AnesthesiaOFANOLNCT07917299
Comparison of Intensive and Conservative NOL®-Guided Analgesia Strategies During Opioid-free Anesthesia
A study testing Study Intervention in people with Anesthesia and Bariatric Surgery (Gastric Bypass), run by Prof Urs Zingg.
Trial summary
Participants will be randomized to one of two predefined NOL®-guided analgesia strategies during bariatric surgery performed under OFA. In both groups the NOL® index will be continuously monitored intraoperatively and dexmedetomidine will be administered according to the assigned study algorithm based on the NOL®… Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Anesthesia, Bariatric Surgery (Gastric Bypass)
- What is being tested?
- Study Intervention
- Type of treatment
- Injection or infusion, Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 400 participants
- Where
- No sites listed yet
- Study dates
- 1 Nov 2026to 1 Oct 2027
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Signed informed consent
- Age ≥ 18 years
- bariatric surgery (sleeve/bypass/Re-Do)
Who cannot join
- Patients with contraindications for dexmedetomidine or lidocaine
- Lack of ability to follow the study procedure, e.g. due to severe language barriers, mental disorders, dementia - Patients requiring preoperative or postoperative treatment in the intensive care unit (ICU) (excluding Obstructive sleep apnea syndrome (OSAS))
- Patients with conditions precluding the use of the NOL® sensor, such as neuromuscular deficits affecting hand function
- BMI <25 kg/m2
Trial locations and contacts
No sites are listed yet. Contact the study team or a site near you to ask about taking part.
About this study
Official title: Comparison of Intensive and Conservative NOL®-Guided Analgesia Strategies During Opioid-free Anesthesia for Bariatric Surgery: A Prospective Randomized Controlled Trial
Participants will be randomized to one of two predefined NOL®-guided analgesia strategies during bariatric surgery performed under OFA. In both groups the NOL® index will be continuously monitored intraoperatively and dexmedetomidine will be administered according to the assigned study algorithm based on the NOL® index using lean body weight (LBW) for dosing.
Read the detailed description
The study aims to evaluate whether different intraoperative target ranges of the NOL® index during bariatric surgery performed under OFA are associated with differences in postoperative analgesic consumption and postoperative pain control without significant differences in intraoperative hemodynamics. Based on the physiological mechanisms outlined above, we hypothesize that during OFA with alpha-2 agonists such as dexmedetomidine, intensified NOL® target ranges (potentially 0-10) may be appropriate compared to the established range of 10-25 for opioid based TIVA. If this hypothesis is confirmed, clinical implications would include the need to establish OFA-specific NOL® target ranges to avoid under-treatment of nociception when applying TIVA-derived thresholds to OFA patients. Conversely, using inappropriately high NOL® targets derived from opioid-based anesthesia might lead to inadequate pain control and to excessive administration of analgesics postoperatively.
- Conditions
- Anesthesia, Bariatric Surgery (Gastric Bypass)
- Being tested
- Study Intervention, Control Intervention
- Keywords
- NOL®-guided analgesia, opioid-free anesthesia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Study InterventionProcedure or surgery
Induction: An initial dexmedetomidine bolus of 0.3ug/kg LBW will be administered, followed by a continuous infusion of 0.3 ug/kg LBW/h.
Control InterventionProcedure or surgery
Induction: An initial dexmedetomidine bolus of 0.3ug/kg LBW will be administered, followed by a continuous infusion of 0.1 ug/kg LBW/h.
| Study group | Role | What they receive |
|---|---|---|
| Intensive NOL®-guided strategy | Active comparator | Induction: An initial dexmedetomidine bolus of 0.3ug/kg LBW will be administered, followed by a continuous infusion of 0.3 ug/kg LBW/h. Receives: Procedure: Study Intervention |
| Conservative NOL®-guided strategy | Experimental | Induction: An initial dexmedetomidine bolus of 0.3ug/kg LBW will be administered, followed by a continuous infusion of 0.1 ug/kg LBW/h. Receives: Procedure: Control Intervention |
What is being measured
The primary outcome is the main question the study is designed to answer.
Postoperative pain intensity Measured by the numeric rating scale (NRS) in the Post-anesthesia care unit (PACU)
To evaluate whether an intensive NOL®-guided analgesia strategy reduces postoperative pain intensity in the post-anesthesia care unit (PACU) compared to a conservative NOL®-guided analgesia strategy in patients undergoing bariatric surgery under OFA.
Measured: At the Date of Surgery + 1 day after at Post-anesthesia care unit (PACU): two assessments within 2 consequent days
Postoperative pain intensity Measured by the Behavioral Pain Scale (BPS) in the Post-anesthesia care unit (PACU)
To evaluate whether an intensive NOL®-guided analgesia strategy reduces postoperative pain intensity in the post-anesthesia care unit (PACU) compared to a conservative NOL®-guided analgesia strategy in patients undergoing bariatric surgery under OFA.
Measured: At the Date of Surgery + 1 day after at Post-anesthesia care unit (PACU): two assessments within 2 consequent days
Secondary outcomes (8)
Difference between postoperative pain intensity measurement using the Behavioral Pain Scale (BPS) (outcome 1) and numeric rating scale (NRS) (outcome 2) in the Post-anesthesia care unit (PACU)
Difference between the outcome 1 and outcome 2
Measured: At the Date of Surgery + 1 day after at Post-anesthesia care unit (PACU): two assessments within 2 consequent days
Total opioid consumption in the Post-anesthesia care unit (PACU)
Morphin (mg), Oxynorm (mg), Oxycodon/Naloxon (mg)
Measured: At the Date of Surgery + 1 day after at Post-anesthesia care unit (PACU): two assessments within 2 consequent days
- Total non-opioid analgesic consumption in the Post-anesthesia care unit (PACU)
Paracetamol (mg), Metamizol (mg), Ketamin (mg)
Measured: At the Date of Surgery + 1 day after at Post-anesthesia care unit (PACU): two assessments within 2 consequent days
- Total non-opioid analgesic consumption in the Post-anesthesia care unit (PACU)
Lidocain-P (mg/kgLBW/h)
Measured: At the Date of Surgery + 1 day after at Post-anesthesia care unit (PACU): two assessments within 2 consequent days
- Total non-opioid analgesic consumption in the Post-anesthesia care unit (PACU)
Ketamin-Perfusor (mg/h)
Measured: At the Date of Surgery + 1 day after at Post-anesthesia care unit (PACU): two assessments within 2 consequent days
- Incidence of Postoperative nausea and vomiting (PONV)
The proportion of patients who experience at least one episode of postoperative nausea, retching, or vomiting, or who require the administration of any antiemetic rescue medication (such as Ondansetron, Metoclopramide, Domperidone, or Itinerol).
Measured: At the Date of Surgery + 1 day after at Post-anesthesia care unit (PACU): two assessments within 2 consequent days
- Richmond Agitation-Sedation Scale (RASS) scores during Post-anesthesia care unit (PACU) stay
Measured: At the Date of Surgery + 1 day after at Post-anesthesia care unit (PACU): two assessments within 2 consequent days
- Quality of Recovery-15 (QoR-15) score on postoperative day 1
Measured: At the Date of Surgery + 1 day after at Post-anesthesia care unit (PACU): two assessments within 2 consequent days
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted4 Nov 2026
- Study start1 Nov 2026 (estimated)
- Primary completion1 Oct 2027 (estimated)
- Study completion1 Oct 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for AnesthesiaStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Intensive NOL®-guided strategy (Corresponding to the Standard Procedure at Spital Limmattal): Induction: An initial dexmedetomidine bolus of 0.3ug/kg LBW will be administered, followed by a continuous infusion of 0.3 ug/kg LBW/h. Conservative NOL®-guided strategy corresponding to the recommended NOL® index for opioid-based anesthesia: Induction: An initial dexmedetomidine bolus of 0.3ug/kg LBW will be administered, followed by a continuous infusion of 0.1 ug/kg LBW/h.
- Masking
- None (open label)
- Enrolment
- 400 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Prof Urs Zingg
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor-investigator, Prof Urs Zingg, Spital Limmattal Schlieren
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07917299
- Sponsor's protocol ID
- 2026-01332
- Acronym
- OFANOL
- Status last verified
- Nov 2026
- First submitted
- 5 Oct 2026
- Last updated
- 4 Nov 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 4 Nov 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Comparison of Intensive and Conservative NOL®-Guided Analgesia Strategies During Opioid-free Anesthesia for Bariatric Surgery: A Prospective Randomized Controlled Trial
- ClinicalTrials.gov ID
- NCT07917299
- Acronym / sponsor ID
- OFANOL / 2026-01332
- Conditions
- Anesthesia, Bariatric Surgery (Gastric Bypass)
- Keywords
- NOL®-guided analgesia, opioid-free anesthesia
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 400 participants (estimated)
- Lead sponsor
- Prof Urs ZinggUniversity, hospital or other
- Study start
- 1 Nov 2026 (estimated)
- Primary completion
- 1 Oct 2027 (estimated)
- Study completion
- 1 Oct 2027 (estimated)
- First posted
- 4 Nov 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Participants will be randomized to one of two predefined NOL®-guided analgesia strategies during bariatric surgery performed under OFA. In both groups the NOL® index will be continuously monitored intraoperatively and dexmedetomidine will be administered according to the assigned study algorithm based on the NOL® index using lean body weight (LBW) for dosing.
Detailed description
The study aims to evaluate whether different intraoperative target ranges of the NOL® index during bariatric surgery performed under OFA are associated with differences in postoperative analgesic consumption and postoperative pain control without significant differences in intraoperative hemodynamics. Based on the physiological mechanisms outlined above, we hypothesize that during OFA with alpha-2 agonists such as dexmedetomidine, intensified NOL® target ranges (potentially 0-10) may be appropriate compared to the established range of 10-25 for opioid based TIVA. If this hypothesis is confirmed, clinical implications would include the need to establish OFA-specific NOL® target ranges to avoid under-treatment of nociception when applying TIVA-derived thresholds to OFA patients. Conversely, using inappropriately high NOL® targets derived from opioid-based anesthesia might lead to inadequate pain control and to excessive administration of analgesics postoperatively.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
- Model description
- Intensive NOL®-guided strategy (Corresponding to the Standard Procedure at Spital Limmattal): Induction: An initial dexmedetomidine bolus of 0.3ug/kg LBW will be administered, followed by a continuous infusion of 0.3 ug/kg LBW/h. Conservative NOL®-guided strategy corresponding to the recommended NOL® index for opioid-based anesthesia: Induction: An initial dexmedetomidine bolus of 0.3ug/kg LBW will be administered, followed by a continuous infusion of 0.1 ug/kg LBW/h.
| Arm | Type | Receives |
|---|---|---|
| Intensive NOL®-guided strategy | Active comparator | Procedure: Study InterventionInduction: An initial dexmedetomidine bolus of 0.3ug/kg LBW will be administered, followed by a continuous infusion of 0.3 ug/kg LBW/h. |
| Conservative NOL®-guided strategy | Experimental | Procedure: Control InterventionInduction: An initial dexmedetomidine bolus of 0.3ug/kg LBW will be administered, followed by a continuous infusion of 0.1 ug/kg LBW/h. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- Signed informed consent
- Age ≥ 18 years
- bariatric surgery (sleeve/bypass/Re-Do)
Key exclusion criteria (4 listed)
- Patients with contraindications for dexmedetomidine or lidocaine
- Lack of ability to follow the study procedure, e.g. due to severe language barriers, mental disorders, dementia - Patients requiring preoperative or postoperative treatment in the intensive care unit (ICU) (excluding Obstructive sleep apnea syndrome (OSAS))
- Patients with conditions precluding the use of the NOL® sensor, such as neuromuscular deficits affecting hand function
- BMI <25 kg/m2
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Study InterventionInduction: An initial dexmedetomidine bolus of 0.3ug/kg LBW will be administered, followed by a continuous infusion of 0.3 ug/kg LBW/h. | Procedure or surgery | Intensive NOL®-guided strategy |
| Control InterventionInduction: An initial dexmedetomidine bolus of 0.3ug/kg LBW will be administered, followed by a continuous infusion of 0.1 ug/kg LBW/h. | Procedure or surgery | Conservative NOL®-guided strategy |
Primary outcome
Postoperative pain intensity Measured by the numeric rating scale (NRS) in the Post-anesthesia care unit (PACU)
Time frame: At the Date of Surgery + 1 day after at Post-anesthesia care unit (PACU): two assessments within 2 consequent days
To evaluate whether an intensive NOL®-guided analgesia strategy reduces postoperative pain intensity in the post-anesthesia care unit (PACU) compared to a conservative NOL®-guided analgesia strategy in patients undergoing bariatric surgery under OFA.
Postoperative pain intensity Measured by the Behavioral Pain Scale (BPS) in the Post-anesthesia care unit (PACU)
Time frame: At the Date of Surgery + 1 day after at Post-anesthesia care unit (PACU): two assessments within 2 consequent days
To evaluate whether an intensive NOL®-guided analgesia strategy reduces postoperative pain intensity in the post-anesthesia care unit (PACU) compared to a conservative NOL®-guided analgesia strategy in patients undergoing bariatric surgery under OFA.
8 secondary outcomes
Difference between postoperative pain intensity measurement using the Behavioral Pain Scale (BPS) (outcome 1) and numeric rating scale (NRS) (outcome 2) in the Post-anesthesia care unit (PACU)
Time frame: At the Date of Surgery + 1 day after at Post-anesthesia care unit (PACU): two assessments within 2 consequent days
Total opioid consumption in the Post-anesthesia care unit (PACU)
Time frame: At the Date of Surgery + 1 day after at Post-anesthesia care unit (PACU): two assessments within 2 consequent days
- Total non-opioid analgesic consumption in the Post-anesthesia care unit (PACU)
Time frame: At the Date of Surgery + 1 day after at Post-anesthesia care unit (PACU): two assessments within 2 consequent days
- Total non-opioid analgesic consumption in the Post-anesthesia care unit (PACU)
Time frame: At the Date of Surgery + 1 day after at Post-anesthesia care unit (PACU): two assessments within 2 consequent days
- Total non-opioid analgesic consumption in the Post-anesthesia care unit (PACU)
Time frame: At the Date of Surgery + 1 day after at Post-anesthesia care unit (PACU): two assessments within 2 consequent days
- Incidence of Postoperative nausea and vomiting (PONV)
Time frame: At the Date of Surgery + 1 day after at Post-anesthesia care unit (PACU): two assessments within 2 consequent days
- Richmond Agitation-Sedation Scale (RASS) scores during Post-anesthesia care unit (PACU) stay
Time frame: At the Date of Surgery + 1 day after at Post-anesthesia care unit (PACU): two assessments within 2 consequent days
- Quality of Recovery-15 (QoR-15) score on postoperative day 1
Time frame: At the Date of Surgery + 1 day after at Post-anesthesia care unit (PACU): two assessments within 2 consequent days
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 4 Nov 2026.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Questions about this trial
What is this clinical trial studying?
A study testing Study Intervention in people with Anesthesia and Bariatric Surgery (Gastric Bypass), run by Prof Urs Zingg.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 4 Nov 2026. Status can change between updates, so confirm with the study contact before making plans.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Isabel Marcolino, Dr. med. (+41 44 733 2891, isabel.marcolino@spital-limmattal.ch), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Postoperative pain intensity Measured by the numeric rating scale (NRS) in the Post-anesthesia care unit (PACU) (time frame: At the Date of Surgery + 1 day after at Post-anesthesia care unit (PACU): two assessments within 2 consequent days). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 4 Nov 2026.