The case for why it matters Fluid balance a common concern Patients - - PDF document

5/9/2015 1 Goal-Directed Fluid Resuscitation

Christopher G. Choukalas, MD, MS

Department of Anesthesia and Perioperative Care University of California, San Francisco

Goal-Directed Fluid Resuscitation

Christopher G. Choukalas, MD, MS

Department of Anesthesia and Perioperative Care University of California, San Francisco

The case for why it matters

• Fluid balance a common concern
• Sepsis
• ALI/ARDS
• Sepsis PLUS ARDS!
• Patients with Sepsis who developed ALI
• 4 groups:

– Adequate initial + Conservative late fluids – Adequate initial only – Conservative late only – Neither

5/9/2015 2

Murphry, CV, et al. 2009. Chest. 136(1)

It matters

• And it’s hard…
• … and we’re really bad at it!
• Retrospective, 8000 cases,

uncomplicated, elective

• mL/kg/hr by center, case type, provider

– 6.7 vs 8.2 – Huge inter-provider differences

• 700 vs 5.4
• Exceeded differences due to blood loss,

hemodynamic factors, case type

It matters

• And it’s hard…
• So how do we do it?

5/9/2015 3

I would posit two factors:

• Hemodynamic:

– Is the circulation adequate?

• Metabolic

– Are oxygen delivery and utilization adequate?

• Both have their own goals.

Hemodynamic Goals

• Blood pressure
• CVP
• Dynamic respiratory indices:

– Pulse pressure/systolic pressure/perfusion index variation

Hemodynamic Goals

• Blood pressure
• CVP
• Dynamic respiratory indices:

– Pulse pressure/systolic pressure/perfusion index variation

Blood pressure

• A proxy for flow, end organ perfusion
• Flow = pressure/resistance
• Do we ever really KNOW resistance?

5/9/2015 4

Wax, et al.

• Non-cardiac cases with both ABP and

NIBP.

• Compared SBP, DBP, and MAP btwn

technologies:

– A-line alone vs A-line + cuff

Randomized trials

• This used to be the 2nd joke of the talk

5/9/2015 5

Interesting review

• Reviewed 2 trials and 1 meta-analysis (13

studies)

– Target BP – Actual BP

• Dissociation

– BPs invariably higher than goal – Higher goal ranges permitted higher actual ranges:  pressors

The NEJM study

• Randomized to MAP 65 vs 85 (800 total)
• Norepinephrine
• Mortality
• AKI/RRT, stratified by HTN

5/9/2015 6

Blood pressure

• Necessary but not sufficient
• Goals are nebulous
• We’re really bad at following them
• Supra-normal levels common, not helpful

Hemodynamic

• Blood pressure
• CVP
• Dynamic respiratory indices:

– Pulse pressure/systolic pressure/perfusion index variation

Concept: assumptions

Adequate DO2 Adequate contractility Optimal actin-myosin match Normal CVP

5/9/2015 7

The data

• Critical target in EGDT for sepsis
• Incorporated into SSC guidelines

Sepsis +  CVP = Death

• Retrospective analysis of VASST trial

– 778 pts w/ septic shock on NE

• CVP at 12 hrs did predict 28-d mortality in

patients:

Boyd, JH, et al. 2011. CCM. 39(2)

HR CVP < 8 0.61 CVP 8-12 0.76 CVP >12 1

Marik, PE, et al. 2008. Chest. 134(1)

Fluid responsiveness and total blood volume

• Volume responsiveness
• Cardiac output before and after fluid

challenge

• 19 evaluated CVP and volume

responsiveness

5/9/2015 8

Fluid responsiveness

• Calculated a Receiver Operating

Characteristic curve

• Likelihood that at any given point (CVP

level, score, etc) the true positives will exceed false positives.

• Higher = better discrimination

Volume responsiveness

Marik, PE, et al. 2008. Chest. 134(1)

Deja vu

• 43 studies, half ICU
• Same design

– AUC btwn CVP and ΔSV

• Same pooled AUC

– 0.56

• Same aggressive conclusion

CVP

• Necessary?
• Certainly not sufficient
• Potentially misleading

5/9/2015 9

Hemodynamic

• Blood pressure
• CVP
• Dynamic respiratory indices:

– Pulse pressure/systolic pressure/perfusion index variation

The Principles

Decreased RV SV

 RV Preload  RV Afterload

 LV Preload  LV SV

Applies to lots of measures

• Systolic pressure variation
• Pulse pressure variation
• Plethysmogram variation
• Outcome is “fluid responsiveness”

Variations on a theme…

• A waveform…
• A peak and trough…
• And a proprietary algorithm:

5/9/2015 10

The data

• Small studies
• Mostly OR

SVV, Vigileo 40% MORE fluid Lower lactate Fewer “complications” PVI, Masimo 1/3 LESS fluid Lower lactate

• 29 studies, 685 patients

– 9 ICU – 20 OR (15 in cardiac surgery)

• All included correlation/ROC between

SPV, PPV, or SVV and ΔSVI/CI after a fluid challenge.

Measure r AUC for ROC Threshold PPV 0.78 0.94 12.5% SVV 0.72 0.84 15.3% SPV 0.72 0.86 CVP 0.56

Now, keep in mind…

• Regular HR
• Sedated, mechanically ventilated
• Vt = 8 mL/kg

5/9/2015 11

Non-invasive CO toys Hemodynamic goals

• Numerous
• State of the art: Dynamic indices

– PPV – SPV – PVI – VTI and esophageal doppler

• Necessary but not sufficient

Metabolic

• Mental status, urine output
• Lactate
• S(c)vO2

Metabolic

• Mental status, urine output
• Lactate
• S(c)vO2

5/9/2015 12

Metabolic

• Mental status, urine output
• Lactate
• S(c)vO2

Lactate

• The product of anaerobic respiration
• Presence implies inadequate oxygen

utilization, shock

• Easily, quickly measured in arterial blood

Lactate: the data Two trials:

• JAMA: 300 patients, EGDT vs lactate

clearance

– Non-inferiority

• AJRCCM: 348 patients, EGDT vs lactate

clearance

– Improved mortality (multivariate) – Less time on vent, in ICU

5/9/2015 13

How did they do it?

Jones, et al (JAMA) Jansen et al (AJRCCM) Monitoring interval 2 2 Goal 10% clearance 20% clearance Fluid totals (L) Control: 4.3 Intervention: 4.5ns Control: 2.2 Intervention: 2.7* Outcome Non-inferiority to EGDT Decreased time on vent, in ICU

The underpinnings… Metabolic

• Mental status, urine output
• Lactate
• S(c)vO2

5/9/2015 14

How it’s used:

 ScvO2 attributed to:

 Supply (cardiac output)  Demand (hypermetabolism)

• In either case, treat by increasing DO2

– Volume, inotropes, RBCs

• But does it work?

DOGS

Humans w/ sepsis Humans w/ shock Changes in SvO2 and ScvO2

But does it work?

• Rivers, et al.

Metabolic goals

• Lactate
• ScvO2
• Physiological rationale meets objective

data.

5/9/2015 15

Does any of this…

• Save lives?
• Save money?
• Actually work?

Single point design

• Close to the patient
• “does this surrogate metric predict optimal

filling/SV/some outcome”

• These seem to work

5/9/2015 16

Subgroup Mortality Complications Jadad high

• +++

Jadad low +++ +++ 1980s-1990s +++ +++ 2000s

• +++

Taking a step back… Similar goals (SVV), similar protocols…

5/9/2015 17

…different outcomes

• Fewer post-op complications
• Left the ICU and hospital a full day sooner
• No difference in fluid totals, RBCs, UOP

»VS

• No difference on any clinical measure

So is GDT no good, or…

• Basically shows the NICOM doesn’t work?
• Complication rate much lower than

expected (underpowered?)

• GDT group bolused starch and gelatin

(twice the control group)

• Indictment of GDT?

Does the PROCESS of GDT aRISE to the challenge? Does the PROCESS of GDT aRISE to the challenge? Will GDT SURVIVE?

5/9/2015 18

Putting it all together:

• Volume isn’t easy
• Volume is important
• Common conditions; competing goals
• Stepwise plan

– Hemodynamic – Metabolic

• It seems to work

The end

The End