What is the best way to assess What is the best way to assess fluid responsiveness fluid responsiveness

in a spontaneously breathing in a spontaneously breathing patient patient ??

Edward M. Omron MD, MPH, FCCP

Critical Care

Alta Bates Summit

Case Example

• 46 yo female presents to IRMC with 24 hours of left flank and left lower quadrant pain, 8/10 severity, fevers, nausea and vomiting– PMH: GERD– PSH: BAH+TSO– Med: prilosec– NKDA

• Exam: – Anxious, uncomfortable– 97.9 F, 136/84, 91, 20, 100% sat room air– Pupils equal, sclera non-icteric– Tachicardia, Nl S1, S2– B CTA– TTP LLQ, +CVAT, no guarding or rebound– No edema or mottling – Alert and Oriented, Appropriate MSE

• Admission Labs– WBC 3.4– Total CO2 = 18– B/C = 16/0.8

• Pyelonephritis secondary to obstructive nephrolithiasis is diagnosed

• Levafloxacin is started with narcotics, maintainance crystalloid at 125 cc/ Hr and patient is transferred to the medical floor

• Within 24 hours patient becomes febrile to 103˚F, BP 71/50, HR 122

• Transferred to ICU– Levophed are started– Fluid resuscitation is initiated

• SHOCK is clinically apparent– Blood pressure normalizes and and a renal

stent is placed– Patient crashes again and is mechanically

ventilated on 2 pressors!– What Happened?

• In a spontaneously breathing patient how do you determine how much fluid to administer?– Eyeball it? CVP? Swan Ganz and PCWP? – Wait and see if the BP increases?– Is to much fluid harmful?– Why not increase the vasopressors and forget

about the fluid?– Does mechanical ventilation change any of

the above parameters?

What is the best way to assess What is the best way to assess fluid responsiveness fluid responsiveness

in a spontaneously breathing patient ?in a spontaneously breathing patient ?

Definition:fluid responsiveness denotes an increase in cardiac output after infusion of a crystalloid, colloid, or PRBC

Three different scenariosThree different scenarios

1 Patients in the ER for acute blood losses or body 1 Patients in the ER for acute blood losses or body fluid lossesfluid losses

2 Patients in the ER for high suspicion of septic shock2 Patients in the ER for high suspicion of septic shock

3 Patients in the ICU, already resuscitated for several 3 Patients in the ICU, already resuscitated for several hours or dayshours or days

1- Patients in the ER for acute blood losses or body fluid losses1- Patients in the ER for acute blood losses or body fluid losses

Diagnosis of hypovolemia is almost certainDiagnosis of hypovolemia is almost certain

Presence of clinical signs of hemodynamic instability clinical signs of hemodynamic instability

No therapeutic dilemmaNo therapeutic dilemma

good prediction of volume responsiveness prediction of volume responsiveness

although lacking of sensitivitylacking of sensitivity

2- Patients in the ER for high suspicion of septic shock2- Patients in the ER for high suspicion of septic shock

Most often, no needsno needs for searching sophisticated predictors predictors

of volume responsiveness of volume responsiveness since volume resuscitation is mandatory volume resuscitation is mandatory

in the first hours in the first hours (Rivers et al NEJM 2001)

- with hemodynamic instability requiring therapy- with hemodynamic instability requiring therapy

- without certainty of volume responsiveness- without certainty of volume responsiveness

- with potential risks of pulmonary edema with potential risks of pulmonary edema

and/or excessive cumulative fluid balanceand/or excessive cumulative fluid balance

3- Patients in the ICU, already resuscitated for several 3- Patients in the ICU, already resuscitated for several hours or dayshours or days

OUR PATIENT

Cumulative Fluid Balance is a Predictor of Mortality in Septic

Shock

Critical Care Medicine 2006; 34: 344-353

3- Patients in the ICU, already resuscitated for several hours or days3- Patients in the ICU, already resuscitated for several hours or days

How to deal with this therapeutic dilemma?

Prediction Prediction of volume responsiveness ?of volume responsiveness ?Fluid challenge ?Fluid challenge ?

- with hemodynamic instability requiring therapy- with hemodynamic instability requiring therapy

- without certainty of volume responsiveness- without certainty of volume responsiveness

- with potential risks of pulmonary edema with potential risks of pulmonary edema

and/or excessive cumulative fluid balanceand/or excessive cumulative fluid balance

Rate of infusion: 500-1000 mL crystalloids Rate of infusion: 500-1000 mL crystalloids or 300-500 mL colloids 300-500 mL colloids over 30 mins 30 mins

Goal:Goal: reversal of the marker of perfusion failure that prompted the fluid challengereversal of the marker of perfusion failure that prompted the fluid challenge

(ex: hypotension, tachycardia, oliguria, etc)

Safety limitsSafety limits: : CVPCVP

Crit Care Med 2006; 34:1333-1337

of 15 mmHg measured every 10 minsof 15 mmHg measured every 10 mins

CHEST 2002, 121:2000-8 CHEST 2002, 121:2000-8

Fluid Challenge only successful in 50% of cases

• If no response to fluid challenge, what happens if you continue aggressive resuscitation?

• Pulmonary and interstitial edema with secondary complications

• Risky and potentially quite harmful

Stroke Volume

Ventricular preload

preload-dependencepreload-dependence

preload-independencepreload-independence

Volume expansion will increase stroke volume Volume expansion will increase stroke volume only if ventricles are preload-dependentonly if ventricles are preload-dependent

How to predict preload-dependence How to predict preload-dependence

and hence volume responsiveness in spontaneously and hence volume responsiveness in spontaneously

Breathing patients?Breathing patients?1- By estimating cardiac preload 1- By estimating cardiac preload

- using filling pressures:- using filling pressures: RAP, PAOP ? RAP, PAOP ?

Normal Subjects spontaneously breathing

Critical Care Medicine 2004; 32: 691-699

N =40

More to the story than meets the eye!

Relationship of initial CVP prior to 3L infusion and RVEDVI and CIafter infusion: NONE

Relationship of CVP to 3L infusion And RVEDVI and CI: NONE

Normal Spontaneously Breathing Patients

Critical Care Medicine 2004; 32: 691-699

Relationship of initial PCWP to LVEDVIand CI after 3 L infusion: NONE

Relationship of PCWP to LVEDVI and CI after 3 L infusion:NONE

Normal Spontaneously Breathing Patients

Critical Care Medicine 2004; 32: 691-699

Assessment of preload is not assessment of preload dependence!

.

Stroke volume

Ventricular preload

normal heart normal heart

failing heart failing heart

preload-dependencepreload-dependence

preload-independencepreload-independence

Passive Leg RaisingPassive Leg Raising

45 °45 °

Venous blood shiftVenous blood shift (Rutlen et al. (Rutlen et al. 19811981, , Reich et al. 1989)Reich et al. 1989)

Increase in left ventricular preloadIncrease in left ventricular preload (Rocha 1987, Takagi 1989, De Hert 1999, Kyriades 1994 ) Reversible effects Reversible effects

Increase in right ventricular preloadIncrease in right ventricular preload (Thomas et al 1965)

Passive Leg RaisingPassive Leg Raising

45 °45 °

Venous blood shiftVenous blood shift (Rutlen et al. (Rutlen et al. 19811981, , Reich et al. 1989)Reich et al. 1989)

Increase in right ventricular preload Increase in right ventricular preload (Thomas et al 1965)

Increase in left ventricular preload Increase in left ventricular preload (Rocha 1987, Takagi 1989, De Hert 1999, Kyriades 1994 )

Transient effect Transient effect (Gaffney 1982)(Gaffney 1982)

PLR could be used as a test to detect volume responsiveness PLR could be used as a test to detect volume responsiveness

rather than as a therapyrather than as a therapy

HypothesisHypothesis

The increase in pulse pressure during PLRThe increase in pulse pressure during PLR

predicts thepredicts the increase in stroke volume increase in stroke volume

afler volume loadingafler volume loading

Chest 2002; 121: 1245-1252

Pulse pressure = SV/Arterial Compliance

PLR-induced changes in Pulse Pressure PLR-induced changes in Pulse Pressure (mmHg)(mmHg)

Fluid-induced Fluid-induced changes in changes in

Stroke Volume Stroke Volume

(%)(%)n = 39n = 39r = 0.74r = 0.74

Chest 2002; 121: 1245-52

-40

-20

0

20

40

60

80

RRNRNR

PLR-induced changes

in pulse pressure

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RRNRNR

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PLR-induced changes

in aortic blood flow

ConclusionConclusion

In spontaneously breathing patientsIn spontaneously breathing patients

Prediction of volume responsiveness is a difficult issuePrediction of volume responsiveness is a difficult issue

markers of preloadmarkers of preload

CVP, PCWPCVP, PCWP

Response to passive leg raisingResponse to passive leg raisingCCI, SVO2, Delta PCO2CCI, SVO2, Delta PCO2

unreliableunreliable

valuablevaluable