Thiamine Influenced on Substrate Energy Effectiveness in Indonesian Children Undergoing Congenital Heart Disease Surgery With Cardiopulmonary Bypass Procedure and Oral Thyroid Supplementation

All patients who undergo open cardiac surgery for their congenital heart disease on the research period will be recruited consecutively and evaluated according to the study criteria. Parents or guardians were explained about the procedure. Agreement will be concluded by signing the informed consent. Baseline data including age, nutritional status, diagnosis, types of heart disease (cyanotic or acyanotic), restrictive or non restrictive pulmonary blood flow heart disease, pre-surgical peripheral saturation, pulmonary hypertension and any syndromes associated with heart disease will be recorded on the study sheets.

Patients will be randomised using block randomisation procedure with a block size of 4 on treatment and control group. Included participants will be marked by specific randomisation number by a research assistant physician who is not involved in patients' management. A pharmacist will acquire and open a prepared envelope containing the randomisation number. The patients, parents/guardians, research physicians, other physicians or paramedics involved in patients' treatment will be blinded.

Placebo (Intravenous Normal Saline) and intravenous thiamine (2 mg/kg) will be administered at induction time, 1 hours after surgery and once everyday for three days by pharmacist according to randomization result. All subject are given oral T3 supplementation (1 mcg/kg) every 6 hours by pharmacist as research protocol. Oral T3 supplementations are given every 6 hours, started from induction time until 11 doses (60 hours until the first dose). Drugs is diluted with 2.5 cc aqua and administerednisterd using nasogastric tube.

Blood will be withdrawn from arterial line access for 2.5 cc in order to test thiamine, lactate, and pyruvate concentration, as well as, measuring LDH and PDH activity. Thiamine will be examined from blood plasma using liquid chromatography tandem mass spectometry. Thiamine concentration below ≤ 7 nmol/L is considered low. PDH will be examined from Peripheral Blood Mononuclear Cells (PBMCs) which will be isolated from fresh blood. PDH activity will be tested after breaking cell membrane to initiate mitochondria lysis, this process will be done by immunocapture and micro-plate based assay. Lactate and pyruvate measurement will be tested using an enzymatic kit specific for lactate and pyruvate called Sigma Aldrich reagent. Thiamine concentration, lactate concentration, pyruvate concentration, LDH and PDH activity is going to be measured at 4 time; induction time, one hour, 24 hours, 72 hours after aortic clamp removal.

Measurement of blood gas analysis, blood glucose, central vein saturation and oxygen extraction ratio will be performed at induction time, 1 hours, and 12 hours post-surgery.