Phase 3
N=44
Nitrous Oxide for the Treatment of Complex Regional Pain Syndrome
Complex Regional Pain Syndrome
Bottom Line
View on ClinicalTrials.gov: NCT03879538 ↗Enrolled (actual)
44
Serious AEs
0.0%
Results posted
Feb 2024
Primary outcome: Primary: Pain Score — 5.9; 6.0; 6.5; 6.8 score on a scale — p=0.19
Study Design & Population
- Study type
- Interventional
- Phase
- Phase 3
- Interventions
- Nitrous Oxide (Drug); Oxygen (Drug)
- Age
- Adult, Older Adult · 18+ yrs
- Sex
- All
- Sponsor
- The Cleveland Clinic
- Primary completion
- Jul 2022
Outcome Measures
| Outcome | Result | p-value |
|---|---|---|
| PRIMARY Pain Score |
5.9; 6.0; 6.5; 6.8 | 0.19 |
| SECONDARY PROMIS-29 Survey Physical Health Z-score, Mental Health Z-score |
-1.4; -1.4; -1.4; -1.5; -1.01; -0.91 | 0.36 |
| SECONDARY PGIC Scale |
2; 4; 2; 2 | 0.23 |
Summary
Patients will then be randomized via a web-based randomization system Redcap Allocation will be stratified based on the presence of a pre-existing spinal cord stimulator to either the nitrous oxide study group or the oxygen control group.
The nitrous oxide group will receive 50% nitrous oxide mixed with 50% oxygen, and the control group will receive 50% oxygen (oxygen plus air mixture). Both groups will undergo inhalation therapy for a duration of 2 hours via an FDA-approved mask breathing circuit. Vital signs (blood pressure, respiratory rate, heart rate) will be monitored every 30 minutes. Pulse oximetry monitoring will be continuous. Patients will be monitored for side effects including nausea, vomiting, desaturation, sedation, respiratory depression, and dizziness. Patients and other involved providers will be blinded to the treatment type.
Eligibility Criteria
Inclusion Criteria
- Patients must be diagnosed with CRPS based on the revised International Association for the Study of Pain criteria.
- Duration of disease must be at least 6 months.
- Written informed consent.
Exclusion Criteria
- Patients who had no subjective benefit from ketamine infusions, as determined by interview during the recruitment process.
- Patients taking more than 60mg of morphine equivalents or more daily for an alternative chronic pain condition.
- Patients with both coronary artery disease (as determined by cardiac catheterization) and a functional status of less than 4 metabolic equivalents. The limited functional status must be secondary to cardiopulmonary symptoms (angina, dyspnea on exertion). Patients with coronary artery disease and a limited functional status (<4 METS) secondary to chronic pain can be included.
- Patients with congestive heart failure of any etiology that are NYHA Class III or IV
- Patients with moderate or severe pulmonary hypertension as determined by echocardiogram or right heart catheterization.
- Patients with intraocular surgery within the past 14 days
- Patients with worker's compensation claims and active litigation.
- Patients who have been diagnosed with COPD.
- Patients who use home oxygen therapy for any condition.
- Diagnosis of Alcohol Use Disorder as defined by the Diagnostic and Statistical Manual of Mental Disorders (DSM-5).
- Illicit drug use within the past three months (not including marijuana).
- Pregnant patients or patients with upcoming planned pregnancy.
Data sourced from ClinicalTrials.gov (NCT03879538). Outcome figures and adverse-event rates are extracted automatically from the registry's posted results and are provided for clinician reference, not as a substitute for the primary publication.