Conditioned Open Label Placebo for Postoperative Pain Management

Study Overview
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Brief Summary
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The primary objective is to evaluate the efficacy of two Conditioned Open Label Placebos (COLP): COLP pill and COLP odor to reduce opioid intake for postoperative (thoracic and spinal surgery) pain management compared to the opioid only usual treatment (TAU).

Detailed Description
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Patients, eligible for an elective thoracic or spinal surgery, will be randomized into either standard of care, COLP_pill or COLP_odor. Patients in COLP groups will be asked to pair each opioid intake with an open label placebo intake (either a pill or an inhalation) for postoperative (POD) day 0 to 17. From POD 2, patients in the intervention arms will be additionally asked to take OLP alone 3 times a day. Patients will have unrestricted access to pain killers. Patients will daily assess opioid intake, pain intensity, side effects, mobility and sense of agency using a e-dairy.

Official Title
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A Randomized Controlled Trial Evaluating the Efficacy of Conditioned Open Label Placebo (COLP) to Limit Opioid Reliance for Postoperative Pain Management

Conditions
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Pain, Postoperative

Intervention / Treatment
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* Behavioral: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Spinal or thoracic elective surgery for the indications mentioned above Able to give informed consent Interested in trying COLP as complementary pain management therapy Able to fill a e-diary at home Exclusion Criteria: Cognitive impairment (MOCA score <26) Inability to engage in the intervention of the study e.g. inability to communicate in French without a translator, severe hearing impairment without any hearing aid available at the time of intervention, anosmia or intolerance to eugenol. Acute psychiatric (e.g. psychotic or suicidal ideation) or somatic (e.g. unstable cardio-respiratory condition) co-morbidity preventing full engagement during intervention Opioid use disorder (toxicomania) or contraindication to pain management using opioids (allergy, refusal, ...) Intolerance to placebo ingredients

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Efficacy of conditioned open label placebo pill<br>On postoperative day 0, participant will self-administer one OLP with all opioid analgesics (whether administered intravenously or orally). This pairing will be done from postoperative day 0 to postoperative day 17. Starting on postoperative day 2, participants take 3 scheduled placebo doses (pills or inhalation) every day, at 3 convenient times. In parallel, the OLP pairing to standard and rescue doses of opioids will continue. The patients are told to continue taking both scheduled standalone COLP and paired COLP (if needed) until postoperative day 17. | Behavioral: Placebo<br>* Participant take 1 dose placebo (odor or pill) on post-op day 0 (POD 0) and 3 placebo dose from POD 2 to POD 17<br>|
| Experimental: Efficacy of conditioned open label placebo odor<br>1 drops of clove oil (i.e. eugenol) will be disposed on a cotton and inserted into a stick. The patients will be asked to actively smell them by sniffing using a stick of inhalation. On postoperative day 0, participant will self-administer one OLP with all opioid analgesics (whether administered intravenously or orally). This pairing will be done from postoperative day 0 to postoperative day 17. On postoperative day 2, participants take 3 scheduled placebo doses (pills or inhalation) every day, at 3 convenient times. In parallel, the OLP pairing to standard and rescue doses of opioids will continue. The patients are told to continue taking both scheduled standalone COLP and paired COLP (if needed) until postoperative day 17 | Behavioral: Placebo<br>* Participant take 1 dose placebo (odor or pill) on post-op day 0 (POD 0) and 3 placebo dose from POD 2 to POD 17<br>|
| Active Comparator: Standard of care<br>Usual postoperative pain management, relying mainly on opioids | Behavioral: Placebo<br>* Participant take 1 dose placebo (odor or pill) on post-op day 0 (POD 0) and 3 placebo dose from POD 2 to POD 17<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Opioids consumption | Cumulative opioids intake as postoperative consumption (in MgMeq) | 17 days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Time to Opioid withdrawal (in days) | Time to Opioid withdrawal calculated for COLP compared to treatment as usual | until the 6 months follow-up | 
| Postoperative pain intensity | Daily Visual Analog Score from the e-diary (score from 0 to 10, 10=worst pain) | 17 days | 
| Satisfaction with postoperative management | Daily Visual Analog Score from the e-diary (score from 0 to 10, 10=highest satisfaction) | 17 days | 
| Mobility | Daily Visual Analog Score from the e-diary (score from 0 to 10, 10=best ability to move) | 17 days | 
| Sense of agency | Daily Visual Analog Score from the e-diary (score from 0 to 10, 10=best sense of agency) | 17 days | 
| Side effects intensity | Daily Visual Analog Score from the e-diary (score from 0 to 10, 10=worst intensity) | 17 days |