Hypernatraemia in preterm infants born at less than 27 weeks gestation

Area of Science:

• Neonatalogy
• Pediatric Nephrology
• Critical Care Medicine

Background:

• Hypernatraemia, defined as plasma sodium >145 mmol/L, is a critical electrolyte imbalance.
• Extremely preterm infants (<27 weeks gestation) are particularly vulnerable due to immature renal function and high insensible water loss.

Purpose of the Study:

• To determine the incidence of hypernatraemia in preterm infants (<27 weeks gestation) within the first 5 days of life.
• To identify factors predisposing to hypernatraemia and its associated complications in this vulnerable population.

Main Methods:

• Retrospective analysis of patient records for 66 preterm infants (<27 weeks gestation).
• Data collected included gestational age, birthweight, fluid/sodium intake, and clinical outcomes.
• Plasma sodium, urea, and creatinine levels were monitored.

Main Results:

• Hypernatraemia occurred in 69.7% of infants, most frequently between 24-48 hours of age.
• Lower gestational age was associated with higher incidence.
• Increased fluid intake was observed in hypernatraemic infants, and all cases resolved.

Conclusions:

• Hypernatraemia is a frequent occurrence in extremely preterm infants.
• While not statistically significant, hypernatraemic infants showed trends towards increased chronic lung disease, patent ductus arteriosus, intraventricular haemorrhage, necrotising enterocolitis, and mortality.
• Increasing fluid intake effectively resolved hypernatraemia in this cohort.