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Trial details imported from ClinicalTrials.gov

For full trial details, please see the original record at https://clinicaltrials.gov/study/NCT00164047




Registration number
NCT00164047
Ethics application status
Date submitted
13/09/2005
Date registered
14/09/2005
Date last updated
31/07/2009

Titles & IDs
Public title
ENIGMA - Evaluation of Nitrous Oxide In the Gas Mixture for Anaesthesia: a Randomised Controlled Trial
Scientific title
Evaluation of Nitrous Oxide In the Gas Mixture for Anaesthesia: a Randomised Controlled Trial
Secondary ID [1] 0 0
NHMRC 236956
Secondary ID [2] 0 0
204/02
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Quality of Recovery From Anaesthesia 0 0
Effects of Nitrous Oxide Following Anaesthesia 0 0
Induced Endothelial Dysfunction 0 0
Condition category
Condition code

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Comparator / control treatment
Control group

Outcomes
Primary outcome [1] 0 0
The primary endpoint is hospital length of stay (LOS), defined from the start of surgery until actual hospital discharge. Patients transferred to another hospital will be tracked until final discharge to home (or other final destination). LOS is likely
Timepoint [1] 0 0
Secondary outcome [1] 0 0
Secondary endpoints will be detected by a research assistant who will be masked to Group identity, using chart review up to 30 days postoperatively; confirmation of each will be sought by an independent member of the Endpoint Committee:
Timepoint [1] 0 0
Secondary outcome [2] 0 0
Wound infection - if associated with purulent discharge or a positive microbial culture (46)
Timepoint [2] 0 0
Secondary outcome [3] 0 0
Myocardial infarction - confirmed by ECG and/or troponin or CK-MB enzyme rise
Timepoint [3] 0 0
Secondary outcome [4] 0 0
Venous thromboembolism - symptomatic DVT or PE, confirmed by venography, duplex ultrasonography, V-Q scan or spiral CT, or autopsy
Timepoint [4] 0 0
Secondary outcome [5] 0 0
Stroke - a new neurological deficit persisting for 24 hours, confirmed by neurologist assessment and/or CT scan or MRI
Timepoint [5] 0 0
Secondary outcome [6] 0 0
Awareness - postoperative recollection of intraoperative events
Timepoint [6] 0 0
Secondary outcome [7] 0 0
Blood transfusion - any red cell transfusion within 30 days of surgery
Timepoint [7] 0 0
Secondary outcome [8] 0 0
Pneumothorax, atelectasis, or pneumonia - confirmed by chest x-ray; for pneumonia: also 2 or more of temp> 38oC, white cell count >12,000/ml, positive sputum culture
Timepoint [8] 0 0
Secondary outcome [9] 0 0
Severe vomiting - at least 2 episodes >6 hrs apart, or if requiring >2 doses of antiemetic medication
Timepoint [9] 0 0
Secondary outcome [10] 0 0
Quality of recovery on the morning after surgery -using the validated QoR Score instrument (14), a 9-item patient-orientated measure of early postoperative health status. This is associated with patient satisfaction.
Timepoint [10] 0 0
Secondary outcome [11] 0 0
30-day mortality - for safety analysis only (study not powered for this rare event).
Timepoint [11] 0 0

Eligibility
Key inclusion criteria
1. Males and females, age 18 years and over
2. Planned general anaesthesia for surgery that includes a skin incision and expected to exceed two hours, and the patient is expected to be in hospital for at least three days
Minimum age
18 Years
Maximum age
No limit
Sex
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
1. Endoscopic or radiological procedures
2. Cardiac surgery
3. Marked impairment of gas-exchange (requiring Fi02> 0.3)
4. Thoracic surgery requiring one-lung ventilation (requiring Fi02> 0.3)
5. Specific circumstances where N2O is contraindicated (eg. volvulus, pulmonary hypertension, raised intracranial pressure)
6. Lack of provision of N2O.

Study design
Purpose of the study
Prevention
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?



Intervention assignment
Parallel
Other design features
Phase
Phase 4
Type of endpoint/s
Statistical methods / analysis

Recruitment
Recruitment status
Completed
Data analysis
Reason for early stopping/withdrawal
Other reasons
Date of first participant enrolment
Anticipated
Actual
1/04/2003
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
1/12/2004
Sample size
Target
2070
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)
VIC
Recruitment hospital [1] 0 0
Alfred Hospital - Melbourne
Recruitment postcode(s) [1] 0 0
3004 - Melbourne

Funding & Sponsors
Primary sponsor type
Government body
Name
Bayside Health
Address
Country
Other collaborator category [1] 0 0
Other
Name [1] 0 0
National Health and Medical Research Council, Australia
Address [1] 0 0
Country [1] 0 0
Other collaborator category [2] 0 0
Government body
Name [2] 0 0
Australia: Theapeutic Goods Administration
Address [2] 0 0
Country [2] 0 0

Ethics approval
Ethics application status

Summary
Brief summary
We aim to investigate the effectiveness and safety of nitrous oxide (N2O) in anaesthesia.

Hypothesis In patients undergoing anaesthesia for major surgery, avoidance of N2O will reduce hospital length of stay when compared with otherwise identically managed surgical patients receiving N2O as a component of their anaesthesia.
Trial website
https://clinicaltrials.gov/study/NCT00164047
Trial related presentations / publications
Myles PS, Leslie K, Silbert B, Paech MJ, Peyton P. A review of the risks and benefits of nitrous oxide in current anaesthetic practice. Anaesth Intensive Care. 2004 Apr;32(2):165-72. doi: 10.1177/0310057X0403200202. No abstract available.
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.
Leslie K, Myles PS, Chan MT, Paech MJ, Peyton P, Forbes A, McKenzie D; ENIGMA Trial Group. Risk factors for severe postoperative nausea and vomiting in a randomized trial of nitrous oxide-based vs nitrous oxide-free anaesthesia. Br J Anaesth. 2008 Oct;101(4):498-505. doi: 10.1093/bja/aen230. Epub 2008 Aug 5.
Public notes

Contacts
Principal investigator
Name 0 0
Paul S Myles, MB BS MPH MD
Address 0 0
The Alfred
Country 0 0
Phone 0 0
Fax 0 0
Email 0 0
Contact person for public queries
Name 0 0
Address 0 0
Country 0 0
Phone 0 0
Fax 0 0
Email 0 0
Contact person for scientific queries



Summary Results

For IPD and results data, please see https://clinicaltrials.gov/study/NCT00164047