Chronic PainPhase 2PROTOXNCT00210158
Intraoperative Nitrous Oxide and Postoperative Pain for Patients With Current Opioid Treatment
A Phase 2 study testing Air and Protox in people with Chronic Pain, run by Institut Bergonié at 1 site in France.
Trial summary
Peroperative opioids are known to induce N-Methyl-D-Aspartate dependent enhancement of postoperative hyperalgesia. For patients with current opioid treatment, these phenomena could be exagerated and could produce greater postoperative opioid consumption and higher pain score. Read more about this study
- Who is it for?
- Ages 18 to 100 years
- Conditions the study is for
- Chronic Pain
- What is being tested?
- Air and Protox
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 39 participants
- Where
- 1 siteFrance
- Study dates
- 1 Jan 2005to 31 Dec 2006
- Phase
- Phase 2
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 100 years
- All sexes
- No healthy volunteers
- Adult, Older adult
- Older than 18 years
- Current opioid treatment > 1 month
- patients scheduled to undergo vertebroplasty with general anesthesia
Trial locations and contacts
1 site in 1 country.
France1 site
Institut Bergonié - Centre Régional de Luttre Contre le Cancer DE Bordeaux et du Sud Ouest
Bordeaux, 33076
About this study
Official title: Effects of Intraoperative Nitrous Oxide on Postoperative Pain for Patients With Current Opioid Treatment After Vertebroplasty.
Peroperative opioids are known to induce N-Methyl-D-Aspartate dependent enhancement of postoperative hyperalgesia. For patients with current opioid treatment, these phenomena could be exagerated and could produce greater postoperative opioid consumption and higher pain score. Since Nitrous oxide has anti- N-Methyl-D-Aspartate properties, the aim of this study was to evaluate, in patients with current opioid treatment, the effects of peroperative Nitous oxide on postoperative opioid consumption and pain score, after vertebroplasty.
- Conditions
- Chronic Pain
- Being tested
- Air, Protox
- Keywords
- Current opioid treatment, Nitrous oxide, Chronic pain, Opioid therapy, Postoperative hyperalgesia, Acute opioid tolerance
- Medical subject headings
- Chronic Pain
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
AirProcedure or surgery
Patients undergo long-term morphine treatment and vertebral cementoplasty. During the procedure, patients are ventilated with a mixture of air and oxygen.
ProtoxProcedure or surgery
Patients undergo long-term morphine treatment and vertebral cementoplasty. During the procedure, patients are ventilated with a mixture of oxygen and nitrous oxide.
| Study group | Role | What they receive |
|---|---|---|
| Air arm (Reference) | Sham comparator | Patients undergo long-term morphine treatment and vertebral cementoplasty. During the procedure, patients are ventilated with a mixture of air and oxygen. Receives: Procedure: Air |
| Protox Arm (Experimental) | Experimental | Patients undergo long-term morphine treatment and vertebral cementoplasty. During the procedure, patients are ventilated with a mixture of oxygen and nitrous oxide. Receives: Procedure: Protox |
What is being measured
The primary outcome is the main question the study is designed to answer.
Post-operative Morphine Consumption
Morphine consumption (mg) during PCA (Patient Controlled Analgesia)
Measured: Between surgery and up to 48 hours
Secondary outcomes (1)
Proportion of Participants With Post-operative Pain
Pain is measured using a visual analog scale (VAS), ranging from 0 (no pain) to 100 (worst pain ever).
A participant is considered to have pain if VAS score is >= 40.
Measured: Between surgery and up to 48 hours
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted21 Sep 2005 (estimated)
- Study start1 Jan 2005
- Primary completion31 Dec 2006
- Study completion31 Dec 2006
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Other trials for Chronic PainStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 2
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind
- Who is masked
- Participant, Care provider, Investigator
- Enrolment
- 39 participants (actual)
Sponsor and investigators
- Lead sponsor
- Institut Bergonié
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Fabrice Lakdja, MD, Principal investigator, Institut Bergonié
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT00210158
- Sponsor's protocol ID
- IB2005-05
- Acronym
- PROTOX
- Status last verified
- Aug 2025
- First submitted
- 12 Sep 2005
- Last updated
- 9 Sep 2025
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 9 Sep 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effects of Intraoperative Nitrous Oxide on Postoperative Pain for Patients With Current Opioid Treatment After Vertebroplasty.
- ClinicalTrials.gov ID
- NCT00210158
- Acronym / sponsor ID
- PROTOX / IB2005-05
- Conditions
- Chronic Pain
- Keywords
- Current opioid treatment, Nitrous oxide, Chronic pain, Opioid therapy, Postoperative hyperalgesia, Acute opioid tolerance
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 39 participants (actual)
- Lead sponsor
- Institut BergoniéUniversity, hospital or other
- Study start
- 1 Jan 2005 (actual)
- Primary completion
- 31 Dec 2006 (actual)
- Study completion
- 31 Dec 2006 (actual)
- First posted
- 21 Sep 2005 (estimated)
- Results
- Posted 9 Sep 2025
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Peroperative opioids are known to induce N-Methyl-D-Aspartate dependent enhancement of postoperative hyperalgesia. For patients with current opioid treatment, these phenomena could be exagerated and could produce greater postoperative opioid consumption and higher pain score. Since Nitrous oxide has anti- N-Methyl-D-Aspartate properties, the aim of this study was to evaluate, in patients with current opioid treatment, the effects of peroperative Nitous oxide on postoperative opioid consumption and pain score, after vertebroplasty.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind (participant, care provider, investigator)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Air arm (Reference) | Sham comparator | Procedure: AirPatients undergo long-term morphine treatment and vertebral cementoplasty. During the procedure, patients are ventilated with a mixture of air and oxygen. |
| Protox Arm (Experimental) | Experimental | Procedure: ProtoxPatients undergo long-term morphine treatment and vertebral cementoplasty. During the procedure, patients are ventilated with a mixture of oxygen and nitrous oxide. |
Who may qualify
- Ages
- 18 to 100 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| AirPatients undergo long-term morphine treatment and vertebral cementoplasty. During the procedure, patients are ventilated with a mixture of air and oxygen. | Procedure or surgery | Air arm (Reference) |
| ProtoxPatients undergo long-term morphine treatment and vertebral cementoplasty. During the procedure, patients are ventilated with a mixture of oxygen and nitrous oxide. | Procedure or surgery | Protox Arm (Experimental) |
Primary outcome
Post-operative Morphine Consumption
Time frame: Between surgery and up to 48 hours
Morphine consumption (mg) during PCA (Patient Controlled Analgesia)
1 secondary outcome
Proportion of Participants With Post-operative Pain
Time frame: Between surgery and up to 48 hours
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 9 Sep 2025.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Fabrice Lakdja, MD principal investigator
Institut Bergonié
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing Air and Protox in people with Chronic Pain, run by Institut Bergonié at 1 site in France.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 9 Sep 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in France. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
Yes. Results are posted in the registry (first posted 9 Sep 2025). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Post-operative Morphine Consumption (time frame: Between surgery and up to 48 hours). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 9 Sep 2025.