Background: In high-risk newborns indirect hyperbilirubinemia can lead to acute bilirubin encephalopathy and kernicterus. Despite the current therapeutic modalities, preventing or reversing the neurotoxicity cannot be achieved in all infants. Objective: To investigate the neuroprotective effects of hypothermia on bilirubin-induced toxicity in primary mouse neuronal cell cultures. Methods: Hippocampal cell cultures, isolated from newborn mouse brains, were incubated with unconjugated bilirubin (UCB) at 3 days in vitro (DIV) and immediately exposed to varying degrees of hypothermia. Neuronal viability and mitochondrial health were compared between the normothermia (37°C), mild (34°C), moderate (32°C) and severe (29°C) hypothermia groups. Confocal microscopy and fluorescent dyes (propidium iodide and JC-1) were used for cell evaluation. To determine the late effects of hypothermia, the cultures were also examined at 7 DIV after returning to normothermic conditions. Results: Induction of any degree of hypothermia increased the neuronal survival after 24 h of UCB treatment. Neuronal death rate and mitochondrial membrane potential loss were lowest in the neurons exposed to moderate hypothermia. We also observed that mild to moderate hypothermia had late protective effects on neuronal cell viability, whereas deep hypothermia did not improve neuronal survival. Conclusions: We conclude that hypothermia reduces the cell death induced by bilirubin toxicity in neuronal cells. Although moderate hypothermia has a better outcome than mild hypothermia, deep hypothermia as low as 29°C has adverse effects on neuronal cell viability.

Objective The aim of this study was to determine if the Newborn Weight Loss Tool (NEWT) can predict hospital readmission due to hyperbilirubinemia. Study Design This is a case–control study of 93 newborns and 186 controls ≥35 weeks' gestation. All were discharged from the Mother–Baby unit of an urban academic center and subsequently readmitted for hyperbilirubinemia. Controls were matched for date of birth, gestational age, and Bhutani risk zone. All infants were screened for hyperbilirubinemia prior to discharge and managed according to American Academy of Pediatrics guidelines in place at the time. Chi-square, Fisher's exact test, and multivariate analysis were utilized as appropriate. Results There was no significant difference between the groups for a NEWT < 50% at discharge. More cases than controls breastfed. A significantly greater percentage of cases had NEWT > 50% at readmission than discharge. NEWT > 90% was moderately associated with readmission for hyperbilirubinemia (p = 0.081). Conclusion NEWT provides a more nuanced assessment of weight loss following birth and can aid in highlighting newborns at risk for readmission due to hyperbilirubinemia. Key Points

Hypochloremic metabolic alkalosis occurs in pseudo-Bartter's syndrome (PBS) without a primary renal tubular defect. Usually seen in cystic fibrosis, this syndrome can also be caused by recurrent vomiting for various reasons. We present a case of multiple gastrointestinal anomalies, each by itself capable of causing the clinical condition, in a 10-day-old infant with PBS.