Perioperative Analgesia in EndometriosisENDONOLNCT06732050
Influence of Intraoperative Nociception Guided Analgesia on Perioperative Total Analgesic Requirement Endometriosis
A study testing nociception guided treatment in people with Perioperative Analgesia in Endometriosis, run by Prof Urs Zingg at 1 site in Switzerland.
Trial summary
Adequate analgesia in the perioperative setting is one of the most important pillars of anesthesiology. It is generally understood that poorly managed acute postoperative pain correlates with increased morbidity, prolonged recovery periods, extended opioid utilization, and serves as a predictor for chronic pain onset… Read more about this study
- Who is it for?
- Ages 18 years and older, women only
- Conditions the study is for
- Perioperative Analgesia in Endometriosis
- What is being tested?
- nociception guided treatment
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 125 participants
- Where
- 1 siteSwitzerland
- Study dates
- 6 Aug 2024to 5 Sep 2025
- Phase
- Interventional
- Are there results?
- None posted in the registry
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
- Women only
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Age ≥ 18 years
- Premenopausal females
- Undergoes any type of laparoscopic surgery for suspected endometriosis or adenomyosis (diagnostic/therapeutic and/or hysterectomy)
Who cannot join
- Age < 18 years
- Patients with contraindications for opioids and/or ketamine/clonidine (standard medications)
- Pregnant or breastfeeding women
- 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
- Patients with conditions precluding the use of the NOL® sensor, such as neuromuscular deficits affecting hand function
- Regular consumption of opioids (Mankoski Score ≥6)
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Influence of Intraoperative Nociception Guided Analgesia on Perioperative Analgesia Consumption in Patients Undergoing Laparoscopic Resection of Endometriosis
Adequate analgesia in the perioperative setting is one of the most important pillars of anesthesiology. It is generally understood that poorly managed acute postoperative pain correlates with increased morbidity, prolonged recovery periods, extended opioid utilization, and serves as a predictor for chronic pain onset . On the other hand, the overuse of opioid-based analgesics during surgery may evoke respiratory depression, constipation, nausea, sedation, and opioid-induced hyperalgesia . Thus far, the lack of an objective intraoperative pain monitor has constrained anesthesia practitioners to rely on the interpretation of physiological cues such as tachycardia, hypertonia, and lacrimation as surrogate markers of pain (3). Variability in the educational background and clinical experience among providers may predispose to either excessive or inadequate administration of analgesics, consequently allowing for unfavorable postoperative outcomes. However, recent advancements have introduced novel devices for nociception measurement. Thus, a quantifiable assessment of nociception has become feasible. The most widely approved device is the Nociception Level (NOL®) index developed by Medasense in Israel. This index operates by discerning various sympathetic responses of the body to nociceptive stimuli and has been thoroughly tested on opioid-based analgesic regimens. The NOL® index uses a multiparametric approach including a random forest algorithm to measure the balance between sympathetic and parasympathetic system activity. Recently, a strong correlation has been reported between the response of the NOL® index and analgesia during surgery.
Patients being scheduled for endometriosis surgery do have a significant history of chronic pain thus being more prone to postoperative complications and therefore will benefit the most from a tailored analgesic regimen.
Read the detailed description
Adequate analgesia in the perioperative setting is one of the most important pillars of anaesthesiology. It is generally understood that poorly managed acute postoperative pain correlates with increased morbidity, prolonged recovery periods, extended opioid utilization, and serves as a predictor for chronic pain onset. On the other hand, the overuse of opioid-based analgesics during surgery may evoke respiratory depression, constipation, nausea, sedation, and opioid-induced hyperalgesia. Thus far, the lack of an objective intraoperative pain monitor has constrained anaesthesia practitioners to rely on the interpretation of physiological cues such as tachycardia, hypertonia, and lacrimation as surrogate markers of pain. Variability in the educational background and clinical experience among providers may predispose to either excessive or inadequate administration of analgesics, consequently allowing for unfavorable postoperative outcomes. However, recent advancements have introduced novel devices for nociception measurement. Thus, a quantifiable assessment of nociception has become feasible. The most widely approved device is the Nociception Level (NOL®) index developed by Medasense in Israel. This index operates by discerning various sympathetic responses of the body to nociceptive stimuli and has been thoroughly tested on opioid-based analgesic regimens. The NOL® index uses a multiparametric approach including a random forest algorithm to measure the balance between sympathetic and parasympathetic system activity. Recently, a strong correlation has been reported between the response of the NOL® index and analgesia during surgery.
Patients being scheduled for endometriosis surgery do have a significant history of chronic pain thus being more prone to postoperative complications and therefore will benefit the most from a tailored analgesic regimen. Patients' existing analgesic regimen, typically comprising Paracetamol, NSAIDs, and Metamizol, will be carefully documented during preoperative anesthetic consultations and taken into account in the study protocols.
Preoperatively, patients will be staged by their gynecologists using the ENZIAN classification. The ENZIAN classification is a diagnostic system for endometriosis that covers various localizations and forms of the disease. It enables a standardized assessment for both non-invasive and invasive diagnostic procedures. The classification considers specific compartments and uses standardized coding for the severity and location of lesions. The classification is performed preoperatively using ultrasound diagnostics as well as intraoperatively and is annotated with the lower-case letters: (s)= Surgical, (u)= Ultrasound (Keckstein J, 2021). Thereby, a comprehensive picture of the disease is obtained. Deeply infiltrating endometriosis requires a more invasive procedure, a longer operating time and a higher consumption of analgesics.
- Conditions
- Perioperative Analgesia in Endometriosis
- Being tested
- nociception guided treatment
- Keywords
- endometriosis surgery, perioperative analgesia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
nociception guided treatmentDevice
For the nociception level-guided group the same standard narcosis will be applied whilst ensuring that the NOL® level value will be maintained between 10 and 25.
| Study group | Role | What they receive |
|---|---|---|
| Control group | No intervention | The control group will undergo standard treatment for laparoscopic endometriosis/adenomyosis surgery at Spital Limmattal. Although the control group will not be using NOL®-monitoring to guide analgesic requirement, the monitor will be installed with a blinded screen to investigate whether our multimodal anesthesia model is in coherence with values between 10 and 25. The anesthesia care team will not be able to see the values during surgery in order to tailor analgesic requirement only by conventional clinical judgement. |
| nociception guided treatment | Experimental | For the nociception level-guided group the same standard narcosis will be applied whilst ensuring that the NOL® level value will be maintained between 10 and 25. Receives: Device: nociception guided treatment |
What is being measured
The primary outcome is the main question the study is designed to answer.
Total analgestic requirement
Total analgesic requirement. Intra- and postoperative medication administration will be systematically documented throughout until two hours after arrival at the recovery room or until the patient has been discharged from the recovery room.
Measured: Start of anaesthesia until discharge from the recovery room (max. lenghth of stay in the recovery 2 hours)..
Secondary outcomes (3)
Postoperative Numeric Rating Scale (NRS) scores in PACU
Postoperative Numeric Rating Scale (NRS) scores. The NRS icludes values from 0 to 10 (indicating no pain at 0 and maximized pain at 10, which is a worse outcome). The NRS score will be assessed every 15 minutes starting with arrival at the recovery room until 2 hours after admission or until the patient has been discharged from the recovery room.
Measured: Start Start at arrival in the recovery room until discharge from the recovery room (max. lenghth of stay in the recovery 2 hours)
Total length of Stay in the PACU (min)
Measured: Start at arrival in the recovery room until discharge from the recovery room (max. lenghth of stay in the recovery 2 hours)
Postoperative Numeric Rating Scale (NRS) scores at discharge
Postoperative Numeric Rating Scale (NRS) scores at discharge (indicating no pain at 0 and maximized pain at 10, which is a worse outcome) will be assessed every 15 minutes starting with arrival at the recovery room until 2 hours after admission or until the patient has been discharged from the recovery room. One more NRS assessement will be made at discharge.
Measured: Immediately postoperatively until discharge (1-3 days).
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted13 Dec 2024
- Study start6 Aug 2024
- Primary completion5 Sep 2025
- Study completion5 Sep 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Perioperative Analgesia in EndometriosisStudies 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
- Single group
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 125 participants (actual)
Sponsor and investigators
- Lead sponsor
- Prof Urs Zingg
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor-investigator, Prof Urs Zingg, Spital Limmattal Schlieren
- Investigators
- Isabel Marcolino, Dr. med., Principal investigator, Spital STS AG
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06732050
- Sponsor's protocol ID
- 2024-00822
- Acronym
- ENDONOL
- Status last verified
- Apr 2026
- First submitted
- 21 Aug 2024
- Last updated
- 1 May 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 1 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Influence of Intraoperative Nociception Guided Analgesia on Perioperative Analgesia Consumption in Patients Undergoing Laparoscopic Resection of Endometriosis
- ClinicalTrials.gov ID
- NCT06732050
- Acronym / sponsor ID
- ENDONOL / 2024-00822
- Conditions
- Perioperative Analgesia in Endometriosis
- Keywords
- endometriosis surgery, perioperative analgesia
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 125 participants (actual)
- Lead sponsor
- Prof Urs ZinggUniversity, hospital or other
- Study start
- 6 Aug 2024 (actual)
- Primary completion
- 5 Sep 2025 (actual)
- Study completion
- 5 Sep 2025 (actual)
- First posted
- 13 Dec 2024 (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.
Adequate analgesia in the perioperative setting is one of the most important pillars of anesthesiology. It is generally understood that poorly managed acute postoperative pain correlates with increased morbidity, prolonged recovery periods, extended opioid utilization, and serves as a predictor for chronic pain onset . On the other hand, the overuse of opioid-based analgesics during surgery may evoke respiratory depression, constipation, nausea, sedation, and opioid-induced hyperalgesia . Thus far, the lack of an objective intraoperative pain monitor has constrained anesthesia practitioners to rely on the interpretation of physiological cues such as tachycardia, hypertonia, and lacrimation as surrogate markers of pain (3). Variability in the educational background and clinical experience among providers may predispose to either excessive or inadequate administration of analgesics, consequently allowing for unfavorable postoperative outcomes. However, recent advancements have introduced novel devices for nociception measurement. Thus, a quantifiable assessment of nociception has become feasible. The most widely approved device is the Nociception Level (NOL®) index developed by Medasense in Israel. This index operates by discerning various sympathetic responses of the body to nociceptive stimuli and has been thoroughly tested on opioid-based analgesic regimens. The NOL® index uses a multiparametric approach including a random forest algorithm to measure the balance between sympathetic and parasympathetic system activity. Recently, a strong correlation has been reported between the response of the NOL® index and analgesia during surgery.
Patients being scheduled for endometriosis surgery do have a significant history of chronic pain thus being more prone to postoperative complications and therefore will benefit the most from a tailored analgesic regimen.
Detailed description
Adequate analgesia in the perioperative setting is one of the most important pillars of anaesthesiology. It is generally understood that poorly managed acute postoperative pain correlates with increased morbidity, prolonged recovery periods, extended opioid utilization, and serves as a predictor for chronic pain onset. On the other hand, the overuse of opioid-based analgesics during surgery may evoke respiratory depression, constipation, nausea, sedation, and opioid-induced hyperalgesia. Thus far, the lack of an objective intraoperative pain monitor has constrained anaesthesia practitioners to rely on the interpretation of physiological cues such as tachycardia, hypertonia, and lacrimation as surrogate markers of pain. Variability in the educational background and clinical experience among providers may predispose to either excessive or inadequate administration of analgesics, consequently allowing for unfavorable postoperative outcomes. However, recent advancements have introduced novel devices for nociception measurement. Thus, a quantifiable assessment of nociception has become feasible. The most widely approved device is the Nociception Level (NOL®) index developed by Medasense in Israel. This index operates by discerning various sympathetic responses of the body to nociceptive stimuli and has been thoroughly tested on opioid-based analgesic regimens. The NOL® index uses a multiparametric approach including a random forest algorithm to measure the balance between sympathetic and parasympathetic system activity. Recently, a strong correlation has been reported between the response of the NOL® index and analgesia during surgery.
Patients being scheduled for endometriosis surgery do have a significant history of chronic pain thus being more prone to postoperative complications and therefore will benefit the most from a tailored analgesic regimen. Patients' existing analgesic regimen, typically comprising Paracetamol, NSAIDs, and Metamizol, will be carefully documented during preoperative anesthetic consultations and taken into account in the study protocols.
Preoperatively, patients will be staged by their gynecologists using the ENZIAN classification. The ENZIAN classification is a diagnostic system for endometriosis that covers various localizations and forms of the disease. It enables a standardized assessment for both non-invasive and invasive diagnostic procedures. The classification considers specific compartments and uses standardized coding for the severity and location of lesions. The classification is performed preoperatively using ultrasound diagnostics as well as intraoperatively and is annotated with the lower-case letters: (s)= Surgical, (u)= Ultrasound (Keckstein J, 2021). Thereby, a comprehensive picture of the disease is obtained. Deeply infiltrating endometriosis requires a more invasive procedure, a longer operating time and a higher consumption of analgesics.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Single group
- Masking
- Single blind (participant)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Control group | No intervention | –The control group will undergo standard treatment for laparoscopic endometriosis/adenomyosis surgery at Spital Limmattal. Although the control group will not be using NOL®-monitoring to guide analgesic requirement, the monitor will be installed with a blinded screen to investigate whether our multimodal anesthesia model is in coherence with values between 10 and 25. The anesthesia care team will not be able to see the values during surgery in order to tailor analgesic requirement only by conventional clinical judgement. |
| nociception guided treatment | Experimental | Device: nociception guided treatmentFor the nociception level-guided group the same standard narcosis will be applied whilst ensuring that the NOL® level value will be maintained between 10 and 25. |
Who may qualify
- Ages
- 18 years and older
- Sex
- Female only
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- Age ≥ 18 years
- Premenopausal females
- Undergoes any type of laparoscopic surgery for suspected endometriosis or adenomyosis (diagnostic/therapeutic and/or hysterectomy)
Key exclusion criteria (7 listed)
- Age < 18 years
- Patients with contraindications for opioids and/or ketamine/clonidine (standard medications)
- Pregnant or breastfeeding women
- 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
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 |
|---|---|---|
| nociception guided treatmentFor the nociception level-guided group the same standard narcosis will be applied whilst ensuring that the NOL® level value will be maintained between 10 and 25. | Device | nociception guided treatment |
Primary outcome
Total analgestic requirement
Time frame: Start of anaesthesia until discharge from the recovery room (max. lenghth of stay in the recovery 2 hours)..
Total analgesic requirement. Intra- and postoperative medication administration will be systematically documented throughout until two hours after arrival at the recovery room or until the patient has been discharged from the recovery room.
3 secondary outcomes
Postoperative Numeric Rating Scale (NRS) scores in PACU
Time frame: Start Start at arrival in the recovery room until discharge from the recovery room (max. lenghth of stay in the recovery 2 hours)
Total length of Stay in the PACU (min)
Time frame: Start at arrival in the recovery room until discharge from the recovery room (max. lenghth of stay in the recovery 2 hours)
Postoperative Numeric Rating Scale (NRS) scores at discharge
Time frame: Immediately postoperatively until discharge (1-3 days).
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 1 May 2026.
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. This study is not recruiting at the moment.
Isabel Marcolino, Dr. med. principal investigator
Spital STS AG
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing nociception guided treatment in people with Perioperative Analgesia in Endometriosis, run by Prof Urs Zingg at 1 site in Switzerland.
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 7 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: finished, as of the sponsor's last update on 1 May 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Switzerland. Whether a site is taking part right now should be confirmed with that site. See every site.
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?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Total analgestic requirement (time frame: Start of anaesthesia until discharge from the recovery room (max. lenghth of stay in the recovery 2 hours)..). 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 1 May 2026.