest deformity (odds ratios of 5.0 and 4.8, confidence intervals of 1-24 and 1-21, P < .05). Use of an absorbable patch was associated with the highest risk of surgical complications. CONCLUSIONS For long-term survivors of CDH, specific perinatal and operative variables, particularly patch repair, are associated with subsequent adverse surgical outcomes.

Infant pulmonary function in a randomized trial of fetal tracheal occlusion for severe congenital diaphragmatic hernia

Congenital diaphragmatic hernia (CDH) carries a high mortality risk secondary to pulmonary hypoplasia and respiratory failure. In experimental animals, fetal tracheal occlusion (TO) induces lung growth and morphologic maturation. We measured indicators of pulmonary function in 20 infants who were enrolled in a randomized trial of fetal TO as treatment for severe CDH [nine with conventional treatment (controls); 11 with TO]. We hypothesized that TO would improve lung function. At birth, the TO group had a lower mean gestational age (30.8 ± 2.0 versus 37.4 ± 1.0 wk; p = 0.0002). All infants required assisted ventilation. Mortality did not differ between groups (64 versus 78%, TO and control, respectively; p = 0.64). We measured respiratory mechanics at four study points: 1) first 24 h, 2) before CDH operative repair (5.9 ± 2.2 d), 3) immediately after repair (7.0 ± 2.2d), and 4) before elective extubation (32.5 ± 16.1 d). We calculated perioperative oxygenation index and alveolar-arterial oxygen difference to assess efficiency of pulmonary gas exchange. Data were analyzed by univariate and repeated measures techniques. Respiratory system compliance (Crs) was low. The rate of increase in Crs over the four study points was greater in the TO group than in control subjects. Crs in the TO group was significantly greater at study 2 (0.28 ± 0.12 versus 0.17 ± 0.04 mL · cm H2O−1 · kg−1; p = 0.02) and study 4 (0.93 ± 0.45 versus 0.51 ± 0.16 mL · cm H2O−1 · kg−1; p = 0.02). oxygenation index did not differ between groups, but alveolar-arterial oxygen difference was lower in the TO infants. We conclude that fetal TO for severe CDH results in modest improvements in neonatal pulmonary function that are of questionable clinical significance.

The lung-to-head ratio and fetoscopic temporary tracheal occlusion: prediction of survival in severe left congenital diaphragmatic hernia

To evaluate the reliability of sonographic lung‐to‐head ratio (LHR) measurement as a predictor of survival in fetuses with congenital diaphragmatic hernia (CDH) and to compare the probability of survival in those with temporary tracheal occlusion (TO) or standard care with respect to the LHR.

Treatment of rebound and chronic pulmonary hypertension with oral sildenafil in an infant with congenital diaphragmatic hernia.

Objective We describe a case of chronic pulmonary hypertension in a 7-wk-old infant with congenital diaphragmatic hernia and an oral teratoma. Our patient was dependent on low-dose inhaled nitric oxide and was still very unstable with systemic right ventricular pressures leading to frequent oxygen desaturations. We administered sildenafil therapy to stabilize the infant with discontinuation of inhaled nitric oxide. We describe successful discontinuation of the inhaled therapy as well as a period of stabilization and improvement with continued sildenafil administration. Design Case report. Setting Intensive care nursery in tertiary academic center. Patient A 7-wk-old infant with congenital diaphragmatic hernia who was mechanically ventilated from birth. Intervention Oral sildenafil 0.3 mg/kg/dose every 12 hrs. Measurements and Results Right ventricular pressure (from tricuspid valve regurgitant flow) to systemic systolic arterial pressure was measured by echocardiogram. Right ventricular to systemic pressure ratio was marginally improved with the initiation of sildenafil therapy. Inhaled nitric oxide was successfully discontinued, and the patient clinically stabilized temporarily, but he ultimately succumbed to his pulmonary hypertension. Conclusion Sildenafil may be a useful therapy for chronic pulmonary hypertension in congenital diaphragmatic hernia, but further studies of safety and efficacy need to be performed.

Abnormal vascular tone in infants and children with lung hypoplasia: Findings from cardiac catheterization and the response to chronic therapy.

Objective: We describe four cases of chronic pulmonary hypertension in infants and children with chronic lung disease and pulmonary hypoplasia due to severe congenital diaphragmatic hernia (CDH) or congenital cystic adenomatoid malformation (CCAM). We report data from cardiac catheterization under various conditions: baseline respiratory support and room air, hyperoxic and inhaled nitric oxide challenge. We further report cardiac catheterization measures after chronic pulmonary vasodilator therapy with sildenafil alone or a combination of sildenafil and inhaled nitric oxide (three patients). Design: Case series. Setting: Tertiary academic center. Patients: Infants and children ages 0–11 yrs with CDH (n = 3) or CCAM (n = 1) with evidence of chronic pulmonary hypertension by echocardiogram and cor pulmonale (n = 3). Interventions: Catheterization and pulmonary vasodilator therapy. Measurements and Main Results: Pulmonary vascular resistance, pulmonary arterial pressure, and changes in these measures were assessed. A 20% change in pulmonary vascular resistance was considered a clinically significant response. Ten catheterizations were performed in four patients. All patients had elevated pulmonary vascular resistance and pulmonary arterial pressures at initial catheterizations and significant vasodilation during inhaled nitric oxide. Conclusions: Chronic lung disease following pulmonary hypoplasia from CDH and CCAM is associated with abnormal pulmonary vascular tone in infants and children with evidence of chronic pulmonary hypertension. Chronic pulmonary vasodilator therapy may improve pulmonary vascular function and enhance lung growth in infants and children who are treated during their period of potential for rapid lung growth.

Two-Year Neurodevelopmental Outcomes of Ventilated Preterm Infants Treated with Inhaled Nitric Oxide

OBJECTIVE In a randomized multi-center trial, we demonstrated that inhaled nitric oxide begun between 7 and 21 days and given for 24 days significantly increased survival without bronchopulmonary dysplasia (BPD) in ventilated premature infants weighing <1250 g. Because some preventative BPD treatments are associated with neurodevelopmental impairment, we designed a follow-up study to assess the safety of nitric oxide. STUDY DESIGN Our hypothesis was that inhaled nitric oxide would not increase neurodevelopmental impairment compared with placebo. We prospectively evaluated neurodevelopmental and growth outcomes at 24 months postmenstrual age in 477 of 535 surviving infants (89%) enrolled in the trial. RESULTS In the treated group, 109 of 243 children (45%) had neurodevelopmental impairment (moderate or severe cerebral palsy, bilateral blindness, bilateral hearing loss, or score <70 on the Bayley Scales II), compared with 114 of 234 (49%) in the placebo group (relative risk, 0.92; 95% CI, 0.75-1.12; P = .39). No differences on any subcomponent of neurodevelopmental impairment or growth variables were found between inhaled nitric oxide or placebo. CONCLUSIONS Inhaled nitric oxide improved survival free of BPD, with no adverse neurodevelopmental effects at 2 years of age.