Faster Induction, Lower Consumption, and Quicker Recovery: A Comparison of Eleveld and Schnider TCI Models for Sedation in Outpatient Colonoscopy
TL;DR
The Eleveld TCI model was associated with faster induction, lower propofol consumption, and faster recovery than the Schnider model during outpatient colonoscopy, with comparable sedation adjustment requirements and post-procedural agitation.
Abstract
Introduction: Outpatient colonoscopy is commonly performed under sedation, and propofol is frequently selected because of its rapid onset and short recovery profile. Target-controlled infusion (TCI) may improve dosing precision, but the comparative performance of the Eleveld and Schnider models during outpatient colonoscopy remains insufficiently defined. This study compared the Eleveld and Schnider TCI models for propofol sedation in patients undergoing outpatient colonoscopy. Patients and Methods: This randomized, participant- and assessor-blinded, parallel-group controlled trial included 36 adults aged 20-65 years with ASA physical status I-III and BMI <30 kg/m2 who underwent elective outpatient colonoscopy. Participants were allocated to receive propofol using either the Eleveld or Schnider TCI model. The initial effect-site concentration was 2 µg/mL and was titrated by 0.5 µg/mL until a BIS value of 70 was achieved. The primary outcome was induction time, defined as the time from propofol infusion initiation to BIS 70. Secondary outcomes were mean propofol consumption, number of effect-site concentration adjustments, post-procedural agitation assessed using RASS, and recovery time to GCS 15. Results: The Eleveld model was associated with shorter induction time than the Schnider model (4.03 ± 0.81 vs 5.32 ± 0.98 minutes; p <0.001) and lower propofol consumption (92.47 ± 28.29 vs 119.24 ± 31.56 µg/kg/min; p = 0.011). Recovery time was also shorter in the Eleveld group (5.27 ± 1.71 vs 7.88 ± 1.94 minutes; p <0.001). The number of effect-site concentration adjustments and postprocedural agitation did not differ significantly between groups. Conclusion: The Eleveld TCI model was associated with faster induction, lower propofol consumption, and faster recovery than the Schnider model during outpatient colonoscopy, with comparable sedation adjustment requirements and post-procedural agitation. These findings suggest that the Eleveld model may improve sedation efficiency in this setting, although larger studies are needed to confirm its clinical and safety advantages.