Haemodynamic Monitoring

Haemodynamic Monitoring

Theory and Practice

2


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


1. Principles of function

2. Thermodilution

3. Pulse contour analysis

4. Contractility parameters

5. Afterload parameters

6. Extravascular lung water

7. Pulmonary permeability


PiCCO Technology

Parameters for guiding volume therapy

Introduction to the PiCCO-Technology

CO

Volumetric preload

EVLW

Contractility

Differentiated Volume Management

- static - dynamic

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




2. Thermodilution




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

Comparison with the Fick Method

0,970,68 ± 0,6237/449Sakka SG et al., Intensive Care Med 25, 1999

- / - 0,19 ± 0,219/27McLuckie A. et a., Acta Paediatr 85, 1996

0,960,16 ± 0,3130/150Gödje O et al., Chest 113 (4), 1998

0.980,32 ± 0,2923/218Holm C et al., Burns 27, 2001

0,930,13 ± 0,5260/180Della Rocca G et al., Eur J Anaest 14, 2002

0,95-0,04 ± 0,4117/102Friedman Z et al., Eur J Anaest, 2002

0,950,49 ± 0,4545/283Bindels AJGH et al., Crit Care 4, 2000

0,980,03 ± 0,1718/54Pauli C. et al., Intensive Care Med 28, 2002

24/120

n (Pts / Measurements)

0,990,03 ± 0,24Tibby S. et al., Intensive Care Med 23, 1997

r bias ±SD(l/min)

Comparison with Pulmonary Artery Thermodilution

Validation of the Transpulmonary 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

Pulmonary Thermal Volume (PTV)

Intrathoracic Thermal Volume (ITTV)

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

Summary and Key Points - Thermodilution

• PiCCO Technology is a less invasive method for monitoring the volume status and cardiovascular function.

• Transpulmonary thermodilution allows calculation of various volumetric parameters.

• The CO is calculated from the shape of the thermodilution curve.

• The volumetric parameters of cardiac preload can be calculated through advanced analysis of the thermodilution curve.

• For the thermodilution measurement only a fraction of the total injected indicator needs to pass the detection site, as it is only the change in temperature over time that is relevant.

Introduction to the PiCCO-Technology




2. Thermodilution






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

n (Pts / Measurements)

0,940,03 ± 0,6312 / 36Buhre W et al., J Cardiothorac Vasc Anesth 13 (4), 1999

19 / 76

24 / 517

62 / 186

20 / 360

25 / 380

22 / 96 - / --0,40 ± 1,3Mielck et al., J Cardiothorac Vasc Anesth 17 (2), 2003

0,880,31 ± 1,25Zöllner C et al., J Cardiothorac Vasc Anesth 14 (2), 2000

0,88-0,2 ± 1,15Gödje O et al., Crit Care Med 30 (1), 2002

0,94-0,02 ± 0,74Della Rocca G et al., Br J Anaesth 88 (3), 2002

0,93-0,14 ± 0,33Felbinger TW et al., J Clin Anesth 46, 2002

- / - 0,14 ± 0,58Rauch H et al., Acta Anaesth Scand 46, 2002

r

bias ±SD (l/min)

Comparison with pulmonary artery thermodilution

Validation 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





2. Thermodilution






Contractility is a measure for the performance of the heart muscle

Contractility parameters of PiCCO technology:

- dPmx (maximum rate of the increase in pressure)

- GEF (Global Ejection Fraction)

- CFI (Cardiac Function Index)

Contractility

Introduction to the PiCCO-Technology – Contractility parameters

kg

Contractility parameter from the pulse contour analysis


dPmx = maximum velocity of pressure increase

The contractility parameter dPmx represents the maximum velocity of left ventricular pressure increase.

Contractility parameter from the pulse contour analysis


femoral dP/max [mmHg/s]

LV dP/dtmax [mmHg/s]

dPmx was shown to correlate well with direct measurement of velocity of left ventricular pressure increase in 70 cardiac surgery patients

de Hert et al., JCardioThor&VascAnes 2006

n = 220y = -120 + (0,8* x)r = 0,82p < 0,001

0

500

1000

1500

0 1000 1500

2000

2000500

dPmx = maximum velocity of pressure increase

• is calculated as 4 times the stroke volume divided by the global end-diastolic volume

• reflects both left and right ventricular contractility

GEF = Global Ejection Fraction

Contractility parameters from the thermodilution measurement


4 x SVGEF =

GEDV

LA

LVRA

RV

Combes et al, Intensive Care Med 30, 2004

GEF = Global Ejection Fraction

Comparison of the GEF with the gold standard TEE measured contractility in patients without right heart failure

sensitivity

0

0,4

0,6

0,8

0

1

0,2

0,2

0,4 0,6 0,81 specifity

22

20

19

18

16

12 8

FAC, %

GEF, %

5

10

-5

-20 -10 10 20

15

-15

-10

r=076, p<0,0001n=47



• is the CI divided by global end-diastolic volume index

• is - similar to the GEF – a parameter of both left and right ventricular contractility

CFI = Cardiac Function Index

CICFI =

GEDVI



Combes et al, Intensive Care Med 30, 2004

sensitivity

0

0,4

0,6

0,8

0

1

0,2

0,2

0,4 0,6 0,81 specificity

6

5

43,5

3 2

FAC, %

GEF, %

5

10

-5

-20 -10 10 20

15

-15

-10

r=079, p<0,0001n=47

CFI = Cardiac Function Index


CFI was compared to the gold standard TEE measured contractility in patients without right heart failure



E. Introduction to PiCCO technology

1. Functions

2. Thermodilution






• is calculated as the difference between MAP and CVP divided by CO

• as an afterload parameter it represents a further determinant of the cardiovascular situation

• is an important parameter for controlling volume and catecholamine therapies

(MAP – CVP) x 80SVR =

CO

Afterload parameter

SVR = Systemic Vascular Resistance

MAP = Mean Arterial PressureCVP = Central Venous PressureCO = Cardiac Output80 = Factor for correction of units

Introduction to the PiCCO –Technology – Afterload parameter

• The parameter dPmx from the pulse contour analysis as a measure of the left ventricular myocardial contractility gives important information regarding

cardiac function and therapy guidance

• The contractility parameters GEF and CFI are important parameters for assessing the global systolic function and supporting the early diagnosis of myocardial insufficiency

• The Systemic Vascular Resistance SVR calculated from blood pressure and cardiac output is a further parameter of the cardiovascular situation, and gives additional information for controlling volume and catecholamine therapies

Summary and Key Points

Introduction to the PiCCO –Technology – Contractility and Afterload


E. Introduction to PiCCO technology


2. Thermodilution






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)


Boeck J, J Surg Res 1990; 254-265

High extravascular lung water is not reliably identified by blood gas analysis

EVLW as a quantifier of lung edema

PaO2 /FiO2

10

20

550

30

150 2500 450

ELWI (ml/kg)

050 350


ELWI = 7 ml/kg

ELWI = 8 ml/kgELWI = 14 ml/kg

ELWI = 19 ml/kg

Extravascular lung water index

(ELWI) normal range:

3 – 7 ml/kg

Pulmonary

oedem

a Normal rangeEVLW as a quantifier of lung oedema


40

Halperin et al, 1985, Chest 88: 649

Chest x ray – does not reliably quantify pulmonary oedema and is difficult to judge, particularly in critically ill patients

r = 0.1p > 0.05

0

20

80

15-10-15 10

60

radiographic score

-80

-60

-40

-20 ELWI

EVLW as a quantifier of lung oedema


ELWI (ml/kg)

> 21 n = 54

14 - 21 n = 100

7 - 14 n = 174

< 7 n = 45

Mortality(%)

10

00

n = 373*p = 0.002

20

30

40

50

60

70

80

Sturm J in: Lewis, Pfeiffer (eds): Practical Applications of Fiberoptics in Critical Care Monitoring, Springer Verlag Berlin - Heidelberg - NewYork 1990, pp 129-139

Relevance of EVLW Assessment

The amount of extravascular lung water is a predictor for mortality in the intensive care patient

ELWI (ml/kg) 4 - 6

30

0

Mortality (%)

20

n = 81

40

50

60

70

80

6 - 8 8 - 10 10 - 12 12 - 16 16 - 20 > 20

90

100

Sakka et al , Chest 2002


Intensive Care days

Mitchell et al, Am Rev Resp Dis 145: 990-998, 1992

Relevance of EVLW Assessment

Volume management guided by EVLW can significantly reduce time on ventilation and ICU length of stay in critically ill patients, when compared to PCWP oriented therapy,

Ventilation Days

PAC Group

n = 101* p ≤ 0,05

PAC GroupEVLW Group EVLW Group

22 days 15 days9 days 7 days

* p ≤ 0,05





2. Thermodilution






Differentiating Lung Oedema

PVPI = Pulmonary Vascular Permeability Index

• is the ratio of Extravascular Lung Water to Pulmonary Blood Volume

• is a measure of the permeability of the lung vessels and as such can classify the type of lung oedema (hydrostatic vs. permeability caused)

EVLWPVPI =

PBVPBV

EVLW

Introduction to PiCCO Technology – Pulmonary Permeability

permeability

PVPI normal (1-3) PVPI raised (>3)

Classification of Lung Oedema with the PVPI

Difference between the PVPI with hydrostatic and permeability lung oedema:

Lung oedema

hydrostatic

PBV

EVLW

PBV

EVLW

PBV

EVLW

PBV

EVLW


16 patients with congestive heart failure and acquired pneumonia. In both groups EVLW was 16 ml/kg.

Validation of the PVPI

PVPI can differentiate between a pneumonia caused and a cardiac failure caused lung oedema.

Benedikz et al ESICM 2003, Abstract 60

Cardiac insufficiency

PVPI

Pneumonia

4

3

2


EVLWI answers the question:

Clinical Relevance of the Pulmonary Vascular Permeability Index

PVPI answers the question:

and can therefore give valuable aid for therapy guidance!

How much water is in the lungs?

Why is it there?


Summary and Key Points

• EVLW as a valid measure for the extravascular water content of the lungs is the only parameter for quantifying lung oedema available at the bedside.

• Blood gas analysis and chest x-ray do not reliably detect and measure lung edema

• EVLW is a predictor for mortality in intensive care patients

• The Pulmonary Vascular Permeability Index can differentiate between hydrostatic and a permeability caused lung oedema

Introduction to PiCCO Technology – EVLW and Pulmonary Permeability

Haemodynamic Monitoring

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