hb sao oxygen delivery - intensive.orgintensive.org/.../presentations_2019/svo2_distribu.pdf ·...

VO2

SvO2

Hb SaO2

DO2 = Cardiac output x Arterial O2 content

OXYGEN DELIVERY

OXYGEN CONSUMPTION

OXYGEN EXTRACTION

= VO2 / DO2

+ MICROCIRCULATORY FACTORS

OXYGEN DELIVERY(oxygen transport)

OXYGEN CONSUMPTION(oxygen uptake)

THE FUNDAMENTALS OF LIFE

OXYGEN DEMAND(oxygen requirements)

income

expenses

needs

SvO2

lactate


hemoglobin SaO2

OXYGEN DELIVERY

OXYGEN CONSUMPTIONVO2 = Cardiac output x (CaO2 - CvO2)

SvO2hemoglobin SaO2

O2ER = VO2/DO2

OXYGEN EXTRACTION

O2ER = CO x (CaO2 - CvO2) / CO x CaO2

O2ER = (CaO2 - CvO2) / CaO2

O2ER = (Hb.SaO2.C - Hb.SvO2.C) / Hb.SaO2.C

O2ER = (SaO2 - SvO2) / SaO2

SvO2 is directly influenced by SaO2

Hemoglobin is not a primary determinant of O2ER

BASIC

CONCEPTS

back to

CI x CaO2 = CI x Hb.SaO2.C

CI x (CaO2 - CvO2)

O2

CO

NS

UM

PT

ION

AWAKE

REST

STRESS

O2 DELIVERY

Hemorrhage

Tamponade

O2 DELIVERY

O2

CO

NS

UM

PT

ION

O2 EXTRACTION =

VO2

DO2

My income

My expenses

VO2/DO2

dependency

Hemorrhage

Tamponade

O2

CO

NS

UM

PT

ION

O2 DELIVERY

lactate

LACTATE CONCENTRATIONS IN ACUTE BLEEDING

(dogs)

0 100 200 300 400

0

20

40

60

80

100

120

140

DO2 ml/min

VO

2 m

l/m

in

50 150 250 350

LACTATE CONCENTRATIONS IN ACUTE BLEEDING

(dogs)

0 100 200 300 400

0

20

40

60

80

100

120

140

0

2

4

6

8

10

12

DO2 ml/min

VO

2 m

l/m

in

Lacta

te m

mo

l/l

50 150 250 350

0 100 200 300 400

0

2

4

6

8

10

12

14

DO2 ml/min

Lacta

te m

mo

l/l

(15 mongrel dogs)

HEMORRHAGIC SHOCK

O2 TRANSPORT

VO2/DO2

dependency

O2 EXTRACTION =

VO2

DO2

Hemorrhage

Tamponade

O2

CO

NS

UM

PT

ION

O2 TRANSPORT

VO2

DO2

Hemorrhage

Tamponade

after endotoxin

O2 EXTRACTION =

O2

CO

NS

UM

PT

ION

OXYGEN TRANSPORT

PHYSIOLOGIC STATE

SHOCK STATES

O2 C

ON

SU

MP

TIO

NLOW OUTPUT

STATECIRCULATORY

SHOCK

OXYGEN TRANSPORT

hypovolemic

cardiogenic

obstructive

PHYSIOLOGIC STATE

SHOCK STATES

O2 C

ON

SU

MP

TIO

N

INFLAMMATORY STATE

distributive

O2 DELIVERY

INCREASED

O2 DEMAND

ALTERED

O2 EXTRACTION

IMPAIRED

MYOCARDIAL CONTRACTILITY

O2 C

ON

SU

MP

TIO

N

SEPTIC SHOCK

INFLAMMATORY

MEDIATORS

ALTERED

O2 EXTRACTION

INCREASED

O2 DEMANDMYOCARDIAL

DEPRESSION

DO2 = CI x CaO2 x 10

= CI x Hb x SaO2 x 13.9

"normal" = 3 x 12 x 0.96 x 13.9 = 500 ml/min.M²

O2 TRANSPORT

anemia = 6 x 6 x 0.96 x 13.9 = 500 ml/min.M²

hypoxemia = 6 x 12 x 0.48 x 13.9 = 500 ml/min.M²

low CO = 1.5 x 12 x 0.96 x 13.9 = 250 ml/min.M²

O2 TRANSPORT

RESERVE

DO2 = CI x CaO2 x 10

= CI x Hb x SaO2 x 13.9


hemoglobin SaO2

PaO2

OXYGEN DELIVERY

CaO2 = Hb.SaO2.13.9 + 0.0031 PaO2

VO2 = CI x (CaO2 - CvO2) x 10

= CI x Hb x (SaO2 - SvO2) x 13.9

O2 UPTAKE

"normal" = 3 x 12 x (0.96 - 0.72) x 13.9 = 125 ml/min.M²

anemia = 6 x 6 x (0.96 - 0.72) x 13.9 = 125 ml/min.M²

= 4.5 x 6 x (0.96 - 0.64) x 13.9 = 125 ml/min.M²

(let us spare the heart)



O2 UPTAKE


anemia

hypoxemia = 6 x 12 x (0.48 - 0.36) x 13.9 = 125 ml/min.M²

= 4.5 x 6 x (0.96 - 0.64) x 13.9 = 125 ml/min.M²

low CO = 1.5 x 12 x (0.96 - 0.48) x 13.9 = 125 ml/min.M²

O2 UPTAKE

RESERVE



RESERVE

CONSTANT O2 DEMAND

1- Hypoxemia

2- Anemia

3- Inadequate cardiac output

Low SvO2

usually corrected



O2 UPTAKE


anemia

hypoxemia = 6 x 12 x (0.48 - 0.36) x 13.9 = 125 ml/min.M²

low CO = 1.5 x 12 x (0.96 - 0.48) x 13.9 = 125 ml/min.M²

= 4.5 x 6 x (0.96 - 0.63) x 13.9 = 125 ml/min.M²

exercice = 4.5 x 12 x (0.96 - 0.63) x 13.9 = 250 ml/min.M²

1- CONSTANT O2 DEMAND


VO2 = CI x (Hb.SaO2. 1.39) - (Hb.SvO2. 1.39) x 10

VO2 = CI x Hb x (SaO2 - SvO2) x 13.9

2- INCREASED O2 DEMAND






low flow

anemia

hypoxemia

exercise

sepsis/cirrhosis

CaO2 CO

low CaO2

low SvO2 low CO

high VO2

Low SvO2

Chronic

heart

failure

Anemia

Recent

exercise

Hypoxemia

A low cardiac output

does not necessarily

require an intervention

A low SvO2

does not necessarily

require an intervention

Message

CARDIAC OUTPUT

HIGH LOW HIGH LOW

INFLAMMATION

PERIPHERAL

SHUNTING

LOW VO2 LOW OUTPUT

SYNDROME

( hypovolemia,

altered cardiac pump,

obstruction)

( anesthesia,

hypothermia,...)

SvO2 SvO2

HIGH LOW

( vasodilators,

cirrhosis )ANEMIA

HYPOXEMIAHIGH VO2

(cf exercise)

SaO2 / Hb

low normal

( incl. sepsis )

HYPERVOLEMIA

CO 5.0 L/min / CI 3.0 L/min.M²

Cardiac output is normal

Is cardiac output adequate ?

CO 5.0 L/min / CI 3.0 L/min.M²

T° 35.0AFTER CARDIAC SURGERY

MECH. VENTILATED

SEDATED/ANESTHETIZED

If DOBU 5 mcg/kg/min

T° 39.0PNEUMONIA

RR 30/min

ANXIOUS, DISTRESSED

If CVP 5 mmHg

STOP DOBU FLUID CHALLENGE

PaO2 100 mmHg

SvO2

76 % SvO260 %

SvO2 70 % SvO2 55 %

Hypovolemia ? PAOP ?Hypoxemia ? SpO2 (PaO2) ?Anemia ? Hb ?

OK check

after trauma

CO 6 L/min(normal/high

CO)

INTERPRETATION OF CARDIAC OUTPUT

Hypovolemia cardiac filling ?

Hypoxemia SpO2 / PaO2 ?

Anemia Hb ?

after cardiac surgery

CO 3.5 L/min

SvO2 70 % SvO2 55 %

low O2 requirements(sedation,

mechanical ventilation,

hypothermia ?)

PAOP low: hypovolemia

PAOP elevated: altered contractility

+ elevated RAP tamponade ?

(+ SpO2 (PaO2) + Hb)

OK check

INTERPRETATION OF CARDIAC OUTPUT

Hypovolemia cardiac filling ?

Altered contractility cardiac filling ?

Major arrhythmia ? cardiac monitoring ?

Tamponade ? pericardial fluid ?

High SvO2

Low SvO2

SvO2 low

SaO2 low

(hypoxemia)

SaO2 normal

Increased O2 extraction

CO high CO low

Hemoglobin

Normal

Elevated VO2

(exercise, stress, anxiety)

Low

(Anemia)

filling high filling low

Heart

failure

(or obstruction)

Hypovolemia

Crit Care Med 33:1119-22, 2005

SvO2

CO

PAP / PAOP

ScvO2

(CO)

RAP

K Reinhart

Regional SvO2

ScvO2 < SvO2

NORMAL

ScvO2 > SvO2

SEPSIS / ARDS

➢Barrat-Boyes & Wood, J Lab Clin Med 50: 93-106, 1957

➢De Sepibus et al, Schweiz Med Wochensch 105: 1445-7, 1975

➢Weber et al, Z Kardiol 69: 504-7, 1980

➢Reinhart et al, Intensive Care Med 30: 1572-8, 2004

➢Chawla et al, Chest 126: 1891-6, 2004

O2ER increases more

in the spanchnic/renal regions

than in the upper part of the body

preserved blood flow to brain and heart

increased VO2 in the splanchnic region

AuthorsNo of

patientsBias

Limits of

agreement

Edwards et al 30 2.9 + 18.0

Martin et al 7 1.1 + 20.0

Tumaoglu et al 73 6.4 + 10.2

Chamla et al 53 5.2 + 10.3

Reinhart et al 29 7.1 + 8.0

Varpula et al 16 4.2 + 12.4

-

-

-

-

-

-

ScvO2 vs. SvO2

« The ranges and 95% confidence limits

were found to be clinically unacceptable. »

Edwards & Mayall, Crit Care Med 26: 1356-60, 1998

Martin et al, Intensive Care Med 18: 101-4, 1992

« ScvO2 was not reliable… »

Differences between ScvO2 and SvO2 greater than 5%

In 50% of measurements.

Abrupt changes in SvO2 not detected

by ScvO2 monitoring in 18% of the measurements.

ScvO2 vs SvO2 ?

Faber, Acta Anaesth Scand Suppl 107: 33-6, 1995

« A relatively poor correlation between ScvO2 and SvO2 was found. »

R = 0.75

« ScvO2 is not a reliable surrogate for SvO2. »

Chawla et al, Chest 126: 1891-6, 2004

R = 0.88 bias 5.2 %

« In fact, some individual measurements of ScvO2

differed more than 10% from corresponding SvO2 values. »

« Individual values of ScvO2 cannot substitute true SvO2 values. »

Dueck et al, Anesthesiology 103: 249-57, 2005R = 0.69-0.80

Reinhart et al, Intensive Care Med 30: 1572-8, 2004

« We agree that precise determination

of absolute values for SvO2 from ScvO2 is not possible »Bland & Altman : Bias 7.1 %

Precision 8.0 %

« …clinically unacceptable correlation, with low mean bias,

but clinically unacceptably high limits of agreemant. »

R² = 0.38-0.46Sander et al, Intensive Care Med 33:1719-25, 2007

ScvO2 vs SvO2 ?


ScvO2 is a cheap surrogate for SvO2

R = 0.87R = 0.88

Chawla et al, Chest, 2004 Reinhart et al, ICM, 2004

« unreliable » « reliable »

ScvO2 vs SvO2 ?

http://www.chestjournal.org/cgi/content/full/126/6/1891/F1

ScvO2 is the SvO2 of the poor

…but changes in ScvO2

may be more reliable ??

ARE TRENDS ANY BETTER ?

Dueck et al, Anesthesiology 103: 249-57, 2005

Reinhart et al, Intensive Care Med 30: 1572-8, 2004R = 0.76

R = 0.76

Critically ill

Neurosurgical operations

Martin et al, Intensive Care Med 18: 101-4, 1992

Abrupt changes in SvO2 not detected

by ScvO2 monitoring in 18% of the measurements.

ScvO2 vs SvO2 ?



r = 0.761

r = 0.866ScvO2

DScvO2

…the correlation is WORSE

than for absolute values

ScvO2 is the SvO2 of the poor

Thermodilution

Transpulmonary

dilution

Lithium dilution

Arterial waveform

analysis

Doppler

techniques

CO2 rebreathing

Bioimpedance

Bioreactance

CARDIAC OUTPUT MONITORING

Invasiveness

SeverityCritically ill(shock, ARDS…) Intermediate

care unitHigh risk

postoperativeHealthy(physiological studies)

PA catheter

PAP / PAOP

CVP

(or volumes ?)

Less accurate

technique

Thermodilution

cardiac outputSvO2

ScvO2

Approximation

( trend OK ? )Approximation

( trend OK ? )

Approximation

( trend OK ? )

“less invasive”

? ? ?+ +

HEMODYNAMIC MANAGEMENT

DO2 = arterial O2 content x cardiac output

SaO2

(PaO2)Hemoglobin

Heart rate

Preload

Afterload

Contractility

Oxygen

PEEP

Transfusions

Pacemaker

Isoproterenol

Fluids

Dobutamine

Nitrates

Therapeutic options SEPSIS

OXYGEN DELIVERY

EARLY GOAL-DIRECTED THERAPY IN THE TREATMENTOF SEVERE SEPSIS AND SEPTIC SHOCK

E Rivers et al, N Engl J Med 345: 1368-77, 2001

ScvO2guided protocol

of EGDT

CONTROL EARLY GOAL-DIRECTED THERAPY

for at least 6 hours

CVPMAP

urine output

Patients with sepsis + hypotensionand/or lactate > 4 mEq/L

IV FLUIDS TRANSFUSIONS DOBUTAMINE

0

1000

2000

3000

4000

5000

6000

mL

0

10

20

30

40

50

60

70

% of patients

0

2

4

6

8

10

12

14

16

% of patients

EARLY GOAL-DIRECTED THERAPY IN THE TREATMENT

OF SEVERE SEPSIS AND SEPTIC SHOCK


first 6 hours standard EGDT

0

5

10

15

20

25

30

35

% of patients

0

10

20

30

40

50

60

% of patients

VASOPRESSORS MECH. VENTILATION

standard EGDTfirst 6 hours




0

10

20

30

40

50

60

% of patients

0

10

20

30

40

50

60

70

80

% of patients

VASOPRESSORS MECH. VENTILATION PA CATHETER




0

5

10

15

20

25

30

35

% of patients

0

10

20

30

40

50

60

% of patients

0

10

20

30

40

50

60

70

80

% of patients

0

5

10

15

20

25

30

35

% of patients

0 - 6 h 0 -72 h 0 - 6 h 0 -72 h 0 - 6 h 0 -72 h

The Rivers'study

Relatively small, monocentric study

Particular patient population (late arrival, comorbidities)

Only reflects that a good doctor makes a difference

Sepsis management has improved over time

Large multicentric studies negative

Should we apply EGDT ?

Protocolized Care for Early Septic Shock (ProCESS) University of Pittsburgh

Early Goal Directed Therapy (EGDT) – 650 patients

vs.

Protocolized Standard Care (PSC) – 650 patients

vs.

Usual Care (UC) – 650 patients

Australasian Resuscitation In Sepsis

Evaluation Randomised Controlled Trial (ARISE)

PROMISE trial (UK)


vs. Standard Care (PSC) – 650 patients


vs. Standard Care – 630 patients

Data were presented at the 34th International Symposium

on Intensive Care and Emergency Medicine (March 2014)

Data will bepresented at the 35th International Symposium

on Intensive Care and Emergency Medicine (March 2015)

Data were presented at the ESICM Congress (October 2014)

the ProCESS TRIAL

the ARISE TRIAL

the ProMISe TRIAL

Early Goal-Directed Therapy

EGDT

ScvO2 71%

ScvO2 70%

ScvO2 73%

ScvO2 49 %

Rivers et al

… but three large RCTs on EGDT were negative !

Two possible explanations

1-The physiology is wrong

(or without importance)

Simplistic question

Wrong population (not very sick)

2-The RCTs have a problem

EGDT

In the recent trials

Less severely ill patients

Higher initial ScvO2 (already in the target range)

Improved early resuscitation?

Higher patient selection

Less commonly treated by mechanical ventilation

Lower mortality rate

Not all needed ICU admission!

Enrolment primarily during office hours(but greater benefit of a protocol outside these hours?)

Gattinoni et al, NEJM 333:1025-32, 1995

ENTRY CRITERIA

high risk after surgery

massive blood loss/trauma

septic shock or sepsis syndrome

acute respiratory failure

decompensated COPD

SAPS score > 11

+

GOAL-ORIENTED HEMODYNAMIC THERAPY

GOAL-ORIENTED HEMODYNAMIC THERAPY

Gattinoni et al, NEJM 333:1025-32, 1995

No of patients 762

252 253 257

Group CI Normal CI > 4.5 L/min.M² SvO2>70%

Mortality rate 48.4% 48.6 % 52.1 %

(SaO2-SvO2 < 20%)

Early goal-directed therapy

(EGDT)

Late

ScvO2

monitoring

Low

ScvO2

Argument forMore fluids

Transfusion

Dobutamine

Normal

ScvO2

Argument forVasopressor only

My recommendationScvO2

SvO2

75 %

70 %

65 %

60 %

55 %

Fluids

Transfusion

Dobutamine

Vasopressors(primarily)

Therapeutic implications

SvO2 low

SaO2 low

(hypoxemia)

SaO2 normal

Increased O2 extraction

CO high CO low

Hemoglobin

Normal

Elevated VO2physical activity, stress, anxiety

Low

(Anemia)

filling high filling low

Heart

failure Hypovolemia

Oxygen

PEEP

Transfusion Dobutamine

(vasodilators ?)

Fluids

ReassurancePinsky MR & Vincent JL, Crit Care Med 33: 1119, 2005

Vincent et al, Crit Care 15: 229, 2011

Integration

of variables

cardiac

filling pressures

Skin

perfusion

SvO2

Lactate

levels

Heart rate

Arterial

pressure

Microcirculation

(OPS, NIRS, …)

PgCO2

Cardiac

output

Cardiac

chambers

size

Urine

output

High SvO2

Low SvO2

SvO2 high

Decreased O2 extraction

CO high CO normal or low

Normal

ventricular filling

Inflammatory response(sepsis, polytrauma,

after major surgery...)

cirrhosis

(A-V shunts)

High

ventricular filling

Decreased VO2

(anesthesia, hypothermia…)

Hypervolemia

Hypoxemia is impossible

Anemia is unlikely

(hyperkinetic state)

High ScvO2 are associated with worse outcomes

Non-survivors Survivors

max ScvO2

152 patients

133 patients (ER)

6.2

37 %

5.7

12 %

7.7

42 %

SOFA

Mortality

SvO2low

range

normal

range

high

range

Non-Responders (n=31)

Responders (n=34)

SvO2 Responders / total (%)

<50% 2 / 5 (40%)

50-60% 4 / 12 (33%)

60-70% 15 / 23 (65%)

>70% 13 / 25 (52%)

Non-Responders (n=31)

Responders (n=34)

THE SIMPLISTIC APPROACH

In septic shock

ScvO2

< 70 %

More fluids

Transfusions

Dobutamine

> 70 %

Nothing

What ifNo vasopressors

Urine output OK

Skin perfusion OK

Mental status OK

What ifOn vasopressors

Anuria

Mottled skin

Obtundation

lactate

ScvO2 in complex cases

Do not forget

VAPCO2 in complex cases

SvO2

OK

Delta PCO2

6 mmHg

65 %

AbnormalReassuring

(anemia?)

Persisting

hypoperfusion?

VA PCO2 gradients

Early goal-directed therapy

(EGDT)

Late

ScvO2

monitoring

Low

ScvO2

Argument forMore fluids

Transfusion

Dobutamine

Normal

ScvO2

Argument forVasopressor only

ScvO2

Elevated

VAPCO2

How I treat septic shock

SvO2OVERSIMPLIFICATIONS

A low SvO2 is always pathological

think at exercise, anemia, …

A high SvO2 is always a good sign

think at hyperkinetic septic shock

SvO2 should always be maintained above 70 %

think at the Gattinoni's study

and the risks of overtreatment

Hopefully things are not so simple….

(bad news for those who like simple protocols)

RELATION BETWEEN VO2 AND DO2

IN PATIENTS AFTER CARDIAC SURGERY

Routsi et al, Anesth Analg 77: 1104-10, 1993

0

0,5

1

1,5

2

2,5

3

3,5

CI, L/min.M²

admission 2-4 h 4-12 h 12-24 h

normal

range

Admission 2-4 h 4-12 h 12-24 h

Temp, °C 34.6 0.6 35.8 0.7 36.7 0.6 36.9 0.6

HR, bpm 84 16 89 16 87 14 89 10

MAP, mmHg 76 12 73 12 73 9 83 10

CI, L/min.M² 1.8 0.4 2.1 0.4 2.2 0.4 2.8 0.7

Hb, g/dL 9.8 1.0 10.1 1.4 10.3 1.4 10.5 1.0

SvO2, % 61.8 8.5 63.5 7.3 64.8 7.1 61.8 6.3

+-

+-

+-

+-

+-

+-

+-

+-

+-

+-

+-

+-

+-

+-

+-

+-

+-

+-

+-

+-

+-

+-

+-

+-

RELATION BETWEEN VO2 AND DO2

IN PATIENTS AFTER CARDIAC SURGERY

Routsi et al, Anesth Analg 77: 1104-10, 1993

Pulmonary artery catheter

Pressures

Cardiac output

SvO2

SvO2

Cardiac output

Pressures

O2ER = VO2/DO2

OXYGEN EXTRACTION

O2ER = CO x (CaO2 - CvO2) / CO x CaO2

O2ER = (CaO2 - CvO2) / CaO2

O2ER = (SaO2 - SvO2) / SaO2

0 5 10 15 20 25 30 35 40 45 50

O2 EXTRACTION, %

0

1

2

3

4

5

6

CARDIAC INDEX, L/min.M²

ANEMIA

EXERCISEDANGER

0 5 10 15 20 25 30 35 40 45 50

O2 EXTRACTION, %

0

1

2

3

4

5

6

CARDIAC INDEX, L/min.M²

1

2

34

THE RELATIONSHIP BETWEEN CARDIAC INDEX AND O2 EXTRACTION

hb sao oxygen delivery - intensive.orgintensive.org/.../presentations_2019/svo2_distribu.pdf ·...

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