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What is the relevance of central or mixed venousoxygen saturation ?
K. Reinhart MDDept. of Anaesthesiology and Intensive Care Medicine
Friedrich-Schiller-University Jena, Germany
ATS / ESICM / ERS /
SCCM / SRLF7th International Consensus
Conference
Paris, 2006
Shock is defined Shock is defined as inadequate as inadequate
tissuetissueoxygenationoxygenation
Which are the Which are the most appropriate most appropriate
cardio-cardio-respiratory respiratory
variables to variables to detect and to detect and to monitor the monitor the
course of tissue course of tissue hypoxia in the hypoxia in the
clinical setting ?clinical setting ?
What can we What can we learn from learn from
physiology ?physiology ?
Conventional cardio-Conventional cardio-respiratory parameters are respiratory parameters are
of limited value for the of limited value for the assessment of the adequacy assessment of the adequacy
of tissue oxygenation !of tissue oxygenation !
The cardio-respiratory system The cardio-respiratory system fullfills its physiological task by fullfills its physiological task by
guaranteeing cellular oxygen guaranteeing cellular oxygen supply and to remove the waste supply and to remove the waste
products of metabolismproducts of metabolism
Pflüger 1872
It was fatal for the development of our It was fatal for the development of our understanding of circulation, that blood understanding of circulation, that blood flow is relatively difficult to measure, flow is relatively difficult to measure, whereas blood pressure is easily whereas blood pressure is easily measured: measured: This is the reason why the blood This is the reason why the blood pressure meter has gained such a pressure meter has gained such a fascinating influence, although most fascinating influence, although most organs do not need pressure, but blood organs do not need pressure, but blood flow. flow.
AA. Jarisch, “Kreislauffragen“ 1928. Jarisch, “Kreislauffragen“ 1928
The two main The two main determinants of determinants of
oxygen supply to the oxygen supply to the tissues are arterial tissues are arterial oxygen content and oxygen content and
cardiac outputcardiac output
DO2 ml*m-2*min-1
100 300 500 700 900 1100
n= 123230
60
90
120
150
180
MA
P m
mH
gCorrelation Between Arterial Correlation Between Arterial
Pressure And Oxygen DeliveryPressure And Oxygen Delivery
DO2 ml*m-2*min-1
100 300 500 700 900 1100
n= 123630
60
90
120
150
180
HR
b/m
inCorrelation Between Heart Rate Correlation Between Heart Rate
And Oxygen DeliveryAnd Oxygen Delivery
Shepard AP et al. 1973 Am.J.Physiol. 225: 747
0 2 4 6 8 10 1260
100
140
180
220
260
Control A-VO2 vol.%
Control Cardiac Output ml/ min/ kg
Control Oxygen Consumption
ml/ min/ kg
12
10864
Reinhart K et al. (1989) Am J Physiol 257:
H238
Individual points of limb OIndividual points of limb O22 uptake vs. O uptake vs. O22
delivery over range of progressive ischemiadelivery over range of progressive ischemiaO
2 U
ptak
e (m
l*kg
-1*m
in-1
)
O2 Delivery (ml*kg-1*min-1 )
2
0
4
6
8
2520151050
Oxygen Debt: To Pay or Not to Pay?
SvO2 (%)**p < 0.01**p < 0.01
3.5
3.0
2.5
2.0
1.5
1.0
50 60 70 80 90
****
n=9n=9 n=29n=29n=77n=77
n=150n=150n=148n=148
n=110n=110n=27n=27
Lact
ate
(mM
ol/l)
Car
dic
Inde
x l/m
in/m
2
A-V Oxygen Content Difference Vols. %
O2 U
ptak
e m
l/min
/m2
4
6
8
10
12
2 4 6 8 10 12
300
500
700
900
1100
Donald K.W. et al. (1954) J.Clin.Invest. 33: 1146
Kenneth WD et al. (1954) J.Clin.Invest. 33: 1146
Car
dic
Inde
x l/m
in/m
2
A-V Oxygen Content Difference Vols. %
O2 U
ptak
e m
l/min
/m2
0
2
4
6
8
2 4 6 8 10 12 14 16
100
200
300
400
500
The arterio-venous The arterio-venous oxygen content difference oxygen content difference informs on the extent to informs on the extent to which the compensatory which the compensatory
mechanisms of the cardio-mechanisms of the cardio-respiratory system are respiratory system are
exhaustedexhausted
25 40 55 70 85 100
9.3
8.2
7.1
6.0
4.9
3.8
2.7
1.6
0.5
r= -0.864
y= 12.7 -0.12x
n= 1191
SO2 %
avD
O2 m
l/dl
Correlation of Arterio- Venous Oxygen ContentCorrelation of Arterio- Venous Oxygen ContentDifference with Mixed Venous Oxygen Difference with Mixed Venous Oxygen
SaturationSaturation
Rudolph, T., et al., 1989
ScvOScvO22 vs. avDO vs. avDO22
30 40 50 60 70 80 90 100
8.0
7.0
6.0
5.0
4.0
3.0
2.0
1.0
0
r= -0.707
n= 447
avDO2= 11.4 -0.1*ScvO2
ScvO2 %
avD
O2 m
l/dl
Correlation of Oxygen - Supply to - Demand Correlation of Oxygen - Supply to - Demand Ratio with Mixed Venous Oxygen SaturationRatio with Mixed Venous Oxygen Saturation
SO2 %
DO
2/
VO
2
25 705540 85 1001.0
2.8
4.6
6.4
8.2
10.0
r= 0.906
y= -9.58 + 0.19*x
n= 1149
75%
Factors that influence mixed and central venous Factors that influence mixed and central venous SOSO22
VO2 DO2 DO2 VO2 Stress
Pain
Hyperthermia
Shivering
PaO2
Hb
Cardiac output
PaO2
Hb
Cardiac output
Hypothermia
Anesthesia
_+
What can we What can we learn from learn from
clinical studies ? clinical studies ?
November 8, 2001
MortalityMortality
0.0090.58 (0.38-0.87)30.546.5In-hospital
P-value RR (95% C.I.) TreatmentControl
0.030.67 (0.46-0.96)44.356.960-day Mortality
0.010.58 (0.39 – 0.87)33.349.228-day Mortality
Resuscitation Endpoints
0 12 24 36 48 60 723 6
40
50
60
70
80 * *
* ** *
Sc
vO
2
0 12 24 36 48 60 723 6
0
2
4
6
8*
** *
La
cta
te
* ControlTreatment
0 12 24 36 48 60 723 6
-2
2
6
10*
**
*
*
***
Ba
se
De
fic
it
0 12 24 36 48 60 723 6
7.25
7.30
7.35
7.40
7.45
*
* *
*pH
Hours
Global Tissue Hypoxia (Cryptic Shock)Global Tissue Hypoxia (Cryptic Shock)Despite Normalization of Vital SignsDespite Normalization of Vital Signs
• 39.8% of control vs. 5.1% of treatment
group had global tissue hypoxia ( ScvO2
and lactate) at 6 hours.
SVO2 Monitoring in Cardiac Surgery
• Polonen et al have studied a cohort 403 of cardiac surgical patients
– The control group received standard care whilst in the protocol group, SvO2 was maintained above 70% and lactate below 2mmol/l with fluid and inotropes
– The study was undertaken in the immediate 8 hour post-operative period
Polonen Anesth. Analg 2000
Goal oriented hemodynamic therapy in cardiac surgical patients n = 411
Goals: SvO2 > 70% and lactate 2mmol/l from admission to the ICU and 8 hrs thereafter
6 p<0,005 7hospital stay (days)
1,1% p<0,001 6,1%morbidity at hospital
discharge
n.s.ICU stay
goal oriented control
(Polonen et al., Anesthesia and Analgesia 2000)
Failure of Vital SignsFailure of Vital Signs
• 31 of 36 medical shock patients:
– Resuscitated to normal MAP and CVP
– Have global tissue hypoxia (Scv02 < 70%
and lactate >2 mmol/L).
Rady, AJEM, 1994
SCVO2 Can Predict Occult Shock in CHF
0
10
20
30
40
50
60
SCVO2 %
Control Low Lactate High Lactate
Patients enrolled in decompensated CHF with EF<30%No difference in vital signs or clinical category of HF between groups.
Ander Am J Card 98
ScvOScvO22 is superior to CVP to reflect is superior to CVP to reflect
reduced central blood volumereduced central blood volume
(Madsen et al., Scand J Clin Lab Invest 1993)
before
blood loss
after
blood loss
CVPmm Hg
3 *(6 – 1)
1(5 – -3)
ScvO2 %
75 **(69 – 78)
60(49 – 67)
SSCVCVOO22 Monitoring in Trauma Monitoring in Trauma
• 26 consecutive patients with injury suggestive of blood loss.
• HR, BP, Urine output, CVP and SCVO2 measured.
• Blood loss estimated.• SCVO2 most sensitive indicator blood loss• SCVO2 <65% associated with increased injury,
blood loss and transfusion requirements.
Scalea J Trauma 1990
Continuous central venous ScvOContinuous central venous ScvO22 monitoring monitoring
can reliably indicate ROSC during CPRcan reliably indicate ROSC during CPR (n = 100) (n = 100)
Patients with ROSC had higher initial mean and
maximal ScvO2.
No ROSC in patients without ScvO2 > 30%
A ScvO2 > 75% was 100% predictive of ROSC.
(Rivers et al., Ann Emerg. Med. 1992)
Complications in patients with high vs. low ScvO2 after major surgery
Evolution of ScvO2, base excess, and lactate in 65 patients with septic
shock
Parks M et al. CLINICS 2006;61(1):47
Does it matter wether we Does it matter wether we measure central venous measure central venous or mixed venous oxygen or mixed venous oxygen
saturation ?saturation ?
Lee J et al. (1972) Anaesthesiology 36:
472
% S
svc O
2
% SO2
100
80
60
40
20
0 20 40 60 80 100
r= 0.73
r= 0.88
Shock
Normal
Reinhart K et al, Reinhart K et al, Chest, 1989; 95:1216-1221Chest, 1989; 95:1216-1221
SvOSvO22 closely correlates with ScvO closely correlates with ScvO22
Zeit (min)Zeit (min)
% S
at%
Sat
8080
6060
4040
2020
00
303000 6060 9090 120120 150150 180180 210210 240240
NormoxieNormoxie BlutungBlutung Volumentherapie (HAES)Volumentherapie (HAES) BlutungBlutung
Hyp
oxi
eH
ypo
xie
No
rmo
xie
No
rmo
xie
Hyp
ero
xie
Hyp
ero
xie
Gemischt-venösGemischt-venös
Zentral-venösZentral-venös
t (min)
%
20 30 40 50 60100
SvO2
50
60
70
80
90
100
40
ScvO2
Zeit (min)
%
0 10 20 30 40
40
50
60
70
80
90
100
ScvO2
SvO2
All DeterminationsAll Determinations
Scheinmann MM et al. 1969 Circulation 40: 165
M.V. O2- % Saturation
R.A
. O
2 an
d C
.V.
O2 -
%S
atur
atio
n
R.A. O2 (r= 0.95)
C.V. O2 (r= 0.90)
SvO2 % Sat
Scv
O2 %
Sat
80
60
40
20
0
-20
-40
-60
-80-80 -60 -40 -20 0 20 40 60 80
r= 0.9761
p< 0.001
n= 131
Reinhart K et al, Reinhart K et al, Chest, 1989; 95:1216-1221Chest, 1989; 95:1216-1221
Changes in SvO2 and ScvO2 in general anesthesia during
neurosurgery
Conclusion: Despite some large differences between absolute values, in patients with varying hemodynamic situations, the trend in ScvO2 may be used as a surrogate variable for the trend in SvO2.
Dueck MH et al. Anesthesiology 2005; 103:249
Changes in mixed venous Changes in mixed venous oxygen saturation are well oxygen saturation are well
matched by changes in matched by changes in central venous oxygen central venous oxygen
saturation !saturation !
Differences between SvODifferences between SvO22 and ScvO and ScvO2 2 in in
different patient groupsdifferent patient groups
SO2n = number of measurements
high risk surgical
n = 18 7,25 % 220 313
septic shock
n = 11 7,90 % 148 534
severe head injury
n = 3 10,7 % 26 281
Reinhart K et al., unpublished
SvO
2 -
ShO
2 [
%]
SvO2 [%]
Differences between mixed venous and Differences between mixed venous and hepatohepato--venous Ovenous O22 saturation in patients saturation in patients
with septic shockwith septic shock
-10
0
10
20
30
40
60 62 64 66 68 70 72 74 76 78 80 82
Normalbereich
Percentage of splanchnic O2 consumption
from total body O2 consumption
in septic shock patients
60% (n=34)
In patients with In patients with severe sepsis or severe sepsis or
septic shock a goal of septic shock a goal of 70% for central 70% for central venous oxygen venous oxygen
saturation saturation corresponds to a corresponds to a
mixed venous oxygen mixed venous oxygen saturation between saturation between
60 and 65% !!!60 and 65% !!!
Does it matter wether we Does it matter wether we measure central venous measure central venous
oxygen saturation oxygen saturation continuously or continuously or
discontinuously ?discontinuously ?
Blood gas analyses in patients with severe sepsis and septic shock
Central venous blood gas analysis
Total amount all patients; all days
16,936
Average amount during ICU stay (range)
76.9 (1-393)
Average amount per patient and day1
3.5
1: average ICU length of stay 21.5 days
All patients with severe sepsis or septic shock between April 2004 and May 2005 (n=221)
Average costs per patient (Euro)
approx. 300,00
Limitations of mixed and Limitations of mixed and central venous oxygen central venous oxygen
saturation for the saturation for the assessment of tissue assessment of tissue
oxygenation oxygenation
pHirCO2
Hepatic venous blood flow(splanchnic blood flow)
ICG-clearanceMEGX-test
Hepatic venous O2-saturation
Transcutaneous liver near infrared spectroscopy (TOI) in 20 children during surgical hemorrhage
• TOILiver provided a better trend monitor of central venous oxygen saturation than gastric intramucosal pH.
• Because of its limited sensitivity and specificity to indicate deterioration of SvO2, liver tissue oxygenation measured by transcutaneous NIRS does not provide additional practical information for clinical management.
Weiss M et al. Pediatric Anesthesia 2004; 14: 989
Correlation between central venous oxygen saturation and near-infrared spectroscopic
cerebral oxygenation (cTOI) in 43 critically ill children
Nagdyman N. et al. Intensive Care Med (2004) 30:468
Inadequate tissue Inadequate tissue oxygenation may exist on oxygenation may exist on
the regional and organ the regional and organ level despite normal level despite normal
central and mixed venous central and mixed venous oxygen saturation oxygen saturation
Summary• ScvO2 and SvO2 are superior to conventional hemodynamic monitoring
parameters in the assessment of the adequacy of global tissue oxygenation
• Continuous monitoring of ScvO2 and SvO2 in the framework of hemodynamic
goals and treatment algorithms have resulted im improved patient outcome
• ScvO2 closely parallels SvO2 saturation
• In patients with shock ScvO2 is 7 – 10% (mean) higher than SvO2
• These differences between ScvO2 and SvO2 saturation result from changes
in the regional blood flow and oxygen supply/demand ratio
• Normal or high ScvO2 and SvO2 do not rule out tissue hypoxia on the organ
or regional level