International Substudy Enigma2 on Postoperative Cognitive Disorders
NCT ID: NCT02489097
Last Updated: 2020-12-16
Study Results
The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.
Basic Information
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TERMINATED
PHASE4
140 participants
INTERVENTIONAL
2013-09-30
2016-05-31
Brief Summary
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Substudy Hypothesis: In patients undergoing anaesthesia for major surgery, administration of N2O will reduce postoperative cognitive disorders when compared with otherwise identically managed surgical patients not receiving N2O as a component of their anaesthesia.
Detailed Description
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There is strong evidence that N2O is a major risk factor for postoperative nausea and vomiting. It is clear that (even) brief exposure to N2O impairs methionine synthetase, an enzyme required for DNA production, red and white blood cell formation. Tissue hypoxia may be more common. These adverse effects are enhanced in "sick" patients (ie. those at highest risk, with increased hospital length of stay and healthcare expenditure), and will be more likely in longer surgery. At the same time, observational studies and subgroup analysis of published trials suggest that N2O may have beneficial effects in preventing pain and postoperative cognitive disorders
Outcome trial data on postoperative cognitive disorders are lacking in this area for an anaesthetic gas used in more than 90% of all surgery around the world. The enigma2 substudy as a nested study of the large Enigma2 randomised controlled trial aims at answering this question.
The investigators aim at recruiting 420 patients in 2 of the 25 centres participating to the Enigma 2 trials, who are undergoing major surgery.
Conditions
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Study Design
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RANDOMIZED
PARALLEL
TREATMENT
TRIPLE
Study Groups
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Nitrous Oxide
Receives a mixture of 70% Nitrous Oxide in 30% Oxygen
Nitrous Oxide
Administration of a concentration of 70% Nitrous Oxide with 30% Oxygen in the anaesthetic gas mixture
Air/Oxygen (placebo)
Receives a mixture of 70% Air in 30% Oxygen
Placebo
Administration of a concentration of 70% Air with 30% Oxygen in the anaesthetic gas mixture
Interventions
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Nitrous Oxide
Administration of a concentration of 70% Nitrous Oxide with 30% Oxygen in the anaesthetic gas mixture
Placebo
Administration of a concentration of 70% Air with 30% Oxygen in the anaesthetic gas mixture
Other Intervention Names
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Eligibility Criteria
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Inclusion Criteria
At increased risk of cardiac events, defined as any of:
* history of coronary artery disease (angina, MI, Coronary revascularisation-Coronary Artery Bypass Graft (CABG) and Percutaneous Transluminal Coronary Angiography ( PTCA)-, positive stress testing, angiography/other imaging, Q waves on ECG)
* heart failure
* cerebrovascular disease due to atherothrombotic disease
* aortic or peripheral vascular disease
OR
three or more of the following risk factors: age ≥70 years, history of heart failure, diabetes (medicated), hypertension (medicated), preoperative serum creatinine \>175 mmol/L, cholesterol ≥6.2 mmol/L, history of a transient ischemic attack (TIA),
Exclusion Criteria
2. Parkinson Disease
3. Patients taking regularly (\>2 weeks) tricyclic antidepressants or neuroleptics
4. Patients suffering from Alcohol Dependency (WHO CRITERIA )
5. Patients suffering from severe hypoacusis or visual loss or any other reason hindering the CANTAB battery testing process
6. Patients with untreated deficit in Vitamin B6, B12 and folic acid
7. Patients with marked impairment of gas-exchange requiring Fi02\> 0.5 intraoperatively
8. Patients with specific circumstances where N2O is contraindicated (eg. volvulus, pulmonary hypertension, raised intracranial pressure) or the use of supplemental oxygen is planned (eg. colorectal surgery)
9. N2O unavailable
18 Years
ALL
No
Sponsors
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Prince of Wales Hospital, Shatin, Hong Kong
OTHER
Chinese University of Hong Kong
OTHER
University Hospital, Geneva
OTHER
Responsible Party
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Dr Guy Haller
Staff Anaesthetist
Principal Investigators
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Myles Paul, MD, FANZCA
Role: STUDY_CHAIR
Bayside Health
Locations
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The Chinese University of Hong Kong Prince of Wales Hospital
Hong Kong, Hong Kong, China
Geneva University Hospitals
Geneva, , Switzerland
Countries
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References
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Chan MTV, Wan ACM, Gin T, Leslie K, Myles PS. Chronic postsurgical pain after nitrous oxide anesthesia. Pain. 2011 Nov;152(11):2514-2520. doi: 10.1016/j.pain.2011.07.015. Epub 2011 Sep 1.
Sanders RD, Weimann J, Maze M. Biologic effects of nitrous oxide: a mechanistic and toxicologic review. Anesthesiology. 2008 Oct;109(4):707-22. doi: 10.1097/ALN.0b013e3181870a17.
Myles PS, Leslie K, Chan MT, Forbes A, Paech MJ, Peyton P, Silbert BS, Pascoe E; ENIGMA Trial Group. Avoidance of nitrous oxide for patients undergoing major surgery: a randomized controlled trial. Anesthesiology. 2007 Aug;107(2):221-31. doi: 10.1097/01.anes.0000270723.30772.da.
Other Identifiers
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Enigma II nested NCT00430989
Identifier Type: OTHER
Identifier Source: secondary_id
NAC 08-021
Identifier Type: -
Identifier Source: org_study_id