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).
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
- Conditions the study is for
- Spinal (Fusion) Surgery, Total Intravenous Anesthesia, Target Controlled Infusion of Propofol
- 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
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.
Turkey (Türkiye)1 site, 1 recruiting
- Recruiting
Istanbul University
Istanbul
Tugce Aydin Ozata, MD, 0090 533 711 6090, tugceaydin1@gmail.com
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.
- Conditions
- Spinal (Fusion) Surgery, Total Intravenous Anesthesia, Target Controlled Infusion of Propofol, Anesthesia Depth Monitoring, BIS-EEG
- 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 group | Role | What they receive |
|---|---|---|
| Eleveld Model | Eleveld model used patients Receives: Other: TCI Propofol Injection Models- Eleveld | |
| Schnider Model | Schnider 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.
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)
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
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
Time till BIS < 40
time period till BIS value under 40 after induction
Measured: first 10 minutes after induction
Response to intubation
Responce during intubation
Measured: perioperative
Burst suppression period
Burst suppression period during first 10 minutes after induction
Measured: first 10 minutes after induction
Hemodynamic response to intubation
Hemodynamic response to intubation ( >%20 decrease to baseline mean arterial pressure or heart rate)
Measured: first 10 minutes after induction
Total propofol dosage
Total propofol dosage
Measured: first 5 minutes after induction
Additional Propofol Dose Requirement
Additional Propofol Dose Requirement during Induction
Measured: First 5 minutes after induction
Total Fentanyl Dosage
Total Fentanyl Dosage (2mcg/kg)
Measured: perioperative
Total Rocuronium Dosage
Total Rocuronium Dosage (0.5mg/kg)
Measured: perioperative
Brevibloc Requirement
Brevibloc Requirement
Measured: First 5 minutes after induction
Period of time until Delta wave
Period of time until Delta wave on EEG
Measured: First 10 minutes of induction period
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.
- First posted14 May 2026
- Study start18 May 2026
- Primary completion15 Aug 2026
- Study completion30 Aug 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (7)Papers the sponsor has linked to this study.
- Other trials for Spinal (Fusion) SurgeryStudies 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
- 50 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Istanbul University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Tugce Aydin Ozata, Istanbul University
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 40421498Linassi 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 37895446Safrankova 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 40289063Lee 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 38395779Eleveld 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 29661412Vellinga 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 33317804Absalom 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