Biosensors Data for Systems Analysis DuringConvalescence Palmer Q. Bessey, MD Burn Center Weill Medical College Biomedical Engineering Retreat Ithaca, NY 27 July 2007

Systems Analysis in Surgical Patients Systems Analysis : “.. study of a system... in an attempt to elucidate its effectiveness or performance... and the effect of parameter variations on these quantities.” System : Multiple components (subsystems) Large and complex. Complicated inter-relationships Integrity – Common purpose Biomedical Engineering Retreat Ithaca, NY 27 July 2007

Systems Analysis in Surgical Patients Systems Analysis : “.. study of a system... in an attempt to elucidate its effectiveness or performance... and the effect of parameter variations on these quantities.” System : Multiple components (subsystems) Large and complex. Complicated inter-relationships Integrity – Common purpose Biomedical Engineering Retreat Ithaca, NY 27 July 2007

The Surgical Patient is a System Components (Sub-systems) : CardiovascularMetabolic PulmonaryNeurologic RenalHematologic Gastro-intestinalImmunologic Large and complex. Complicated Inter-relationships Integrity. Common purpose: Recovery Biomedical Engineering Retreat Ithaca, NY 27 July 2007

The Surgical Patient is a System Altered Normal Homeostasis. Threats of Operation (Injury) : Tissue Disruption Hemorrhage Ischemia / Hypoxia Acidosis Bacterial ContaminationTransfusion Re-perfusionHypothermia Complicated Inter-relationships. Integrity. Common purpose: Recovery Biomedical Engineering Retreat Ithaca, NY 27 July 2007

Systems Analysis in Surgical Patients Task of Convalescent Care : Guide the patient through recovery. Systems Analysis : Gather and assemble performance data Analysis – Efficacy. Risk assessment. Decision making regarding intervention Biomedical Engineering Retreat Ithaca, NY 27 July 2007

Systems Analysis in Surgical Patients Biomedical Engineering Retreat Ithaca, NY 27 July 2007 Hypothesis : The care and treatment of... patients is best done using numerical data in an orderly set of rules.

Systems Analysis in Surgical Patients Data Sources : Events Vital signs Nurse observations MD observations Physiologic measuresLab data Special studies Imaging Analysis and Decision Making : Gathering dataMultiple individuals Knowledge differencesEfficiency Biomedical Engineering Retreat Ithaca, NY 27 July 2007

Systems Analysis in Surgical Patients Interventions : Risk AssessmentLead time End point – DoseFeed back Issues : Time consuming Multiple steps CommunicationIncomplete data Error prone Delayed feed back Risks – All interventions / monitoring Opportunites : Biomedical Engineering Retreat Ithaca, NY 27 July 2007

Systems Analysis – Opportunities More Complete Performance Data : For any / all compents (sub-systems) Cardiac performance (organ perfusion) Respiratory work / efficacy (gas exchange) Blood glucose Hematology / Immunology Wound healing Balance usefulness vs. invasiveness Less invasive is better. Biomedical Engineering Retreat Ithaca, NY 27 July 2007

Systems Analysis – Opportunities More Timely Data : Point of care testing. Real time data More Efficient Decision Making Standardized patient care protocols. Biomedical Engineering Retreat Ithaca, NY 27 July 2007

Hyperglycemia Clinical Effects : Impairs PMN / Immunologic defenses Increased incidence of infection Increased vascular tone / hypoperfusion. Increased ventilatory work (CO 2 Production) Exaggerate hypermetabolism Impaired wound healing Biomedical Engineering Retreat Ithaca, NY 27 July 2007

Biomedical Engineering Retreat Ithaca, NY 27 July 2007 Control of Hyperglycemia Van Den Bergh, 2001

Biomedical Engineering Retreat Ithaca, NY 27 July 2007 Control of Hyperglycemia Van Den Bergh, 2001

ONGOING INSULIN DOSING Biomedical Engineering Retreat Ithaca, NY 27 July 2007 Control of Hyperglycemia

43 yom, Sepsis, ARDS, Renal Failure 65% BSAB PBD # Tube Feedings

Insulin Protocol - Nursing Work Biomedical Engineering Retreat Ithaca, NY 27 July 2007

Insulin Protocol - Performance Biomedical Engineering Retreat Ithaca, NY 27 July 2007

Insulin Protocol Summary and Conclusions : N = 17 patients, hour periods Nutritional Intake: 1,938 ± 57 kcal/24 hr Total daily insulin dose: 133 ± 12 U/24 hr POC Glucose determinations: 1,849 Hourly POC Glucose: 1,528 (83 %) Under 60 or over 180 mg/dl: 79 (4.3%) Conclusion : Insulin protocol safe and effective. Adds substantially to nursing work load. Biomedical Engineering Retreat Ithaca, NY 27 July 2007

Systems Analysis in Surgical Patients Hypothesis : The care and treatment of... patients is best done using numerical data in an orderly set of rules. Biomedical Engineering Retreat Ithaca, NY 27 July 2007

Systems Analysis – Opportunities Automation : Sheppard et al, Ann Surg, Cardiac Surgery Patients BP, LAP, Urine output, Chest tube drainage. Automated protocol for blood infusion -- Rules More reliable, consistent More efficient Cost effective Safer Biomedical Engineering Retreat Ithaca, NY 27 July 2007