Hemodynamic Monitoring Pressure or Volumes? Antonio Pesenti University of Milan Italy

Hemodynamic Monitoring Pressure or Volumes? Antonio Pesenti University of Milan Italy antonio.pesenti@unimi.it CCCF 2017

Is it useful? YES: CVP It is an important diagnostic element!

Your best guess CVP CI HR SBP 0-2 2.0 160 70/?? CVP CI HR SBP 10 2.0 160 70/??

Your best guess CVP CI HR SBP 0-2 2.0 160 70/?? CVP CI HR SBP 10 2.0 160 70/??

Your best guess CVP CI HR SBP 0-2 2.0 160 70/?? CVP CI HR SBP 15 2.0 160 70/??

Hemodynamic monitoring Tools Cardiac function or cardiac output? Filling pressures? Single measure or trend? Accuracy, precision, stability?

Echo ( TEE vs TTE) CO +- Trend+- No real pressure Tools (Thermo)dilution: reference Pressures, continuous Doppler output +- Pulse contour (calibration) Impedance +---

Cecconi et al Intensive Care Med 2015 500 ml in 24 min Static Marker in 36% Dynamic Markers in 22% No safety parameter in 72%

What is a Positive fluid challenge? We give the prescribed amount of fluid and the CO or the SV or the BP increased more than a certain amount ( 10-15%). In my book: if no improvement and CVP increases more than 3 mmhg, then stop If improvement and no change in CVP then may repeat If no improvement and no change: think

FLUID RESPONSIVENESS Is not a disease Normal subjects respond to fluid load by an increase in CO ( transient) Preload Dependence is a normal condition Lack of fluid responsiveness is an abnormal state ( not necessarily pathological)

Effect of 3 l saline infusion in 3hrs normal subjects Kumar Crit Care Med 2004

Fluid responsiveness tests Q. Why a test for fluid responsiveness? A. To be able to administer fluid safely. Q. When is fluid administration safe? A. When it does not cause filling pressures to rise over safety limits.

Am Heart J 1984:107: 404 We assert that the essential function of the right ventricle is not to provide blood flow through the pulmonary but to maintain a low pressure in the highly compliant systemic venous system. By maintaining this low central venous pressure, the RV prevents the development of venous distension and massive peripheral edema

Function of the right ventricle Keep systemic venous pressure low

Function of the Left ventricle Keep pulmonary venous pressure low

Value of filling pressures Filling pressures tell us how well the heart works A better working heart gives the same output with a lower filling pressure A worse heart function results in higher filling pressures for the same output

Filling Pressures It is true that Frank Starling s law of the heart is based upon lenght rather than pressures Lenght and volumes are best to study the heart Pressures however is what tissues see The body survives on pressures not volumes

CVP CVP is a stopping rule Would you give a fluid load to this patient: MAP 55 mmhg CVP 18 mmhg CO 4.5 l/min Sat v 65%? What if this patient had 20 cm H20 PEEP?

CVP Would you give a fluid load to this patient: MAP 55 mmhg CVP 0 to 2, CO 4.5 l/min Sat 65% What if this patient is spontaneously breathing?

CVP CVP in itself is not a predictor of fluid responsiveness CVP is always a predictor of the risk of fluid loading and of the price your patient is going to pay.

CONCLUSION 1 Filling pressures are important global parameters for adequacy of volemia and heart function

CONCLUSION 1 Filling pressures are important global parameters for adequacy of volemia and heart function Identical filling pressures may be associated with very different CO

CONCLUSION 1 Filling pressures are important global parameters for adequacy of volemia and heart function Identical filling pressures may be associated with very different CO Identical CO may be associated with different filling pressures

CONCLUSION 1 Filling pressures are important global parameters for adequacy of volemia and heart function Identical filling pressures may be associated with very different CO Identical CO may be associated with different filling pressures Filling pressures AND fluid responsiveness are notthe same thing

CONCLUSION 2 PAOP is critical because it is the major determinant of EVLW

CONCLUSION 2 PAOP is critical because it is the major determinant of EVLW CVP is critical because it is the major determinant of body organs edema and dysfunction

CONCLUSION 2 PAOP is critical because it is the major determinant of EVLW CVP is critical because it is the major determinant of body organs edema and dysfunction If you want to do a fluid responsiveness test, best are DRY Fluid challenges: Mech Ventilation Leg Raising Anti shock trousers

Monnet and Teboul Crit Care 2015