Early Pulmonary Hypertension in Preterm Infants.

Pulmonary hypertension (PH) in preterm neonates has multifactorial pathogenesis with unique characteristics. Premature surfactant-deficient lungs are injured following exposure to positive pressure ventilation and high oxygen concentrations resulting in variable phenotypes of PH. The prevalence of early PH is variable and reported to be between 8% and 55% of extremely preterm infants. Disruption of the lung development and vascular signaling pathway could lead to abnormal pulmonary vascular transition. The management of early PH and the off-label use of selective pulmonary vasodilators continue to be controversial.

Fluid Intake in the First Week of Life and the Duration of Hemodynamically Significant Patent Ductus Arteriosus in Extremely Preterm Infants.

OBJECTIVE: This study aimed to determine the association between daily fluid intake and the duration of hemodynamically significant patent ductus arteriosus (hsPDA). STUDY DESIGN: This is a retrospective cohort study of extremely preterm infants (<29 weeks) admitted in the Neonatal Intensive Care Unit of the Advent Health for Children from January 2013 to March 2016, if hsPDA was diagnosed in first week of life and serial echocardiograms were available. Diagnosis of hsPDA was based on a scoring system and its duration was estimated from serial echocardiograms. Cohort was divided into two groups based on duration of hsPDA (<1week, group A and ≥1 week, group B). Daily fluid intake was categorized as prescribed and actual. Prescribed volume was ordered by clinicians based on birth weight, not including trophic feeds, intravenous (IV) boluses or transfusions, etc. Actual intake was calculated by the electronic medical records based on daily weights and included all enteral or parenteral fluids. Multivariate analysis was performed to determine an association between total daily fluid intake over the first week of life and the duration of hsPDA. Two groups were compared to observe the difference between prescribed and actual daily fluid intakes. RESULTS: We enrolled 50 infants in group A and 76 in group B. Infants in group B were of significantly lower gestation and required prolonged ventilation and hospitalization. An association between higher fluid intake in the first 2 days of life and prolonged duration of hsPDA was confirmed by multivariate analysis. Actual fluid intake was significantly higher than prescribed total fluid intake in first 4 days of life for infants in both groups. CONCLUSION: In extremely preterm infants, higher fluid intake in first 2 days of life is associated with prolonged duration of hsPDA. Actual daily fluid intake can be significantly higher than prescribed daily fluids due to daily weight changes and additional fluid administration. KEY POINTS: · In preterm infants, actual daily fluid intake may be higher than prescribed volume.. · Higher daily fluid intake in first week of life is associated with prolonged duration of PDA.. · PDA scoring system can be helpful for objective assessment of PDA in preterm infants..

Tracheomegaly among Extremely Preterm Infants on Prolonged Mechanical Ventilation.

By using phantom radiographs, the accuracy of tracheal measurements was established. Preterm infants (≤29 weeks) were enrolled in short (<7 days) and prolonged ventilation (≥28 days) groups. Both groups had 3 weight categories, namely, <1000 g, 1000-1999 g, and >2000 g. Tracheal sizes were measured on serial chest radiographs (CXR). We noted tracheomegaly in association with prolonged ventilation at ≥1000 g.

Duration of significant patent ductus arteriosus and bronchopulmonary dysplasia in extremely preterm infants.

OBJECTIVE: To demonstrate the association between the duration of significant patent ductus arteriosus (PDA) and bronchopulmonary dysplasia (BPD) in extremely preterm infants. METHODS: All extremely preterm infants (<29 weeks) treated in our Neonatal Intensive Care Unit from January 2013 to March 2016 were included if their PDA status was confirmed at <7 days of life. Infants with genetic syndromes, complex congenital anomalies and insignificant PDAs were excluded. Total duration of significant PDA was estimated by reviewing serial echocardiograms. Significant PDA was diagnosed using our scoring system that was based upon echocardiographic parameters and clinical status of the infants. Study cohort was divided into four groups based on the duration of significant PDA. Group A-No PDA, Group B-PDA <1-week, Group C- PDA 1-2 weeks, and Group D-PDA >2 weeks. ANOVA and multivariate analysis were performed to compare the groups. RESULTS: There were 147 infants with no PDA (Group A), 50, 35, and 41 infants were enrolled in Groups B, C, and D, respectively. There were no differences in maternal and neonatal variables among groups except for the following: maternal smoking, chorioamnionitis, antenatal indomethacin, gestation, birth weight, mode of delivery and incidence of death or BPD. Logistic regression analysis showed that longer duration of significant PDA was associated with higher risk for death or BPD (adjusted OR 1.37, 95% CI 1.03-1.82). CONCLUSION: Longer duration of significant PDA is associated with the higher risk for BPD/death in extremely preterm infants.

Natural History of Postnatal Cardiopulmonary Adaptation in Infants Born Extremely Preterm and Risk for Death or Bronchopulmonary Dysplasia.

OBJECTIVE: To study the natural history of postnatal cardiopulmonary adaptation in infants born extremely preterm and establish its association with death or bronchopulmonary dysplasia (BPD). STUDY DESIGN: This was a prospective, observational, cohort study of infants born extremely preterm (<29 weeks). Initial echocardiogram was performed at <48 hours of life, followed by serial echocardiograms every 24-48 hours until 14 days of life. Resolution or no resolution of pulmonary hypertension (PH) at 72-96 hours was considered normal or delayed postnatal cardiopulmonary adaptation, respectively. PH between 96 hours and 14 days was defined as subsequent PH. Elevated pulmonary artery pressure throughout the 14 days of life was considered persistent PH. BPD was assessed at 36 weeks of postmenstrual age. RESULTS: Sixty infants were enrolled; 2 died before a sequential echocardiogram could be done at 72-96 hours. Normal and delayed cardiopulmonary adaptation were noted in 26 (45%) and 32 (55%) infants, respectively. Five patterns of postnatal cardiopulmonary adaptation were recognized: normal without subsequent PH (n = 20), normal with subsequent PH (n = 6), delayed adaptation without subsequent PH (n = 6), delayed adaptation with subsequent PH (n = 16), and persistent PH (n = 10). Infants with delayed cardiopulmonary adaptation were of lower gestation and birth weight and required prolonged ventilation and supplemental oxygen (P < .05). On multivariate analysis, the incidence of death or BPD was significantly greater among infants with delayed adaptation (P < .001). CONCLUSION: Infants born extremely preterm have normal or delayed postnatal cardiopulmonary adaptation that can be complicated by subsequent or persistent PH. Delayed cardiopulmonary adaptation is associated independently with death or BPD.

A National Survey of Neonatologists: Barriers and Prerequisites to Introduce Point-of-Care Ultrasound in Neonatal ICUs.

Point-of-care (POC) ultrasound refers to the use of portable imaging. Although POC ultrasound is widely available to the neonatologists in Australia and Europe, neonatologists in the United States report limited availability. Our objective was to seek the US neonatologists' perception of barriers and prerequisites in adopting POC ultrasound in neonatal intensive care units. An online survey link was sent via e-mail to 3000 neonatologists included in the database maintained by the American Academy of Pediatrics. Survey results (n = 574) were reported as percentage of total responses. Personal experience requiring an urgent sonography in managing cardiac tamponade or pleural effusion was reported by 78% respondents. However, emergent ultrasound (≤10 min) was not available in 80% of the neonatal intensive care units. We compared the responses based on years of clinical experience (>20 vs <20 years), with 272 (48%) neonatologist reporting more than 20 years of experience. Similarly, results from neonatal fellowship programs were compared with nonteaching/teaching hospitals, with 288 (50%) replies from neonatology fellowship programs. Compared with senior neonatologists, respondents with less than 20 years of clinical experience consider POC ultrasound enhances safety and accuracy of clinical procedures (87% vs 82%) and favor adopting POC ultrasound in clinical practice (92% vs 84%). There were no differences in opinion from neonatology fellowship programs compared with the nonteaching/teaching hospitals. Lack of training guidelines, inadequate support from local radiology department, and legal concerns were reported as the top 3 primary barriers in adopting POC ultrasound. If these barriers could be resolved, 89% respondents were inclined to adopt POC ultrasound in clinical practice.

Temporal Profile of Early Pulmonary Hypertension in Preterm Infants.

Objective The objective of this study was to study the temporal profile of pulmonary hypertension (PH) in preterm infants. Study Design Infants < 28 weeks were screened for early PH at 10 to 14 days of life. Infants with early PH (n = 10) and gestationally matched controls (n = 18) underwent serial echocardiography every 7 to 10 days until 36 weeks postmenstrual age. Results Groups with and without early PH were comparable except for higher Fio 2 by day 10 among infants with early PH. Early PH was moderate in extent and resolved in all infants with recurrence in one infant. Among infants without early PH, five infants developed late PH. In both groups, development of late PH occurred in association with important neonatal morbidities, such as patent ductus arteriosus, bronchopulmonary dysplasia, and infection. Conclusion Early moderate PH among preterm infants resolves over a variable time period but recurrence is possible. Late PH can appear during the course of hospitalization in association with other clinical morbidities.

Effects of indomethacin prophylaxis timing on intraventricular haemorrhage and patent ductus arteriosus in extremely low birth weight infants.

OBJECTIVE: Indomethacin prophylaxis (IP) reduces the risk of intraventricular haemorrhage (IVH) and patent ductus arteriosus (PDA) in preterm infants. However, the optimal time to administer IP has not been determined. We hypothesised that IP at ≤6 h is associated with a lower incidence of IVH or death than if administered at >6-24 h of age. METHODS: We performed a retrospective cohort study of extremely low birth weight infants (≤1000 g birth weight) treated in the neonatal intensive care units in the Neonatal Research Network from 2003 to 2010 and who received IP in the first 24 h of age. Infants were dichotomised based upon receipt of IP at ≤6 or >6-24 h of age. The primary outcomes were IVH alone and IVH or death. Secondary outcomes were PDA alone and PDA or death. We used multivariable analyses to determine associations between the age of IP and the study outcomes expressed as an OR and 95% CI. RESULTS: IP was given at ≤6 h to 2340 infants and at >6-24 h to 1915 infants. Infants given IP at ≤6 h had more antenatal steroid exposure, more inborn and less cardiopulmonary resuscitation (p<0.01). After multivariable analyses, age of IP receipt was not associated with IVH, and IVH or death but PDA receiving treatment/ligation or death was lower among IP at ≤6 h compared with IP at >6-24 h (OR 0.83, 95% CI 0.71 to 0.98). CONCLUSIONS: IP at ≤6 h of age is not associated with less IVH or death, but is associated with less PDA receiving treatment/ligation or death.

Pulmonary hypertension in preterm infants: prevalence and association with bronchopulmonary dysplasia.

OBJECTIVE: To determine whether early pulmonary hypertension (PH) at 10-14 days of life in preterm infants is associated with bronchopulmonary dysplasia (BPD) at 36 weeks' postmenstrual age (PMA). STUDY DESIGN: This was a prospective observational cohort study of infants <28 weeks' gestation. Exclusion criteria were any major anomaly, genetic syndrome, or death before the initial echocardiogram. Echocardiograms were performed between 10 and 14 days of life and at 36 weeks' PMA to assess PH. BPD and its severity were determined at 36 weeks PMA by the National Institutes of Health workshop definition. RESULTS: From March 2011 to April 2013, of 146 consecutively admitted infants <28 weeks, 120 were enrolled. One infant was excluded, 17 did not consent, and 8 died before undergoing a study echocardiogram. At 10-14 days of life, 10 infants had early PH (8%). Male sex (56% vs 40%), gestational age (26(+2) ± 1(+2) vs 25(+6) ± 1(+4) weeks), birth weight (837 ± 205 g vs 763 ± 182 g), and small for gestational age (14% vs 20%) were not significantly different among infants with no PH and early PH, respectively. Infants with early PH required >0.3 fraction of inspired oxygen by day 10 of life (70% vs 27%, P < .01). Moderate/severe BPD or death was greater among infants with early PH (90%) compared with no PH (47%, relative risk 1.9, 95% CI 1.43-2.53). CONCLUSION: In this prospective, single-center cohort, early PH was associated with moderate/severe BPD or death at 36 weeks' PMA.

Indomethacin prophylaxis to prevent intraventricular hemorrhage: association between incidence and timing of drug administration.

OBJECTIVE: To test the hypothesis that administration of indomethacin prophylaxis before 6 hours of life results in a lower incidence of intraventricular hemorrhage (IVH) compared with administration after 6 hours of life, and that the effects of early prophylaxis depend on gestational age (GA) and sex in very low birth weight infants (birth weight <1250 g). STUDY DESIGN: Very low birth weight infants admitted to our neonatal intensive care unit between 2003 and 2010 who received indomethacin prophylaxis were analyzed retrospectively. Exclusion criteria included unknown time of indomethacin prophylaxis, death at <12 hours of life, congenital anomalies, and unavailable head ultrasound report. Infants were dichotomized based on the timing of indomethacin prophylaxis (<6 hours or >6 hours of life) to compare incidence of IVH all grades and severe (grade 3-4) IVH. Secondary analyses examined the effects of the time of indomethacin prophylaxis initiation by GA and sex on the incidence of IVH. RESULTS: A total of 868 infants (431 males and 437 females) met the criteria for analysis. Indomethacin prophylaxis was given at <6 hours of life in 730 infants and at >6 hours of life to 168 infants. The 2 groups differed with respect to antenatal steroid exposure, GA, outborn prevalence, and pneumothoraces. After multivariate analysis, there were no between-group differences in all-grade or severe IVH. However, females, but not males, treated at <6 hours of life had a lower incidence of severe IVH (P < .05), particularly at lower GAs. CONCLUSION: Prophylactic indomethacin administered before 6 hours of life is not associated with lower incidence of IVH.

Ipsilateral lobar emphysema in an infant with a repaired congenital diaphragmatic hernia.

OBJECTIVE: To report a case of lobar emphysema in an infant who had a congenital diaphragmatic hernia that was surgically repaired at birth. DESIGN: Case report. SETTING: Pediatric critical care unit in a tertiary care hospital. PATIENT: A 9-month-old infant who had massive hyperinflation of the right lung and respiratory failure. INTERVENTIONS: Confirmation of lobar hyperinflation of the right lung with ventilation and perfusion defects and surgical treatment with lobectomy. MEASUREMENTS AND MAIN RESULTS: Successful treatment of respiratory failure. CONCLUSION: Lobar emphysema can be a rare development in patients who had a congenital diaphragmatic hernia at birth. This can result in respiratory failure and needs surgical intervention.