Extubation Guided by Bedside Ultrasound

This observational cohort study evaluates risk factors for extubation failure in elderly surgical patients. All participants receive standard pre-extubation clinical assessments per institutional protocol, including LUS、DE and oxygenation index (PaO₂/FiO₂), arterial blood gas analysis, and the patients'laboratory results before and after surgery. The association between these parameters and extubation failure will be analyzed.