The Thiamine Administration After Cardiac Surgery Trial

Thiamine (Vitamin B1) is essential for cell function and as a co-factor of the enzyme Pyruvate Dehydrogenase to initiate the Krebs cycle and thus the aerobic metabolism of glucose.

Thiamine deficiency, can be caused by alcoholism or bariatric surgery and is associated with severe complications such as Wernicke's encephalopathy or Beri-Beri syndrome.

Thiamine deficiency can also be the cause for an increase in lactate levels due to the transformation of pyruvate to lactate. An increase in lactate levels is associated with a worse prognostic. A decrease is, on the contrary, associated with an improved prognostic, during CPR and also after cardiac arrest.

Recently, studies have shown that thiamine deficiency is underdiagnosed in ICU patients.

On top of this, extra-corporeal circulation can worsen this deficiency. This could explain why certain on-pump cardiac surgery patients have increased lactate levels post-operatively, despite optimal blood pressure, cardiac output, diuresis, peripheral perfusion Donnino et al have shown that in a sepsis context thiamine administration improved lactate clearance during the first 24 hours of ICU admission and improved mortality rates at 28 days post-ICU admission.

Therefore, the hypothesis of this study is that thiamine supplementation improves the clearance of lactate in the first 24 hours after cardiac surgery with extracorporeal circulation in patients with high lactate concentration.

Inclusion criteria

• Adult patients scheduled for elective cardiac surgery with extra-corporeal circulation in the CHU de Charleroi between November 2020 and December 2021. Written informed consent will be obtained from each patient/ family member participating in the study.

Exclusion criteria

• Patients already supplemented with vitamins
• Patients with an allergy to thiamine
• Patients who are priorly treated with linezolide, antiretrovirals and/or metformin treatment within 48 hours preoperatively
• Patients with mitochondrial disorders
• Patients with Child Pugh C cirrhosis
• Patients with a history of epilepsy with tonic-clonic movements postoperatively.
• Pregnant patients