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Vigileo Monitor
A New Platform for Minimally Invasive Hemodynamic
Monitoring
PreSep ScvO2 Flotrac APCCO
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System Configuration
PreSep Catheter (central vein)
Oximetry
Vigileo Instrument
Cardiac Output
FloTrac Sensor (peripheral artery)
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PreSepTM Central Venous Oximetry Better
indication of tissue oxygenation
23 Oct 2006
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What is Venous Oxygen Saturation (SvO2/ScvO2)

• SvO2 shows the balance between oxygen delivery
  (DO2) and oxygen demand.
• SvO2 decreases when DO2 is compromised or demand
  exceeds supply.

Oxygen Demand
Oxygen Consumption
Oxygen Delivery
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What is ScvO2?

• ScvO2 is the measurement of oxygen saturation in
  the central venous system.
• Superior vena cava ScvO2 is consistently higher
  than SvO2 by 5-18 in shock states.

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SvO2 and ScvO2

• SvO2 Mixed venous oxygen saturation
• ScvO2 Central venous oxygen saturation

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ScvO2 is a reliable and sensitive method for
detecting blood loss in patients deemed stable
after injury

• Patients with ScvO2 lt 65 required more
  transfusions.
• Linear progression analysis demonstrated the
  superiority of ScvO2 to predict blood loss
  (plt0.005) as compared to regularly used
  parameters.

(Scalea et al., J. Trauma 1990)
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Why ScvO2?

• ScvO2 can be used as a surrogate for SvO2 when
  PAC placement is not feasible.
• In resuscitation of critically ill patients,
  ScvO2 monitoring has been shown to be a better
  indicator of tissue oxygenation and derangement
  of cellular oxygen utilization than vital signs.

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Early Goal-Directed Therapy

• EGDT is the protocol used and published by Dr.
  Rivers in the NEJM.
• Determine efficacy of goal-directed therapy prior
  to admission to ICU.
• Protocol implemented in E.R. on random basis for
  three years as prospective study.
• EGDT used ScvO2 in addition to standard care
  factors CVP, MAP and urine output.

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3.8 days reduction in hospital days using
EGDT
Early Goal-Directed Therapy

• 12,000 reduction of in- hospital charges per
  patient using EGDT.

• 34 reduction of in-hospital mortality using
  EGDT.

• Rivers, NEJM 2001

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Other applications for ScVO2/SvO2)

• Acute myocardial infarction (Goldman 1968, Muir
  1970)
• Medical ICU patients (Birman 1984)
• Postop. cardiovascular surgery (Polonen 2000)
• Trauma (Kremzar 1997, Rady 1994, Kazarian 1980)
• Septic shock (Heiselman 1986, Krafft 1993,
  Edwards 1991, Rivers 2001)
• Cardiogenic shock (Crearmer 1990)
• Diseases related to oxygen consumption

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PreSep provides Continuous Venous Oxygen
Saturation(CVP SvO2)
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How does the APCCO algorithm work?
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The proportionality of PP to SV

• The difference between these two pressures
  systolic and diastolic pressures. . . is called
  the pulse pressure.
• - Guyton AC, Textbook of medical physiology, WB
  Saunders, 1991 221-233.
• Aortic pulse pressure is proportional to SV and
  is inversely related to aortic compliance.
  - Boulain (CHEST 2002
  1211245-1252)
• In general, the greater the stroke volume
  output, the greater is the amount of blood that
  must be accommodated in the arterial tree with
  each heartbeat and, therefore, the greater the
  pressure rise and fall during systole and
  diastole, thus causing a greater pulse pressure.
  
• - Guyton AC, Textbook of medical physiology, WB
  Saunders, 1991 221-233.

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The proportionality of PP to SV
SBP

SV
PP
DBP
PP SV SD(AP) PP SD(AP) SV
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pulse pressure is proportional to SV and is
inversely related to aortic compliance.
Boulain (CHEST 2002 1211245-1252)
(PP)
CO HR SV

• Measures pulse rate
• Beats identified by upslope of waveforms
• Pulse rate computed from time period of beats

• Compensates for vascular differences (compliance
  resistance)
• Patient to patient differences estimated from
  demographic data
• Dynamic changes estimated by MAP and waveform
  distributions

• Measures stroke volume
• PP µ SV
• Computed on a beat by beat basis

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Trending Stroke Volume
20 sec.

• Arterial pressure is sampled at 100 Hz
  (i.e., 20sec x 100Hz
  2000 data points)
• An equivalent for pulse pressure is achieved by
  taking the standard deviation (SD) of the 2000
  sampled data points
• SD(Arterial pressure) µ Pulse Pressure µ Stroke
  Volume
• Changes in stroke volume will result in
  corresponding changes in the pulse pressure
• SV estimates are updated over 20 seconds

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SD is a measure of variation of the AP
Therefore, with a constant vasculature
? AP Variation ? ? SD(AP) ? ? SV
? AP Variation ? ? SD(AP) ? ? SV
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The effect of compliance on PP
Age, gender and BSA factors
vs.

• Younger
• Male
• Higher BSA

• Older
• Female
• Lower BSA

vs.
vs.
For the same X mmHg ?

• Compliance inversely affects PP
• The algorithm compensates for the effects of
  compliance on PP based on age, gender, and BSA

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The effect of changes in vascular tone on the
arterial pressure over time

• The algorithm looks for characteristic changes in
  arterial pressure that affect flow
• Those changes are included in the calculation of
  SV

Dynamic increase/decrease in pressure within same
time Increased resistance
Quick rise in pressure - Increased resistance
Increase MAP - Increased resistance
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Summary
Analysis of patient specific arterial pressure
over time . . .

• Calculation of Stroke Volume
• Stroke volume is proportional to pulse pressure
• Patient specific measurement of vascular
  influence
• The algorithm takes into consideration 2 key
  factors affecting the arterial pulse pressure
  (and thus SV)
• Larger vessel compliance (reason for age,
  gender, height, and weight input)
• Peripheral resistance effects on arterial
  pressure
• (Assessment of waveform elements associated with
  changes in peripheral resistance)
• Heart rate measured by from the waveform

SV
x
HR
Robust pressure analysis ? no manual calibration
process
CO
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VigileoTM Monitor

• The Vigileo monitor continuously computes patient
  specific stroke volume from. . .
• Arterial pressure analysis
• Inputs of age, gender, height, and weight
  determine patient-specific vascular compliance.
• Dynamic changes in the vasculature (peripheral
  resistance and vascular tone), which affect
  arterial pressure, are measured and compensated
  for.
• The Vigileo displays cardiac output on a
  continuous basis (every 20 sec) by multiplying
  the pulse rate and computed stroke volume.
• Venous oximetry available when used with
  appropriate Edwards catheters.

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Parameters
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FloTracTM Sensor

• The specially designed FloTrac sensor provides
  the high fidelity arterial pressure signal
  required by the Vigileo monitor to calculate the
  stroke volume.

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Performance
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Validation of a Continuous Cardiac Output
Measurement Using Arterial Pressure Waveforms
William T. McGee, MD, MHA, et al.

• Methods
• APCO, ICO, CCO data collected from 84 patients
• (69 OR and in ICU, 15 ICU only)
• 2 US, 2 European centers
• Average age 67.7 (/- 12.0) years, 65.5 male
• Grouped measurements (562 data points) for APCO,
  ICO and CCO were analyzed for bias, precision and
  correlation via Bland-Altman analysis.

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Validation of a Continuous Cardiac Output
Measurement Using Arterial Pressure Waveforms
William T. McGee, MD, MHA, et al.
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Validation of a Continuous Cardiac Output
Measurement Using Arterial Pressure Waveforms
William T. McGee, MD, MHA, et al.
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Validation of a Continuous Cardiac Output
Measurement Using Arterial Pressure Waveforms
William T. McGee, MD, MHA, et al.
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Validation of a Continuous Cardiac Output
Measurement Using Arterial Pressure Waveforms
William T. McGee, MD, MHA, et al.
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Comparison of APCO vs CCO trended over 25 hrs
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Cardiac Output Determination using the Arterial
Pulse Wave A Comparison of a Novel Algorithm
Against Continuous and Intermittent
Thermodilution Gerard R. Manecke Jr., M.D.,
Mathew Peterson, M.D., William R. Auger,
M.D. UCSD Medical Center, San Diego, CA
Introduction Assessment of cardiac output using
the arterial pulse wave has been accomplished
with varying success, usually requiring
calibration with another method(1). We tested a
new algorithm based on arterial pulsatility that
does not require such calibration. Comparisons
were made against standard thermodilution
techniques using a pulmonary artery catheter.
Methods In 11 cardiothoracic surgery patients (7
men and 4 women) cardiac output (CO) was
monitored immediately after surgery. An arterial
pressure based algorithm calculated cardiac
output from arterial pressure (APCO) in real time
while a pulmonary artery (PA) catheter (777HF8
CCO Catheter, Edwards Lifesciences, Irvine,
California) was used to measure continuous (CCO)
and intermittent bolus thermodilution cardiac
output (ICO). A laptop-based data acquisition
system provided continuous calculation and
storage of APCO, as well as storage of the
PA-based CO determinations. Each bolus cardiac
output was calculated as the average of four
measurements taken over approximately 5 minutes.
APCO values were determined by averaging the
individual values (3 per minute) over a 5 minute
interval surrounding the time of bolus
determination. CCO values were taken immediately
prior to the bolus determinations, and represent
a 5 minute average. Bland-Altman analysis, based
on 65 comparison points, was used to determine
bias and precision in the comparison of the CO
techniques.
Results The CCO range was 2.77-9.60 L/min, with
the mean being 6.02?1.58 L/min. The mean bias
between APCO and CCO was 0.38?0.83 L/min (figure
1), and the mean bias between APCO and ICO was
0.04?0.99 L/min.
Conclusion This APCO algorithm provides a
reliable, minimally invasive method for measuring
CO that requires neither dilution nor CO
reference for calibration. It shows strong
correlation and minimal bias with both
traditional intermittent bolus thermodilution and
continuous cardiac output over a wide range of
values.
Bland-Altman plot. Mean -0.38, 2SD 1.28,
-2SD -2.04
References 1. J Cardiothoracic Vasc Anesth
18185-189, 2004
Supported by Edwards Lifesciences, LLC
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CCO . . . directly from the arterial line
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