Continuous Glucose Monitoring and Preterm Infants
Condition: Infant, Very Low Birth Weight; Neonatal Hypoglycemia
MeSH terms: Hypoglycemia; Birth Weight
Study type: Interventional
Phase: Phase 4

Summary: 
      Neonatal hypoglycemia is associated with brain injury and impaired neurodevelopment outcomes
      in very low birth weight infants (VLBWI). Glycemic monitoring is usually performed by
      capillary or central line sampling but does not identify up to 81% of hypoglycemic episodes
      in preterm newborns.

      The investigators aim to assess if a continuous glucose monitor (CGM) can be used to maintain
      euglycemia (defined as a target value 72-144mg/dl) in VLBWI.

      It will be enrolled newborns ≤32 weeks gestational age and/or of birthweight ≤1500 g, within
      48 hours of life, they will be randomized in two study arms, both them will wear Dexcom G4
      Platinum CGM: 1) Unblinded group (UB): glucose daily intake will be modulated according to
      CGM (Dexcom G4 Platinum) during the first 7 days of life, alarms for hypos/hyper will be
      active; 2) Blinded group (B), glucose infusion rate will be modified according to 2-3 daily
      capillary glucose tests, alarms for hypos will be switched off. Pain at insertion will be
      evaluated with the validated Premature Infant Pain Profile (PIPP) scale.

      The estimated numerosity is 50 patients (25 for each arm).
    

Detailed description: 
      Background - Neonatal hypoglycemia is a common event during the first week of life and has
      been associated to brain injuries and poor neurodevelopment. Unfortunately it may be
      unrecognized for several hours from its occurrence, since it is asymptomatic/poor symptomatic
      in newborns (Hay WW, 2009; Cornblath, 2000; Adamkin DH, 2011; Burns et al, 2008; Wong, 2013;
      Duvanel et al, 1999) Despite the dramatic consequences of prolonged hypoglycemia on the
      neonatal brain are well known, the only tool to recognize it is represented by the capillary
      glycemic test performed according to risk-based protocols of Neonatal Intensive Care Units
      (NICUs): they consider a limited window of intervention based on 2-3 glycemic tests a day
      (Thomas F et al, J. Diab Science Technol. 2014).

      Continuous glucose monitoring systems have offered, in the last decade, a new powerful tool
      to recognize more hypoglycemic events in neonates than traditional monitoring. All the works
      developed in neonates, to date, have been aimed to evaluate the performance of the CGM
      devices and have been used to record the effect of medical "intervention" in the correction
      of hypo or hyperglycemia (Neonatal Insulin Replacement Therapy in Europe (NIRTURE, Beardsall
      et al, NEJM 2008; McKinlay et al, NEJM 2015) (Harris et al J Pediatrics, 2010; Beardsall et
      al, Arch Dis Child Fetal Neonatal 2013). The CGM has never been used to drive medical
      inteventions in newborns and evaluate as independent tool to improve time-in-target for
      glycemia.

      Previous studies demonstrated that up to 81% of the hypoglycemic episodes were not detected
      with blood glucose measurement (Harris et al, J Pediatrics 2010). All the published studies
      in neonates, to date, have used Medtronic CGM systems (Medtronic, USA). No adverse effects,
      associated to the implant of CGM, have been reported neither in late-preterm neither in
      preterm newborns.

      Glycemic control in terms, and moreover, in preterm newborns still represent a challenge for
      physicians and the wide fluctuation (both hyperglycemia and hypoglycemia) commonly observed
      in such population still remains difficult to be managed with traditional blood glucose
      monitoring (few data/day, delay of therapeutic intervention).

      Aim - The study the Investigators are going to conduct is aimed to evaluate if CGM, as driver
      of therapeutic decisions in preterm newborns (birthweight ≤1500g, gestational age ≤32 weeks)
      during the first week of life, may be able to maintain "euglycemia". Euglycemia will be
      defined as values within the range 72-144mg/dl (4-8mmol/L)(Harris et al J Pediatrics, 2010;
      Beardsall et al, Arch Dis Child Fetal Neonatal Ed 2013)

      Study design - Randomized Controlled Trial

        -  Patients: newborns with GA ≤32weeks and/or BW≤ 1500 g. They will be enrolled within the
           first 48 hours of life

        -  Intevention group: Unblinded CGM (DexcomG4Platinum) data to adequate daily glucose
           intake

        -  Control group: Blinded CGM with daily glucose intake adequated according to SMBG (=2
           blood glucose/day)

        -  Primary Outcome: to evaluate if Unblinded CGM increases the time within "euglycemic"
           range (72-144mg/dl)

      Materials and Methods - Dexcom G4 Platinum (Dexcom Inc, CA - USA) sensor will be applied
      within 48 hours from birth to the study population on the lateral side of thigh, after
      parents' consent collection.

      All the patients will be randomized to the blinded or unblinded group before the application
      of CGM. Randomization will be performed using a randomization list electronically generated.

      Unblinded group (intervention/open CGM group): they will wear CGM for 7 days, the alarms of
      CGM will be switched on and the daily intake of carbohydrates will be adapted according to
      CGM data. The study staff will record data every three hours in absence of hypo alarms (see
      below for carbs adjustment procedure).

      Blinded group: they will wear CGM for 7 days, the alarms and the CGM monitor will be blinded.
      At least two calibrations a day, according to manufacturer instruction, will be inserted. The
      daily amount of carbohydrates will be decided according to blood glucose test (at least
      2/day) and to recommendation of American Academy of Pediatrics (see below).

      Numerosity: the estimated numerosity is 50 patients according to primary outcome.
      Unfortunately no data are available on this population; 10 extra patients will be recruited
      in case of premature interruption of recording (due to sensor detachment, malfunction, loss
      of the patient or interruption of monitoring due to local/systemic complication) in order to
      ensure a total amount of 250 days of monitoring (50% in the UB-CGM group and 50% in the B-CGM
      group) with a maximum amount of 350 days of monitoring. So the estimated time of monitoring
      is expected to be min 250, max 350 days, divided into the two groups.

      Reasons for study interruption: local and/or systemic complication due to the application of
      device, transfer of patient to another center of care, withdrawal of consent, death,
      malfunction of device. Reasons for interruption of monitoring will be specified in the final
      report.

      Carbohydrates adjustment procedure: the procedure for carbohydrates adjustment uses a
      worksheet described in Agus MSD, Steil G et al NEJM 2012 and adapted to NICU standard of
      nutrition suggested from American Academy of Pediatrics. The worksheet has been set up
      according to the NICU protocols in agreement with recommendation of American Academy of
      Pediatrics, Committee on Nutrition.

      The 1st day intake is set on 6-8gr/kg of carbohydrates; a default daily increase of
      1gr/kg/day in case of euglycemia is applied; such increase may variate according to the CGM
      data in the unblinded group or to the 2 glycemic tests performed in the blinded group in
      order to achieve the target as following:

      i. if the average was >= 180 mg/dL decrease the calculated GIR by 1 g/kg/d ii. If the average
      was between 144 and 179 mg/dL do not make any adjustment iii. If the average was between 72
      and 143 mg/dL check if the minimum GIR has been reached and if not increase the value to the
      minimum GIR for that day iv. If the average was lower than 72 mg/dL increase the rate to the
      either the minimum rate + 2 or the calculated rate plus 2, whichever is bigger; v. if
      glycemia <41mg/gl: increase of 2.8g/kg/die the GIR and perform a bolus of 2ml/kg/d of G10%.

      Details of the worksheet have been described in Agus et al (NEJM2012).

      Worksheet has been designed considering as follows:

      Target 108,00 Low limit 72,00 High limit 144,00 Hyper Theshold 180,00 Hypo Threshold 40,00 A
      decrease has been considered above hyper threshold of 1g/kg/d up to a minimum GIR of
      4.5g/k/d. No increase will be performed between 144 and 180mg/dl.

      Data analysis will be performed as intention to treat (ITT).

      Discussion: perspective and limits - Euglycemia definition remains controversial in
      neonatology. Even though, in our study, we have decided to adopt the NIRTURE targets
      (Beardsall et al, 2010) considering optimal a range from 72 mg/dl (4 mmol/L) to 144mg/dl (8
      mmol/L). Values below 40mg/dl will require a G10% bolus (2ml/kg) and an increase of 2.8gr/kg
      of intake of carbs; values between 40 and 77mg/dl require an increase of carbs adapted to
      reach the middle point of the expected target. Similarly for values above the upper limit we
      have considered a decrease of carbs intake (minimum 4.5gr/kg/day).

      The main difference between the two study groups is represented by the number of information
      available for the physician and, consequently, from the number of changes in glucose intake.

      The use of a worksheet will allow the investigators to avoid inter-individuals variability in
      making infusion changes standardizing the interventions in two groups.

      Actually the traditional system of monitoring of glycemia has been demonstrated to be unable
      to detect a significant number of glycemic variations during the daytime. Increasing the
      number of blood glycemic test (by heel prick) would mean to increase the number of painful
      procedures for the newborn with an uncertain benefit and the workload of the staff.

      Disclosures: Dexcom Inc, USA will provide materials for the study as donation to the Neonatal
      Intensive Care Unit of University Hospital of Padua, Italy.

      The study has been designed as a no-profit research project by the Principal Investigators
      and Collaborators of Neonatal Intensive Care Unit of University of Padua, Department of
      Bioengineering (University of Padua) and Boston Children's Hospital.

      Dexcom Inc has not been involved in the study design and will not be involved in results
      evaluation.
    

Intervention name(s): Unblinded - CGM; Blinded - CGM
Intervention type(s): Device; Device
Intervention description(s): Data from device will be readable and alarms on; Data from device will be blinded and alarms off
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Outcomes Assessor)
Keywords: continuous glucose monitoring (cgm); neonatal hypoglycemia; very low birth weight infants (VLBWI); preterm infants