Hyponatremia in children under 100 days old: incidence and etiologies.

Hyponatremia is one of the most common electrolyte disorders in hospitalized children. The underlying mechanisms are poorly understood and potentially multifactorial, making management difficult, particularly in neonates. This retrospective study aimed to determine the incidence and etiologies of hyponatremia in hospitalized children under the age of 100 days, in our pediatric tertiary care hospital over a 1-year period. The etiology of hyponatremia was determined by reviewing the data noted in each patient's medical reports. Neonatal hyponatremia had a prevalence of 4.3% (86/2012 patients) and was mostly hospital-acquired (74/86 patients). Fifty-nine patients (68.9%) were preterm neonates. The etiology was iatrogenic in 26 cases (30.2%). In other cases, hyponatremia was due to transient (23 patients, 26.7%) or genetic abnormalities of the renal mineralocorticoid pathway (3 patients, 3.4%), SIADH (12 patients, 14%), digestive disease (3 patients, 3.5%), acute renal failure (3 patients, 3.5%), or heart failure (1 patient, 1.2%).Conclusion: Our findings confirm that hyponatremia is a frequent electrolyte disorder in neonates. Various mechanisms underlie this condition, most of which could be prevented by optimized management. The prevalence of genetic hypoaldosteronism and pseudohypoaldosteronism was higher than expected. We provide a simple diagram to help physicians identify the mechanisms underlying neonatal hyponatremia. What is Known: • In neonates, hyponatremia may be multifactorial, making it difficult to treat. • Newborns display partial resistance to aldosterone, and preterms have a defect in aldosterone secretion. What is New: • Four percent of hospitalized neonates had hyponatremia, 86% hospital-acquired. Hyponatremia was due to a transient or constitutional defect of the mineralocorticoid pathway in 26/86 patients (30%) which is higher than expected. • We propose a tree diagram for improving the management of hyponatremia in neonates.

Indications for extensively hydrolyzed cow's milk protein in the neonatal period.

A large proportion of prescriptions for extensively hydrolyzed cow's milk protein (CMP) in newborns are not based on any scientific data justifying the indication. Many of these prescriptions are old habits or are based on incomplete data. The aim of this article is to analyze these practices and propose recommendations. The following points are covered: (a) indications for extensively hydrolyzed formula based on studies demonstrating their benefits in these situations-newborns with a proven allergy to CMP and occasional prescription of supplements to breastfeeding; (b) possible indications not based on a high level of evidence-re-initiation of feeding due to necrotizing enterocolitis, short bowel syndrome, re-initiation of feeding of newborns following intestinal surgery, and laparoschisis if neither the mother's own milk nor milk from a lactarium is available; (c) unjustified indications-newborns at risk of atopy, prematurity, severe neurological pathologies, newborns who are hemodynamically unstable and/or have congenital cardiopathy, neonatal hypoxic-ischemic encephalopathy treated with hypothermia, and newborns with esophageal atresia or diaphragmatic hernia. By following this classification, the prescriber will be guided to use the milk best suited to the pathology, bearing in mind that each situation must be adapted individually and the tolerance and effectiveness of the food reassessed from a nutritional and functional point of view.

Early urine output monitoring in very preterm infants to predict in-hospital neonatal outcomes: a bicentric retrospective cohort study.

OBJECTIVE: To evaluate whether urine output (UO), rarely assessed in the literature, is associated with relevant neonatal outcomes in very preterm infants, and which UO threshold may be the most clinically relevant. DESIGN: Retrospective cohort study. SETTING: Two Level IV neonatal intensive care units. PATIENTS: Very preterm infants born between 240/7 and 296/7 weeks of gestation documented with eight UO measurements per day between postnatal day 1 and day 7. MAIN OUTCOME MEASURES: Composite outcome defined as death before discharge, or moderate to severe bronchopulmonary dysplasia, or severe brain lesions. The association between this outcome and UO was studied using several UO thresholds. RESULTS: Among 532 infants studied, UO <1.0 mL/kg/hour for at least 24 consecutive hours was measured in 55/532 (10%) infants and the primary outcome was recorded in 25 patients. The association between a UO threshold <1.0 mL/kg/hour and the primary outcome was found marginally significant (crude OR 1.80, 95% CI 1.02 to 3.16, p=0.04). The primary outcome was recorded in 112/242 (46%) patients with a UO <2.0 mL/kg/hour and only 64/290 (22%) patients with a UO ≥2.0 mL/kg/hour (p<0.001). This UO threshold was found significantly associated with the primary outcome (crude OR 3.1, 95% CI 2.1 to 4.7, p<0.001), an association confirmed using a multivariate logistic regression model including baseline covariates (adjusted OR 3.7, 95% CI 2.2 to 6.4, p<0.001). CONCLUSION: A UO <2 mL/kg/hour over 24 hours between postnatal day 1 and day 7 strongly predicts neonatal mortality or severe morbidities in very preterm infants.

Urine Output Monitoring for the Diagnosis of Early-Onset Acute Kidney Injury in Very Preterm Infants.

BACKGROUND AND OBJECTIVES: The current threshold used for oliguria in the definition of neonatal AKI has been empirically defined as 1 ml/kg per hour. Urine output criteria are generally poorly documented, resulting in uncertainty in the most accurate threshold to identify AKI in very preterm infants with known tubular immaturity. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We conducted a bicentric study including 473 very preterm infants (240/7-296/7 weeks of gestation) born between January 2014 and December 2018 with urine output measurements every 3 hours during the first 7 days of life and two serum creatinine measurements during the first 10 days of life. AKI was defined using the neonatal Kidney Disease Improving Global Outcomes (KDIGO) definition. We tested whether higher urine output thresholds (1.5 or 2 ml/kg per hour) in modified AKI definitions may better discriminate neonatal mortality compared with the current definition. RESULTS: Early-onset AKI was developed by 101 of 473 (21%) very preterm infants. AKI was diagnosed on the basis of urine output criteria alone (no rise in creatinine) for 27 of 101 (27%) participants. Early-onset AKI was associated with higher risk of death before discharge (adjusted odds ratio, 3.9; 95% confidence interval, 1.9 to 7.8), and the AKI neonatal KDIGO score showed good discriminative performance for neonatal mortality, with an area under the receiver operating characteristic (ROC) curve of 0.68 (95% confidence interval, 0.61 to 0.75). Modified AKI definitions that included higher urine output thresholds showed significantly improved discriminative performance, with areas under the ROC curve of 0.73 (95% confidence interval, 0.66 to 0.80) for the 1.5-ml/kg per hour threshold and 0.75 (95% confidence interval, 0.68 to 0.81) for the 2-ml/kg per hour threshold. CONCLUSIONS: Early-onset AKI was diagnosed on the basis of urine output exclusively for a quarter of the cases. Furthermore, modified AKI definitions that included higher urine output improved the discriminative performance for predicting mortality.

Placental Findings and Effect of Prophylactic Hydrocortisone in Extremely Preterm Infants.

OBJECTIVES: To investigate the relationship between histologic findings of the placenta and response to early postnatal hydrocortisone treatment used to prevent bronchopulmonary dysplasia (BPD) in extremely preterm infants. METHODS: In an exploratory analysis of the Early Low-Dose Hydrocortisone to Improve Survival Without Bronchopulmonary Dysplasia in Extremely Preterm Infants (PREMILOC) trial, detailed placental analyses were performed on the basis of standardized macroscopic and histologic examinations. Placental histology, categorized into 3 groups, was correlated to neonatal outcomes and response to hydrocortisone treatment. RESULTS: Of 523 randomly assigned patients, 457 placentas were analyzed. In total, 125 out of 457 (27%) placentas were classified as normal, 236 out of 457 (52%) placentas were classified as inflammatory, and 96 out of 457 (21%) placentas were classified as vascular. Placental inflammation was associated with a significant, increased rate of BPD-free survival at 36 weeks' postmenstrual age, independent of gestational age, treatment group, and sex (adjusted odds ratio: 1.72, 95% confidence interval [CI]: 1.05 to 2.82, P = .03). Regarding the response to treatment, the strongest benefit of hydrocortisone compared with placebo was found in infants born after placental vascular disease, with significantly more patients extubated at day 10 (risk difference: 0.32, 95% CI: 0.08 to 0.56, P = .004) and similar positive direction on survival without BPD (risk difference: 0.23, 95% CI: 0.00 to 0.46, P = .06). Adjusted to gestational age and treatment groups, placental inflammation was associated with significantly fewer patent ductus arteriosus ligation (adjusted hazard ratio: 0.58, 95% CI: 0.36 to 0.95, P = .03). Placental histology was not found to be associated with other adverse events related to preterm birth. CONCLUSIONS: With these findings, we confirm that early low-dose hydrocortisone confers benefits in extremely preterm infants overall and we suggest there is a higher treatment effect in those born after placental vascular disease.