Thoracic surgery often produces severe postoperative pain due to nerve injury and inflammation. Effective pain control is essential to reduce complications and opioid use. This prospective observational cohort study evaluated adult patients undergoing pulmonary resection by thoracotomy or video-assisted thoracoscopic surgery (VATS). The study examined whether intraoperative administration of intravenous lidocaine, ketamine, and magnesium, used as part of multimodal analgesia, was associated with reduced postoperative morphine consumption and lower early postoperative pain scores. Outcomes included 24-hour morphine use, pain intensity at 3 and 24 hours, complications, and chronic pain at 3 months. No study-directed interventions were performed; anesthetic management followed routine clinical practice.