title: Stochastic modelling of insulin sensitivity and adaptive glycemic control for critical care.
abstract: Targeted, tight model-based glycemic control in critical care patients that can reduce mortality 18-45% is enabled by prediction of insulin sensitivity, S(I). However, this parameter can vary significantly over a given hour in the critically ill as their condition evolves. A stochastic model of S(I) variability is constructed using data from 165 critical care patients. Given S(I) for an hour, the stochastic model returns the probability density function of S(I) for the next hour. Consequently, the glycemic distribution following a known intervention can be derived, enabling pre-determined likelihoods of the result and more accurate control. Cross validation of the S(I) variability model shows that 86.6% of the blood glucose measurements are within the 0.90 probability interval, and 54.0% are within the interquartile interval. "Virtual Patients" with S(I) behaving to the overall S(I) variability model achieved similar predictive performance in simulated trials (86.8% and 45.7%). Finally, adaptive control method incorporating S(I) variability is shown to produce improved glycemic control in simulated trials compared to current clinical results. The validated stochastic model and methods provide a platform for developing advanced glycemic control methods addressing critical care variability.
authors.affiliation: Department of Mechanical Engineering, Centre for Bio-Engineering, University of Canterbury, Christchurch, New Zealand. chl29@student.canterbury.ac.nz
authors.forename: Jessica
authors.initials: J
authors.lastname: Lin
authors.forename: Dominic
authors.initials: D
authors.lastname: Lee
authors.forename: J Geoffrey
authors.initials: JG
authors.lastname: Chase
authors.forename: Geoffrey M
authors.initials: GM
authors.lastname: Shaw
authors.forename: Aaron
authors.initials: A
authors.lastname: Le Compte
authors.forename: Thomas
authors.initials: T
authors.lastname: Lotz
authors.forename: Jason
authors.initials: J
authors.lastname: Wong
authors.forename: Timothy
authors.initials: T
authors.lastname: Lonergan
authors.forename: Christopher E
authors.initials: CE
authors.lastname: Hann
mesh_terms: D000368:Aged; D001786:Blood Glucose / Q000032:analysis; D003422:Critical Care; D005260:Female; D038321:Glycemic Index; D006801:Humans; D007333:Insulin Resistance / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D009520:New Zealand; D015203:Reproducibility of Results; D013269:Stochastic Processes
chemical_list: D001786:Blood Glucose