Background: SCV02 is an indicator that is affected by four factors, namely, cardiac output, hemoglobin, oxygenation and oxygen consumption. Perioperatively, anesthesiologists/ pediatric intensivists make use of the traditional parameters of hemodynamic stability as basis for the administration or use of inotropic drugs, giving blood products and setting the mechanical ventilation without direct consideration on oxygen consumption which may be accessed through venous oximetry such as Scv02 values.
Method: This is a prospective cohort study involving 67 patients aged 3-12 years old undergoing either palliative or corrective surgery for Tetralogy of Fallot. SCVO2 were determined on the following intervals: Baseline (after induction on placement of central line, prior to sternotomy), on CPB, rewarming before off CPB, 6th hour SICU, and before extubation. The following are outcomes observed: Mortality, prolonged weaning time from CPB, prolonged extubation time, prolonged SICU stay, number of pressors, increased blood products given.
Results: The cut off values are as follows: pre- CPB is 70.2 (p= 0.012 AUC 0.68), CPB 81.3 (p=0.88 AUC 0.51), before off CPB 79.5 (p=0.67 AUC 0.54), 6th hour SICU 75.4 (p=0.00 AUC 0.85) and before extubation 77.8 (p= 0.00 AUC 0.704). Pre CPB, 6th hour SICU stay and before extubation are significant to outcomes with p-values below 0.05. These significant time points have the highest area under the curve value of 0.681, 0.856 and 0.704 respectively.
Conclusion: The SCVO2 vaues taken pre bypass, 6th hour SICU and before extubation demonstrate a significant association in the outcome of TOF patients undergoing palliative or total correction.