Outcome of fetuses with lower urinary tract obstruction and normal amniotic fluid volume in second trimester of pregnancy

OBJECTIVE

Congenital lower urinary tract obstruction (LUTO) is a rare condition with high perinatal mortality and morbidity when associated with severe oligohydramnios or anhydramnios in the second trimester of pregnancy. Severe pulmonary hypoplasia and end-stage renal disease are the underlying causes of poor neonatal outcome in these cases. However, little is known about the subset of fetal LUTO that is associated with a normal volume of amniotic fluid at midgestation. The objective of the current study was to describe the natural history, underlying causes, survival and postnatal renal function outcomes in pregnancies with fetal LUTO and normal amniotic fluid volume during the second trimester of pregnancy.

METHODS

This was a retrospective study of all pregnancies with fetal LUTO and normal amniotic fluid volume in the second trimester that received prenatal and postnatal care at our quaternary care institution between 2013 and 2017. Data on demographic characteristics, fetal interventions, perinatal survival, need for neonatal respiratory support, postnatal renal function and need for dialysis at the age of 1 and 24 months were analyzed.

RESULTS

Of the 18 fetuses that met the study criteria, 17 (94.4%) survived the perinatal period. Eleven (61.1%) pregnancies developed oligohydramnios in the third trimester, six of which were eligible for and underwent fetal intervention with vesicoamniotic shunt placement, which was performed successfully in all six cases. Two (11.1%) neonates required respiratory support owing to pulmonary hypoplasia. At the age of 2 years, 14 children had follow-up information available, two (14.3%) of whom had normal renal function, eight (57.1%) had developed some degree of chronic kidney disease (Stage 1-4) and four (28.6%) had developed end-stage renal disease (ESRD), including two who had already manifested ESRD in the neonatal period.

CONCLUSIONS

Most fetuses diagnosed prenatally with LUTO that is associated with a normal volume of amniotic fluid at midgestation will have a favorable outcome in terms of perinatal survival and few will need long-term respiratory support. However, these children are still at increased risk for chronic renal disease, ESRD and need for renal replacement therapy. Larger multicenter studies are needed to characterize the prenatal factors associated with postnatal renal function, and to investigate the role of fetal intervention in the group of fetuses that present with late-onset oligohydramnios and evidence of preserved fetal renal function. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Short term evaluation of respiratory effort by premature infants supported with bubble nasal continuous airway pressure using Seattle-PAP and a standard bubble device

Background

Almost one million prematurely born infants die annually from respiratory insufficiency, predominantly in countries with limited access to respiratory support for neonates. The primary hypothesis tested in the present study was that a modified device for bubble nasal continuous positive airway pressure (Bn-CPAP) would provide lower work of spontaneous breathing, estimated by esophageal pressure-rate products.

Methods

Infants born <32 weeks gestation and stable on Bn-CPAP with FiO₂ <0.30 were studied within 72 h following delivery. Esophageal pressures during spontaneous breathing were measured during 2 h on standard Bn-CPAP, then 2 h with Bn-CPAP using a modified bubble device presently termed Seattle-PAP, which produces a different pattern of pressure fluctuations and which provided greater respiratory support in preclinical studies, then 2 h on standard Bn-CPAP.

Results

All 40 infants enrolled completed the study and follow-up through 36 wks post menstrual age or hospital discharge, whichever came first. No infants were on supplemental oxygen at completion of follow-up. No infants developed pneumothoraces or nasal trauma, and no adverse events attributed to the study were observed. Pressure-rate products on the two devices were not different, but effort of breathing, assessed by areas under esophageal pressure-time curves, was lower with Seattle-PAP than with standard Bn-CPAP.

Conclusion

Use of Seattle-PAP to implement Bn-CPAP lowers the effort of breathing exerted even by relatively healthy spontaneously breathing premature neonates. Whether the lower effort of breathing observed with Seattle-PAP translates to improvements in neonatal mortality or morbidity will need to be determined by studies in appropriate patient populations.

Respiratory severity score on day of life 30 is predictive of mortality and the length of mechanical ventilation in premature infants with protracted ventilation

OBJECTIVE

We tested the hypothesis that Respiratory Severity Score (RSS) on day of life 30 is predictive of mortality and length of mechanical ventilation in premature infants on prolonged mechanical ventilation.

METHODS

A retrospective chart review was performed using the Nationwide Children's Hospital medical record and Vermont-Oxford Network databases. The primary outcome variable was survival to hospital discharge and the secondary outcome was length of mechanical ventilation after day of life 30.

RESULTS

We identified 199 neonates admitted to Nationwide Children's Hospital between 2004 and 2007 with birth weight less than 1,500 g that received prolonged mechanical ventilation in the first 30 days of their life. A total of 184 infants were included in the analysis, excluding 14 patients with congenital anomalies and one infant with incomplete data. RSS on day of life 30 was significantly greater in the group of infants that died compared to those that survived (P = 0.003, 95% CI = [0.08, 0.40]). Further analysis demonstrated that the maximum difference in mortality was obtained with a threshold RSS of 6. Of the 109 patients who had RSS less than 6 on day of life 30, mortality rate was 4.6% (5/109) while those greater than or equal to 6 had a mortality rate of 21.3% (16/75). Both Kaplan-Meier survival curves comparing mortality and length of mechanical ventilation in infants with RSS < 6 versus those with RSS ≥ 6 demonstrated strong associations between RSS on day of life 30 and survival (P = 0.002) and length of ventilation after day of life 30 (P < 0.001).

CONCLUSION

RSS ≥ 6 on day of life 30 is associated with higher mortality and longer period of mechanical ventilation in premature infants requiring mechanical ventilation through 30 days of life.

Safety and pharmacokinetics of a chimerized anti-lipoteichoic acid monoclonal antibody in healthy adults

A chimerized (murine/human) monoclonal antibody (pagibaximab) against lipoteichoic acid (LTA) and protective in animal models for coagulase-negative staphylococci (CONS) and Staphylococcus aureus bacteremia, was developed for prevention of staphylococcal infection in high-risk populations. This open label two-dose study of a single intravenous dose of 3 or 10 mg/kg of pagibaximab evaluated the safety/tolerability, pharmacokinetics, and opsonophagocytic activity of pagibaximab in healthy adults. Eight participants were enrolled (four in each dose group). No infusion, drug, or dose related adverse events occurred. Serum anti-LTA levels were dose-related; mean concentrations peaked at 87.75 and 259.24 microg/mL for 3 and 10 mg/kg groups, respectively. The half-life (beta) of pagibaximab was approximately 33 days. Opsonophagocytic activity of serum samples on a human clinical isolate of Staphylococcus epidermidis in a standard bacterial killing assay was dose-related, and peaked at a mean of 88.5 and 95.5% at 1:90 dilution for 3 and 10 mg/kg groups, respectively. Serum anti-LTA and opsonophagocytic activity levels exhibited statistically significant correlation. The results suggest that pagibaximab at 3 and 10 mg/kg administered as a single intravenous dose in healthy adults appears to: 1) provide preliminary safety and tolerability data, 2) produce dose-related serum anti-LTA and opsonophagocytic activity levels, 3) have a half-life similar to other immunoglobulin G1 antibodies, 4) exhibit statistically significant correlation between serum anti-LTA and opsonophagocytic activity levels. This study supports conducting safety and pharmacokinetic trials of pagibaximab in populations at high-risk of developing CONS infection.

Endotracheal continuous positive airway pressure after rescue surfactant therapy

OBJECTIVE

To determine if premature infants greater than 31 weeks of gestation with established hyaline membrane disease (HMD) can be treated with endotracheal continuous positive airway pressure (ETCPAP) after rescue surfactant replacement therapy.

STUDY DESIGN

Retrospective study of 46 premature infants (>31 weeks of gestation) admitted to Texas Children's Hospital with HMD. Tolerance to ETCPAP after surfactant replacement was evaluated. Prenatal and postnatal characteristics and outcome were compared in the success and failure groups. Multiple logistic regression was used to determine predictive factors associated with failure.

RESULTS

Thirty infants (65.2%) were successfully treated with rescue surfactant and ETCPAP. Cesarean section, higher 1-minute Apgar score, and higher FiO2 level at entry were independent predictors of failure to remain on CPAP due to hypoxemia (56.3%), hypercapnia (31.2%), and apnea (12.5%). In the success group duration of intubation (p < 0.001), oxygen administration (p < 0.01), >40% oxygen requirement (p < 0.001), hospital stay (p < 0.05), and respiratory support on day 7 (p < 0.001) were significantly favorable.

CONCLUSION

Two thirds of infants greater than 31 weeks of gestation, with HMD needing rescue surfactant treatment, can be successfully managed with ETCPAP.