fluid responsiveness

Fluid ResponsivenessDr. Daniel Rankmore

JHH ICU Junior Doctor Teaching 7th March 2012

Today’s TopicWhy give fluids“Fluid responsive”What fluids are avalible

Why give fluidsOxygen Delivery (DO2)the air goes in and out and the blood goes round and round

Why give fluids

Intra-venous fluid

Intra-vascular volume

Cardiac Output

Tissue Perfusion

Oxygen Delivery

DO2 VO2> = Shock= Bad

DO2

Oxygenation

Cardiac Output+

DO2

Oxygenation

Cardiac Output+

(Bersten & Soni, 2009, pp. 317-318):

FiO2

Airway

Gas Movem

entHeam

Hb

TissueDiffusio

nCytochro

meMitochon

rial

Alveolar

Diffusion

DO2Cardiac Output

SV HR x

DO2Cardiac Output

SV HR x

PreloadContractilityAfterloadFilling Time

Frank StarlingSt

roke

Vol

ume

‘Preload’

A ‘normal’ heart

A heart ‘failing’

Frank StarlingSt

roke

Vol

ume

‘Preload’

500mlBolus

SVCO

Frank Starling CurveSt

roke

Vol

ume

‘Preload’

500mlBolus

SVCO

Frank Starling CurveSt

roke

Vol

ume

‘Preload’

500mlBolus

SVCO

EVLWPulmonary Oedema

Liberal Fluid Therapy compared with either Goal Directed Therapy or Restrictive Fluid Therapy3861 patients in 35 RCTsLiberal vs Restrictive

Pneumonia RR 2.2 95% CI 1-4.5Pulmonary Oedema RR 2.8 95% CI 1.1-13Longer Hospital Stay Mean 2 Days 95% CI 0.5-3.4

Goal Directed vs Not Goal DirectedPneumonia RR 0.7 (CI 0.6-0.9)Renal Complications RR 0.7 (CI 0.5-0.9)Reduced Hospital Stay Mean 2 Days (CI 1-3)

LiberalProlonged Hospital Stay Mean 4 Days (CI 3.4-4.4)Time to first bowel movement 2 Days (CI 1.3-2.3)

RCT 1000 patients with ALI 60 day follow upPrimary end point – mortality.Secondary end points – lung physiology, vent free days, organ failure free days7 day fluid balance 136ml vs. 6992mls.

Conserve

Liberal

p

Mortality

25.5%

28.4%

0.3

Vent Free Days

14.6 12.1 <0.001

ICU free days

13.4 11.2 <0.001

Shock & RRT

10% 14% 0.6

Three studies of colorectal surgeryReduced incidence of cardiorespiratory and fewer post operative problems.

88 patients undergoing major abdo surgery.PVI group – 500ml crystalloid bolus then 2ml/kg/hr if PVI <13% then 250ml colloid given, MAP maintained with vassopressors.Control group – 500ml crystalloid then fluid management per CVP and MAP.PVI group – improved intra-op and post op lactate and reduced total fluid input.

Retrospective review of IV fluids in the first 4 days of 778 patients in the VASST (Vasopressin in Septic Shock Trial)Conclusion:

A more positive fluid balance at 12 hours and 4 days was associated with increased mortality.CVP correlated with IV Fluid given for the first 12 hours.

When to give fluids

Fluid ResponsivenessGiving what the patient needs when the patient needs it

Fluid Responsiveness>15% increase in Cardiac Output following 500-1000ml fluid bolus

Static MeasurementsBP (MAP)UOCVPPAOP – ‘the wedge’ ITBVMVSaO2

IVC DiameterLVEDA

Central Venous PressureThe number that keeps getting measured…

Studies includedCVP & Blood volume (5 studies)CVP or ΔCVP cf: SI and CI pre & post boluses

(24 studies heterogeneous patient cohort including vascular surg, CABG, Sepsis, Health, 803 patients)

Central Venous Pressure

Central Venous PressureCVP & blood volume: 0.16 (95% CI: 0.03-0.28) CVP & SVI/CI: 0.18 (95% CI: 0.08-0.28) ROC 0.56∆CVP & SVI/CI: 0.11 (95% CI: 0.015-0.25)

ROC 0.5 true-positive = false positiveROC 0.9+ an adequate testConclusion

In none of the included studies was CVP able to predict fluid responsive or blood volume.

Central Venous Pressure

Hea32 healthy people given 3L saline over 3 hoursCVP PAOP useless..

Mixed Venous Saturations

Dynamic MeasurementsThe Fluid ChallengePassive Leg RaiseWaveform Analysis

Systolic Pressure VariationPulse Pressure VariationStroke Volume Variation

EchocardiographyPleth Variability IndexBioimpedance & Bioreactance

Fluid ResponsiveGive some fluid… see what happens…

Passive Leg RaisePLR. Free. Reversible. Effective.

39 patient. 4min PLR. 300ml bolus. Circ insufficiency and Mech Ventilation.Measurements: PP (rad artline), HR, PAOP, CO.Correlation between PLR and SV – 0.77 P < 000.1Correlation between PLR and Bolus – 0.84 P <000.1

Question: Can PLR induced ΔCardiac Output ΔPulse Pressure predict fluid responsiveness9 articles 353 patientsPLR-cCO – sensitivity 89.4% specificity 91.4%Not altered by ventilation mode or cardiac rhythm. PLR-cCO – ROC 0.95 cf. PLR-cPP – ROC 0.76 P<0.001

Thermodilution

How much water is in my bucket?

Thermodilution• Like the bucket analogy• Add to this concentration change over time

and • You can calculate flow

Waveform AnalysisNumerous. Complex. Useful.

Stroke Volume VarianceInvasive: pulse contour analysis (PICCO, LIDCO, Flotrac, Vigileo)Noninvasive: echo, pulse ox waveform,

Pulse Pressure Variance

Broad inclusion criteria: SVV, PVV, CVP, GEDI, ΔSV, & ΔCI compared with PEEP challenge or fluid challenge.29 studies 685 patientsBaseline and ΔCI

PPV (threshold 12.5%) – ROC 0.94 Sens 0.89 Spec 0.88 OR 59SVV (threshold 11.6%) – ROC 0.84 Sens 0.82 Spec 0.88 OR 27SBPV – ROC 0.86 CVP – ROC 0.55GEDI – ROC 0.56LVEDI – ROC 0.64

LimitationMandatory ventilation

PiccoThermodilutionWaveform analysis

Vigileo

EchocardiographyPretty. Skilled. Detailed. .

EchoSV = VTI x CSAVTI – AUC of dopplerCSA – valve area

Changes in resp cycle20% VTI12% peak flow

Bioreactance

110 Patients. PAC-CCO (thermodilution) cf. NICOMStable CO – correlation coefficient R = 0.82Increasing CO – correlation increased to 96%Decreasing CO – correlation decreased to 84-90%Changes seen on NICOM 3 +/- 3 minutes faster

75 Adult patients post cardiac surgeryCorrelation between PLR FR and NICOM and FRBut I couldn’t get the article in time…

Which fluids to give

Choice of IV therapyThink contentsThink compartmentsThink volume

Compartments

(Ganong’s Review of Medical Physiology, 23e)

The SalinesFluid Na Cl K Glucos

eOsmola

itypH

Plasma0.18% NaCl4% Glucose

30 30 - 40g/L637kJ

282 3.5-6.5

0.45% NaCl 76 76 - - 150 4.0-7.00.9% NaCl

“Normal Saline”154 154 - - 300 4.0-7.0

3%“Hypertonic”

513 513 - - 1000 4.5-7.0

23.4% 4000 4000 - - 80000.9% Saline + 30mmol KCL

154 184 30 - 368 3.5-7.0

0.9% NaCl + 40mmol KCL

100 140 40 - 280 4.0-7.0

The SugarsFluid Na Cl Glucose Osmolali

typH

PlasmaWater - - - -

0.18% NaCl + 4% Glucose

30 30 40g/L637kJ

282 3.5-6.5

0.45% NaCl + 2.5% Glucose

77 77 25g/L398kJ

292 3.5-6.5

5% Glucose - - 55g/L835kJ

278 3.5-5.5

10% Glucose - - 100g/L796kJ

556 3.5-6.5

50% Glucose - - 500g/L~4000kJ

Pre-mixed drinks and other concoctions

Fluid Na Cl Lactate

Ca K Bicarb

Mg Glucose

Osmality

pH

PlasmaCompou

nd Sodium Lactate“Hartma

n’s”

129 109

29 2 5 - - - 274 5.0-7.0

Plasma-lyte

140 98 - - 5 27Acetate

1.5 23 gluconat

e66kJ

294 4.0-6.0

Sodium Bicarb 8.4%

1000

- - - - 1000 - - 2000 7.2-8.7

Voluven 6%

154 154

- - - - - - 304 4.0-5.5

Blood ProductsFluid Na Cl Octonat

eAlbumin pH Osmol

Plasma4% Albumex 140 128 Octonate

6.440g/L 250

20% Albumex 48-100 Octonate 32

200g/L

pRBC

The Colloids

Double Blinded, RCT, 0.9% saline vs. 4% Albumin.6997 pt critically ill patientsPrimary Outcome: 28 day mortality.Secondary Outcomes: length of stay (ICU & Hosp), days on vent, days on RRT, new onset organ dysfucntion.Result: No difference.

Severe Sepsis subset analysis of SAFE Trial1218 patients AlbuminHR and CVP day 1-3 (p 0.002, 0.03)No diff Sequential Organ Failure Assessment (p. 0.98)Improved mortality 0.87 (CI 0.74-1.02, p 0.06)Multiriant logistic regression anaylsis mortality 0.71 (Ci 0.52-097, p 0.03)

460 patients, GCS 3-8.Post hoc subgroup analysis with 2 year follow upEnd point mortalityTotal Alb 71 of 214 0.9% 42 of 206 (RR 1.63 p 0.003)GCS 3-8 Alb 61 of 146 0.9% of 32 of 144 (RR 1.88 p <0.001)

Final ThoughtsConclusion

Understand the question you are asking.Think of fluids as you would a drug – dose, kinetics, dynamics, side effectsThink of alternatives – pressors or inotropes.Remember there are many tools in the toolbox.ABCD and repeat.