Endotracheal Tube Malposition Causing Acute Airway Obstruction in an Obese Patient with Ankylosing Spondylitis: A Case Report

A 63-year-old obese male with severe ankylosing spondylitis (AS) underwent general anesthesia for total hip replacement. Despite apparently successful video-assisted intubation, the patient developed acute ventilation failure characterized by significant air leakage, elevated peak inspiratory pressure (PIP), and an abnormal end-tidal carbon dioxide (E t CO 2 ) waveform. Suction catheter insertion met resistance at approximately 30 cm, suggesting distal endotracheal tube (ETT) malposition, likely due to tracheal wall impingement caused by altered airway anatomy from severe kyphotic deformity. Prompt recognition, aggressive secretion management, and emergency reintubation using a video-assisted technique successfully restored ventilation. There was no desaturation during the event, but PIP increased to 44 cm H 2 O, and continuous air leakage was noted. This case report highlights the importance of early recognition of ETT malposition, the challenges of airway management in patients with combined AS and obesity, and the value of a structured, team-based approach using multimodal airway strategies.