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Safe and effective glycaemic control in premature infants: observational clinical results from the computerised STAR-GRYPHON protocol
  1. Jennifer L Knopp (nee Dickson)1,
  2. Adrienne M Lynn2,
  3. Geoffrey M Shaw3,
  4. J Geoffrey Chase1
  1. 1 Department of Mechanical Engineering, University of Canterbury, Christchurch, New Zealand
  2. 2 Neonatal Intensive Care Unit, Christchurch Women’s Hospital, Christchurch, New Zealand
  3. 3 Intensive Care Unit, Christchurch Hospital, Christchurch, New Zealand
  1. Correspondence to Dr Jennifer L Knopp (nee Dickson), Department of Mechanical Engineering, University of Canterbury, Christchurch 8041, New Zealand; jennifer.dickson{at}


Objective Previous studies examine clinical outcomes of insulin therapy in neonatal intensive care units (NICUs), without first developing safe and effective control protocols. This research quantifies the safety and performance of a computerised model-based control algorithmSTAR-GRYPHON (Stochastic TARgeted Glucose Regulation sYstem to Prevent Hyper- and hypO-glycaemia in Neonates).

Design Retrospective observational study of glycaemic control in very/extremely low birthweight infants treated with insulin from Christchurch Women’s Hospital NICU between January 2013 and June 2017. Blood glucose (BG) outcomes and control performance is compared with retrospective data (n=22) and literature.

Interventions Insulin infusion doses were calculated from 3 to 4 hourly BG measurements using a computerised model-based control algorithm, STAR-GRYPHON.

Main outcome measures Mean BG, time in targeted range and incidence of hypoglycaemia.

Results STAR-GRYPHON (n=35) had lower mean BG concentration (7.0mmol/L vs 7.9 mmol/L), higher %BG within the 4.0–8.0 mmol/L target range (71.1% vs 50.9%) and lower %BG <4.0 mmol/L (0.6% vs 2.1%). There were only 2 BG <2.6 mmol/L (over n=2, 5.5% of patients, 0.03% of all BG outcomes), one of which may be attributed to clinical error. These results show better control to target and lower incidence of hypoglycaemia than most literature results from intensive insulin therapy protocols or study groups in children and infants.

Conclusions Model-based protocols can safely and effectively control BG in very premature infants and should be used in future studies to determine the effect of insulin therapy on clinical outcomes.

  • intensive care
  • insulin therapy
  • premature infants
  • insulin sensitivity
  • glycaemic control

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  • Contributors JLD developed the clinical protocol as part of a project headed up by JGC and GMS. JLD did the data analysis and developed the protocol. AML was involved in development of the clinical interface of the protocol and was responsible for all clinical aspects of delivering glycaemic control.

  • Funding Early financial support for JLD provided by a University of Canterbury Doctoral Scholarship. JLD and JGC are supported by the National Science Challenge Science for Technological Innovation (NSC SfTI, Ministry of Business, Innovation and Employment, New Zealand) and the MedTech Centre of Research Excellence (MedTech CoRE, Tertiary Education Commission, New Zealand). JGC is funded by a Royal Society of New Zealand Cook Fellowship.

  • Disclaimer The funding bodies had no role in study design, in the collection, analysis, and interpretation of data; in the writing of the manuscript; and in the decision to submit the manuscript for publication.

  • Competing interests None declared.

  • Ethics approval Christchurch Women’s Hospital, Clinical Audit Committee.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Data sharing statement If there is interest, we are willing to provide all clinical BG, insulin and glucose data as Excel spreadsheet files.