Nociceptive PainNOLvsSPINCT07084935
Comparison of the Surgical Pleth Index and the Nociception Level Index in the Pediatric Population
An observational study of Nociceptive Pain and Anesthesia, run by Radboud University Medical Center at 1 site in Netherlands.
Trial summary
This observational study aims to compare two nociception monitoring methods. The Nociception Level (NOL) index and the Surgical Pleth Index (SPI) in the pediatric population during general anesthesia. Read more about this study
- Who is it for?
- Ages 1 year to 12 years
- Conditions the study is for
- Nociceptive Pain, Anesthesia, Pediatric Anesthesia
- What is being tested?
- Connecting all patients to the nociception level index(NOL) and the surgical pleth index (SPI) and All patient will receive a tetanic stimuli (60mA, 100hz) of 5 seconds before start of incision
- Type of treatment
- Medical device
- How many people
- 40 participants
- Where
- 1 siteNetherlands
- Study dates
- 4 Jul 2025to 25 Jun 2026
- How long will I take part?
- 1 Day
- 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 1 year to 12 years
- All sexes
- No healthy volunteers
- Child
Study population: pediatric patients scheduled to undergo surgery with general anesthesia at the Radboud university medical centre in Nijmegen, the Netherlands
Who may be able to join
- Male or female
- ASA I, ASA II and ASA III
- Aged 1 to 12 years old
- Scheduled to undergo elective surgery with general anaesthesia
Who cannot join
- Patients with chronic pain
- Patients with chronic analgesia usage.
- Known allergy to the adhesives used in the sensors.
- No free available limb to attach the probes to.
Trial locations and contacts
1 site in 1 country.
Netherlands1 site
Radboud university medical centre
Nijmegen, Gelderland, 6525 GA
About this study
Official title: Comparison of the Surgical Pleth Index and the Nociception Level Index in the Pediatric Population: An Observational Study
This observational study aims to compare two nociception monitoring methods. The Nociception Level (NOL) index and the Surgical Pleth Index (SPI) in the pediatric population during general anesthesia. While both monitors are designed to assess nociceptive responses through autonomic nervous system activity, they differ in methodology and parameters measured. The NOL index integrates multiple physiological signals using a self-learning algorithm, while SPI focuses on heart rate variability and plethysmographic amplitude. Although both have been studied individually in children, a direct comparison has not yet been conducted. This study will evaluate and compare each monitor's ability to detect and quantify nociceptive stimuli (surgical and tetanic) in children.
The investigators hypothesize that the NOL monitor and SPI monitor will both be able to quantify surgical stimuli and tetanic stimuli with monitors response to surgical stimuli > monitors response to tetanic stimuli. However, the investigators also hypothesize that the NOL index will do this superiorly, as it utilizes a self-learning algorithm and more parameters are incorporated in its algorithm
Read the detailed description
This is a single centre, observational prospective non-interventional study. The study will take place at the Radboudumc. After obtaining informed consent participants will be enrolled. Each participant will be treated according to the standard Radboudumc anaesthesia protocol with heartrate monitoring, respiratory rate monitoring, neuromuscular monitoring (TOF-Watch SX ) , intermittent non-invasive blood pressure monitoring and Bispectral index monitoring. Participants will be connected to the NOL index PMD-200 device using the finger probe and the SPI device (Carescape b650) using the pulse oxymeter directly after induction of anesthesia with propofol/sevoflurane. Before start of surgery, after recording a period of 30 seconds with no stimulation (no nociception) a standardised tetanic stimulus of 5 seconds with 60 mA and 100hz will be applied with the neuromuscular monitor on the patients ulnary nerve trajectory with two adhesive electrodes. This is a stimulus that is part of common anesthesiology practice in order to assess the patients neuromuscular blockade. Previous research has used tetanic stimuli of similar intensity as standardised nociceptive stimuli in order to validate nociception monitors. After SPI and NOL monitor values return to baseline (pre-tetanic stimulus value) surgery with first incision will commence.
During the operation the response to the standardised stimuli and nociceptive events such as intubation, insertion of supraglottic airway, surgical incision and administration of opioids will be registered by a trained researcher. After surgery, upon discharge to the anaesthesia recovery room, patients will be disconnected from both monitors. Post-operative pain/comfort scores and post-operative analgesia usage will be registered by the researcher at the recovery room. Total duration of the study inclusion period is expected to be 1 year.
- Being tested
- Connecting all patients to the nociception level index(NOL) and the surgical pleth index (SPI), All patient will receive a tetanic stimuli (60mA, 100hz) of 5 seconds before start of incision
- Keywords
- Nociception monitoring, Pediatric population, NOL index, Surgical pleth index
- Medical subject headings
- Nociceptive Pain
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Connecting all patients to the nociception level index(NOL) and the surgical pleth index (SPI)Device
All patients will be connected to the NOL and SPI during surgery after induction of general anesthesia.
All patient will receive a tetanic stimuli (60mA, 100hz) of 5 seconds before start of incisionDevice
All patient will receive a tetanic stimuli (60mA, 100hz) of 5 seconds before start of incision.
| Study group | Role | What they receive |
|---|---|---|
| Patients aged 1 to 12 years undergoing surgery with general anesthesia. | Not described Receives: Device: Connecting all patients to the nociception level index(NOL) and the surgical pleth index (SPI); Device: All patient will receive a tetanic stimuli (60mA, 100hz) of 5 seconds before start of incision |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in surgical pleth index (∆SPI) during surgical stimuli and standardized tetanic stimuli
∆SPI = pre stimulus -30s-0s mean SPI value - post stimulus +5s to 30s-120s SPI value.
Measured: During surgery with general anesthesia.
Change in nociception level index (∆NOL) during surgical stimuli and standardized tetanic stimuli
∆NOL = pre stimulus -30s-0s mean NOL value - post stimulus +5s to 30s-120s NOL value.
Measured: During surgery with general anesthesia
Secondary outcomes (12)
Change in surgical pleth index (∆SPI) following intraoperative opioid administration.
Response of the SPI to intraoperative administration of opioids. Evaluate SPI mean values -20s to 0s before opioid administration to mean value after opioid administration in accordance with the utilized opiod farmacokinetics(time of mean measurement in seconds depends on opioid used).
Measured: During surgery with general anesthesia]
Change in nociception level index (∆NOL) following intraoperative opioid administration.
Response of the NOL index to intraoperative administration of opioids. Evaluate NOL mean values -20s to 0s before opioid administration to mean value after opioid administration in accordance with the utilized opiod farmacokinetics(time of mean measurement in seconds depends on opioid used).
Measured: During surgery with general anesthesia
Time NOL index is >25 and SPI is >40 during surgery and before intra-operative opioid administration. Defined as time NOL index is >20-25 and SPI is >40 during surgery time.
Defined as time in seconds NOL index is >25 and SPI is >40 during surgery time.
Measured: During surgery with general anesthesia
Comparing mean (total surgery time) and last 5-min mean values before disconnection for intra-operative NOL and SPI to the post-operative pain scores.
- For patients aged <4 Faces, legs, activity, cry and consolability (FLACC) will be used
- For patients aged >4 a faces pain scale, numeric rating scale (NRS) or visual analogue scale (VAS) will be used.
- Pain scores will be obtained at recovery admittance, after one hour and at recovery departure and when recovery personnel deem it is necessary based on their clinical view.
Measured: perioperative/periprocedural
Change in surgical pleth index (∆SPI) after administration of vasoactive medication.
Compare mean values -20 to 0 sec for administration of vasoactive medication to mean 5+-30 sec, 5+-60sec and 5+-120sec after administration vasoactive medication (noradrenaline, ephedrine and atropine).
Measured: During surgery with general anesthesia
Change in nociception level index (∆NOL) after administration of vasoactive medication.
Compare mean values -20 to 0 sec for administration of vasoactive medication to mean 5+-30 sec, 5+-60sec and 5+-120sec after administration vasoactive medication (noradrenaline, ephedrine and atropine).
Measured: During surgery with general anesthesia
Change in heartrate (∆HR) following a nociceptive event and opioid administration.
Change in heartrate following a nociceptive event. pre stimulus -30s-0s mean HR value - post stimulus +5s to 30s-120s HR value.
Following opioid administration:
Change in heartrate mean values -20s to 0s before opioid administration to mean value after opioid administration in accordance with the utilized opiod farmacokinetics(time of mean measurement in seconds depends on opioid used).
Measured: During surgery with general anesthesia
Change in mean arterial bloodpressure(∆MAP) following nociceptive event and opioid administration
Comparision of mean arterial bloodpressure measurement before nociceptive event/opioid administration to measurement after nociceptive event/opioid administration.
Measured: During surgery with general anesthesia
Change in respiratory rate (∆RR) following a nociceptive event and opioid administration.
Change in respiratory rate following a nociceptive event. pre stimulus -30s-0s mean HR value - post stimulus +5s to 30s-120s HR value.
Following opioid administration:
Change in respiratory rate mean values -20s to 0s before opioid administration to mean value after opioid administration in accordance with the utilized opiod farmacokinetics(time of mean measurement in seconds depends on opioid used).
Measured: During surgery with general anesthesia
Change in nociception level index (Δ NOL) after incision under loco-regional/neuraxial blockade.
Defined as Δ NOL following nociceptive stimuli in patients with an active loco-regional or neuraxial blockade.
Compare mean values of SPI and NOL -30-0 before incision to mean 5+-30 sec, 5+-60sec and 5+-120sec after incision.
Measured: During surgery with general anesthesia.
Change in surgical pleth index (Δ SPI) after incision under locoregional/neuraxial blockade.
Defined as Δ SPI following nociceptive stimuli in patients with an active loco-regional or neuraxial blockade.
Compare mean values of SPI and NOL -30-0 before incision to mean 5+-30 sec, 5+-60sec and 5+-120sec after incision.
Measured: Δ SPI
Response time of both monitors after nociceptive stimulation.
Defined as time in seconds of onset to change in SPI and NOL after nociceptive stimuli.
Measured: During surgery with general anesthesia
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted25 Jul 2025
- Study start4 Jul 2025
- Primary completion25 Jun 2026
- Study completion25 Jun 2026
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.
- More trials run by Radboud University Medical CenterThe sponsor's other registered studies.
- 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
- Other
- Time perspective
- Prospective
- Enrolment
- 40 participants (actual)
- Target duration
- 1 Day
Sponsor and investigators
- Lead sponsor
- Radboud University Medical Center
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Ignacio Malagon, Radboud University Medical Center
- Investigators
- Ignacio Malagon, Professor, Principal investigator, Radboud University Medical Center
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07084935
- Sponsor's protocol ID
- 2025-18010
- Other IDs
- 2025
- Acronym
- NOLvsSPI
- Status last verified
- Jul 2025
- First submitted
- 2 Jul 2025
- Last updated
- 8 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Study at a glance
From the registry record, last updated by the sponsor on 8 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Comparison of the Surgical Pleth Index and the Nociception Level Index in the Pediatric Population: An Observational Study
- ClinicalTrials.gov ID
- NCT07084935
- Acronym / sponsor ID
- NOLvsSPI / 2025-18010
- Keywords
- Nociception monitoring, Pediatric population, NOL index, Surgical pleth index
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 40 participants (actual)
- Lead sponsor
- Radboud University Medical CenterUniversity, hospital or other
- Study start
- 4 Jul 2025 (actual)
- Primary completion
- 25 Jun 2026 (actual)
- Study completion
- 25 Jun 2026 (actual)
- First posted
- 25 Jul 2025 (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.
This observational study aims to compare two nociception monitoring methods. The Nociception Level (NOL) index and the Surgical Pleth Index (SPI) in the pediatric population during general anesthesia. While both monitors are designed to assess nociceptive responses through autonomic nervous system activity, they differ in methodology and parameters measured. The NOL index integrates multiple physiological signals using a self-learning algorithm, while SPI focuses on heart rate variability and plethysmographic amplitude. Although both have been studied individually in children, a direct comparison has not yet been conducted. This study will evaluate and compare each monitor's ability to detect and quantify nociceptive stimuli (surgical and tetanic) in children.
The investigators hypothesize that the NOL monitor and SPI monitor will both be able to quantify surgical stimuli and tetanic stimuli with monitors response to surgical stimuli > monitors response to tetanic stimuli. However, the investigators also hypothesize that the NOL index will do this superiorly, as it utilizes a self-learning algorithm and more parameters are incorporated in its algorithm
Detailed description
This is a single centre, observational prospective non-interventional study. The study will take place at the Radboudumc. After obtaining informed consent participants will be enrolled. Each participant will be treated according to the standard Radboudumc anaesthesia protocol with heartrate monitoring, respiratory rate monitoring, neuromuscular monitoring (TOF-Watch SX ) , intermittent non-invasive blood pressure monitoring and Bispectral index monitoring. Participants will be connected to the NOL index PMD-200 device using the finger probe and the SPI device (Carescape b650) using the pulse oxymeter directly after induction of anesthesia with propofol/sevoflurane. Before start of surgery, after recording a period of 30 seconds with no stimulation (no nociception) a standardised tetanic stimulus of 5 seconds with 60 mA and 100hz will be applied with the neuromuscular monitor on the patients ulnary nerve trajectory with two adhesive electrodes. This is a stimulus that is part of common anesthesiology practice in order to assess the patients neuromuscular blockade. Previous research has used tetanic stimuli of similar intensity as standardised nociceptive stimuli in order to validate nociception monitors. After SPI and NOL monitor values return to baseline (pre-tetanic stimulus value) surgery with first incision will commence.
During the operation the response to the standardised stimuli and nociceptive events such as intubation, insertion of supraglottic airway, surgical incision and administration of opioids will be registered by a trained researcher. After surgery, upon discharge to the anaesthesia recovery room, patients will be disconnected from both monitors. Post-operative pain/comfort scores and post-operative analgesia usage will be registered by the researcher at the recovery room. Total duration of the study inclusion period is expected to be 1 year.
Study design
- Observational model
- Other
- Time perspective
- Prospective
- Target follow-up
- 1 Day
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Patients aged 1 to 12 years undergoing surgery with general anesthesia. | – | Device: Connecting all patients to the nociception level index(NOL) and the surgical pleth index (SPI), Device: All patient will receive a tetanic stimuli (60mA, 100hz) of 5 seconds before start of incision |
Who may qualify
- Ages
- 1 year to 12 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child
- Study population
- pediatric patients scheduled to undergo surgery with general anesthesia at the Radboud university medical centre in Nijmegen, the Netherlands
Key inclusion criteria (4 listed)
- Male or female
- ASA I, ASA II and ASA III
- Aged 1 to 12 years old
- Scheduled to undergo elective surgery with general anaesthesia
Key exclusion criteria (4 listed)
- Patients with chronic pain
- Patients with chronic analgesia usage.
- Known allergy to the adhesives used in the sensors.
- No free available limb to attach the probes to.
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 |
|---|---|---|
| Connecting all patients to the nociception level index(NOL) and the surgical pleth index (SPI)All patients will be connected to the NOL and SPI during surgery after induction of general anesthesia. | Device | Patients aged 1 to 12 years undergoing surgery with general anesthesia. |
| All patient will receive a tetanic stimuli (60mA, 100hz) of 5 seconds before start of incisionAll patient will receive a tetanic stimuli (60mA, 100hz) of 5 seconds before start of incision. | Device | Patients aged 1 to 12 years undergoing surgery with general anesthesia. |
Primary outcome
Change in surgical pleth index (∆SPI) during surgical stimuli and standardized tetanic stimuli
Time frame: During surgery with general anesthesia.
∆SPI = pre stimulus -30s-0s mean SPI value - post stimulus +5s to 30s-120s SPI value.
Change in nociception level index (∆NOL) during surgical stimuli and standardized tetanic stimuli
Time frame: During surgery with general anesthesia
∆NOL = pre stimulus -30s-0s mean NOL value - post stimulus +5s to 30s-120s NOL value.
12 secondary outcomes
Change in surgical pleth index (∆SPI) following intraoperative opioid administration.
Time frame: During surgery with general anesthesia]
Change in nociception level index (∆NOL) following intraoperative opioid administration.
Time frame: During surgery with general anesthesia
Time NOL index is >25 and SPI is >40 during surgery and before intra-operative opioid administration. Defined as time NOL index is >20-25 and SPI is >40 during surgery time.
Time frame: During surgery with general anesthesia
Comparing mean (total surgery time) and last 5-min mean values before disconnection for intra-operative NOL and SPI to the post-operative pain scores.
Time frame: perioperative/periprocedural
Change in surgical pleth index (∆SPI) after administration of vasoactive medication.
Time frame: During surgery with general anesthesia
Change in nociception level index (∆NOL) after administration of vasoactive medication.
Time frame: During surgery with general anesthesia
Change in heartrate (∆HR) following a nociceptive event and opioid administration.
Time frame: During surgery with general anesthesia
Change in mean arterial bloodpressure(∆MAP) following nociceptive event and opioid administration
Time frame: During surgery with general anesthesia
Change in respiratory rate (∆RR) following a nociceptive event and opioid administration.
Time frame: During surgery with general anesthesia
Change in nociception level index (Δ NOL) after incision under loco-regional/neuraxial blockade.
Time frame: During surgery with general anesthesia.
Change in surgical pleth index (Δ SPI) after incision under locoregional/neuraxial blockade.
Time frame: Δ SPI
Response time of both monitors after nociceptive stimulation.
Time frame: During surgery with general anesthesia
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 8 Sep 2026.
- Individual participant dataSharing planned: Undecided
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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.
Ignacio Malagon, Professor principal investigator
Radboud University Medical Center
1 site 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 Anesthesia, run by Radboud University Medical Center at 1 site in Netherlands.
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 4 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: finished, as of the sponsor's last update on 8 Sep 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 Netherlands. 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?
Change in surgical pleth index (∆SPI) during surgical stimuli and standardized tetanic stimuli (time frame: During surgery with general anesthesia.). 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 8 Sep 2026.