Analyse Neuromuscular Monitoring for Developing a Model to Predict TOF Ratio During AnesthesiaNCT04518761
Predictive Modelling of the Intraoperative Train-of-Four (TOF) Ratio
An observational study of Analyse Neuromuscular Monitoring for Developing a Model to Predict TOF Ratio During Anesthesia, run by Universitair Ziekenhuis Brussel at 2 sites in Belgium.
Trial summary
Neuromuscular Blocking Agents (NMBAs) are routinely administered to patients in a multiplicity o anaesthetic settings in order to paralyze and impede (re)active muscular contraction. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Analyse Neuromuscular Monitoring for Developing a Model to Predict TOF Ratio During Anesthesia
- What is being tested?
- Elective surgery
- Type of treatment
- Surgery or procedure
- How many people
- 200 participants
- Where
- 2 sitesBelgium
- Study dates
- 1 Jul 2020to 31 Dec 2026
- How long will I take part?
- 2 Days
- Phase
- Observational
- 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
Study population: Adult patients (18 years old and above) receiving General Anesthesia for noncardiac surgery requiring the use of a neuromuscular blocking agent.
Who may be able to join
- Adult patients (18 years old and above) receiving General Anesthesia for noncardiac surgery requiring the use of a neuromuscular blocking agent.
- Administration of General Anesthesia by means of Total Intravenous Anesthesia technique.
- Use of Rocuronium as a neuromuscular blocking agent.
Who cannot join
- Use of different types of neuromuscular blocking agents for the same patient within the same surgical procedure
- Known Neuromuscular diseases/syndromes judged to condition accurate neuromuscular monitoring.
Trial locations and contacts
2 sites in 1 country. Contact the study team or a site near you to ask about taking part.
Belgium2 sites, 2 recruiting
- Not yet recruiting
AZ Sint Jan
Bruges, WV, 8000
Hugo Carvalho, MD, PhD
Hugo Carvalho, MD, PhD
- Recruiting
UZ Brussel
Jette, Brussels Capital, 1090
Evelien Vandeurzen, Biomedical Sciences, 024749237, evelien.vandeurzen@uzbrussel.be
Hugo Carvalho, MD, PhD
About this study
Neuromuscular Blocking Agents (NMBAs) are routinely administered to patients in a multiplicity o anaesthetic settings in order to paralyze and impede (re)active muscular contraction. The availability of monitoring devices allowing an accurate measurement fo the degree of neuromuscular block during anesthesia has raised the standards for a proper evidence-based use of NMBAs.
For this purpose, one of the most widely used methods is the Train of Four (TOF): transcutaneous application of a series of 4 square-wave supra-maximal electrical stimuli over the course of a nerve of choice (most commonly the ulnar nerve). These are applied at a frequency of 2Hz, and each with a duration of 0.2ms. These stimuli elicit a motor response on the adductor pollicis muscle, which on its turn dictates the adduction of the thumb. The acceleration of this movement can be followed by means of an uni/multi-directional accelerometer attached to the thumb. The ratio of the acceleration of the 4th and 1st elicited contractions is called the TOF-Ratio - a clinically and scientifically established method of assessing neuromuscular block recovery. A value of 1 translates a full recovery of the muscular function of a patient. In modern Anesthesia, the bar for deeming a recovery as adequate has been set at a minimum of a TOF-ratio of >0.9, with some authors advocating a ratio of 1 as the only acceptable and complications avoiding result.
- Conditions
- Analyse Neuromuscular Monitoring for Developing a Model to Predict TOF Ratio During Anesthesia
- Being tested
- Elective surgery
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Elective surgeryProcedure or surgery
Any patient who needs to undergo an elective surgery.
| Study group | Role | What they receive |
|---|---|---|
| Prospective group | Not described Receives: Procedure: Elective surgery | |
| Retrospective group | Not described Receives: Procedure: Elective surgery |
What is being measured
The primary outcome is the main question the study is designed to answer.
TOF-ratio
Train of four percentage
Measured: 1 day
Secondary outcomes (1)
TOF-count
Train of four count
Measured: 1 day
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted19 Aug 2020
- Study start1 Jul 2020
- Primary completion31 Dec 2026 (estimated)
- Study completion31 Dec 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (2)Papers the sponsor has linked to this study.
- Other trials for Analyse Neuromuscular Monitoring for Developing a Model to Predict TOF Ratio During AnesthesiaStudies of the same condition, open and under way.
- More trials run by Universitair Ziekenhuis BrusselThe 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
- Case only
- Time perspective
- Prospective
- Enrolment
- 200 participants (estimated)
- Target duration
- 2 Days
Sponsor and investigators
- Lead sponsor
- Universitair Ziekenhuis Brussel
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04518761
- Sponsor's protocol ID
- TOFPROS02
- Status last verified
- Apr 2026
- First submitted
- 14 Aug 2020
- Last updated
- 29 Apr 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided: Publication via medical article.
Publications
Verdonck M, Carvalho H, Fuchs-Buder T, Brull SJ, Poelaert J. Machine learning based analysis and detection of trend outliers for electromyographic neuromuscular monitoring. J Clin Monit Comput. 2024 Oct;38(5):1163-1173. doi: 10.1007/s10877-024-01141-6. Epub 2024 Apr 4.
PubMed 38573367Carvalho H, Verdonck M, Eleveld DJ, Ramirez D, D'Haese J, Flamee P, Geerts L, Wylleman J, Cools W, Barbe K, Struys MMRF, Poelaert J. Neuromuscular end-point predictive capability of published rocuronium pharmacokinetic/pharmacodynamic models: An observational trial. J Clin Anesth. 2023 Nov;90:111225. doi: 10.1016/j.jclinane.2023.111225. Epub 2023 Aug 3.
PubMed 37542918
Study at a glance
From the registry record, last updated by the sponsor on 29 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Predictive Modelling of the Intraoperative Train-of-Four (TOF) Ratio
- ClinicalTrials.gov ID
- NCT04518761
- Acronym / sponsor ID
- TOFPROS02
- Conditions
- Analyse Neuromuscular Monitoring for Developing a Model to Predict TOF Ratio During Anesthesia
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 200 participants (estimated)
- Lead sponsor
- Universitair Ziekenhuis BrusselUniversity, hospital or other
- Study start
- 1 Jul 2020 (actual)
- Primary completion
- 31 Dec 2026 (estimated)
- Study completion
- 31 Dec 2026 (estimated)
- First posted
- 19 Aug 2020 (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.
Neuromuscular Blocking Agents (NMBAs) are routinely administered to patients in a multiplicity o anaesthetic settings in order to paralyze and impede (re)active muscular contraction. The availability of monitoring devices allowing an accurate measurement fo the degree of neuromuscular block during anesthesia has raised the standards for a proper evidence-based use of NMBAs.
For this purpose, one of the most widely used methods is the Train of Four (TOF): transcutaneous application of a series of 4 square-wave supra-maximal electrical stimuli over the course of a nerve of choice (most commonly the ulnar nerve). These are applied at a frequency of 2Hz, and each with a duration of 0.2ms. These stimuli elicit a motor response on the adductor pollicis muscle, which on its turn dictates the adduction of the thumb. The acceleration of this movement can be followed by means of an uni/multi-directional accelerometer attached to the thumb. The ratio of the acceleration of the 4th and 1st elicited contractions is called the TOF-Ratio - a clinically and scientifically established method of assessing neuromuscular block recovery. A value of 1 translates a full recovery of the muscular function of a patient. In modern Anesthesia, the bar for deeming a recovery as adequate has been set at a minimum of a TOF-ratio of >0.9, with some authors advocating a ratio of 1 as the only acceptable and complications avoiding result.
Study design
- Observational model
- Case only
- Time perspective
- Prospective
- Target follow-up
- 2 Days
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Prospective group | – | Procedure: Elective surgery |
| Retrospective group | – | Procedure: Elective surgery |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Adult patients (18 years old and above) receiving General Anesthesia for noncardiac surgery requiring the use of a neuromuscular blocking agent.
Key inclusion criteria (3 listed)
- Adult patients (18 years old and above) receiving General Anesthesia for noncardiac surgery requiring the use of a neuromuscular blocking agent.
- Administration of General Anesthesia by means of Total Intravenous Anesthesia technique.
- Use of Rocuronium as a neuromuscular blocking agent.
Key exclusion criteria (2 listed)
- Use of different types of neuromuscular blocking agents for the same patient within the same surgical procedure
- Known Neuromuscular diseases/syndromes judged to condition accurate neuromuscular monitoring.
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 |
|---|---|---|
| Elective surgeryAny patient who needs to undergo an elective surgery. | Procedure or surgery | Prospective group, Retrospective group |
Primary outcome
TOF-ratio
Time frame: 1 day
Train of four percentage
1 secondary outcome
TOF-count
Time frame: 1 day
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 29 Apr 2026.
- Derived from this study: PubMed 38573367Verdonck M, Carvalho H, Fuchs-Buder T, Brull SJ, Poelaert J. Machine learning based analysis and detection of trend outliers for electromyographic neuromuscular monitoring. J Clin Monit Comput. 2024 Oct;38(5):1163-1173. doi: 10.1007/s10877-024-01141-6. Epub 2024 Apr 4.
- Derived from this study: PubMed 37542918Carvalho H, Verdonck M, Eleveld DJ, Ramirez D, D'Haese J, Flamee P, Geerts L, Wylleman J, Cools W, Barbe K, Struys MMRF, Poelaert J. Neuromuscular end-point predictive capability of published rocuronium pharmacokinetic/pharmacodynamic models: An observational trial. J Clin Anesth. 2023 Nov;90:111225. doi: 10.1016/j.jclinane.2023.111225. Epub 2023 Aug 3.
- Individual participant dataSharing planned: Undecided. Publication via medical article.
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.
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 Analyse Neuromuscular Monitoring for Developing a Model to Predict TOF Ratio During Anesthesia, run by Universitair Ziekenhuis Brussel at 2 sites in Belgium.
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 2 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: looking for participants now, as of the sponsor's last update on 29 Apr 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 Belgium. 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?
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?
Each site lists its own contact: choose the nearest one under Trial locations. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
TOF-ratio (time frame: 1 day). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT04518761, which also lists 2 linked publications.
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 29 Apr 2026.