This prospective observational study evaluated the role of bedside ultrasound in confirming endotracheal tube placement in adult patients who underwent endotracheal intubation in the emergency department. Correct placement of the endotracheal tube is critical because unrecognized incorrect placement may cause hypoxemia, hypoxic brain injury, or death.

In this study, bedside ultrasound was performed during or immediately after endotracheal intubation without interfering with the intubation procedure. Ultrasound findings were compared with capnographic end-tidal carbon dioxide measurement, which was used as the reference method for confirming tube placement. The main aim was to assess whether bedside ultrasound is a useful and reliable method for confirming endotracheal tube position in emergency department patients.

This single-center, prospective observational diagnostic accuracy study was conducted in the Emergency Department of Antalya Training and Research Hospital. Adult patients who underwent endotracheal intubation in the emergency department after ethics committee approval were included.

Endotracheal intubation was performed as part of routine emergency care by the most senior emergency medicine resident or an experienced emergency physician. Bedside ultrasound assessment was performed during or immediately after intubation by trained emergency physicians without interrupting or delaying the intubation procedure. The ultrasound examination was performed from the suprasternal notch region to assess the position of the endotracheal tube.

The physicians who performed bedside ultrasound had at least two years of emergency medicine experience and had completed accredited ultrasound training. Before study data collection, they received additional theoretical and practical training focused on ultrasound confirmation of endotracheal tube placement.

Ultrasound findings were compared with capnometric end-tidal carbon dioxide measurement, which was used as the reference method for confirmation of endotracheal tube placement. Ultrasound images were stored in the hospital computer system and reviewed by two qualified, independent radiology specialists. Images or measurements with insufficient quality were excluded from analysis. Agreement between ultrasound assessments was evaluated statistically.

The study aimed to determine whether bedside ultrasound can be used as a rapid, reliable, and practical method for confirming endotracheal tube placement in emergency department patients.

Inclusion Criteria:

• Patients aged 18 years or older
• Patients who underwent endotracheal intubation in the emergency department as part of routine emergency care
• Patients in whom bedside ultrasound and capnometric end-tidal carbon dioxide assessment were performed for confirmation of endotracheal tube placement

Exclusion Criteria:

• Patients younger than 18 years of age
• Patients with missing or incomplete study data
• Patients with ultrasound images of insufficient quality for evaluation

The study population consisted of adult patients aged 18 years or older who presented to the Emergency Department of Antalya Training and Research Hospital and underwent endotracheal intubation as part of routine emergency care. Patients were included after ethics committee approval if bedside ultrasound and capnometric end-tidal carbon dioxide assessment were performed for confirmation of endotracheal tube placement.

Individual participant data will not be shared publicly because the study includes clinical data from emergency department patients and there may be confidentiality and institutional restrictions. De-identified aggregate results will be reported in scientific publications.