Effects of an Opioid Free/Sparing Care Pathway for Patients Undergoing Obesity Surgery

The opioid consumption has exploded in the western world, and for some patient populations such as obese patients, patients with sleep apnoea or patients undergoing cancer treatment, opioid-sparing/ opioid-free strategies could have positive effects on outcomes. Studies suggest that opioids could have opioid-induced immunosuppression, induce chronic post-operative pain syndrome and hyperalgesia in addition to the more well-known side effects such as respiratory depression, nausea, bladder, and bowel dysfunction. Hence, new studies are needed on the impact of person-centered care programs that combine pharmaceutical and non-pharmaceutical strategies to reduce the adverse short and long-term effects of opioid therapy.

The overall aim is to evaluate the short-, medium- and long-term effects of opioid-free care pathways with or without person-centred care compared to conventional opioid-based treatment in patients undergoing obesity surgery.

Specific aims

1. Determine the effects of opioid-free care with or without person-centred care compared with conventional opioid-based general anaesthesia on the cognitive and physical quality of recovery after surgery up to 24 months after surgery (short-term: postoperative to discharge, medium-term: 14 days, 3 months, long-term: 6 months, 12 months and 24 months).
2. Describe the clinical monitoring trend regarding nociceptive response intraoperatively between opioid-free and conventional care.
3. Map the impact of opioid-free anaesthesia (with and without person-centred care) on the usage of opioids up to 24 months after hospital discharge.
4. Explore the patients' experience of quality of life, self-efficacy and recovery after surgery in opioid-free care with or without person-centred care during the first year post-surgery.

The aims will be evaluated by a prospective, randomized, non-blinded, non-commercial multi-centre study (Nov 2018-Dec 2022) approved by the Swedish Medicines Agency (EudraCT 2017003830-97) and the ethical review board (DNR 1006-17).

Aim To evaluate the effects of opioid sparing care pathways compared to conventional opioid-based treatment for pain relief, opioid consumption, recovery after surgery, self-efficacy and health economy in patients undergoing obesity surgery. The aim will be investigated by a prospective, randomized, non-blinded, non-commercial multi-centre study(Nov 2018-Dec 2022), approved by the Swedish Medicines Agency (EudraCT 2017003830-97) and the ethical review board (DNR 1006-17).

Hypothesis

1. An opioid-free care pathway provides non-inferior pain relief as the conventional care with opioids during the post-operative phase.

Primary endpoints: Determine the quality of recovery after surgery

1. No difference in pain (NRS pain (0-10)) between opioid-free intervention with or without (Phase 1 \& 2) person-centred care and conventional treatment (control group) during the postoperative phase until discharge to the surgical ward.
2. An opioid-free intervention with or without (Phases 1 \& 2) person-centred care improves recovery after surgery measured with the PostopQRS compared with conventional postoperative therapy, during hospitalisation and afterwards .

   Explorative endpoints
3. Describe the intraoperative nociception level between opioid-free anaesthesia and conventional anaesthesia using the Medasense PMD-200 (NOL) monitor.
4. Map the long-term prescription of opioids and analgesic drugs between the intervention group and the control group.
5. Explore the patients' experiences with opioid-free intervention with or without person-centred care with conventional care regarding:

   1. self-efficacy measured with the General Self-Efficacy Scale (three months, six months, 12 months, 24 months).
   2. quality of life measured with the RAND-36 and EQ5D (three months, six months, 12 months, 24 months)
   3. patient experience and satisfaction, measured with the PostopQRS and interviews (two weeks, three months, 12 months)

Power Pain: To determine noninferiority with a power of 0.8 (i.e., the probability of \> 0.8 for the lower limit of a two-sided 95% confidence interval (using Fisher's nonparametric permutation test)), the difference of change in pain using the NRS from arrival to the recovery unit after surgery to discharge from the recovery unit will be used. Forty-three patients are required in each group and phase, with an SD for the change in the NRS estimated to be 1.62 from a small pilot study (noninferiority margin -1.0). The estimated change was assumed to be equal in the groups. To compensate for a potential interruption in the study or dropouts, we chose to include 55 patients in Intervention Phase 1, 55 patients in Intervention Phase 2 and a total of 110 patients in the control group (to follow intervention Phases 1 and 2, each 55 patients).

Recovery after surgery: To detect an overall difference in the quality of recovery between groups over the entire study length, with a power of 0.8 and P \< 0.05 and taking into consideration a dropout of over 30% as seen in other studies using the PQRS, we need to include at least 30 patients in each group 26.

The control group will receive usual care and treatment according to the hospital's routines, where pain relief is obtained with opioids postoperatively. Pharmacological treatment in the intervention group differs solely from the patients in the usual group by replacing opioids with the following nonopioid perioperative treatment: dexmedetomidine, esketamine, lidocaine and TENS (for exact dosing, please visit ClinicalTrials.gov identifier: NCT03756961). Postoperative patient-controlled pain treatment with high-intensity/high-frequency TENS is used if the patient perceives pain over NRS ≧ 3 postoperatively and during remaining hospitalisation.

Intervention Phase 1 tests the pharmacological and non-pharmacological interventions (TENS) compared to the control group that receives standard care with opioids intra- and postoperatively. Phase 2 intervention that follows after completion of Phase 1 intervention tests the pharmacological and nonpharmacological interventions compared to conventional treatment, supplemented by an evidenced-based PCC approach throughout the continuum of postoperative care.

The two phases will primarily be analysed separately (i.e., between the control group and intervention Phase 1 and between the control group and intervention Phase 2).

Eligibility Criteria:
Inclusion Criteria:

-Patients ≥18 years planned to undergo laparoscopic obesity surgery (GBP alt Sleeve surgery) at the selected site.

Exclusion Criteria:

* ASA\> III
* Cardiovascular disease with bradycardia (\<50 bpm)
* Serious liver disease failure
* Insufficient knowledge of the Swedish language
* Serious untreated psychiatric disease
* Neurocognitive dysfunction
* Pregnancy
* Women of childbearing age without contraception
* Malignant disease with expected short survival
* Patients treated with opioids for chronic pain
* Substance abuse
* Hypersensitivity to Oxycodone, Esketamine, Dexmedetomidine, and Lidocaine
* Pacemaker or ICD
* Inability to fill in questionnaires
* Decline participation,