Conditions: Cardiovascular Abnormalities
Keywords: Nitrous oxide cobalamin homocysteine vitamin B12 folate No specific diseases targeted
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 63
Healthy volunteers: no

Brief summary:
The goal of this study is to find out if giving intravenous B-vitamins before general anesthesia with nitrous oxide prevents the increase in homocysteine, a metabolite that has been linked to cardiovascular complications.

Detailed description:
Patients will be randomized into the following arms:

* Arm A: patients will receive N2O (60% N2O/40% O2) in an open-label fashion during surgery and vitamin supplementation (vitamin B12, 1 mg, and folate, 5 mg) before surgery.
* Arm B: patients will receive N2O 60% N2O/40% O2) in an open-label fashion during surgery and placebo before and after surgery.
* Arm C: patients will not receive N2O, vitamin supplementation, or placebo during/before surgery. Patients in this arm will not be randomized.

Patients will have blood drawn (total of 1-2 teaspoons over 3 days). We will take these samples before their surgery, when their surgery is completed, and in the morning of post-operative day 1. We will be checking their troponin I and troponin T, homocysteine, Vitamin B12, and folate levels. We will also perform a 12-lead EKG. Before and after surgery for patients in Arm A or B, will receive either vitamin B12 (1 mg) and folic acid (5 mg) (or placebo) added to their IV infusion. We also plan to use a non-invasive test known as a nerve conduction study to measure the function of their nerve system. Briefly, 2 small electrodes are attached to their skin over a nerve and, like an EKG, faint electrical pulses are generated and recorded. A typical nerve conduction measurement lasts about 10 minutes.

After the patients surgery we will do genetic testing of MTHFR genotype.

All study samples have been collected.

Of note: there were no secondary outcomes.

Arms:
arm 1: B12-Folic acid, nitrous oxide arm 2: Nitrous oxide (NO) and placebo arm 3: oxygen nitrogen

Interventions: intervention 1: B12-Folic Acid, nitrous oxide intervention 2: Nitrous oxide (NO) and placebo intervention 3: Placebo intervention 4: oxygen nitrogen
Intervention descriptions: intervention 1: IV vitamin B12 (cyanocobalamin) 1 mg, single administration over 30 min.

IV folic acid, 5 mg, single administration over 30 min.

Both diluted in 250 ml normal saline. intervention 2: 60% nitrous oxide anesthesia plus saline intervention 3: Saline intervention 4: 60% air and oxygen mix.

Protocol document: