Comparison of Eleveld and Schnider Models for Target-Controlled Infusion of Propofol in Intensive Care Unit Sedation
Conditions: Intensive Care Unit Sedation, Sedation, Target Controlled Infusion of Propofol
Sponsor: Hacettepe University

Hacettepe University Faculty of Medicine 
Department of Anesthesiology and Reanimation 
Clinical Trial Study Protocol 
Official Title: Comparison of Eleveld and Schnider Target-Controlled Infusion (TCI) Models 
for Propofol Sedation in Intensive Care Unit Patients 
NCT Number: NCT PENDİNG  
Date: October 28, 2025 
 
Principal Investigator: Assoc. Prof. Başak Akça 
Co-Investigators: Prof. Seda Banu Akıncı, Dr. Duygu Özdemir Şimşek 
Hacettepe University Hospital, Ankara, Türkiye 
 
 

Background and Rationale 
Evidence-based international guidelines on ICU sedation for mechanically ventilated 
patients provide similar recommendations. Sedation is routinely administered in critically 
ill patients to reduce anxiety, facilitate procedures, decrease oxygen consumption and 
autonomic hyperactivity, and minimize ventilator asynchrony. The goal is to maintain 
patient comfort and hemodynamic stability while ensuring easy arousability, except in cases 
requiring deep sedation. Current guidelines recommend using the minimum effective 
sedation level and performing daily awakening to improve outcomes. Propofol is the 
preferred sedative due to its rapid onset and predictable recovery. Target-Controlled 
Infusion (TCI) systems help achieve desired effect-site concentrations based on 
pharmacokinetic and pharmacodynamic models. The Schnider model is widely used, while 
the newer Eleveld model integrates broader demographic covariates and has superior 
predictive performance. This study compares both models in ICU sedation regarding 
hemodynamic stability, sedation performance, awakening, extubation, ICU discharge, and 
delirium incidence. 
Study Objectives 
To compare the clinical performance of the Eleveld and Schnider propofol TCI models in ICU 
patients regarding hemodynamic stability, sedation performance, awakening and 
extubation times, delirium incidence, and ICU length of stay. 
Study Design 
Study Type: Observational (Prospective Cohort Study) 
Time Perspective: Prospective 
Study Location: Hacettepe University Faculty of Medicine, Department of Anesthesiology 
and Reanimation, Intensive Care Unit, Ankara, Türkiye 
Study Period: February 2025 – December 2025 
Estimated Enrollment: 84 participants (42 per group) 
Sampling Method: Consecutive sampling 
 
Two groups will be observed: 
1. Patients sedated with propofol using the Schnider TCI model. 
2. Patients sedated with propofol using the Eleveld TCI model. 
 
Sedation with TCI propofol is routine practice in the ICU, and this study will not alter clinical 
management or drug choice. The responsible anesthesiologist will decide on sedation use 
independently. 
Eligibility Criteria 
Inclusion Criteria: 
- Age ≥18 years 
- ASA I–IV 
- Sedation required for mechanical ventilation 

- Sedation ≤72 hours 
- Informed consent obtained 
 
Exclusion Criteria: 
- ASA >IV 
- BMI ≥35 
- Propofol allergy or lipid metabolism disorder 
- Sedation >72 hours 
- Neurological or neurodegenerative disease affecting consciousness assessment 
Outcome Measures 
Primary Outcome: 
- Sedation depth accuracy (BIS 40–60, Riker SAS 3–4) 
 
Secondary Outcomes: 
1. Hemodynamic stability (MAP, HR) 
2. Awakening and extubation times 
3. Delirium incidence (CAM-ICU) 
4. ICU length of stay 
5. Adverse events 
Data Collection and Analysis 
Demographic and clinical data (age, sex, height, weight, comorbidities) will be recorded. 
Sedation depth will be evaluated every 4 hours using BIS and Riker SAS. Statistical tests: 
Shapiro–Wilk for normality; Student’s t-test or Mann–Whitney U for continuous variables; 
Chi-square or Fisher’s exact test for categorical variables; significance set at p<0.05. 
Ethical Considerations 
Approved by the Hacettepe University Clinical Research Ethics Committee. Written 
informed consent will be obtained. No deviation from standard ICU practice will occur. The 
study is purely observational. 
Research Team 
Principal Investigator: Assoc. Prof. Başak Akça 
Co-Investigators: Prof. Seda Banu Akıncı, Dr. Duygu Özdemir Şimşek 
Hacettepe University Faculty of Medicine, Department of Anesthesiology and Reanimation.