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Completed

NCT Number: NCT00210158

Intraoperative Nitrous Oxide and Postoperative Pain for Patients With Current Opioid Treatment

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.

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Key information

Conditions

Chronic Pain Neurologic Manifestations Pain Pathological Conditions, Signs and Symptoms Signs and Symptoms

Age range

18 year–100 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 2

Primary location

Institut Bergonié - Centre Régional de Luttre Contre le Cancer DE Bordeaux et du Sud Ouest

Bordeaux, 33076, France

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

  • Older than 18 years
  • Current opioid treatment > 1 month
  • patients scheduled to undergo vertebroplasty with general anesthesia

Treatment and study plan

air

Procedure

Patients undergo long-term morphine treatment and vertebral cementoplasty. During the procedure, patients are ventilated with a mixture of air and oxygen.

Protox

Procedure

Patients undergo long-term morphine treatment and vertebral cementoplasty. During the procedure, patients are ventilated with a mixture of oxygen and nitrous oxide.

Primary outcomes

  1. Post-operative Morphine Consumption

    Time frame: Between surgery and up to 48 hours

    Morphine consumption (mg) during PCA (Patient Controlled Analgesia)

Secondary outcomes

  1. Proportion of Participants With Post-operative Pain

    Time frame: Between surgery and up to 48 hours

    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.

Sponsors and collaborators

Lead sponsor

Institut Bergonié

Other

Registry information

Official study title

Effects of Intraoperative Nitrous Oxide on Postoperative Pain for Patients With Current Opioid Treatment After Vertebroplasty.

Acronym: PROTOX

Important dates

Study start
2005
Primary completion
2006
Study completion
2006
First posted
Sep 21, 2005
Registry last updated
Sep 9, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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