Effect of Apneic Oxygenation of the Non-ventilated Lung During Lung Cancer Surgery.

Inclusion Criteria: * Adults aged 18 years or older * Patients scheduled to undergo surgical resection of a single lung segment for lung cancer * Written informed consent provided Exclusion Criteria: * Age younger than 18 years * Chronic corticosteroid therapy and/or other immunomodulatory treatments * Severe pulmonary diseases, including: Chronic obstructive pulmonary disease classified as GOLD stage 3-4 (Global Initiative for Chronic Obstructive Lung Disease). Severe asthma according to GINA classification (Global Initiative for Asthma), step 4. Severe interstitial lung disease defined by: Forced vital capacity (FVC) \< 50% predicted, diffusing capacity of the lung for carbon monoxide (DLCO) \< 40% predicted, presence of extensive pulmonary fibrosis on computed tomography (CT) * Surgical procedure expected to last less than 2 hours * Intraoperative hemodynamic instability, defined as: Mean arterial pressure \< 60 mmHg for more than 30 minutes despite adequate volume resuscitation, requirement for high-dose vasopressor support (norepinephrine \> 0.2 µg/kg/min) * New-onset intraoperative cardiac arrhythmias * Significant intraoperative blood loss, defined as the need for transfusion of more than two units of packed red blood cells * Intraoperative ventilatory instability, defined as: Severe hypoxemia (PaO₂ \< 60 mmHg or SpO₂ \< 85% with FiO₂ 1.0), hypercapnia (PaCO₂ \> 70 mmHg with pH \< 7.2), inability to achieve adequate ventilation.