RESUMEN
Low Cardiac Output Syndrome [LCOS] contributes to postoperative morbidity and mortality. This article tries to find a predictive factor to interpret outcome after cardiac operation. In a cross-sectional study, 100 children with congenital heart disease undergoing cardiovascular surgery with cardiopulmonary bypass [CPB] without significant left-to-right shunt were selected. Arterial and central venous oxygen saturation values were measured via blood samples simultaneously obtained in 6-hr intervals for a total of 24-hr during postoperative period at hours 0, 6, 12, 18, and 24. Postoperative ventilation support [intubation period] and cardiovascular support were also obtained from the hospital records. Statistical analysis was later performed comparing the arterial-mixed venous oxygen saturation differences and durations of required ventilatory and cardiovascular support, both for the complicated and non-complicated patient groups. The data was processed with correlation Pearson and Mann-Whitney U tests in SPSS 15 software, P less than 0.05 was significant. Mortality following cardiac operation is 6% and complications may happen in 45% of the cases. The highest Arterial-mixed venous oxygen saturation difference occurred immediately post operation [up to 57%]. These measures were high up to 18 hours in complicated and non-complicated groups [36% vs. 31% ; P< 0.05]. This factor cannot predict prolongation of intubation period in patients [P > 0.05]. Arterial-mixed venous oxygen saturation difference may be high as much as 57% or as low as 23%.These different measures, being higher up to 18 hours in complicated to non-complicated groups after 18 hours, can be related to tissue ischemia during surgery and cannot be discriminative.