Effect of a new neonatal maintenance solution on potassium, calcium and phosphate homeostasis in sick neonates

A new neonatal maintenance solution (Neonatalyte; Sabax) was administered to 12 newborn infants with respiratory distress. Under closely controlled conditions, the infusion was commenced at a mean age of 12 +/- 10 hours. The mean serum potassium level increased from 4,6 +/- 0,6 mmol/l to 5,6 +/- 1,4 mmol/l (P less than 0,02), while in 5 infants (42%) hyperkalaemia (greater than or equal to 6,5 mmol/l) occurred within 8 hours of commencement of Neonatalyte infusion. The mean serum calcium level decreased from 2,1 mmol/l on day 1 to 1,7 mmol/l on day 2 (P less than 0,001) and was 1,8 mmol/l on day 3 (P less than 0,01), despite mean calcium intakes of 18,33 and 45 mg on days 1, 2 and 3 respectively. The early hypocalcaemia may be related to the phosphate content of Neonatalyte. We conclude that Neonatalyte is not an ideal solution for sick newborn infants who cannot be fed orally for the first few days of life.