Can central venous oxygen saturation intermittently measured within the first 24 postoperative hours of cardiac surgery predict death?
© BioMed Central Ltd 2005
Published: 7 March 2005
Central venous oxygen saturation (ScVO2) has been considered an important parameter for follow-up, prognostic estimate, and therapeutic target in the management of critically ill patients.
To analyze the impact of ScVO2 on the postoperative period of cardiac surgery, and to correlate it with inhospital death. Three ScVO2 measurements were taken within the first 24 postoperative hours, and the overall mean was calculated.
Case series and methods
A classic cohort of 132 consecutive patients selected from January 2004 to August 2004 and divided into the following two groups: Group I, death (n = 11, 8.3%); and Group II, survivors. Blood samples were collected through a central venous catheter properly positioned in the right atrium according to a previously validated method. The ScVO2 measurements were taken in the postoperative period as follows: immediately (SV0), after 6 hours (SV1), and after 24 hours (SV2). A mean of the three measurements was calculated (mSV). Inhospital mortality was the occurrence of death during hospitalization. The Student t test was used for statistical analysis.
The mean ScVO2 values of Group I compared with those of Group II were as follows, respectively: SV0, 54.8% ± 12.6 vs 65.4% ± 8.9 (P < 0.0001); SV1, 56.6% ± 7.3 vs 68.5% ± 5.9 (P < 0.001); SV2, 61.1% ± 7 vs 69.3% ± 5.3 (P < 0.001); and mSV, 57.3% ± 7.8 vs 67.7% ± 4.9 (P < 0.001). The distribution of variation of ScVO2 was normal. The EuroScore was as follows: in the total sample, 5.3 ± 3.6; in Group I, 8.7 ± 6.1; and in Group II, 5 ± 3.1 (P = 0.001). The predicted mortality was around 11%, and the inhospital mortality was 8.3%.