Presented at the Neonatal Society 2017 Spring Meeting.
Thomson L, Howlett J, Bond S, Hovorka, R, Dunger DB, Beardsall K
University of Cambridge and University of Cambridge Addenbrookes Hospital NHS Trust, Cambridge Biomedical Campus, Cambridge, CB2 0QQ
Background: Extremely preterm infants are at high risk of glucose dysregulation and this is associated with increased mortality and morbidity. In these babies the desire to reduce frequency of blood sampling and handling means glucose monitoring is infrequent and controlling glucose levels is challenging. This study aimed to determine the feasibility of real time continuous glucose monitoring (CGM) to support glucose control in extremely preterm infants requiring intensive care.
Methods: A single center feasibility study (n=21) in infants with a birth weight <1200g. The enhanced enlite glucose sensor was inserted subcutaneously manually and connected to a transmitter sending data via bluetooth connection to a CGM reader device. CGM information was combined with a specifically designed paper based algorithm to guide glucose control. Accuracy of the CGM was assessed by comparison with blood glucose measurements from the point of care Stat Strip (Novobiomed) and the blood gas analyser (Radiometer). Safety was assessed in terms of episodes of hypoglycaemia (sensor or blood glucose <2.6mmol/l) and utility with a staff questionnaire. Cambridge Central Ethics committee provided approval for this study which is funded by the Efficacy and Mechanism Evaluation (EME) Programme, an MRC and NIHR partnership and equipment was provided by Medtronic.
Results: There were 21 babies recruited. Comparative data was available at 247 time points. The sensor performed well compared to the point of care blood glucose with mean difference 0.31 (95%CI 0.14, 0.49). Three babies were recorded clinically to have a single episode of hypoglycaemia (BG <2.6mmol/l >1 hour). In two of these it was the CGM that highlighted unanticipated falling glucose levels. The CGM data documented 3 babies each with a single episode (SG<2.6mmol/l >10 minutes), one of which was not detected clinically. Despite initial concerns about impact on workload the clinical staff reported a positive impact on clinical care.

Conclusion: CGM glucose values with enhanced enlite appear sufficiently accurate to be used to support clinical management in the preterm infant. Clinical staff reported a beneficial impact on patient care, but larger studies are required to determine impact on targeting glucose control.
Corresponding author: kb274@cam.ac.uk
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The views expressed in this publication are those of the author(s) and not necessarily those of the MRC, NHS, NIHR or the Department of Health.