Intravenous Lidocaine, Ketamine, and Magnesium in Thoracic Surgery (LKM-Thorax)

Evaluation of Intraoperative Intravenous Lidocaine, Ketamine, and Magnesium on Postoperative Pain and Opioid Use After Pulmonary Resection: A Prospective Observational Cohort Study

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.

Study Overview

• Status: Completed
• Conditions: Postoperative Pain; Thoracic Surgery; Multimodal Analgesia; Opioid Consumption, Postoperative

Detailed Description

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.

• Study Type: Observational
• Enrollment (Actual): 118

Contacts and Locations

Study Locations

• Spain
  • Girona, Spain, 17007
    • University Hospital Dr. Josep Trueta

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

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.

Description

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.

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort
Lidocaine-Ketamine-Magnesium Group (LKM); Adult patients undergoing elective pulmonary resection who received intraoperative multimodal analgesia including continuous infusions of lidocaine, ketamine, and magnesium according to institutional protocol.
Standard Analgesia Control Group; Adult patients undergoing elective pulmonary resection who received standard intraoperative analgesia without lidocaine, ketamine, or magnesium infusion.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Total intravenous morphine consumption within the first 24 hours postoperatively.	Total amount of intravenous morphine administered during the first 24 postoperative hours. Values will be recorded in milligrams (mg). Higher values indicate greater opioid consumption.	First 24 postoperative hours

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Pain intensity at 3 and 24 hours postoperatively, assessed using a 10-point Visual Analogue Scale (VAS), chronic pain ( 3 months)	Pain intensity assessed using a 10-point Visual Analogue Scale (VAS), where 0 represents no pain and 10 represents the worst imaginable pain. Measurements will be recorded at 3 hours, 24 hours, and 3 months after surgery. Higher scores indicate greater pain intensity. Pain persisting at 3 months will be classified as chronic post-surgical pain.	3 hours, 24 hours, and 3 months after surgery

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Safety Outcomes	Incidence of perioperative and postoperative adverse events, including hypotension, bradycardia, atrial fibrillation, deep vein thrombosis (DVT), pulmonary embolism (PE), prolonged hospital stay, in-hospital mortality, and survival status at 3 months. All events will be recorded as present or absent (yes/no).	Perioperative period (day of surgery through postoperative day 7) and at 3 months

Collaborators and Investigators

• Sponsor: Universidad Pública de Navarra
• Investigators: Principal Investigator: Manuel Murie Fernandez, MD, PhD, Universidad Pública de Navarra ( UPNA)

Study record dates

Study Major Dates

• Study Start (Actual): January 1, 2018
• Primary Completion (Actual): February 3, 2022
• Study Completion (Actual): May 3, 2022

Study Registration Dates

• First Submitted: December 9, 2025
• First Submitted That Met QC Criteria: January 13, 2026
• First Posted (Actual): January 22, 2026

Study Record Updates

• Last Update Posted (Actual): January 22, 2026
• Last Update Submitted That Met QC Criteria: January 13, 2026
• Last Verified: December 1, 2025

More Information

Terms related to this study

• Keywords: Ketamine; Lidocaine; thoracotomy; Magnesium sulphate; Opioid consumption; Multimodal analgesia; VAS pain score; VATS surgery
• Additional Relevant MeSH Terms: Pain; Neurologic Manifestations; Postoperative Complications; Pathologic Processes; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Pain, Postoperative
• Other Study ID Numbers: FR-CP01; EDONA-UPNA-2025 (Other Identifier: Universidad Pública de Navarra (UPNA))

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: 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.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No