Magnetic Resonance Imaging Assessment of Pulmonary Vascularity in Infants with Congenital Diaphragmatic Hernia: A Novel Tool for Direct Assessment of Severity of Pulmonary Hypertension and Hypoplasia.

OBJECTIVES: To assess the feasibility of magnetic resonance imaging (MRI) for postnatal assessment of pulmonary vascularity in infants with congenital diaphragmatic hernia (CDH). STUDY DESIGN: Infants with prenatally diagnosed CDH (n = 24) received postnatal pulmonary MRI. Infants with nonpulmonary birth defects served as controls (n = 5). Semiautomatic segmentation was performed to obtain total vascular volume using time of flight images to assess vascularity. RESULTS: Average vascular density (vascular volume/lung volume) in control infants was 0.23 ± 0.06 mm3/mm3 compared with 0.18 ± 0.06 mm3/mm3 in infants with CDH is (P = .09). When stratified further based on CDH severity, the difference between control infants and moderate CDH group was statistically significant. (0.23 mm3/mm3 vs 0.15 mm3/mm3, P = .01). Ipsilateral vascular density on MRI in infants with CDH significantly correlated with the prenatal pulmonary hypertensive index (P = .0004, Spearman R = +0.87) and with number of days on mechanical ventilation (P = .04, Spearman R = -0.44), total days on inhaled nitric oxide (P = .02, Spearman R = -0.47), use of epoprostenol for acute pulmonary hypertension (PH) (0.14 mm3/mm3 vs 0.20 mm3/mm3, P = .005), and use of sildenafil for chronic PH (0.15 mm3/mm3 vs 0.19 mm3/mm3, P = .03). CONCLUSIONS: Our results suggest that postnatal pulmonary vascularity assessed by MRI strongly correlates with prenatal and postnatal markers of PH severity and that pulmonary vascularity may serve as a direct measure of pulmonary vascular hypoplasia in infants with CDH.

Evaluation of Neonatal Lung Volume Growth by Pulmonary Magnetic Resonance Imaging in Patients with Congenital Diaphragmatic Hernia.

OBJECTIVE: To evaluate postnatal lung volume in infants with congenital diaphragmatic hernia (CDH) and determine if a compensatory increase in lung volume occurs during the postnatal period. STUDY DESIGN: Using a novel pulmonary magnetic resonance imaging method for imaging neonatal lungs, the postnatal lung volumes in infants with CDH were determined and compared with prenatal lung volumes obtained via late gestation magnetic resonance imaging. RESULTS: Infants with left-sided CDH (2 mild, 9 moderate, and 1 severe) were evaluated. The total lung volume increased in all infants, with the contralateral lung increasing faster than the ipsilateral lung (mean ± SD: 4.9 ± 3.0 mL/week vs 3.4 ± 2.1 mL/week, P = .005). In contrast to prenatal studies, the volume of lungs of infants with more severe CDH grew faster than the lungs of infants with more mild CDH (Spearman's ρ=-0.086, P = .01). Although the contralateral lung volume grew faster in both mild and moderate groups, the majority of total lung volume growth in moderate CDH came from increased volume of the ipsilateral lung (42% of total lung volume increase in the moderate group vs 32% of total lung volume increase in the mild group, P = .09). Analysis of multiple clinical variables suggests that increased weight gain was associated with increased compensatory ipsilateral lung volume growth (ρ = 0.57, P = .05). CONCLUSIONS: These results suggest a potential for postnatal catch-up growth in infants with pulmonary hypoplasia and suggest that weight gain may increase the volume growth of the more severely affected lung.

The prevalence and diagnostic utility of systemic inflammatory response syndrome vital signs in a pediatric emergency department.

OBJECTIVES: This study sought to determine the prevalence, test characteristics, and severity of illness of pediatric patients with systemic inflammatory response syndrome (SIRS) vital signs among pediatric emergency department (ED) visits. METHODS: This was a retrospective descriptive cohort study of all visits to the ED of a tertiary academic free-standing pediatric hospital over 1 year. Visits were included if the patient was <18 years of age and did not leave before full evaluation or against medical advice. Exclusion criteria were trauma diagnoses or missing documentation of vital signs. Data were electronically extracted from the medical record. The primary predictor was presence of vital signs meeting pediatric SIRS definitions. Specific vital sign pairs comprising SIRS were evaluated as predictors (temperature-heart rate, temperature-respiratory rate, and temperature-corrected heart rate, in which a formula was used to correct heart rate for degree of temperature elevation). The primary outcome measure was requirement for critical care (receipt of a vasoactive agent or intubation) within 24 hours of ED arrival. RESULTS: There were 56,210 visits during the study period; 40,356 met inclusion criteria. Of these, 6,596 (16.3%) visits had fever >38.5°C, and 6,122 (15.2% of included visits) met SIRS vital sign criteria. Among included visits, those with SIRS vital signs accounted for 92.8% of all visits with fever >38.5°C. Among patients with SIRS vital signs, 4993 (81.6%) were discharged from the ED without intravenous (IV) therapy and without 72-hour readmission. Critical care within the first 24 hours was present in 99 (0.25%) patients: 23 patients with and 76 without SIRS vital signs. Intensive care unit (ICU) admission was present in 126 (2.06%) with SIRS vital signs and 487 (1.42%) without SIRS vital signs. SIRS vital signs were associated with increased risk of critical care within 24 hours (relative risk [RR] = 1.69, 95% confidence interval [CI] = 1.06 to 2.70), ICU admission (RR = 1.45, 95% CI = 1.19 to 1.76), ED laboratory tests (RR = 1.41, 95% CI = 1.37 to 1.45), ED IV medication/fluid administration (RR = 2.54, 95% CI = 2.29 to 2.82), hospital admission (RR = 1.52, 95% CI = 1.42 to 1.63), and 72-hour readmission (RR = 1.31, 95% CI = 1.01 to 1.69). SIRS vital signs were not associated with 30-day in-hospital mortality (RR = 0.37, 95% CI = 0.05 to 2.82). SIRS vital signs had a low sensitivity for critical care requirement (23.2%, 95% CI = 15.3% to 32.8%). The pair of SIRS vital signs with the strongest association with critical care requirement was temperature and corrected heart rate (positive likelihood ratio = 2.74, 95% CI = 1.87 to 4.01). CONCLUSIONS: Systemic inflammatory response syndrome vital signs are common among medical pediatric patients presenting to an ED, and critical illness is rare. The majority of patients with SIRS vital signs were discharged without IV therapy and without readmission. Patients with SIRS vital signs had a statistically significant increased risk of critical care requirement, ED IV treatment, ED laboratory tests, admission, and readmission. However, SIRS vital sign criteria did not identify the majority of patients with mortality or need for critical care. SIRS vital signs had low sensitivity for critical illness, making it poorly suited for use in isolation in this setting as a test to detect children requiring sepsis resuscitation.