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Spinal (Fusion) SurgeryNCT07586189

Comparison of Hemodynamic Responses During Anesthesia Induction Using Eleveld and Schnider

An observational study of Spinal (Fusion) Surgery and Total Intravenous Anesthesia, run by Istanbul University at 1 site in Turkey (Türkiye).

Recruiting

Looking for participants now. Contact the study team or a site below to ask about taking part.

Sites and contacts
Official record
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Trial summary

This randomized prospective study aims to compare the effects of two target-controlled infusion models, the Schnider and Eleveld models, on anesthetic depth and hemodynamic responses during anesthesia induction in adult patients undergoing spinal surgery. Read more about this study

Who is it for?
Ages 18 years and older
What is being tested?
TCI Propofol Injection Models- Eleveld and TCI Propofol Injection Schnider
Type of treatment
Injection or infusion
How many people
50 participants
Where
1 siteTurkey (Türkiye)
Study dates
18 May 2026to 30 Aug 2026
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: The study population will consist of adult patients scheduled for elective spinal surgery under general anesthesia at the Neurosurgery Department of Istanbul University, Istanbul Faculty of Medicine. Eligible patients will be 18 years of age or older and will provide written informed consent before enrollment. Patients with uncontrolled hypertension, uncontrolled diabetes mellitus, those younger than 18 years of age, and patients who do not provide consent will be excluded from the study. Eligible participants will be randomized to receive propofol target-controlled infusion using either the Schnider or Eleveld model for anesthetic induction. Hemodynamic parameters and bispectral index values will be evaluated during the first 10 minutes of the induction period.

Who may be able to join

  • Patients scheduled for elective spinal surgery under general anesthesia
  • Patients who will undergo surgery at the Neurosurgery Department of Istanbul University, Istanbul Faculty of Medicine
  • Patients aged 18 years or older
  • Patients who provide written informed consent to participate in the study

Who cannot join

  • Patients with uncontrolled hypertension
  • Patients with uncontrolled diabetes mellitus
  • Patients younger than 18 years of age
  • Patients who do not provide informed consent to participate in the study

Trial locations and contacts

1 site in 1 country. Contact the study team or a site near you to ask about taking part.

Tugce Aydin Ozata, MD contact

009 0533 711 6090

tugceaydin1@gmail.com

Turkey (Türkiye)1 site, 1 recruiting
  • Istanbul University

    Istanbul

    Tugce Aydin Ozata, MD, 0090 533 711 6090, tugceaydin1@gmail.com

    Recruiting

Other trials in Turkey (Türkiye)

About this study

Official title: Comparison of Hemodynamic Responses During Anesthesia Induction Using Eleveld and Schnider Target-Controlled Infusion Models. A Randomized Trial

This randomized prospective study aims to compare the effects of two target-controlled infusion models, the Schnider and Eleveld models, on anesthetic depth and hemodynamic responses during anesthesia induction in adult patients undergoing spinal surgery.

Patients scheduled for spinal surgery will be randomized into either the Schnider or Eleveld group. Before induction, standard monitoring will be applied, including electrocardiography, peripheral oxygen saturation, invasive arterial blood pressure monitoring, heart rate monitoring, and bispectral index monitoring. Anesthesia induction will be performed with fentanyl 2 mcg/kg, rocuronium 0.6 mg/kg, and propofol administered by target-controlled infusion with an effect-site target concentration of 3 mcg/mL according to the allocated pharmacokinetic model.

Hemodynamic parameters and bispectral index values will be recorded before induction and at the 1st, 3rd, 5th, and 10th minutes after induction. Additional parameters, including time to BIS below 40, time to delta activity, burst suppression duration, total propofol dose during the first 5 minutes, need for additional propofol, hemodynamic response to intubation, vasopressor requirement within the first 10 minutes, and use of esmolol, will also be documented. The primary aim is to evaluate whether the Schnider and Eleveld models differ in terms of induction-related hemodynamic stability and anesthetic depth during the early induction period.

Read the detailed description

This study is designed as a randomized prospective clinical study in adult patients undergoing spinal surgery. The study will evaluate and compare two pharmacokinetic models used for target-controlled infusion of propofol: the Schnider model and the Eleveld model. The main focus of the study is the first 10 minutes of anesthesia induction, a period in which rapid changes in anesthetic depth and hemodynamic variables may occur.

Eligible patients scheduled for spinal surgery will be assigned to one of two groups according to the propofol target-controlled infusion model used during induction: the Schnider group or the Eleveld group. Patients younger than 18 years, patients with uncontrolled hypertension, patients with uncontrolled diabetes mellitus, and patients who do not provide consent will be excluded.

Before anesthesia induction, demographic and clinical variables will be recorded, including age, sex, ASA physical status, height, weight, body mass index, diagnosis, type of operation, operation date, and comorbid diseases. Baseline vital signs will be obtained from the preoperative ward follow-up values and from the immediate pre-induction period.

All patients will receive standard monitoring before induction, including peripheral oxygen saturation, electrocardiography, invasive arterial blood pressure monitoring, heart rate monitoring, and bispectral index monitoring. Invasive arterial pressure monitoring will allow continuous assessment of systolic arterial pressure, diastolic arterial pressure, and mean arterial pressure during the induction period.

Anesthesia induction will be performed using fentanyl 2 mcg/kg, rocuronium 0.6 mg/kg, and propofol administered by target-controlled infusion. Propofol will be administered using the pharmacokinetic model assigned by randomization, either Schnider or Eleveld. The target-controlled infusion pump will be set to achieve an effect-site propofol concentration of 3 mcg/mL. The induction period will be evaluated during the first 10 minutes after induction.

Heart rate, mean arterial pressure, systolic arterial pressure, diastolic arterial pressure, and BIS values will be recorded at predefined time points: ward baseline, immediately before induction, and at the 1st, 3rd, 5th, and 10th minutes after induction. The presence of a hemodynamic response to intubation will be assessed according to whether heart rate or mean arterial pressure increases by more than 20% compared with ward measurements. Patient movement or straining during intubation will also be recorded as none, mild, or severe.

In addition to routine hemodynamic and BIS measurements, several induction-related variables will be documented. These include the time required for BIS to decrease below 40, the time until delta activity is observed, burst suppression duration, total propofol dose during the first 5 minutes, need for additional propofol, total fentanyl and rocuronium doses, and whether esmolol was used, including its dose. The requirement for vasopressor therapy within the first 10 minutes, including the agent and dose used, will also be recorded.

During the first 10 minutes of induction, magnesium administration will not be performed in order to avoid potential confounding effects on hemodynamic parameters. Throughout the operation, the patient's hemodynamic stability will be observed, and any additional drug requirements will be documented.

The primary objective of the study is to compare the Schnider and Eleveld target-controlled infusion models in terms of hemodynamic changes and anesthetic depth during the first 10 minutes of anesthesia induction. Secondary evaluations will include the incidence of intubation-related hemodynamic response, time to BIS below 40, burst suppression duration, need for additional propofol, vasopressor requirement, and total propofol dose during early induction.

Being tested
TCI Propofol Injection Models- Eleveld, TCI Propofol Injection Schnider
Keywords
spinal surgery, total intravenous anesthesia, target controlled infusion, anesthesia depth monitoring

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • TCI Propofol Injection Models- EleveldOther

    Patients in this group will receive propofol for anesthetic induction using target-controlled infusion based on the Eleveld pharmacokinetic/pharmacodynamic model. Standard monitoring will include electrocardiography, peripheral oxygen saturation, invasive arterial blood pressure, heart rate, and bispectral index monitoring. Fentanyl 2 mcg/kg and rocuronium 0.6 mg/kg will be administered according to the study protocol. Hemodynamic variables and BIS values will be recorded before induction and at 1, 3, 5, and 10 minutes after induction.

  • TCI Propofol Injection SchniderOther

    Patients randomized to the Schnider group will receive propofol for anesthetic induction using target-controlled infusion based on the Schnider pharmacokinetic/pharmacodynamic model. Propofol will be administered via a TCI system according to the study protocol. Standard monitoring will include electrocardiography, peripheral oxygen saturation, invasive arterial blood pressure, heart rate, and bispectral index monitoring. Fentanyl 2 mcg/kg and rocuronium 0.6 mg/kg will be administered as part of the standardized induction protocol. Hemodynamic variables and BIS values will be recorded before induction and at 1, 3, 5, and 10 minutes after induction.

Study groups in NCT07586189
Study groupRoleWhat they receive
Eleveld ModelEleveld model used patients
Receives: Other: TCI Propofol Injection Models- Eleveld
Schnider ModelSchnider model used patients
Receives: Other: TCI Propofol Injection Schnider

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Mean Arterial Pressure - Physiological Parameter

    Mean Arterial Pressure Changes

    Measured: Mean Arterial Pressure - Baseline Mean Arterial Pressure - induction 1. minute Mean Arterial Pressure - induction 3. minute Mean Arterial Pressure - induction 5. minute Mean Arterial Pressure - induction 10. Minute

Secondary outcomes (13)
  1. Heart Rate - Physiological Parameter

    Heart Rate Changes

    Measured: Heart Rate - baseline Heart Rate- induction 1. minute Heart Rate- induction 3. minute Heart Rate- induction 5. minute Heart Rate- induction 10. minute

  2. Bisepectal Index values - Physiological Parameter, Processed EEG

    Bisepectal Index values

    Measured: baseline- intraoperative 0. minute induction - 1. minute induction- 3. minute induction- 5. minute induction- 10. Minute

  3. Time till BIS < 40

    time period till BIS value under 40 after induction

    Measured: first 10 minutes after induction

  4. Response to intubation

    Responce during intubation

    Measured: perioperative

  5. Burst suppression period

    Burst suppression period during first 10 minutes after induction

    Measured: first 10 minutes after induction

  6. Hemodynamic response to intubation

    Hemodynamic response to intubation ( >%20 decrease to baseline mean arterial pressure or heart rate)

    Measured: first 10 minutes after induction

  7. Total propofol dosage

    Total propofol dosage

    Measured: first 5 minutes after induction

  8. Additional Propofol Dose Requirement

    Additional Propofol Dose Requirement during Induction

    Measured: First 5 minutes after induction

  9. Total Fentanyl Dosage

    Total Fentanyl Dosage (2mcg/kg)

    Measured: perioperative

  10. Total Rocuronium Dosage

    Total Rocuronium Dosage (0.5mg/kg)

    Measured: perioperative

  11. Brevibloc Requirement

    Brevibloc Requirement

    Measured: First 5 minutes after induction

  12. Period of time until Delta wave

    Period of time until Delta wave on EEG

    Measured: First 10 minutes of induction period

  13. Vazopressor/Inotropic Drug Requirement

    Vazopressor/Inotropic Drug Requirement during induction period

    Measured: first 10 minutes after induction period

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted14 May 2026
  2. Study start18 May 2026
  3. Primary completion15 Aug 2026
  4. Study completion30 Aug 2026 (estimated)

Resources

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
50 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07586189
Sponsor's protocol ID
2025/664
Status last verified
Aug 2026
First submitted
8 May 2026
Last updated
18 Aug 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No: The clinical data of this trial are available upon reasonable request to the corresponding author.

Publications

  • Absalom AR, Schnider TW. The future of target-controlled infusion and new pharmacokinetic models. Curr Opin Anaesthesiol. 2025 Aug 1;38(4):375-381. doi: 10.1097/ACO.0000000000001529. Epub 2025 May 26.

    PubMed 40421498
  • Linassi F, Zanatta P, Spano L, Burelli P, Farnia A, Carron M. Schnider and Eleveld Models for Propofol Target-Controlled Infusion Anesthesia: A Clinical Comparison. Life (Basel). 2023 Oct 16;13(10):2065. doi: 10.3390/life13102065.

    PubMed 37895446
  • Safrankova P, Bruthans J. Target-Controlled Infusion of Propofol: A Systematic Review of Recent Results. J Med Syst. 2025 Apr 28;49(1):54. doi: 10.1007/s10916-025-02187-y.

    PubMed 40289063
  • Lee S, Kang D, Song E, Yoo S, Jeong S. External validation of the modified Marsh and Schnider models for medium-chain triglyceride propofol in target-controlled infusion anesthesia. BMC Anesthesiol. 2024 Feb 23;24(1):70. doi: 10.1186/s12871-024-02461-5.

    PubMed 38395779
  • Eleveld DJ, Colin P, Absalom AR, Struys MMRF. Pharmacokinetic-pharmacodynamic model for propofol for broad application in anaesthesia and sedation. Br J Anaesth. 2018 May;120(5):942-959. doi: 10.1016/j.bja.2018.01.018. Epub 2018 Mar 12.

    PubMed 29661412
  • Vellinga R, Hannivoort LN, Introna M, Touw DJ, Absalom AR, Eleveld DJ, Struys MMRF. Prospective clinical validation of the Eleveld propofol pharmacokinetic-pharmacodynamic model in general anaesthesia. Br J Anaesth. 2021 Feb;126(2):386-394. doi: 10.1016/j.bja.2020.10.027. Epub 2020 Dec 13.

    PubMed 33317804
  • Absalom AR, Glen JI, Zwart GJ, Schnider TW, Struys MM. Target-Controlled Infusion: A Mature Technology. Anesth Analg. 2016 Jan;122(1):70-8. doi: 10.1213/ANE.0000000000001009.

    PubMed 26516798

Questions about this trial

What is this clinical trial studying?

An observational study of Spinal (Fusion) Surgery and Total Intravenous Anesthesia, run by Istanbul University at 1 site in Turkey (Türkiye).

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: looking for participants now, as of the sponsor's last update on 18 Aug 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 Turkey (Türkiye). 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?

Contact Tugce Aydin Ozata, MD (009 0533 711 6090, tugceaydin1@gmail.com), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Mean Arterial Pressure - Physiological Parameter (time frame: Mean Arterial Pressure - Baseline Mean Arterial Pressure - induction 1. minute Mean Arterial Pressure - induction 3. minute Mean Arterial Pressure - induction 5. minute Mean Arterial Pressure - induction 10. Minute). 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 NCT07586189, which also lists 7 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 18 Aug 2026.

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