Assessment of Reintubation Risk Using Multiple Parameters in Postoperative Intensive Care Unit Patients

This prospective, non-interventional observational study will evaluate the risk of reintubation in adult postoperative patients admitted to the intensive care unit after major surgery. Reintubation after extubation is an important clinical problem because it may increase complications, prolong mechanical ventilation, and extend intensive care and hospital stay. The study will include adult patients who are extubated in the operating room and admitted to the intensive care unit with spontaneous breathing. Within the first hours after ICU admission, bedside ultrasound measurements of diaphragm thickness, parasternal intercostal muscle thickness, and lung ultrasound score will be performed. The ROX index will also be calculated using oxygen saturation, inspired oxygen concentration, and respiratory rate. Perioperative fluid balance will be recorded from anesthesia and patient files. Patients will be followed for 48 to 72 hours after ICU admission to determine whether reintubation is required. The study aims to assess whether respiratory muscle ultrasound findings, lung ultrasound score, ROX index, and perioperative fluid balance can help predict reintubation risk in postoperative ICU patients. No additional treatment or intervention will be applied as part of the study, and all clinical decisions will be made by the responsible intensive care team according to routine clinical practice.