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.
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.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
PREVENTION
Masking
QUADRUPLE
Enrollment
63
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.
60% nitrous oxide anesthesia plus saline
Saline
Barnes Jewish Hospital
St Louis, Missouri, United States
Change in Plasma Total Homocysteine Concentration (tHcy)
Difference between baseline (pre-operative) and peak postoperative (i.e., maximum of postoperative value obtained within 30 minutes after anesthesia end time and morning of post-operative day 1) tHcy concentration . Of note: there were no secondary outcomes.
Time frame: Immediately postoperatively and on postoperative day 1
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.
60% air and oxygen mix.