Does Mixed Venous Oxygen Saturation Reflect the Changes in
Cardiac Output During Liver Transplantation?
F. Acosta, T. Sansano, C.G. Palenciano, V. Roque ´ s, N. Clavel, P. Gonza ´ lez, R. Robles, F.S. Bueno,
P. Ramı´rez, and P. Parrilla
I
T HAS BEEN SUGGESTED that mixed venous oxygen
saturation (SvO
2
) in the absence of hypoxemia and
anemia could be useful in managing hemodynamically
unstable patients.
1
Therefore its sensitivity and specificity in
the assessment of cardiac output (CO) are controversial.
2,3
Our aim was to determine whether the constant recording
of SvO
2
during liver transplantation (LT) might anticipate
the frequent changes in CO.
PATIENTS AND METHOD
We studied 23 consecutive cirrhotic patients treated with LT using
the piggyback technique. We performed a complete hemodynamic
profile using a pulmonary artery catheter with a fast-response
thermistor for right ventricular rejection fraction and oxymetry
(RVEF, Baxter-Edwards, Calif). The variables studied were car-
diac index (CI), cardiac preload measured by right ventricular end
diastolic index (RVEDVI), and SvO
2
, at the following time points:
beginning and end of the preanhepatic (A
1
,A
2
), anhepatic (B
1
,B
2
),
and neohepatic (C
1
,C
2
) phases.
Statistics
Linear regression analysis was used with significance set at P .05.
RESULTS
The correlation between SvO
2
and CI was poor (r
2
= 0.36,
P .001), and at certain time points during the operation,
did not even exist. The same occurred with the correlation
between SvO
2
and RVEDVI (r
2
= 0.34, P .001) (Table
1).
DISCUSSION
Jaugh et al
2
in critically ill patients found that changes in
SvO
2
do not predict anticipated changes in CI. In LT we
were also unable to show that the constant measurement of
SvO
2
serves to anticipate the changes in cardiac preload or
output. The reason may be the complex curvilinear rela-
tionship between SvO
2
and CI preventing straightforward
interpretation.
3
In fact, according to this relationship, when
CI exceeds 4 L/min per m
2
the changes in SvO
2
are
minimal. In cirrhotic patients treated with LT, CI usually
exceeds this value.
REFERENCES
1. Norfleet E, Watson C: J Clin Monit 1:4, 1985
2. Vaughn S, Puri V: Crit Care Med 16:495, 1988
3. Vincent J: Crit Care Clin 12:995, 1996
From the Liver Transplant Unit, University Hospital “V.Arrix-
aca”, Murcia, Spain.
Address reprint requests to Dr Francisco Acosta, San Cristo ´-
bal, 4 (3B), 30001-Murcia, Spain.
Table 1. Relationship Between SvO
2
and Hemodynamic Variables During LT
A
1
A
2
B
1
B
2
C
1
C
2
SvO2 (%) 79.6 9.8 81.7 9.5 82.0 7.1 86.1 6.6 87.0 4.9 79.1 9.6
CI (L/min/m
2
) 4.8 1.0 6.3 2.0 5.8 1.7 6.1 2.4 8.5 2.5 7.2 2.0
r
2
0.26 0.48 0.31 0.27 0.53 0.52
P .40 .05 .20 .20 .05 .05
RVEDVI (mL/m
2
) 129.9 27.6 134.7 32.1 122.5 31.3 132.7 35.9 156.0 36.6 138.5 34.7
r
2
0.22 0.60 0.52 0.37 0.41 0.35
P .48 .05 .05 .09 .09 .13
See text for abbreviations.
Values expressed as mean SD.
n = 23.
r
2
: correlation coefficient; P = level of significance.
© 2002 by Elsevier Science Inc. 0041-1345/02/$–see front matter
655 Avenue of the Americas, New York, NY 10010 PII S0041-1345(01)02762-2
Transplantation Proceedings, 34, 277 (2002) 277