Learning Curve Analysis of Double-Lumen Tube Placement in Anesthesiology Residents: The Impact of Prior Experience and Laryngoscope Type

Placement of a double-lumen tube (DLT) is one of the fundamental techniques for safely achieving one-lung ventilation in thoracic anesthesia. Compared with standard single-lumen endotracheal tubes, DLTs have a larger diameter, greater length, and a more rigid structure. These characteristics make intubation with a DLT considerably more challenging in both normal and difficult airways, potentially increasing the risk of upper airway trauma and postoperative complications, thereby contributing to increased overall morbidity and mortality.

Despite its widespread clinical use, DLT placement remains a technically demanding procedure due to anatomical variability, limited visualization, and operator-dependent performance differences. The reported incidence of DLT malposition in the literature ranges from 32% to 83%. Even in studies reporting lower rates (approximately 32.44%), it is acknowledged that a substantial number of malpositions may go undetected, which can critically impact both patient safety and surgical outcomes. In addition to initial misplacement, repeated repositioning of a malpositioned DLT may itself lead to airway injury. Increased manipulation of the DLT within the bronchial tree may result in excessive trauma.

DLT malposition may predispose patients to inadequate lung isolation, hypoxemia, tracheobronchial injury, and potential complications such as barotrauma or pneumothorax. Operator experience is recognized as a key determinant of success in airway management. Previous studies have demonstrated that technical proficiency in advanced airway interventions improves with cumulative clinical experience. However, most existing research has focused on basic airway devices, and evidence regarding advanced airway techniques such as DLT placement remains limited. Furthermore, the relative contributions of operator experience, airway difficulty, and device technology to procedural success have not been fully elucidated.

To address the need for easier and safer endotracheal intubation, various types of video laryngoscopes have been developed as alternatives to direct laryngoscopy. Nevertheless, it remains unclear whether video-assisted airway management reduces DLT malposition rates across different levels of operator experience.

Simulation-based training has become increasingly important in modern anesthesiology education, providing a safe and standardized environment for the assessment of airway management skills. Accordingly, there is a need for simulation-based studies evaluating learning curves and technical performance in DLT placement.

The primary aim of this study is to evaluate the effects of overall clinical experience and prior DLT placement experience on malposition rates during DLT insertion procedures performed in a simulation setting among anesthesiology residents. Secondary objectives include comparing the performance of video laryngoscopy and Macintosh laryngoscopy, as well as analyzing learning curves across repeated attempts. Additionally, the interaction between experience level, type of laryngoscope used, and airway difficulty will be investigated.

Study Design and Population This study will be conducted in accordance with the Declaration of Helsinki and will be carried out at Ankara Atatürk Sanatorium Training and Research Hospital after obtaining approval from the institutional ethics committee.

The study is designed as a prospective, observer-blinded, simulation-based study with repeated measures. It aims to evaluate DLT placement performance using standardized airway simulation models.

All anesthesiology residents working in the Department of Anesthesiology and Reanimation at Ankara Atatürk Sanatorium Training and Research Hospital will be invited to participate on a voluntary basis (total of 33 participants). Written informed consent will be obtained from all participants.

Anesthesiology residents with varying levels of experience will be included voluntarily. Participants will be stratified based on years of residency training and the number of prior DLT placements performed.

Airway simulation will be conducted using high-fidelity airway manikins equipped with bronchial anatomy modules. Intubation will be performed using a 37 Fr DLT. Simulation platforms with fiberoptic verification capability will be utilized. Prior to data collection, participants will receive standardized training on DLT placement.