Flow-Controlled Versus Volume-Controlled Ventilation During Balloon Dilatation Under Direct Laryngoscopy

Exclusion Criteria

• •Age \< 18 years or \> 65 years
• •Known or previously diagnosed pulmonary disease
• •Patients with severe preoperative pulmonary function impairment (e.g., FEV₁ \< 50% predicted, severe restrictive or obstructive pathology)
• •Patients with markedly altered lung anatomy or function due to prior major thoracic surgery
• •Patients who were dependent on supplemental oxygen therapy in the preoperative period
• •ASA physical status IV or higher
• •Refusal or inability to provide informed consent