Continuous glucose monitoring during therapeutic hypothermia for hypoxic ischaemic encephalopathy: a feasibility study

Objectives Glucose dysregulation is common in infants with hypoxic ischaemic encephalopathy (HIE) and is likely to exacerbate cerebral injury. Infrequent measurement of glucose concentrations makes both identification and prevention of this risk challenging. Continuous glucose monitoring (CGM) has the potential to address both these challenges, but has not been explored in these infants. We aimed to evaluate the feasibility and potential impact of real-time CGM in term infants with HIE being treated with therapeutic hypothermia (TH). Design Feasibility study. Setting Tertiary-level neonatal unit, UK. Patients Term infants with HIE undergoing TH. Intervention A CGM sensor was inserted within 48 hours of birth and kept in situ for the first week of life. Clinical staff were blinded to the CGM recordings and clinical decisions were based on blood glucose assays. Main outcome measures (1) Accuracy of CGM values during and post TH, (2) Per cent of time spent outside the clinical range (2.6–10 mmol/L), (3) Episodes of hypoglycaemia and hyperglycaemia, (4) Adverse effects. Results The accuracy of CGM values during TH were comparable to those when infants were normothermic. There was wide variation in per cent time outside the target range (2.6–10 mmol/L) between infants (median 5%, range 0%–34%). CGM identified 44% of infants with ≥1 episode of hypoglycaemia (<2.6 mmol/L) and 50% with ≥1 episode of hyperglycaemia (>10 mmol/L). No adverse events were observed. Conclusions This study demonstrates that CGM could be a useful adjunct for glucose monitoring in babies undergoing TH who are at risk of both hypoglycaemia and hyperglycaemia.