Nociceptive PainNCT05399758
Nociception Evaluated by the NOL® Index in Sedated Patients in the Intensive Care Unit
An observational study of Nociceptive Pain and Sedation Complication, run by University of Chile at 2 sites in Chile.
Trial summary
Due to their underlying pathology and the necessary complicated procedures to which they are exposed, patients in the intensive care unit experience varying degrees of pain at some point in their evolution. Read more about this study
- Who is it for?
- Ages 18 to 70 years
- Conditions the study is for
- Nociceptive Pain, Sedation Complication
- What is being tested?
- NOL monitor
- Type of treatment
- Medical device
- How many people
- 0 participants
- Where
- 2 sitesChile
- Study dates
- 1 Jun 2022to 27 Oct 2025
- Phase
- Observational
- 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 to 70 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: ICU patients sedated with propofol and fentanyl
Who may be able to join
- ICU sedated patients under propofol and fentanyl
Who cannot join
- Sedation duration less than 72 h
- Stroke
- Opioid user before ICU hospitalization
- Atrial fibrillation
- Pregnancy/lactation
- Patient with antiarrhythmic agents
Trial locations and contacts
2 sites in 1 country.
Chile2 sites
Centro de Investigación Cínica Avanzada (CICA), Hospital Clinico de la Universidad de Chile
Santiago, RM, 7690306
Hospital Clinico de la Universidad de Chile
Santiago, RM, 7690306
About this study
Due to their underlying pathology and the necessary complicated procedures to which they are exposed, patients in the intensive care unit experience varying degrees of pain at some point in their evolution. Evidence has established short-term and long-term negative consequences of unresolved pain or excessive analgesic sedation. However, pain assessment or adequate nociceptive monitoring remains a significant challenge, especially in non-communicative patients under deep sedation, who urgently need to expand and improve current tools.
Pain assessment in critically ill patients is challenging; limitations in their ability to communicate (neurocognitive deficit, use of endotracheal tube) or altered consciousness (deep sedation) make them unable to self-report their pain with standard pain scales. The Behavioral Pain Scale (BPS) and the Critical-Care Pain Observation Tool (CPOT) are the pain assessment tools with the best performance and reliability for patients in these conditions.
Read more
Different technologies are used to monitor nociceptive responses caused by surgical stress in patients under general anesthesia that together with the clinical evaluation, manage to keep patients in the best analgesic conditions, improving the post-surgical prognosis. In particular, the NOL® nociceptive index (Medasense, Ramat Gan, Israel) is a multiparametric detection of nociception/pain, delivering a dimensionless score (0 -100) calculated through an algorithm (patented) and based on the registry of four biometric sensors (photoplethysmography, galvanic skin response, temperature, and accelerometer). NOL index value between 10-25 is the most appropriate for maintaining analgesia during general anesthesia.
The ease and low invasiveness of this system (all sensors are implemented in a finger clip, similar to an oxygen saturation monitor) may allow its potential use in the context of intensive care unit patients. Some studies have recently been published that highlight the possible usefulness of the NOL® index in critically ill patients. However, in these studies, the assessment of nociception was limited to acute nociceptive procedures only.
Read the detailed description
In the following protocol, we will study the feasibility of using the NOL® index to evaluate nociception in patients under sedation with propofol and opioid analgesics such as fentanyl.
This study aims to describe the feasibility of using the NOL® nociception index as an objective tool for assessing pain/nociception in patients with sedation in the Intensive Care Unit (ICU).
The values obtained with the use of the NOL® index will be recorded and compared with the standard measurements of pain assessment (Behavioral Pain Scale (BPS) and/or Critical-Care Pain Observation Tool (CPOT)) in patients with a deep/superficial sedation protocol (SAS 1-2). The values obtained after exposure to nociceptive stimuli such as interventions, cleaning, and invasive procedures, among others, will be registered.
In particular, scales such as CPOT and NOL® can be complementary since both measure different components related to pain. The CPOT measures expressive behaviors related to pain, and the NOL measures physiological parameters involved in the process of nociception, which can lead to pain.
Two other aims:
To compare the registration of the NOL® index and the degree of sedation by the BIS® index with variables derived from the processing of the frontal EEG.
To evaluate the effect of sedo-analgesia protocols on the NOL® index. The impact of administering sedation/analgesia protocols with propofol/fentanyl and their effects on the NOL® index will be followed up and evaluated.
- Conditions
- Nociceptive Pain, Sedation Complication
- Being tested
- NOL monitor
- Keywords
- Nociception, Opioids, Pain monitor
- Medical subject headings
- Nociceptive Pain
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
NOL monitorDevice
NOL monitor data will be acquired, as well as clinical assessment of pain and fentanyl dosage.
| Study group | Role | What they receive |
|---|---|---|
| ICU sedated patients | Critical patients sedated with propofol and fentanyl The values obtained with the use of the NOL® index will be recorded and compared with the standard measurements of pain assessment (Behavioral Pain Scale (BPS) and/or CPOT) Receives: Device: NOL monitor |
What is being measured
The primary outcome is the main question the study is designed to answer.
NOL monitor values
Values will be recorded and compared with fentanyl dosage and clinical pain assesment
Measured: Day 3
Secondary outcomes (3)
Fentanyl dosage
Values of fentanyl dosage
Measured: Day 3
Clinical pain assessment (Behavioral Pain Scale)
Values of pain scale
Measured: Day 3
BIS index
Values of BIS index obtained by BIS monitor
Measured: Day 3
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted1 Jun 2022
- Study start1 Jun 2022
- Primary completion31 Jan 2023
- Study completion27 Oct 2025
Why it stopped: Technical issues with NOL monitoring in ICU patients
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Nociceptive PainStudies 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
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 0 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Chile
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Antonello Penna, University of Chile
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05399758
- Sponsor's protocol ID
- OAIC: 1219/21
- Status last verified
- Oct 2026
- First submitted
- 16 May 2022
- Last updated
- 16 Oct 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 16 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Nociception Evaluated by the NOL® Index in Sedated Patients in the Intensive Care Unit
- ClinicalTrials.gov ID
- NCT05399758
- Acronym / sponsor ID
- OAIC: 1219/21
- Conditions
- Nociceptive Pain, Sedation Complication
- Keywords
- Nociception, Opioids, Pain monitor
- Study type
- Observational
- Recruitment status
- WithdrawnReason stopped: Technical issues with NOL monitoring in ICU patients
- Enrolment
- 0 participants (actual)
- Lead sponsor
- University of ChileUniversity, hospital or other
- Study start
- 1 Jun 2022 (actual)
- Primary completion
- 31 Jan 2023 (actual)
- Study completion
- 27 Oct 2025 (actual)
- First posted
- 1 Jun 2022 (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.
Due to their underlying pathology and the necessary complicated procedures to which they are exposed, patients in the intensive care unit experience varying degrees of pain at some point in their evolution. Evidence has established short-term and long-term negative consequences of unresolved pain or excessive analgesic sedation. However, pain assessment or adequate nociceptive monitoring remains a significant challenge, especially in non-communicative patients under deep sedation, who urgently need to expand and improve current tools.
Pain assessment in critically ill patients is challenging; limitations in their ability to communicate (neurocognitive deficit, use of endotracheal tube) or altered consciousness (deep sedation) make them unable to self-report their pain with standard pain scales. The Behavioral Pain Scale (BPS) and the Critical-Care Pain Observation Tool (CPOT) are the pain assessment tools with the best performance and reliability for patients in these conditions.
Different technologies are used to monitor nociceptive responses caused by surgical stress in patients under general anesthesia that together with the clinical evaluation, manage to keep patients in the best analgesic conditions, improving the post-surgical prognosis. In particular, the NOL® nociceptive index (Medasense, Ramat Gan, Israel) is a multiparametric detection of nociception/pain, delivering a dimensionless score (0 -100) calculated through an algorithm (patented) and based on the registry of four biometric sensors (photoplethysmography, galvanic skin response, temperature, and accelerometer). NOL index value between 10-25 is the most appropriate for maintaining analgesia during general anesthesia.
The ease and low invasiveness of this system (all sensors are implemented in a finger clip, similar to an oxygen saturation monitor) may allow its potential use in the context of intensive care unit patients. Some studies have recently been published that highlight the possible usefulness of the NOL® index in critically ill patients. However, in these studies, the assessment of nociception was limited to acute nociceptive procedures only.
Detailed description
In the following protocol, we will study the feasibility of using the NOL® index to evaluate nociception in patients under sedation with propofol and opioid analgesics such as fentanyl.
This study aims to describe the feasibility of using the NOL® nociception index as an objective tool for assessing pain/nociception in patients with sedation in the Intensive Care Unit (ICU).
The values obtained with the use of the NOL® index will be recorded and compared with the standard measurements of pain assessment (Behavioral Pain Scale (BPS) and/or Critical-Care Pain Observation Tool (CPOT)) in patients with a deep/superficial sedation protocol (SAS 1-2). The values obtained after exposure to nociceptive stimuli such as interventions, cleaning, and invasive procedures, among others, will be registered.
In particular, scales such as CPOT and NOL® can be complementary since both measure different components related to pain. The CPOT measures expressive behaviors related to pain, and the NOL measures physiological parameters involved in the process of nociception, which can lead to pain.
Two other aims:
To compare the registration of the NOL® index and the degree of sedation by the BIS® index with variables derived from the processing of the frontal EEG.
To evaluate the effect of sedo-analgesia protocols on the NOL® index. The impact of administering sedation/analgesia protocols with propofol/fentanyl and their effects on the NOL® index will be followed up and evaluated.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| ICU sedated patients | – | Device: NOL monitorCritical patients sedated with propofol and fentanyl The values obtained with the use of the NOL® index will be recorded and compared with the standard measurements of pain assessment (Behavioral Pain Scale (BPS) and/or CPOT) |
Who may qualify
- Ages
- 18 to 70 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- ICU patients sedated with propofol and fentanyl
Key inclusion criteria (1 listed)
- ICU sedated patients under propofol and fentanyl
Key exclusion criteria (6 listed)
- Sedation duration less than 72 h
- Stroke
- Opioid user before ICU hospitalization
- Atrial fibrillation
- Pregnancy/lactation
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 |
|---|---|---|
| NOL monitorNOL monitor data will be acquired, as well as clinical assessment of pain and fentanyl dosage. | Device | ICU sedated patients |
Primary outcome
NOL monitor values
Time frame: Day 3
Values will be recorded and compared with fentanyl dosage and clinical pain assesment
3 secondary outcomes
Fentanyl dosage
Time frame: Day 3
Clinical pain assessment (Behavioral Pain Scale)
Time frame: Day 3
BIS index
Time frame: Day 3
Results and safety
The study was withdrawn before enrolling participants, so there are no results.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 16 Oct 2026.
- Individual participant dataSharing planned: No
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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. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
2 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Nociceptive Pain and Sedation Complication, run by University of Chile at 2 sites in Chile.
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 1 inclusion and 6 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: withdrawn, as of the sponsor's last update on 16 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites in Chile. 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 was withdrawn before enrolling participants, so there are no results.
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?
NOL monitor values (time frame: Day 3). 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 16 Oct 2026.