The goal of this observational study is to learn whether a participant's understanding of the informed consent information is related to the amount of propofol needed during endobronchial ultrasound (EBUS). EBUS is a procedure that uses a thin camera and ultrasound to look at lymph nodes and other areas inside the chest. Propofol is a sedative medicine used to help participants stay comfortable during the procedure.

Before EBUS, all participants will receive the usual information about the procedure as part of routine care. After this routine consent process, participants will answer short questions about what they understood. They will also answer questions about their anxiety before the procedure. The study will not change the usual consent process, sedation plan, or medical care.

During EBUS, participants will receive usual sedation and monitoring according to routine clinical practice. The research team will record how much sedative medicine is used, whether extra sedation is needed, whether any important clinical events occur, and how participants recover after sedation. The main question is whether participants who understand the consent information better need less propofol during EBUS.

Endobronchial ultrasound (EBUS) is a minimally invasive bronchoscopic procedure commonly used to evaluate mediastinal and hilar lymph nodes and other intrathoracic lesions. Because airway stimulation, coughing, and patient movement may occur during the procedure, sedation is commonly used to improve patient comfort and procedural tolerance.

This prospective observational study will evaluate the relationship between participants' understanding of the informed consent information and their sedative requirement during EBUS. All participants will undergo the routine clinical informed consent process before the procedure. After this process, their understanding of the procedure will be assessed using a structured consent understanding assessment form developed by the investigators. Preprocedural anxiety will also be evaluated using a validated anxiety scale.

The study will not assign participants to any intervention and will not modify routine clinical care. Sedation, monitoring, and procedural management will be performed according to usual clinical practice. The research team will record perioperative data related to sedative medication use, need for additional sedation, sedation-related clinical events, and early recovery after the procedure. The planned analysis will assess whether a higher level of consent understanding is associated with lower propofol requirement during EBUS, while considering relevant clinical factors.

Inclusion Criteria:

• Age 18 years or older
• Scheduled for elective endobronchial ultrasound
• ASA physical status I to III
• Ability to read and understand Turkish
• Provision of written informed consent for study participation

Exclusion Criteria:

• Active psychiatric disease that may affect the informed consent process, anxiety assessment, or communication
• Cognitive impairment, including dementia or delirium
• Contraindication or known allergy to propofol, midazolam, or remifentanil
• Emergency EBUS procedure
• Regular anxiolytic or sedative drug use within the last month
• Illiteracy
• Turkish language barrier
• Advanced organ failure or decompensated systemic disease that may significantly affect sedative drug response, hemodynamic stability, communication, or consent assessment

Adult participants scheduled for elective endobronchial ultrasound under routine clinical sedation at Bursa Uludag University Faculty of Medicine Hospital. Eligible participants will be those who meet the study inclusion criteria and provide written informed consent for study participation.

Individual participant data will not be shared because participants did not provide specific consent for public or external individual-level data sharing. The study data will be coded and used only for the purposes of this research. Aggregate results may be reported in scientific publications.