Fluids/Pressors Interactions

Dr. Maurizio Cecconi MD FRCA FICM MD(UK)

Consultant and Honorary Senior Lecturerin Anaesthesia and Intensive Care

St George’s Hospital and Medical School, London, UK

Disclosure

• Edwards Lifescience

• LiDCO

• Cheetah Medical

• Masimo

• Nexfin Bmeye

• Applied Physiology

Fluids/Pressors Interaction

• Guyton and Frank Starling

• CVP and Venous Return

• Venous Return Fluids and Pressors

• Arterial Load

Frank Starling The law of the heart

“The greater the heart muscle is stretched, greater is the force generated and the output from the ventricle.

In practice, within some limits the heart needs to pump all the venous return”

Actin

Myosin

Stroke Volume

Preload

Heart with Preload reserve

Heart with maximum fillingAnd optimal sarcomere lenght

No preload reserve,Heart failure

a

b

cd e

f

Cardiac Output

Afterload

Preload

Contractility SV

Heart Rate

Cardiac OutputVenous Return =

Pms

Resistance

RAP

Filling of Circulation

Resistance to blood

flow

Guyton Theory

Unstressed Volume

Stressed Volume

No pressure generated

Pressure Generated Pms

UnstressedVolume

Stressed Volume

Mean circulatory filling pressure

Right Atrial Pressure

VR =Pms-RAP

RVR

Pms

The mean systemic filling pressure

(Pms) is the pressure in the whole

vascular system when the heart is

stopped and there is no fluid motion

VR 

RAP 0  a  b  c 

Pms a 

Pms b 

Pms c 

Adapted from Guyton Guyton AC. Physiol Rev 1955;35(1):123-9.

2

Clinical death and the measurement of stressed vascular volume.Magder, Sheldon; De Varennes, Benoit

Critical Care Medicine. 26(6):1061-1064, June 1998.

5 Patients, hypothermic cardiac bypass

Stressed volume1290±296 ml20.2±1.0 ml/kg

Stressed volume is 30±17% ofthe total blood volume

Bleeding DecrasedStressed Volume

Fluid Loading

UnstressedVolume

Stressed Volume

UnstressedVolume

Stressed Volume

UnstressedVolume

Stressed Volume

Preload

Stroke Volume

Preload

CVP

CVP / CVP CHANGESPRELOAD AND PRELOAD RESPONSIVENESS

15

10

0

5

-4 0 4 8 12

Right Atrial Pressure (mmHg)

Cardiac Output and

Venous Return(l/min)

IncreasedPms

Venous ReturnCurve

Impaired Cardiac Function Curve

Normal Cardiac Function Curve

Fluid Response

Evaluation of mean systemic filling pressure from pulse contour cardiac output and central venous pressureJacinta J Maas, Bart F Geerts Jos RC Jansen

Clin Monit and Computing 2011 25:193-201

Airway Pressure

CVP (RAP)

CO

Evaluation of mean systemic filling pressure from pulse contour cardiac output and central venous pressureJacinta J Maas, Bart F Geerts Jos RC Jansen

Clin Monit and Computing 2011 25:193-201

Estimation of mean systemic filling pressurein postoperative cardiac surgery patientswith three methodsJacinta J Maas, Michael Pinsky, Bart F Geerts, Rob B Wilde Jos RC Jansen

Intensive Care Medicine 2012

Occlusion

Insufficient volume?

• Case DC9963

• Male 65 y.o.

• 1.77 m 109 Kg

• Admitted to ICU after a MVR and TV

anuloplasty

• 1 Fluid Challenge 20:09:00 10 min

• 2 Fluid Challenge 20:21:00 10 min

• CO monitor• MAP• CVP

Changes in the mean systemic filling pressureduring a fluid challenge in postsurgicalintensive care patients Maurizio Cecconi Hollmann D. Aya Martin Geisen Claudia Ebm Nick Fletcher R. Michael Grounds Andrew Rhodes

Intensive Care Medicine 2013

Pms - RAP Responders

Cecconi et al ICM 2013

Pms - RAP Non Responders

Cecconi et al ICM 2013

35 cm H20

130 mm Hg

5 cm H20

40 mm Hg

Air

way

pre

ssu

reA

rter

ial P

ress

ure

PPmax PPmin

SP max

SP min

SV max SV min

SPV = (SP max – SP min) mmHg

PPV =PPmax – PPmin

Average PPx100

SVV =SVmax – SVmin

Average SVx100

15

10

0

5

-4 0 4 8 12

Right Atrial Pressure (mmHg)

Cardiac Output and

Venous Return(l/min)

Increased Resistance

VR =Pms-RAP

RVR

Resistance

Sepsisdecreased

ToneFluid Loading

UnstressedVolume

Stressed Volume

UnstressedVolume

Stressed Volume

UnstressedVolume

Stressed Volume

Fluid Loading and Pressors

15

10

0

5

Right Atrial Pressure (mmHg)

Cardiac Output and

Venous Return(l/min)

Venous ReturnCurve

CO Increase and Pressors

Stressed Volume Effect

+ Resistance Effect

Stressed Volume Effect

+ Resistance Effect

Maas J et al Crit Care Med 2013

15

10

0

5

Right Atrial Pressure (mmHg)

Cardiac Output and

Venous Return(l/min)

Stressed Volume Effect

+ Resistance Effect

+ heart performance effect

CO Decrease and Pressors

Stressed Volume Effect

+ Resistance Effect

+ heart performance effect

Maas J et al Crit Care Med 2013

15

10

0

5

-4 0 4 8 12

Right Atrial Pressure (mmHg)

Cardiac Output and

Venous Return(l/min)

Combined effect depends on:

Filling/Stressed Volume

ResistenceCardiac Function

Pinsky Functional Hemodynamic Monitoring 2005

FLOW

PRESSURE

STATIC ASSESSMENT OF ARTERIAL LOAD

TSVR = MAP / COC = SV / PPEa = 0.9SAP / SV

CO or SV

MAP

PP

0.9SAP

FLOW

PRESSURE

DYNAMIC ASSESSMENT OF ARTERIAL LOAD

SVV

PPV

Eadyn = PPV / SVV

Monge et al ESICM Paris 2013

AUC SE a 95% CI b

Eadyn 0.94 0.03 0.86 to 0.98

EA 0.50 0.06 0.39 to 0.61

Arterial C 0.54 0.06 0.43 to 0.65

TSVR 0.52 0.06 0.41 to 0.64

Preinfusion MAP 0.59 0.06 0.48 to 0.70

SAMPLE SIZE82 FLUID CHALLENGES

MAP-RESPONDERS 36 fc (44%)

MAP-NONRESPONDERS 46 fc. (56%)

ROC CURVES COMPARISONS FOR ARTERIAL PRESSURE PREDICTIONAFTER FLUID ADMINISTRATION

Monge et al ESICM Paris 2013

Pinsky Functional Hemodynamic Monitoring 2005

Fluids First

PressorNeeded

Fluids and Pressors

Conclusion

• We use Frank Starling and Guyton principles every time we do haemodynamic interventions

• Using both gives us better understanding of changes in:

– CO

– CVP

– Fluid Challenge

– Pressors