Download - Haemodynamic Monitoring

Haemodynamic Monitoring

Theory and Practice

PiCCO Technology is a combination of transpulmonary thermodilution and pulse contour analysis

Principles of Measurement

Left HeartRight Heart

Pulmonary Circulation

Lungs

Body CirculationPULSIOCATHPULSIOCATH

CVC

PULSIOCATH arterial thermodilution catheter

central venous bolus injection

Introduction to the PiCCO-Technology – Function

Bolus injection

concentration changes over time(Thermodilution curve)

After central venous injection the cold bolus sequentially passes through the various intrathoracic compartments

The temperature change over time is registered by a sensor at the tip of the arterial catheter


Left heartRight heart Lungs

RA RV LA LVPBV

EVLW

EVLW

Principles of Measurement

Intrathoracic Compartments (mixing chambers)


Pulmonary Thermal Volume (PTV)

Intrathoracic Thermal Volume (ITTV)

Total of mixing chambers

RA RV LA LVPBV

EVLW

EVLW

Largest single mixing chamber


E. Introduction to PiCCO Technology

1. Principles of function

2. Thermodilution

3. Pulse contour analysis

4. Contractility parameters

5. Afterload parameters

6. Extravascular Lung Water

7. Pulmonary Permeability

Tb x dt

(Tb - Ti) x Vi x

K

Tb

Injection

t

∫ =COTD a

Tb = Blood temperatureTi = Injectate temperatureVi = Injectate volume∫ ∆ Tb

. dt = Area under the thermodilution curve

K = Correction constant, made up of specific weight and specific heat of blood and injectate

The CO is calculated by analysis of the thermodilution curve using the modified Stewart-Hamilton algorithm

Calculation of the Cardiac Output

Introduction to the PiCCO-Technology – Thermodilution

The area under the thermodilution curve is inversely proportional to the CO.

36,5

37

5 10

Thermodilution curves

Normal CO: 5.5l/min


36,5

37

36,5

37

Time

low CO: 1.9l/min

High CO: 19l/min

Time

Time

Temperature

Temperature

Temperature

Transpulmonary vs. Pulmonary Artery Thermodilution

Left heartRight Heart

Pulmonary Circulation

Lungs

Body Circulation

PULSIOCATH arterial thermo-dilution catheter

central venous bolus injection RA

RV

PA

LA

LV

Aorta

Transpulmonary TD (PiCCO) Pulmonary Artery TD (PAC)

In both procedures only part of the injected indicator passes the thermistor.

Nonetheless the determination of CO is correct, as it is not the amount of the detected indicator but the difference in temperature over time that is relevant!

Introduction to the PiCCO –Technology – Thermodilution

MTt: Mean Transit time the mean time required for the indicator to reach the detection point

DSt: Down Slope time the exponential downslope time of the thermodilution curve

Recirculation

t

e-1

Tb

From the characteristics of the thermodilution curve it is possible to determine certain time parameters

Extended analysis of the thermodilution curve


Injection

In Tb

MTt DSt

Tb = blood temperature; lnTb = logarithmic blood temperature; t = time

Pulmonary Thermal Volume

PTV = Dst x CO

By using the time parameters from the thermodilution curve and the CO ITTV and PTV can be calculated

Calculation of ITTV and PTV


Recirculation

t

e-1

Tb

Injection

In Tb

Intrathoracic Thermal Volume

ITTV = MTt x CO

MTt DSt



Calculation of ITTV and PTV

Einführung in die PiCCO-Technologie – Thermodilution

ITTV = MTt x CO

PTV = Dst x CO

RA RV LA LVPBV

EVLW

EVLW

GEDV is the difference between intrathoracic and pulmonary thermal volumes

Global End-diastolic Volume (GEDV)

Volumetric preload parameters – GEDV

RA RV LA LVPBV

EVLW

EVLW

ITTV

GEDV

PTV


Volumetric preload parameters – ITBV

Intrathoracic Blood Volume (ITBV)

GEDV

ITBV

PBVRA RV LA LVPBV

EVLW

EVLW


ITBV is the total of the Global End-Diastolic Volume and the blood volume in the pulmonary vessels (PBV)

ITBVTD (ml)

ITBV = 1.25 * GEDV – 28.4 [ml]

GEDV vs. ITBV in 57 Intensive Care Patients

IIntrantratthoracic horacic BBlood lood VVolume (olume (ITBVITBV))

Volumetric preload parameters – ITBV


ITBV is calculated from the GEDV by the PiCCO Technology

0

1000

2000

3000

0 1000 2000 3000 GEDV (ml)

Sakka et al, Intensive Care Med 26: 180-187, 2000

Intrathoracic Compartments (mixing chambers)




Total of mixing chambers

RA RV LA LVPBV

EVLW

EVLW

Largest single mixing chamber

ITTV

– ITBV

= EVLW

The Extravascular Lung Water is the difference between the intrathoracic thermal volume and the intrathoracic blood volume. It represents the amount of water in the lungs outside the blood vessels.

Calculation of Extravascular Lung Water (EVLW)

Introduction to the PiCCO –Technology – Extravascular Lung Water

Katzenelson et al,Crit Care Med 32 (7), 2004 Sakka et al, Intensive Care Med 26: 180-187, 2000

Gravimetry Dye dilution

EVLW from the PiCCO technology has been shown to have a good correlation with the measurement of extravascular lung water via the gravimetry and dye dilution reference methods

Validation of Extravascular Lung Water

n = 209r = 0.96

ELWI by gravimetry

ELWI by PiCCO

R = 0,97P < 0,001

Y = 1.03x + 2.49

0

10

20

30

20 30

40

10

ELWITD (ml/kg)

0

5

10

20

15 25

25

50 100 20

15

ELWIST (ml/kg)

Introduction to the PiCCO –Technology – Extravascular Lung Water


E. Introduction to PiCCO Technology

1. Principles of function

2. Thermodilution

3. Pulse contour analysis

4. Contractility parameters

5. Afterload parameters

6. Extravascular Lung Water

7. Pulmonary Permeability

Transpulmonary Thermodilution

The pulse contour analysis is calibrated through the transpulmonary thermodilution and is a beat to beat real time analysis of the arterial pressure curve

Calibration of the Pulse Contour Analysis

Introduction to the PiCCO-Technology – Pulse contour analysis

Injection

Pulse Contour Analysis

T = blood temperature t = timeP = blood pressure

COCOTPDTPD= SV= SVTDTD

HRHR

PCCO = cal • HR •P(t)SVR

+ C(p) •dPdt

( ) dt

Cardiac Output

Patient- specific calibration factor (determined by thermodilution)

Heart rate Area under the pressure curve

Shape of the pressure curve

Aortic compliance

Systole


Parameters of Pulse Contour Analysis

SVSVmaxmax – SV – SVminminSVV =SVV =

SVSVmeanmean

SVSVmaxmax

SVSVminmin

SVSVmeanmean

The Stroke Volume Variation is the variation in stroke volume over the ventilatory cycle, measured over the previous 30 second period.


Introduction to the PiCCO-Technology – Pulse Contour Analysis

Dynamic parameters of volume responsiveness – Stroke Volume Variation

PPPPmaxmax – PP – PPminminPPV =PPV =

PPPPmeanmean

The pulse pressure variation is the variation in pulse pressure over the ventilatory cycle, measured over the previous 30 second period.


Introduction to the PiCCO-Technology – Pulse Contour Analysis

Dynamic parameters of volume responsiveness – Pulse Pressure Variation

PPPPmaxmax

PPPPmeanmean

PPPPminmin

Summary pulse contour analysis - CO and volume responsiveness

• The PiCCO technology pulse contour analysis is calibrated by transpulmonary thermodilution

• PiCCO technology analyses the arterial pressure curve beat by beat thereby providing real time parameters

• Besides cardiac output, the dynamic parameters of volume responsiveness SVV (stroke volume variation) and PPV (pulse pressure variation) are determined continuously


Download - Haemodynamic Monitoring

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