Homocysteine After Nitrous Oxide Anesthesia

June 1, 2007 updated by: Medical University of Vienna

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

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.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed 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<T mutation in the MTHFR gene (the most common mutation) have a higher risk of developing hyperhomocysteinemia after N2O anaesthesia.

Study Type

Interventional

Enrollment (Actual)

140

Phase

  • Phase 4

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Austria
      • Vienna, Austria, A-1090
        • Dept of Anesthesiology, Medical University of Vienna

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (ADULT, OLDER_ADULT)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

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 Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: BASIC_SCIENCE
  • Allocation: NA
  • Interventional Model: SINGLE_GROUP
  • Masking: NONE

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Homocysteine levels dependent on MTHFR genotype
Time Frame: 2 years
2 years

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Medical University of Vienna

Investigators

  • Principal Investigator: Peter Nagele, M.D., Medical University of Vienna

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

January 1, 2005

Study Completion (ACTUAL)

March 1, 2007

Study Registration Dates

First Submitted

June 1, 2007

First Submitted That Met QC Criteria

June 1, 2007

First Posted (ESTIMATE)

June 5, 2007

Study Record Updates

Last Update Posted (ESTIMATE)

June 5, 2007

Last Update Submitted That Met QC Criteria

June 1, 2007

Last Verified

May 1, 2007

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • EK 286/2004

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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