Thiamine vs. Placebo to Increase Oxygen Consumption After Cardiac Arrest

Randomized, Double-blind, Placebo-controlled Trial of the Effect of Thiamine on Oxygen Consumption After In-hospital Cardiac Arrest.

This study is to evaluate whether thiamine can increase oxygen consumption and lower lactate in patients who initially survive an in-hospital cardiac arrest. Patients who are successfully resuscitated after an in-hospital cardiac arrest and who are on mechanical ventilation in the intensive care unit will be enrolled, and will get either thiamine or placebo. Their oxygen consumption and lactate will be measured at serial time points and compared between groups. The investigators' hypothesis is that thiamine will help restore the body's ability to metabolize oxygen normally (aerobic metabolism), leading to an increase in oxygen consumption and a decrease in lactate.

In-hospital cardiac arrest often leads to shock and organ failure, and low oxygen consumption and high lactate are associated with worse outcome. Thiamine is a B vitamin necessary to maintain the body's ability to use oxygen effectively, and the investigators have found that many patients are thiamine deficient after cardiac arrest. The investigators have also found that thiamine can decrease lactate in thiamine-deficient patients who are critically ill. Patients in this study will be randomized to receive either thiamine or placebo every 12 hours for 2 days after surviving an in-hospital cardiac arrest. The investigators will measure oxygen consumption continuously during that time with a monitor attached to the ventilator tubing, and will also measure lactate and other lab values at several time points.

Intervention: Thiamine 500mg IV every 12 hours for 2 days. Oxygen consumption will be monitored with a non-invasive monitor continuously for 2 days and lactate, pyruvate dehydrogenase and other routine lab values will be checked at serial time points.

Intervention: Placebo (100mL normal saline) IV every 12 hours for 2 days. Oxygen consumption will be monitored with a non-invasive monitor continuously for 2 days and lactate, pyruvate dehydrogenase and other routine lab values will be checked at serial time points.

The investigators will evaluate the absolute level and the change in lactate over two days, compared between groups

The investigators will evaluate the absolute level and the change in oxygen consumption over two days, compared between groups

The investigators will evaluate the absolute level and the change in pyruvate dehydrogenase levels over two days, compared between groups

Inclusion Criteria: Adult patient (age > 18 years) Cardiac arrest occurring while admitted to the hospital, with sustained (>20 minutes) return of spontaneous circulation (ROSC) Mechanically ventilated at the time of enrollment Within 12 hours of cardiac arrest event Exclusion Criteria: Clinical indication for thiamine administration (alcoholism, known or highly suspected deficiency) or treatment with thiamine beyond the amount found in a standard multivitamin within the last 10 days Comfort measures only or anticipated withdrawal of support within 24 hours Severe agitation Protected populations (pregnant women, prisoners)