Vitamin B12a Vasoplegic Syndrome

Inclusion Criteria: * Any patient for whom we are able to obtain consent ahead of their procedure * Patients presenting for a procedure in which cardiopulmonary bypass will be required * Considered high risk for vasoplegic syndrome * Has no contraindications to arterial line or PA catheter placement * Develops high-dose vasopressors for 30 min or longer and refractory hypotension consistent with vasoplegic syndrome within 24 hours of coming off cardiopulmonary bypass. Exclusion Criteria: * Age\<18 years * Known pregnancy or patients without a documented pregnancy test if not menopausal. * Known prior anaphylactic or allergic reaction to B12a * CKD stage 4 or worse * ECMO (extracorporeal membrane oxygenation) prior to study consent. * Patients currently on cardiopulmonary bypass