Homocysteine After Nitrous Oxide Anesthesia

Anesthesia, General Clinical Trial

Official title:

Influence of the MTHFR 677C>T Mutation on Homocysteine Levels After Nitrous Oxide Anesthesia.

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT00482456
• Other study ID #: EK 286/2004
• Status: Completed
• Phase: Phase 4
• First received: June 1, 2007
• Last updated: June 1, 2007
• Start date: January 2005
• Est. completion date: March 2007

Study information

• Verified date: May 2007
• Source: Medical University of Vienna
• Contact: n/a
• Is FDA regulated: No
• Health authority: Austria: Agency for Health and Food Safety
• Study type: Interventional

Clinical Trial Summary

Our study looks at the interaction of a common mutation in the MTHFR gene and the risk of developing higher homocysteine levels after nitrous oxide (N2O) anesthesia.

Specifically, we want to test the hypothesis that healthy patients carrying the MTHFR 677C>T haplotype develop abnormal homocysteine levels after nitrous oxide anesthesia.

Description:

Nitrous oxide – laughing gas – is a widely used anaesthetic gas with many favourable but also some dangerous properties. Among the latter is the increase in homocysteine levels after nitrous oxide (N2O) exposure by inhibition of enzymes in the vitamin B12 pathway. Elevated homocysteine levels have been found to be an independent risk factor for ischemic events and are associated with an increased risk for perioperative myocardial ischemia. If a patient carries one or more loss-of-function mutations in enzymes of the methionine/homocysteine/folate pathway he is at an increased risk for hyperhomocysteinemia and if exposed to N2O might suffer severe, sometimes disastrous neurological damage. Recently, a case report in the New England Journal of Medicine reported the death of a child with an enzyme defect in the MTHFR gene after anaesthesia with nitrous oxide (NEJM 2003;349:45-50).

Thus, we are convinced that if we can determine the risk of patients who carry mutations in the MTHFR gene and undergo anaesthesia with N2O for developing pathological levels of homocysteine, we can add an important piece of information to the safety profile of N2O.

Our study tests the hypothesis that patients who carry the 677C

Recruitment information / eligibility

• Status: Completed
• Enrollment: 140
• Est. completion date: March 2007
• Accepts healthy volunteers: No
• Gender: Both
• Age group: 18 Years and older

Eligibility

Inclusion Criteria:

• Patient scheduled for general anaesthesia (> 2 hours)

• Age > 18 years

• ASA status I-II

Exclusion Criteria:

• Pregnancy

• Age < 18 years

• contraindication against N2O: pneumothorax, mechanical bowel obstruction, middle ear occlusion, laparoscopic surgery

• recent use of vitamin preps (B12, B6, folate)

Study Design

Endpoint Classification: Pharmacodynamics Study, Intervention Model: Single Group Assignment, Masking: Open Label, Primary Purpose: Basic Science

Related Conditions & MeSH terms

• Adverse Effects
• Anesthesia, General
• Nitrous Oxide

Intervention

Drug:
• Nitrous oxide

Locations

Country	Name	City	State
Austria	Dept of Anesthesiology, Medical University of Vienna	Vienna

Sponsors (1)

Lead Sponsor	Collaborator
Medical University of Vienna

Country where clinical trial is conducted

Austria, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Homocysteine levels dependent on MTHFR genotype		2 years