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.

This prospective observational cohort study included 118 adult patients undergoing elective pulmonary resection between 2018 and 2022. The objective was to evaluate the association between intraoperative intravenous lidocaine, ketamine, and magnesium (LKM) and postoperative analgesic outcomes. Seventy-one patients received intraoperative LKM as part of a standardized multimodal analgesic protocol, consisting of lidocaine (1.5 mg/kg bolus followed by 1.5 mg/kg/h infusion), ketamine (0.3 mg/kg bolus), and magnesium sulfate (1.5 g bolus). Forty-seven patients received standard anesthesia without LKM administration. No study-specific interventions were assigned; exposure was based on routine anesthetic practice.

The primary outcome was total intravenous morphine consumption during the first 24 postoperative hours. Secondary outcomes included pain scores (VAS) at 3 and 24 hours, incidence of chronic postoperative pain at 3 months, pulmonary and cardiovascular complications, renal injury, thromboembolic events, hospital length of stay, and mortality. Safety monitoring included hypotension, bradycardia, arrhythmias, hallucinations, and delayed emergence from anesthesia.

This study aimed to identify perioperative factors influencing postoperative pain and opioid use after thoracic surgery, while evaluating the potential benefit of LKM within a multimodal analgesia strategy. All patients provided informed consent, and the study was approved by the local ethics committee. Data collection and clinical management followed standard institutional protocols.

Inclusion Criteria:

• Adults aged 18 years or older.
• Scheduled for elective pulmonary resection (thoracotomy or VATS).
• Able to provide informed consent.
• ASA physical status I-IV.

Exclusion Criteria:

• Emergency surgery.
• Known allergy or contraindication to lidocaine, ketamine, or magnesium.
• Severe hepatic insufficiency.
• Severe renal dysfunction (eGFR < 30 mL/min/1.73 m²).
• Pre-existing significant arrhythmias (e.g., uncontrolled atrial fibrillation, ventricular arrhythmias).
• Pregnancy.
• Cognitive impairment preventing valid informed consent.
• Patients receiving chronic intravenous analgesics or regional anesthesia techniques preoperatively.

Adult patients undergoing elective pulmonary resection (thoracotomy or video-assisted thoracoscopic surgery) at University Hospital Dr. Josep Trueta. The study population includes individuals receiving standard perioperative analgesic management and monitored in the postoperative care unit. Patients represent a typical thoracic surgery clinical population treated in routine practice.

Individual participant data (IPD) will not be shared because the study is observational and involves retrospective data collected as part of routine clinical care. Data cannot be shared publicly due to privacy and confidentiality restrictions.