The goal of this clinical trial is to compare the capability of 3 different bedside surrogates in children who underwent cardiac surgery and were admitted in intensive care unit. These test are lactate, oxygen saturation from central venous and the carbon dioxide gap between central venous and arterial.

The main questions is which one is the best prognostication for post operation poor outcomes Participants will be taken routine blood test for post cardiac care (at ICU arrival, 6, 12, and 24 hour post operation) and follow the their outcomes. There is no any intervention or drug in this research

Inclusion Criteria:

• Children aged 0-18 years old with either congenital or acquired cardiac disease
• Undergone cardiopulmonary bypass for cardiac surgery
• Be admitted in PICU for post-operative care

Exclusion Criteria:

• Preterm infant (GA < 37 weeks) or weight less than 2 kg
• Patient who weaned off cardiopulmoanry bypass and required extracorporeal membrane oxygenator (ECMO) before leaving the operating room
• Patient who required emergency cardiac operation within 24 hour after hospitalization
• Patient who had significant residual left side outflow tract obstruction (e.g., coarctation of aorta, interrupted aortic arch) which defined by difference of SBP between upper and lower extremities more than 10 mmHg
• Patient who had already participated in another research project
• Patient who does not have both arterial line and central line catheter back from operating room
• Parents or legal guardian refuse to inform consent.

Children with cardiac disease in Songklanagarind hospital who undergone open cardiac surgery with cardiopulmonary bypass (age < 18 years old)

This data might be analyzed in other project and also we need to submit the form of data sharing to local EC unit.