Influence of Nociception Level Monitor (NOL) Guided Analgesic Delivery on Robot-assisted Colorectal Surgery

May 11, 2026 updated by: University of Southern Denmark

Influence of Nociception Level Monitor (NOL) Guided Analgesic Delivery on the Perioperative Course, Quality of Recovery and Hospital Stay in Robot-assisted Colorectal Surgery

Being relatively new, the NOL monitor may offer interesting observations in perioperative nociception levels and appropriate analgesic consumption in diverse surgeries, including robot-assisted surgery. These observations may supplement the current efforts towards further advantages in rapid restitution. Therefore, the investigators planned a trial where intra-operative analgesics were guided using an NOL monitor to study if intra-operative NOL guidance influences peri-operative analgesic consumption, postoperative length of stay and quality of recovery of patients subjected for robot-assisted surgery.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

During anesthesia for surgical procedures, anesthetic and muscle relaxant drugs can be meticulously administered using Bispectral Index (BIS) and neuromuscular monitors. However, analgesic drugs are still dispensed using poor surrogate parameters such as heart rate and blood pressure. This subjective dosing of analgesic drugs may invariably lead to inappropriate intra-operative consumption. This may result in tachycardia, hypertension, and postoperative pain due to e.g. insufficient analgesia, or hypotension, bradycardia, respiratory depression and Post-Operative Nausea and Vomiting (PONV) secondary to excessive analgesia. These effects may be detrimental to the patients especially those with multiple comorbidities with limited vital organ reserves such as patients classified to III or IV by the American Society of Anaesthesia classification (ASA) Similarly, immediate postoperative recovery may also get delayed due to pain, unstable hemodynamics, nausea and vomiting. In that context, there has long been search for a monitor which can guide meticulous administration of analgesics. Recently, a Nociception Level monitor (NOL) based on advanced software algorithms using multiple physiological parameters has been developed. It offers an objective score (NOL Index) which relates to the level of intra-operative pain. NOL technology has been validated and found superior to existing pain indicators in peer-reviewed publications. The NOL monitor may offer interesting observations in perioperative nociception levels and appropriate analgesic consumption in diverse surgeries, including robot-assisted surgery. These observations may supplement the current efforts towards further advantages in rapid restitution. Therefore, the investigators are planning a trial where intra-operative analgesics are guided using an NOL monitor.

Study Type

Interventional

Enrollment (Estimated)

60

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 80 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • American Society of Anaesthesiologists score III-IV
  • Scheduled for elective major robot-assisted colorectal surgeries

Exclusion Criteria:

  • Inability to give informed consent
  • planned spinal or epidural anaesthesia
  • all forms of regional anaesthesia, including wound infiltration
  • nonelective procedures
  • pregnancy or lactation
  • atrial fibrillation

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Placebo Comparator: Standard Clinical Care Group
Hemodynamic changes outside of the normal range i.e., hypertension (systolic blood pressure greater than 140 mm Hg), tachycardia (heart rate greater than 90 min-1) and hypotension (mean arterial pressure less than 60 mm Hg) will be first assessed using the guidance of Bispectral index and Train of four monitors. Sufentanil in doses of 2.5 to 5 mcg (maximum of 0.6-1.2 mic/kg for the entire surgery) is administered if the Bispectral index and Train of four monitor values are within normal range and if required vasopressor infusion is used. Vasoconstrictors may be given as a continuous infusion of norepinephrine, or bolus doses of ephedrine or phenylephrine. Only when blood pressure remains, low additional crystalloids will be given. Finally, in case of bradycardia (heart rate less than 30 min-1), atropine may be given
Device: Standard care
Hemodynamic changes outside of the normal range i.e., hypertension (systolic blood pressure greater than 140 mm Hg), tachycardia (heart rate greater than 90 min-1) and hypotension (mean arterial pressure less than 60 mm Hg) will be first assessed using the guidance of Bispectral index and Train of four monitors. Sufentanil in doses of 2.5 to 5 mcg (maximum of 0.6-1.2 mic/kg for the entire surgery) is administered if the Bispectral index and Train of four monitor values are within normal range and if required vasopressor infusion is used. Vasoconstrictors may be given as a continuous infusion of norepinephrine, or bolus doses of ephedrine or phenylephrine. Only when blood pressure remains, low additional crystalloids will be given. Finally, in case of bradycardia (heart rate less than 30 min-1), atropine may be given
Experimental: Nociception Level-guided Analgesia Group
In the nociception level-guided group, sufentanil will be administered to maintain a nociception level value between 10 and 25. In case the nociception level values rise greater than 25 for more than 60 s, additional 2.5 microgram sufentanil (if nociception level increase remained less than 45) or 5 micrograms (if nociception level increase greater than 45). Atropine will be administered when heart rate decreases less than 30 min-1. Because the nociception level may be sensitive to such medication, nociception level values will then not used for at least 5 min to guide analgesia, with the exception of norepinephrine as this drug will be given as continuous infusion
Device: Nociception Level monitor (NOL)
NOL technology uses a multiparameter-based sensor platform, and advanced algorithm, to continuously monitor Autonomic Nervous System (ANS) functions. NOL reflects a patient's nociceptive state and analgesic effect, helping to optimize the administration of systemic and/or regional analgesics, and avoiding overdose or underuse of these drugs. The nociception level is a multiparameter monitor that combines information from the finger photoplethysmogram amplitude, skin conductance, skin conductance fluctuation, heart rate, heart rate variability, and their time derivatives into one index ranging from 0 (absence of noxious stimulation) to 100 (severe noxious stimulation).

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Total intraoperative consumption of sufentanil Total intraoperative consumption of sufentanil
Time Frame: From induction of anaesthesia up to transfer to recovery room, up to 6 hours
Amount of sufentanil in micrograms administered during the entire operative period i.e. from induction of anaesthesia up to transfer to the recovery room
From induction of anaesthesia up to transfer to recovery room, up to 6 hours

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Eligible time to discharge as per RR discharge score
Time Frame: From admission to recovery room until discharge, up to 24 hours
The RR discharge score is a scoring system developed for general surgery by the Danish Society of Anesthesia and Intensive Care. The score consists of 5 semi-objective variables (sedation, respiration, nausea, pain, and motor function) and 5 objective variables (peripheral saturation, diuresis, arterial blood pressure, heart rate and temperature). The nurses score each variable from 0 to 3 points. Low scores( below 3 for 2 consecutive hours) indicate a stable condition, and patients are considered eligible for discharge. The score values at different time points represent the quality of recovery.
From admission to recovery room until discharge, up to 24 hours
Postoperative Nausea and Vomiting
Time Frame: From admission to recovery room, up to 24 hours
Complaint from patient about nausea on arrival in recovery room assessed as yes or no
From admission to recovery room, up to 24 hours
Change in myocardial function
Time Frame: Before anaesthesia induction and 24 hours after completion of surgery
Difference between preoperative and postoperative (24 hours after surgery) Serum Troponin T and brain natriuretic peptide (proPnP) levels
Before anaesthesia induction and 24 hours after completion of surgery

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of Southern Denmark

Investigators

  • Study Director: Thomas Strøm, Hospital of Southern Denmark - Aabenraa

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

August 1, 2023

Primary Completion (Estimated)

March 31, 2027

Study Completion (Estimated)

March 31, 2027

Study Registration Dates

First Submitted

December 14, 2022

First Submitted That Met QC Criteria

December 14, 2022

First Posted (Actual)

December 22, 2022

Study Record Updates

Last Update Posted (Actual)

May 14, 2026

Last Update Submitted That Met QC Criteria

May 11, 2026

Last Verified

May 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • SHS-An-3-2022

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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