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NCT00212147 · ClinicalTrials.gov registry record · NA
Interaction of Cobalamin Status With Nitrous Oxide in Relation to Postoperative Cognitive Changes in the Elderly
A NA study, sponsored by National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK).
- Completed
- Registry status
- NA
- Development phase
- 444
- Enrollment target
NCT00212147: Completed NA study, sponsored by National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK).
NCT00212147 is a NA study that has completed, run by National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). The registered enrollment target is 444 participants, below the 1,404-participant average among 58,714 other NA trials with a reported enrollment target (68% lower). According to ClinicalTrials.gov, the official US trial registry.
The verdict
NCT00212147, a NA study, has completed, sponsored by National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK).
- COMPLETED
- Registry status
- NA
- Development phase
- 444 participants
- Enrollment target
Study Summary
Low cobalamin (vitamin B12) levels are frequent in the elderly. Most often they reflect a mild metabolic abnormality without clinical symptoms (subclinical cobalamin deficiency). It is unclear if these elderly people require medical intervention, unlike that small minority with clinical symptoms which can progress and create severe blood or nervous system problems. The study aims to determine if nitrous oxide (N2O), a common anesthetic agent, worsens cobalamin status in elderly patients with unrecognized subclinical cobalamin deficiency. The reason for concern is that N2O inactivates cobalamin and can aggravate the clinical picture of patients who already have clinical manifestations of cobalamin deficiency. The elderly are known to have an increased risk of developing mental changes after surgery and it may be that sometimes these result from aggravation of subclinical cobalamin deficiency. The study recruits people over the age of 60 years who are undergoing clinically indicated elective surgery requiring general anesthesia for more than 1 hour. Patients meeting exclusion and inclusion criteria are randomized to receive either a standard anesthetic regimen that includes N2O or a nearly identical one without N2O. Before surgery and 2 weeks and 4 weeks after surgery, each patient undergoes (1) a broad battery of tests of cognition and mood and (2) blood tests measuring cobalamin, folate and homocysteine-methionine metabolism to determine whether they have any subtle biochemical impairment of cobalamin status. DNA from blood cells is also tested for the presence of common mutations that affect key enzymes in those metabolic pathways. A brief testing for postoperative delirium is also done 2 hours after surgery. The patient subgroups' are analyzed for neuropsychologic changes over time, using the preoperative test as the baseline for all comparisons, and associations of those changes with metabolic, genetic, demographic and clinical data. The primary question is wh
Interventions
- DRUG General anesthesia with nitrous oxide
- DRUG General anesthesia without nitrous oxide
Trial Details
| Field | Value |
|---|---|
| Enrollment Target | 444 participants |
| Start Date | 2003-09 |
| Est. Completion | 2008-08 |
| Phase | NA |
What the finished NCT00212147 record still lists
NCT00212147 is an interventional study that assigns participants to a tested intervention. The registered 444 participants enrollment target is mid-sized for trials with a published cap, below the 1,404-participant average among 58,714 other NA trials with a reported enrollment target (68% lower).
The record links to 0 conditions, and to 2 interventions - of which General anesthesia with nitrous oxide is the first listed.
NCT00212147 does not publish any study locations in the registry export this page uses.
Frequently Asked Questions
What is clinical trial NCT00212147 about?
NCT00212147 is a clinical study titled "Interaction of Cobalamin Status With Nitrous Oxide in Relation to Postoperative Cognitive Changes in the Elderly". Low cobalamin (vitamin B12) levels are frequent in the elderly. Most often they reflect a mild metabolic abnormality without clinical symptoms (subclinical cobalamin deficiency). It is unclear if these elderly people require medical intervention, unlike that small minority with clinical symptoms whi...
What is the current status of trial NCT00212147?
This trial is currently completed. It is a NA study. The enrollment target is 444 participants. The study started on 2003-09. Estimated completion is 2008-08.
What interventions are being tested in trial NCT00212147?
The interventions under investigation include: General anesthesia with nitrous oxide (DRUG), General anesthesia without nitrous oxide (DRUG).
Who is sponsoring clinical trial NCT00212147?
This trial is sponsored by National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), which has 490 total clinical trials registered on ClinicalTrials.gov.
Learn More About Clinical Trials
How this trial's enrollment target compares
Where NCT00212147's enrollment target sits among peer trials
444 233rd of 2000 higher than 1,768 of 2,000 other NA trials
participants (enrollment target), bucketed by value
Each bar is a band; taller bars hold more other NA trials. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count and share, and where it sits relative to this entry.
Source ClinicalTrials.gov registry export · 2026-08-08
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