Turkish Neonatal Society Guideline on fluid and electrolyte balance in the newborn

The efficacy and safety of isotonic and hypotonic fluids in intravenous maintenance fluid therapy in term newborns: national multicenter observational "neofluid" study

Objective

The objective of this study was to evaluate the efficacy and safety of isotonic and hypotonic intravenous fluids in maintenance fluid therapy for term infants.

Methods

This was a multi-centre, prospective, observational study conducted in 21 participating centres from December 30, 2020, to June 30, 2023. The study included term newborns requiring parenteral fluid therapy for maintenance (NCT04781361). The fluid treatment was divided into two groups based on the concentration of sodium in the parenteral fluid, designated as hypotonic (NaCl <130 mmol/L) and isotonic (NaCl = 130-154 mmol/L). The primary outcomes were the change in mean plasma sodium (pNa) levels per hour (∆pNa mmol/L/h), the incidence of hyponatremia (pNa <135 mmol/L) and hypernatremia (pNa >145 mmol/L), and the occurrence of clinically significant changes in sodium levels (∆pNa >0.5 mmol/L/h).

Results

A total of 420 patients from 21 centers were included. The ∆pNa was negative in the hypotonic fluid group and positive in the isotonic fluid group, with a significant difference between the groups [respectively -0.07 ± 0.03 (95% CI: -0.13 to -0.02); 0.04 ± 0.03 (95%CI: -0.02 to 0.09), p = 0.04]. There was no difference between the groups in terms of the development of hypernatremia or a clinically meaningful pNa increase. The hypotonic fluid group had a higher incidence of hyponatremia and a clinically meaningful sodium decrease compared to the isotonic fluid group [7.9% vs. 1.2% (OR:6.5, p:0.03)] and [12.2% vs.4.2% (OR:2.9, p = 0.03)].

Conclusion

Contrary to current understanding, this large-scale study is the first to demonstrate that the use of hypotonic fluids in maintenance fluid therapy for newborns poses a risk of hyponatremia development, whereas isotonic fluid therapy appears safe.

Hypernatremia in Newborns: A Practical Approach to Management

Hypernatremia is a potentially serious condition in both term and preterm babies, which can lead to severe and permanent neurological damage. There are many physiological changes in sodium homeostasis that occur soon after birth. Understanding this physiological process, early anticipation of hypernatremia and familiarization with the neonatal management of hypernatremia can prevent mortality and long-term morbidity associated with this condition. This review aims to provide a practical and understandable approach to the diagnosis and management of hypernatremia in neonates.

Evaluation of Term Newborn Patients With Hypernatremic Dehydration

Aim

We aimed to evaluate the demographic, clinical, and laboratory findings and the management of newborns with hypernatremic dehydration (HDH).

Materials and Methods

A total of 85 term newborns with serum sodium (Na) levels higher than 145 mEq/L who admitted to our hospital between January 2011 and December 2018 were included in this study.

Results

Among all cases, 54.1% were female infants with the mean birth weight, weight loss ratio, and median age at diagnosis of 3095 ± 540 g, 13.6 ± 10%, and 8 (2-24) days, respectively. The most common presenting complaints were breastfeeding difficulties (90.5%), fever (63.5%), decreased urination (43.5%), jaundice (22.3%), and convulsion (15.3%). The mean sodium and potassium, and median blood urea and creatinine levels on admission were 167.9 ± 13.4 mEq/L, 5.4 ± 2.8 mmol/L, 213 mg/dL (11-476 mg/dL), and 2.4 mg/dL (0.52-9.96 mg/dL), respectively. There was metabolic acidosis in 67% and acute renal failure in 74.4% of patients, while peritoneal dialysis was performed in 12 of them. There was a positive correlation between weight loss ratio and admission age, serum urea, and creatinine levels; there was a negative correlation between weight loss and blood pH. Eight patients died (9.4%).

Conclusions

In our study, serum urea, creatinine, potassium, metabolic acidosis levels, convulsion, and dialysis requirements at the time of admission of the newborns with HDH were found to be higher in those who died compared to those who survived. Convulsion was a presenting complaint, and it was also observed during the treatment.