Open-Label Placebo Treatment for Acute Postoperative Pain

Open-Label Placebo Treatment for Acute Postoperative Pain: A Randomized Controlled Trial (OLP-POP Study)

This study is to evaluate whether the amount of morphine intake in acute postoperative pain following minimally invasive Transforaminal Lumbar Interbody Fusion (TLIF) can be decreased with an Open-Label Placebo (OLP) intervention (comprising the administration of sodium chloride (NaCl) injections and an evidence-based treatment rationale) in comparison to a "Treatment As Usual" (TAU) control group.

Inclusion Criteria:

• Signed Informed Consent
• Scheduled to receive a TLIF procedure at University Hospital Basel (USB)
• 18 years or older
• German speaking
• Able to understand the study and its outcome measures

Exclusion Criteria:

• Known chronic pain, which is unrelated to problem targeted by the surgery
• Known neuromuscular disease
• Known mental disorders
• Known drug or massive alcohol intake or of other psychoactive substances
• Known kidney or liver disease (glomerular filtration rate (GFR)/ GFR < 30)
• Contraindications to the class of drugs under investigation, e.g., known hypersensitivity or allergy to the investigational product
• Parallel participation in another study with investigational drugs
• More than 30 mg/day (equivalent dose of oral morphine) preoperative opioid consumption