ESPE Abstracts

Introduction: Over recent years, hyperinsulinaemic hypoglycaemia is being increasingly recognised in at-risk neonates; it is important to recognise and manage this promptly in view of the risk of hypoglycaemic brain injury.

Aims: To recognise signs and symptoms of hypoglycaemia in neonates with hyperinsulinaemic hypoglycaemia.

Methods: Neonates from the neonatal intensive care units at two hospitals (The Royal London Children’s Hospital and Tunbridge Wells Hospital) with a diagnosis of hyperinsulinism were retrospectively reviewed over a 3-year period (April 2019 – March 2022) to determine episodes of symptomatic hypoglycaemia. Medical notes were reviewed for signs and symptoms such as lethargy, jitteriness, tachypnoea, tachycardia, change in colour or any abnormal movements at the time of hypoglycaemia. Demographic data including maternal diabetes, birth weight, gestational age, maximum glucose infusion rate (GIR) and outcomes were also collected.

Results: There were 30 neonates in total with a diagnosis of hyperinsulinaemic hypoglycaemia (16 at Tunbridge Wells and 14 at Royal London). Gestation ranged from 28+4 to 41+5 weeks and birthweight was 610-4920g. Of these, 10/30 (33%) were small for gestational age (SGA) with a standard deviation score (SDS) ≤ -2; and 4/33 (13%) were large for gestational age (LGA), SDS ≥2. Four mothers (13%) had either gestational or type 1 diabetes. Out of these, three babies were LGA and all four had asymptomatic hypoglycaemia. There were 175 episodes of hypoglycaemia recorded in these 30 neonates, with a median of 4.3 episodes per neonate (range 2-14). 8/30 neonates were asymptomatic during every episode of hypoglycaemia. Jitteriness occurred in 9 instances (5%); tachypnoea in 26 (14.9%); hypothermia in 5 (2.9%); tachycardia in 1 (0.6%); lethargy and poor feeding in 2 (1.1%) and possible seizures in 1 (0.6%). In the neonates with tachypnoea, respiratory distress was frequently a confounding factor. The median maximum glucose infusion rate was 17.1mg/kg/min (range 9.0-26.3mg/kg/min) and 17/30 (57%) of neonates required diazoxide (3-5mg/kg/day).

Discussion: Nearly 50% of these babies were either SGA or LGA and therefore at higher risk of developing hypoglycaemia. 27% had no symptoms during hypoglycaemia and were detected on monitoring for risk factors. However, this is a retrospective study and it is important for staff to document signs/symptoms. More prospective studies are required with prespecified symptoms to chart.

Conclusion: Hypoglycaemia is frequently asymptomatic in neonates with hyperinsulinaemia, making this more challenging to recognise. Neonates at risk of hypoglycaemia should have close monitoring of blood glucose levels to ensure they are managed appropriately.