Biosensors Data for Systems Analysis During Convalescence

BiosensorsBiosensorsData forData for

Systems AnalysisSystems Analysis

DuringDuring

ConvalescenceConvalescence

Palmer Q. Bessey, MDPalmer Q. Bessey, MD

Burn CenterBurn Center

Weill Medical CollegeWeill Medical College

Biomedical Engineering Biomedical Engineering RetreatRetreat

Ithaca, NYIthaca, NY27 July 200727 July 2007

Systems Analysis in Surgical Systems Analysis in Surgical PatientsPatients

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 Biomedical Engineering RetreatRetreatIthaca, NYIthaca, NY 27 July 27 July 20072007


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


The Surgical Patient is a SystemThe Surgical Patient is a SystemComponents (Sub-systems) : Components (Sub-systems) :

CardiovascularCardiovascular MetabolicMetabolic

PulmonaryPulmonary NeurologicNeurologic

RenalRenal HematologicHematologic

Gastro-intestinalGastro-intestinal ImmunologicImmunologic

Large and complex.Large and complex.

Complicated Inter-relationshipsComplicated Inter-relationships

Integrity. Integrity. Common purpose: RecoveryCommon purpose: Recovery


The Surgical Patient is a SystemThe Surgical Patient is a SystemAltered Normal Homeostasis.Altered Normal Homeostasis.

Threats of Operation (Injury) : Threats of Operation (Injury) : Tissue Disruption Tissue Disruption HemorrhageHemorrhage

Ischemia / Hypoxia Ischemia / Hypoxia AcidosisAcidosis

Bacterial ContaminationBacterial Contamination TransfusionTransfusion

Re-perfusionRe-perfusionHypothermia Hypothermia

Complicated Inter-relationships.Complicated Inter-relationships.

Integrity. Integrity. Common purpose: RecoveryCommon purpose: Recovery



Task of Convalescent Care :Guide the patient through recovery.

Systems Analysis :Gather and assemble performance data

Analysis – Efficacy.

Risk assessment.

Decision making regarding intervention




Hypothesis :Hypothesis :The care and treatment of The care and treatment of

... patients is best done ... patients is best done

using numerical data using numerical data

in an orderly set of rules.in an orderly set of rules.


Data Sources :Events Vital signs

Nurse observations MD observations

Physiologic measures Lab data

Special studies Imaging

Analysis and Decision Making :

Gathering data Multiple individuals

Knowledge differences Efficiency



Interventions : Interventions :

Risk AssessmentRisk Assessment Lead timeLead time

End point – DoseEnd point – Dose Feed backFeed back

Issues :Issues :Time consuming Time consuming Multiple stepsMultiple steps

CommunicationCommunication Incomplete dataIncomplete data

Error prone Error prone Delayed feed backDelayed feed back

Risks – All interventions / monitoring Risks – All interventions / monitoring

Opportunites :Opportunites :


Systems Analysis – OpportunitiesSystems 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. invasivenessLess invasive is better.



More Timely Data :

Point of care testing.

Real time data

More Efficient Decision Making

Standardized patient care protocols.


HyperglycemiaHyperglycemia

Clinical Effects :

Impairs PMN / Immunologic defenses

Increased incidence of infection

Increased vascular tone / hypoperfusion.

Increased ventilatory work (CO2 Production)

Exaggerate hypermetabolism

Impaired wound healing


Biomedical Engineering Biomedical Engineering RetreatRetreatIthaca, NYIthaca, NY 27 July 27 July 20072007Control of HyperglycemiaControl of Hyperglycemia

Van Den Bergh, 2001Van Den Bergh, 2001

Biomedical Engineering Biomedical Engineering RetreatRetreatIthaca, NYIthaca, NY 27 July 27 July 20072007Control of HyperglycemiaControl of Hyperglycemia

Van Den Bergh, 2001Van Den Bergh, 2001

CORNELL

U N I V E R S I T Y

William Randolph Hearst Burn Center

NEWYORK

PRESBYTERIAN

H O S P I T A L

NY CORNELL BURN CENTER ICU INSULIN PROTOCOL 2005 INITIAL INSULIN DOSING Glucose

121 - 150 mg/dl

151 - 200 mg/dl

201 - 250 mg/dl

251 - 300 mg/dl

301 - 350 mg/dl

> 350 mg/dl

Insulin Dose

Give 2 U insulin IVP. Start drip @ 2 U / hr

Give 3 U insulin IVP. Start Drip @ 3 U / hr




Give 10 U IVP

Start Drip @ 8 U / hr

GOAL: Maintain blood glucose measured at bedside in range of 81 - 110 mg/dl.

ONGOING INSULIN DOSING

ONGOING INSULIN DOSING Glucose

Level

Current Drip Rate

1-3 U / hr

Current Drip Rate

4-6 U / hr

Current Drip Rate

7-9 U / hr

Current Drip Rate

10 - 12 U / hr

Current Drip Rate

13 - 16 U / hr

Current Drip Rat

> 16 U / hr

> 350 mg/dl

Give 6 U Insulin IVP

Increase Drip by 6 U / hr











301- 350

mg/dl

Give 5 U insulin IVP












251- 300

mg/dl













201- 250

mg/dl













171- 200

mg/dl

Give 2 U insulin IVP.












141- 170

mg/dl













111- 140

mg/dl

No insulin IVP.


No insulin IVP.


No insulin IVP.


No insulin IVP.


No insulin IVP.


No insulin IVP.

Increase Drip Rate by 1 U / hr


Control of HyperglycemiaControl of Hyperglycemia

43 yom, Sepsis, ARDS, Renal Failure 43 yom, Sepsis, ARDS, Renal Failure 65% 65% BSABBSABPBD # 11 - 12PBD # 11 - 12 Tube Tube FeedingsFeedings

0

50

100

150

200

250

0 2 4 6 8 10 12 14 16 18 20 22 24 26

Time (hr)

Glucose (mg/dl)

0

5

10

15

20

Insulin Dose (U)

BolusDrip

Glucose

Insulin Protocol - Nursing WorkInsulin Protocol - Nursing Work

0

200

400

600

800

1000

1200

1400

1600

1800

TotalSamples

HourlySamples

Adjustments AdjustmentHeld

ExtraAdjustment

Glucose Measurements


Insulin Protocol - PerformanceInsulin Protocol - Performance

0

200

400

600

800

1000

< 60 60 - 120 120 - 150 150-180 >180

Blood Glucose (mg/dl)

Glucose Measurements


Insulin ProtocolInsulin ProtocolSummary and Conclusions :

N = 17 patients, 99 24-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 :Conclusion :Insulin protocol safe and effective.

Adds substantially to nursing work load.



Hypothesis :Hypothesis :

The care and treatment of The care and treatment of

... patients is best done ... patients is best done

using numerical data using numerical data

in an orderly set of rules. in an orderly set of rules.



Automation :

Sheppard et al, Ann Surg, 1968.

154 Cardiac Surgery Patients154 Cardiac Surgery Patients

BP, LAP, Urine output, Chest tube drainage.BP, LAP, Urine output, Chest tube drainage.

Automated protocol for blood infusion -- RulesAutomated protocol for blood infusion -- Rules

More reliable, consistentMore reliable, consistent

More efficientMore efficient

Cost effectiveCost effective

SaferSafer


Biosensors Data for Systems Analysis During Convalescence

Documents

surgical patientsinterventions

surgical patientshypothesis

systemcomponents subsystems

surgical patientsdata

point of care testing

numerical data

effect of parameter

threats of operation