Trial Outcomes & Findings for Nitrous Oxide for the Treatment of Complex Regional Pain Syndrome (NCT NCT03879538)

NCT ID: NCT03879538

Last Updated: 2024-02-09

Results Overview

scales ranging from 0 - "no pain" to 10 - "worst pain ever" based on the PROMIS-29 v2.0 questionnaire.

Recruitment status

COMPLETED

Study phase

PHASE3

Target enrollment

44 participants

Primary outcome timeframe

one-week and one-month follow-up time points

Results posted on

2024-02-09

Participant Flow

Participant milestones

Participant milestones
Measure	The Nitrous Oxide Group Nitrous oxide group will receive 50% nitrous oxide mixed with 50% oxygen, inhalation therapy for a duration of 2 hours via an FDA-approved mask breathing circuit. Nitrous Oxide: A total of three inhalation treatments with 50% Nitrous Oxide plus 50% oxygen (6 total exposure hours) over one week with 2 or 3 days between each session.	The Control Group Control group will receive 100% oxygen, inhalation therapy for a duration of 2 hours via an FDA-approved mask breathing circuit. Oxygen: A total of three inhalation treatments with 100% oxygen (6 total exposure hours) over one week with 2 or 3 days between each session.
Overall Study STARTED	20	24
Overall Study COMPLETED	20	24
Overall Study NOT COMPLETED	0	0

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

Nitrous Oxide for the Treatment of Complex Regional Pain Syndrome

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	The Nitrous Oxide Group n=20 Participants Nitrous oxide group will receive 50% nitrous oxide mixed with 50% oxygen, inhalation therapy for a duration of 2 hours via an FDA-approved mask breathing circuit. Nitrous Oxide: A total of three inhalation treatments with 50% Nitrous Oxide plus 50% oxygen (6 total exposure hours) over one week with 2 or 3 days between each session.	The Control Group n=24 Participants Control group will receive 50% oxygen, inhalation therapy for a duration of 2 hours via an FDA-approved mask breathing circuit. Oxygen: A total of three inhalation treatments with 50% oxygen (6 total exposure hours) over one week with 2 or 3 days between each session.	Total n=44 Participants Total of all reporting groups
Age, Continuous	44.4 years STANDARD_DEVIATION 12.3 • n=5 Participants	46.3 years STANDARD_DEVIATION 13.4 • n=7 Participants	45.4 years STANDARD_DEVIATION 12.8 • n=5 Participants
Sex: Female, Male Female	16 Participants n=5 Participants	22 Participants n=7 Participants	38 Participants n=5 Participants
Sex: Female, Male Male	4 Participants n=5 Participants	2 Participants n=7 Participants	6 Participants n=5 Participants
Race/Ethnicity, Customized Race · White/Caucasian	20 Participants n=5 Participants	21 Participants n=7 Participants	41 Participants n=5 Participants
Race/Ethnicity, Customized Race · Black/African American	0 Participants n=5 Participants	1 Participants n=7 Participants	1 Participants n=5 Participants
Race/Ethnicity, Customized Race · Hispanic/Latino	0 Participants n=5 Participants	1 Participants n=7 Participants	1 Participants n=5 Participants
Race/Ethnicity, Customized Race · Multicultural	0 Participants n=5 Participants	1 Participants n=7 Participants	1 Participants n=5 Participants
Duration of disease	53.5 months n=5 Participants	108.0 months n=7 Participants	89.5 months n=5 Participants
Spinal cord stimulators used	5 Participants n=5 Participants	7 Participants n=7 Participants	12 Participants n=5 Participants
Extremity affected Single location	8 Participants n=5 Participants	5 Participants n=7 Participants	13 Participants n=5 Participants
Extremity affected Multiple locations	12 Participants n=5 Participants	19 Participants n=7 Participants	31 Participants n=5 Participants
Pain score at baseline	7.3 units on a scale STANDARD_DEVIATION 1.7 • n=5 Participants	6.8 units on a scale STANDARD_DEVIATION 1.5 • n=7 Participants	7.0 units on a scale STANDARD_DEVIATION 1.6 • n=5 Participants

PRIMARY outcome

Timeframe: one-week and one-month follow-up time points

Population: A few patients had missing primary outcome measurements. The Mean (SD) values presented here was based on available raw data. In our formal analysis of treatment effect on primary outcome, we used multiple imputation procedures to impute missing primary outcome values.

scales ranging from 0 - "no pain" to 10 - "worst pain ever" based on the PROMIS-29 v2.0 questionnaire.

Outcome measures

Outcome measures
Measure	The Nitrous Oxide Group n=20 Participants Nitrous oxide group will receive 50% nitrous oxide mixed with 50% oxygen, inhalation therapy for a duration of 2 hours via an FDA-approved mask breathing circuit. Nitrous Oxide: A total of three inhalation treatments with 50% Nitrous Oxide plus 50% oxygen (6 total exposure hours) over one week with 2 or 3 days between each session.	The Control Group n=24 Participants Control group will receive 100% oxygen, inhalation therapy for a duration of 2 hours via an FDA-approved mask breathing circuit. Oxygen: A total of three inhalation treatments with 100% oxygen (6 total exposure hours) over one week with 2 or 3 days between each session.
Pain Score one-week follow-up	5.9 score on a scale Standard Deviation 1.5	6.0 score on a scale Standard Deviation 2.5
Pain Score one-month follow-up	6.5 score on a scale Standard Deviation 2.0	6.8 score on a scale Standard Deviation 2.2

SECONDARY outcome

Timeframe: one-week and one-month follow-ups after treatments were ended

Population: A few patients had missing values due to withdrawal from the study or failure of follow-up contact.

As intermediate scores, T-scores for each of the 7 domains used in the survey need to be estimated from raw data in order to obtain final summary Z-scores measuring physical and mental health. T-scores were obtained from an on-line service provided by the HealthMeasures Scoring Service (https://www.assessmentcenter.net/ac\_scoringservice). Physical and mental summary Z-scores were calculated using the formulas given in the document titled "Calculating physical and mental health summary scores for PROMIS-29 v2.0 and v2.1" (dated on August 8, 2018) by Karen L. Spritzer and Ron D. Hays from the website HealthMeasures.net. High T-scores indicates more of the concept being measured which can be either desirable or undesirable outcome, e.g., high T-score on fatigue is undesirable whereas desirable for physical function. Z-scores are standard scores with mean of 0 and SD of 1 in reference population. High Z-scores are desirable for either physical or mental health.

Outcome measures

Outcome measures
Measure	The Nitrous Oxide Group n=20 Participants Nitrous oxide group will receive 50% nitrous oxide mixed with 50% oxygen, inhalation therapy for a duration of 2 hours via an FDA-approved mask breathing circuit. Nitrous Oxide: A total of three inhalation treatments with 50% Nitrous Oxide plus 50% oxygen (6 total exposure hours) over one week with 2 or 3 days between each session.	The Control Group n=24 Participants Control group will receive 100% oxygen, inhalation therapy for a duration of 2 hours via an FDA-approved mask breathing circuit. Oxygen: A total of three inhalation treatments with 100% oxygen (6 total exposure hours) over one week with 2 or 3 days between each session.
PROMIS-29 Survey Physical Health Z-score, Mental Health Z-score Physical health Z-score at one-week follow-up	-1.4 z-score Standard Deviation 0.71	-1.4 z-score Standard Deviation 0.78
PROMIS-29 Survey Physical Health Z-score, Mental Health Z-score Physical health Z-score at one-month follow-up	-1.4 z-score Standard Deviation 0.58	-1.5 z-score Standard Deviation 0.68
PROMIS-29 Survey Physical Health Z-score, Mental Health Z-score Mental health Z-score at one-week follow-up	-1.01 z-score Standard Deviation 0.81	-0.91 z-score Standard Deviation 1.00
PROMIS-29 Survey Physical Health Z-score, Mental Health Z-score Mental health Z-score at one-month follow-up	-1.2 z-score Standard Deviation 0.88	-1.1 z-score Standard Deviation 0.91

SECONDARY outcome

Timeframe: one-week and one-month follow-ups.

Population: A few patients had missing values due to withdrawal from the study or study participants can not be reached for follow-up with phone calls.

patient disease perception as measured by the Patient's Global Impression of Change (PGIC) survey (a seven-point scale ranging from 1 - "no change or condition has gotten worse" to 7 - "very much improve").

Outcome measures

Outcome measures
Measure	The Nitrous Oxide Group n=20 Participants Nitrous oxide group will receive 50% nitrous oxide mixed with 50% oxygen, inhalation therapy for a duration of 2 hours via an FDA-approved mask breathing circuit. Nitrous Oxide: A total of three inhalation treatments with 50% Nitrous Oxide plus 50% oxygen (6 total exposure hours) over one week with 2 or 3 days between each session.	The Control Group n=24 Participants Control group will receive 100% oxygen, inhalation therapy for a duration of 2 hours via an FDA-approved mask breathing circuit. Oxygen: A total of three inhalation treatments with 100% oxygen (6 total exposure hours) over one week with 2 or 3 days between each session.
PGIC Scale PGIC scale at one-week follow-up	2 score on a scale Interval 1.0 to 5.0	4 score on a scale Interval 1.0 to 5.0
PGIC Scale PGIC scale at one-month follow-up	2 score on a scale Interval 1.0 to 4.0	2 score on a scale Interval 1.0 to 5.0

Adverse Events

The Nitrous Oxide Group

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

The Control Group

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Adverse event data not reported

Additional Information

Alparslan Turan

Cleveland Clinic

Phone: 2162172312

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place