Haemodynamic Monitoring

Theory and Practice

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Haemodynamic Monitoring

A. Physiological Background

B. Monitoring

C. Optimising the Cardiac Output

D. Measuring Preload

E. Introduction to PiCCO Technology

F. Practical Approach

G. Fields of Application

H. Limitations

Preload

Filling Pressures

CVP / PCWP

Volumetric Preload Parameters, Volume Responsiveness and Filling Pressures

Measuring Preload

Volume Responsiveness

SVV / PPV

Volumetric

Preload parameters

GEDV / ITBV

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Kumar et al., Crit Care Med 2004;32: 691-699

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Role of the filling pressures CVP / PCWP

Correlation between Central Venous Pressure CVP and Stroke Volume

Measuring Preload

Kumar et al., Crit Care Med 2004;32: 691-699

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Correlation between Pulmonary Capillary Wedge Pressure PCWP and Stroke Volume

Measuring Preload

Role of the filling pressures CVP / PCWP

The filling pressures CVP and PCWP do not give an adequate assessment of cardiac preload.

The PCWP is, in this regard, not superior to CVP (ARDS Network, N Engl J Med 2006;354:2564-75).

Pressure is not volume!

Influencing Factors:-Ventricular compliance-Position of catheter (PAC)-Mechanical ventilation-Intra-abdominal hypertension

Role of the filling pressures CVP / PCWP

Measuring Preload

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Role of the volumetric preload parameters GEDV / ITBV

Measuring Preload

Preload

Filling Pressures

CVP / PCWP

Volume Responsiveness

SVV / PPV

Volumetric Preload parameters

GEDV / ITBV

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Total volume of blood in all 4 heart chambers

Left heartRight Heart

Measuring Preload

Pulmonary Circulation

Lungs

Body Circulation

GEDV = Global Enddiastolic Volume

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Role of the volumetric preload parameters GEDV / ITBV

Measuring Preload

GEDV shows good correlation with the stroke volume

Michard et al., Chest 2003;124(5):1900-1908

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Role of the volumetric preload parameters GEDV / ITBV

ITBV = Intrathoracic Blood Volume

Total volume of blood in all 4 heart chambers plus the pulmonary blood volume

Left heartRight heart

Measuring Preload

Pulmonary Circulation

Lungs

Body Circulation

ITBV =GEDV + PBV

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Role of the volumetric preload parameters GEDV / ITBV

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

Measuring Preload

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ITBVTD (ml)

ITBV = 1.25 * GEDV – 28.4 [ml]

GEDV vs. ITBV in 57 Intensive Care Patients

0

1000

2000

3000

0 1000 2000 3000 GEDV (ml)

ITBV is normally 1.25 times the GEDV

Role of the volumetric preload parameters GEDV / ITBV

The static volumetric preload parameters GEDV and ITBV

Measuring Preload

• Are superior to filling pressures for assessing cardiac preload(German Sepsis Guidelines)

• Are, in contrast to cardiac filling pressures, not falsified by other pressure

influences (ventilation, intra-abdominal pressure)

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Role of the volumetric preload parameters GEDV / ITBV

Measuring Preload

Role of the dynamic volume responsiveness parameters SVV / PPV

Preload

Filling Pressures

CVP / PCWP

Volume Responsiveness

SVV / PPV

Volumetric Preload parameters

GEDV / ITBV

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Intrathoracic pressure

Venous return to left and right ventricle

Left ventricular preload

Left ventricular stroke volume

Systolic arterial blood pressure

Intrathoracic pressure

„Squeezing “ of the pulmonary blood

Left ventricular preload

Left ventricular stoke volume

Systolic arterial blood pressure

PPPPmaxmax PPPPminmin

PPPPmaxmax

PPPPminmin

Inspiration

Reuter et al., Anästhesist 2003;52: 1005-1013

Measuring Preload

Physiology of the dynamic parameters of volume responsiveness

Expiration Inspiration Expiration

Early Inspiration Late Inspiration

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Fluctuations in blood pressure during the respiration cycle

SV

PreloadV

SV

V

SV

Mechanical Ventilation

Measuring Preload

Fluctuations in stroke volume

Intrathoracic pressure fluctuationsChanges in intrathoracic blood volume

Preload changes

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Fluctuations in stroke volume throughout the respiratory cycle

Physiology of the dynamic parameters of volume responsiveness

SVSVmaxmax

SVSVminmin

SVSVmeanmean

Measuring Preload

SVV = Stroke Volume Variation

• The variation in stroke volume over the respiratory cycle

• Correlates directly with the response of the cardiac ejection to preload increase (volume responsiveness)

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mean

Role of the dynamic volume responsiveness parameters SVV / PPV

Sensitivity

- - - CVP___ SVV

SVV is more accurate for predicting volume responsiveness than CVP

Measuring Preload

Berkenstadt et al, Anesth Analg 92: 984-989, 2001

Specificity 1 0,5 0

0

0,2

0,4

0,6

0,8

1

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Role of the dynamic volume responsiveness parameters SVV / PPV

Measuring Preload

PPV = Pulse Pressure Variation

• The variation in pulse pressure amplitude over the respiration cycle • Correlates equally well as SVV for volume responsiveness

PPPPmaxmax

PPPPmeanmean

PPPPminmin

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Role of the dynamic volume responsiveness parameters SVV / PPV

Measuring Preload

A PPV threshold of 13% differentiates between responders and non-responders to volume administration

Michard et al, Am J Respir Crit Care Med 162, 2000

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Respondersn = 16

Non – Respondersn = 24

Role of the dynamic volume responsiveness parameters SVV / PPV

respiratory changes in arterial pulse pressure (%)

The dynamic volume responsiveness parameters SVV and PPV

Measuring Preload

- are good predictors of a potential increase in CO due to volume administration

- are only valid with patients who are fully ventilated and who have no cardiac arrhythmias

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Role of the dynamic volume responsiveness parameters SVV / PPV

Extravascular water content of the lung

Pulmonary circulation

Left Heart

Right Heart

Lungs

Role of extravascular lung water EVLW

Extra

EVLW = Extravascular Lung Water

Body circulation

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Role of extravascular lung water EVLW

Extra

- is useful for differentiating and quantifying lung oedema

- is, for this purpose, the only parameter available at the bedside

- functions as a warning parameter for fluid overload

The Extravascular Lung Water EVLW

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• The volumetric parameters GEDV / ITBV are superior to the filling pressures CVP / PCWP for measuring cardiac preload.

• The dynamic parameters of volume responsiveness (SVV and PPV) can predict whether CO will respond to volume administration.

• GEDV and ITBV show what the actual volume status is, whilst SVV and PPV reflect the volume responsiveness of the heart.

• For optimal control of volume therapy simultaneous monitoring of both the static preload parameters and the dynamic parameters of volume responsiveness is sensible (F. Michard, Intensive Care Med 2003;29: 1396).

Measuring Preload

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Summary and Key Points