Safety and feasibility of a factory-calibrated continuous glucose monitoring system in term and near-term infants at risk of hypoglycemia

Accuracy to detect neonatal hyperglycaemia using real-time continuous glucose monitoring during postoperative period

Identifying hyperglycaemia during postoperative period is essential for neonates. The objective of the study was to analyse the accuracy and reliability of continuous glucose monitoring (CGM) device for detecting hyperglycaemia during postoperative period in neonates. In this prospective study, hourly glucose recordings by CGM device and six hourly by glucometer glucose (GG-reference test for patient management) were collected in ten surgical neonates during first three postoperative days. Mean absolute relative difference (MARD) and proportion of CGM values within ± 15%/15 mg/dL, ± 20%/20 mg/dL, and ± 30%/30 mg/dL of GG, were analysed from matched pair CGM and GG recordings. The diagnostic performance of CGM for neonatal hyperglycaemia (> 150 mg/dL) was expressed as sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV); and the clinical reliability was assessed in Clarke Error Grid Analysis. A total of 720 CGM glucose readings, 120 matched -paired glucose readings by CGM --GG, and 37 episodes were hyperglycaemia by GG. The MARD was 10.76 %; the percentages of glucose readings within 15%/15 mg/dL, 20%/20 mg/dL, and 30%/30 mg/dL were 94.6%, 97.3% and 100% during the hyperglycaemia period. The sensitivity, specificity, PPV and NPV to detect hyperglycaaemia by CGM device were 100%, 93.9%, 88% and 100 % respectively. In Clarke Error Grid Analysis, 97.3 % points were in zone A and B during the hyperglycaemia period.

CONCLUSION

CGM device can be a clinically reliable tool for hyperglycaemia management during postoperative period in neonates.

WHAT IS KNOWN

• Neonates are vulnerable for hyperglycaemia during post-operative period and bed side glucometers are used for frequent glucose monitoring in them. • Continuous glucose monitor(CGM) devices are used for the glucose monitoring in adult and paediatric diabetes care.

WHAT IS NEW

• For the first time, this study analysed the accuracy and clinical reliability of FreeStyle Libre (CGM device) for identifying hyperglycaemia during post-operative period in neonates. • CGM device has very good accuracy for detecting hyperglycaemia in neonates, it may help the clinician for better glucose stability during post-operative period.

Should continuous glucose monitoring be used to manage neonates at risk of hypoglycaemia?

The National Institute for Clinical Excellence (NICE) now recommends that continuous glucose monitoring (CGM) be offered to adults and children with diabetes who are at risk from hypoglycaemia. Hypoglycaemia is common in the neonatal period, and is a preventable cause of poor neurodevelopmental outcome, but is CGM helpful in the management of neonates at risk of hypoglycaemia? Neonatal studies have shown that CGM can detect clinically silent hypoglycaemia, which has been associated with reduced executive and visual function in early childhood. Intervention trials have further shown CGM can support the targeting of glucose levels in high-risk extremely preterm neonates. In spite of significant advances in technology, including smaller sensors, better accuracy and factory calibration, further progress and adoption into clinical practice has been limited as current devices are not designed nor have regulatory approval for the specific needs of the newborn. The use of CGM has the potential to support clinical management, and prevention of hypoglycaemia but must be set within its current limitations. The data CGM provides however also provides an important opportunity to improve our understanding of potential risks of hypoglycaemia and the impact of clinical interventions to prevent it.

Safety and accuracy of neonatal continuous glucose monitoring

BACKGROUND

Hypoglycemia is a significant problem for all neonates and requires minimally invasive and reliable monitoring. The primary objective of this study was to verify the safety and accuracy of the continuous glucose monitoring (CGM) of full-term neonates using Freestyle Libre, a flash glucose monitoring (FGM) device.

METHODS

The study was conducted on 20 neonates. Shortly after birth, we placed the FGM sensor on the outside of the neonates' thighs. We scanned the CGM values at 60, 120, 180, and 360 min after birth and simultaneously obtained blood glucose values with plantar capillaries by heel puncture. The neonates wore the sensors for up to 6 h and then they were removed.

RESULTS

Of the 75 data points to be measured, 65 points (86.7%) were obtained by scan. There was no change in the sensor attachment site in 12 of 18 completed cases in this study but we observed slight induration in four cases (22.2%) and slight redness in one case (5.5%) at the sensor puncture site. A moderate correlation was observed between the CGM and blood glucose values. The CGM values tended to be low at 120, 180, and 360 min after birth, and tended to be high only at 60 min after birth.

CONCLUSIONS

The CGM device was safe to wear on the neonate and the CGM data correlated well with blood glucose levels. There was dissociation between CGM data and blood glucose levels in the acute period soon after birth when the blood glucose levels changed rapidly.