The SPRINT Protocol for Tight Glycaemic Control Geoffrey M Shaw, J. Geoffrey Chase, Xing-Wei Wong, Thomas Lotz, Jessica Lin, Aaron LeCompte, Timothy Lonergan, Michael Willacy and Christopher E. Hann Dept of Intensive Care Christchurch Hospital and Dept of Medicine CSM&HS University of Otago, NZ Dept of Mechanical Engineering, Centre for Bio-Engineering, Universiity of Canterbury, NZ Tight glucose control Hyperglycaemia is prevalent in critical care Impaired endogenous insulin production Increased effective insulin resistance Average blood glucose values > 10mmol/L not uncommon in some critical care units (over length of stay) Stress of condition induces hyperglycaemia Tight control better outcomes: Reduced mortality Reduced length of stay and length of mechanical ventilation 8.46 to 7.26 mmol /L 11.1mmol/L et al All patients LOS >3days Oxidative stress Post-mortem liver biopsies from 20 patients Intensive insulin (11) vs Conventional treatment (9) Hypertrophic mitochondria with an increased number of abnormal and irregular cristae and reduced matrix electron density were observed in 7 of 9 conventionally treated patients. Only 1 of 11 patients given intensive insulin treatment had these morphological abnormalities (p=0·005). Vanhorebeek I. De Vos R, Mesotten D, Wouters P, De Wolf-Peeters C, Van den Berghe G, Protection of hepatocyte mitochondrial ultrastructure and function by strict blood glucose control with insulin in critically ill patients. Lancet 2005;365:53-59 Liver: poor glycaemic control Skeletal Muscle Liver: tight glycaemic control Skeletal Muscle AIC1 AIC4: Prior Art pG SI Gmeasured t + • 4 years prior trials and research • Models mature • Adaptive Control • Short specific trials Update parameters u(t) pG and SI G pG G S I G Ge Gmodelled Q 1 GQ P(t ) u (t ) I nI I b V Overall AIC control system concept is well established The only ways to reduce glucose levels are: increase insulin (Q) which saturates decrease feed (P) G pG G S I G Ge Glucose = G Insulin = Q Feed = P Q 1 GQ P(t ) Insulin-only (AIC3) control of a patient Glucose level mmol/l Tight control target = 4-6 mmol/l Dextrose feed and Insulin input Insulin boluses Feed rate Time (minutes) Insulin-feed (AIC4) control of a patient Glucose level mmol/l Tight control target = 4-6 mmol/l Dextrose feed and Insulin input Feed rate Insulin boluses Time (minutes) Patient 5 = textbook case Wong, XW, Chase, JG, Shaw, GM, Hann, CE, Lotz, T, Lin, J, Singh-Levett, I, Hollingsworth, L, Wong, OS and Andreassen, S (2006). “Model Predictive Glycaemic Regulation in Critical Illness using Insulin and Nutrition Input: a Pilot Study,” Medical Engineering and Physics, In Press SPRINT Specialised Relative Insulin and Nutrition Table Optimises both insulin and nutrition rates to control glycaemic levels Developed through extensive computer simulation Ensures safe protocol before clinical implementation Simple interface for ease of use by nursing staff Combines the very tight control of computerised simulations with minimal implementation cost (no bedside computer required…) SPRINT Step 1 = Feed Rate Table Requires current glucose measurement and last hour change in glucose SPRINT Step 2 = Insulin Table If feed rate = 0 use only insulin wheel Requires current glucose measurement, last hour change and last hours insulin bolus Patient 5008 • Time = 163 hours • Mean = 5.4 mmol/L • 4-6.1 = 85% • 4-7.75 = 97% • Avg Feed = 85% • Avg Insulin = 3.4 U/hr Lonergan, T, LeCompte, A, Willacy, M, Chase, JG, Shaw, GM, Wong, XW, Lotz, T, Lin, J, and Hann, CE (2006). “A Simple Insulin-Nutrition Protocol for Tight Glycemic Control in Critical Illness: Development and Protocol Comparison,” Diabetes Technology & Therapeutics (DT&T), In Press Results Number of respondents Nursing survey: SPRINT 15 Very Good 10 Good Satisfactory 5 Poor 0 Ease of Use Quality Suitability Results 16,063 hours of control on SPRINT; 11,249 measurements 118 admissions Average APAPCHE II score = 21 (41% risk of death) Too high (hypoglycaemia) (hyperglycaemia) Number of measurements Too low 1500 2003 Retrospective Data (Doran, 2004) Mean Glucose = 8.1 Lognormal = outliers to high side Mean 1000 500 0 <4 4 to 6 6 to 8 8 to 10 10 to 12 2003 Numberofof Number measurements measurements 3000 12 to 15 15 to 20 20 plus Blood glucose [mmol/L] SPRINT Mean 2000 2000 Reduction in incidence of high blood glucose 1000 1000 0 0 <3 <4 3 to 4 4 to 6 4 to 5 to 5 6 6 to 7 6 to 8 7 to 8 8 to 10 8 to 9 to 2005 9 10 10 to 12 10 to 11 to 11 12 Normal distribution -- 90% in desired band 12 to 15 15 to 20 20 plus 12 to 13 to 15 to 18 to 20 [mmol/L] 13 15 17 Blood 20 glucose plus Tight control: Tight control: Tight control within target bands Areas under all fitted curves are equal Poor control: BG less than 2.5mmol/L = harmful!! 3.5% of simulated van den Berghe measurements less than 2.5mmol/L Poor control: 70% of simulated Krinsley measurements > 7.75 mmol/L 10% of SPRINT ICU measurements > 7.75 mmol/L 38% of simulated sliding scale measurements > 7.75 mmol/L Cumulative distribution function for all blood glucose measurements Percentiles for ICU data- SPRINT 2.5mmol/L = 4.1x 10-5 3.0mmol/L = 0.001 4.0mmol/L = 0.041 Cumulative probability 6.1mmol/L = 0.59 7.0mmol/L = 0.81 7.75mmol/L =0.91 SPRINT ICU raw data- 26-04-06 ICU data- SPRINT (lognormal) 26-04-06 Model simulation- SPRINT (lognormal) Model simulation- van den Berghe (lognormal) Model simulation- Krinsley Glucose mmol/ L Tight control 15.00 2003 retrospective data Avg BG Range Retroavg Retrorange Flatter is better Tighter is better 15.00 12.50 12.50 Blood 10.00 Glucose Average (mmol/l) 7.50 Blood 10.00 Glucose Average (mmol/l) 5.00 5.00 2005-06 SPRINT Avg BG Max Retroavg Retromax Flatter is better Tighter is better 7.50 R Sq Linear = 0.652 R Sq Linear = 0.283 R Sq Linear = 0.36 P < 0.05 P < 0.05 2.50 2.50 0.0 5.0 10.0 15.0 20.0 Blood Glucose Range (mmol/l) 5.0 10.0 15.0 20.0 Peak Blood Glucose (mmol/l) SPRINT is flatter and tighter in both cases (P < 0.05) R Sq Linear = 0.459 Outcomes: Tightness of glucose control: the first 118 admissions Average BG Average time in 4 -6.1 Average time in 4 -7 Average time in 4 -7.75 Percentage of all measurements less than 4 Percentage of all measurements less than 2.5 Average insulin bolus Average percentage of goal feed Average feed rate (assuming 1.06 cal/ml for feed) 5.9 60% 82% 90% 2.7% 0.1% 2.7 66% 51 1293 mmol/L All performance indicators agree with simulation and tight control! Protocol is safe – no clinically significant hypoglycaemia U Effective use of insulin and nutrition ml/hr cal/day Improved patient outcome: LOS >3 days . 30% Mortality % 25% SPRINT has decreased mortality by 32% 20% 15% 10% 5% 44 deaths in 169 patients 23 deaths in 118 patients 0% 2004-05 SPRINT P=0.04 Outcomes: Tightness of glucose control* SPRINT Mortality grouped by APACHE II APACHE II Number Mortality 0-14 20 5% 15-24 44 20% 25-34 23 26% 35+ 6 67% SPRINT Sepsis data Total sepsis patients Total sepsis LOS<3 Total sepsis LOS≥3 Mortality sepsis all Mortality sepsis LOS<3 Mortality sepsis LOS≥ 3 * Average APACHE II = 21 * Incomplete data * 2004-05 Number 104 200 48 7 2004-05 21 3 18 4 1 3 49% 13% 25% 19% 33% 17% 35.0% 37.0% 34.0% Mortality 1.9% 15.5% 45.8% 71.4% (% change) -46% -10% -51% Average APACHE II =18.3 http:/www.geocities.com/active_insulin_control This is just the beginning… Aim: Tight Glycaemic control for everyone with minimal clinical effort…….. ………from babies to adults….. Acknowledgements Intensive Care Nursing Staff, Christchurch Hospital Acknowledgements AIC1 AIC2 Jessica Lin & AIC3 AIC5: Mike, Aaron and Tim Dunedin Assoc. Prof. Geoff Chase The Danes Thomas Lotz Jason Wong & AIC4 Prof Steen Andreassen Dr Kirsten McAuley Prof Jim Mann Maths and Stats Gurus Dr Dom Lee Dr Bob Broughton Prof Graeme Wake Dr Chris Hann