Effects of Magnesium Sulfate on Oxygenation and Lung Mechanics During One-Lung Ventilation

Effects of Magnesium Sulfate on Intraoperative Oxygenation and Lung Mechanics During One-Lung Ventilation: A Prospective Observational Study

This prospective observational study aims to evaluate the effects of intravenous magnesium sulfate on intraoperative oxygenation and lung mechanics in patients undergoing thoracic surgery with one-lung ventilation. Magnesium sulfate has been reported to have potential bronchodilatory and anti-inflammatory properties, which may improve gas exchange and respiratory mechanics during lung isolation.

In this study, patients who receive magnesium sulfate as part of standard anesthetic management will be compared with those who do not receive the drug. Oxygenation parameters, dynamic and static lung mechanics, airway pressures, and ventilation-related indices will be recorded throughout the intraoperative period. The findings of this study may help clarify whether magnesium sulfate provides measurable respiratory benefits during one-lung ventilation.

Study Overview

• Status: Recruiting
• Conditions: Intraoperative Oxygenation and Pulmonary Mechanics

• Study Type: Observational
• Enrollment (Estimated): 104

Contacts and Locations

• Study Contact: Name: İlayda AKARSU KAYA, Anesthesiology Resident, Principal Investigator; Phone Number: +905073306901; Email: ilaydaakarsu96@gmail.com
• Study Contact Backup: Name: Meliha ORHON ERGÜN; Phone Number: +905413402001; Email: dr.meliha@gmail.com

Study Locations

• Turkey (Türkiye)
  • Istanbul, Turkey (Türkiye), 34854
    • Recruiting
    • Marmara University Faculty of Medicine, Basibuyuk Campus
    • Contact: İlayda AKARSU KAYA, Anesthesiology Resident, Principal Investigator; Phone Number: +905073306901; Email: ilaydaakarsu96@gmail.com

Participation Criteria

Eligibility Criteria

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

• Sampling Method: Non-Probability Sample

Study Population

This study will include adult patients undergoing elective thoracic surgery performed with video-assisted thoracoscopic surgery (VATS) requiring one-lung ventilation under general anesthesia. The study population consists of individuals scheduled for minimally invasive lung resections or other VATS procedures necessitating lung isolation. Patients receiving magnesium sulfate intraoperatively and those not receiving it will be prospectively observed. Patients undergoing pneumonectomy, those with significant organ failure, extreme BMI values, or inadequate pulmonary function will be excluded.

Description

Inclusion Criteria:

Adults aged 18 to 80 years Scheduled for elective thoracic surgery performed with video-assisted thoracoscopic surgery (VATS) requiring one-lung ventilation under general anesthesia.

ASA physical status II-III Ability to provide informed consent Undergoing general anesthesia with double-lumen tube placement

Exclusion Criteria:

• Patients undergoing pneumonectomy
• Patients with renal, hepatic, or cardiovascular failure
• Patients with a BMI < 15 kg/m² or > 35 kg/m²
• Patients with a preoperative pulmonary function test showing FEV₁ < 1.5 liters
• Patients who are transferred to the intensive care unit intubated in the postoperative period
• Patients with physical or mental conditions that prevent the performance of pulmonary function testing factors

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort
Group 1 - Magnesium Sulfate Group Label: Magnesium Sulfate Group; Patients receiving intravenous magnesium sulfate during the surgery as part of standard anesthetic management.
Group 2 - Control Group Label: Control Group; Patients undergoing one-lung ventilation without the administration of magnesium sulfate

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Intraoperative Oxygenation (PaO₂/FiO₂ Ratio)	The PaO₂/FiO₂ ratio will be measured to evaluate intraoperative oxygenation during the surgery. Measurements will be recorded after induction of anesthesia (baseline) and at predefined intraoperative time points. The primary outcome is the change in PaO₂/FiO₂ ratio between baseline and intraoperative measurements in patients receiving magnesium sulfate versus control.	From induction of anesthesia to the end of one-lung ventilation (approximately 2-3 hours)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Changes in Airway Pressures (Peak and Plateau Pressures)	Peak inspiratory pressure (PIP) and plateau pressure (Pplat) will be measured to assess changes in airway pressures during one-lung ventilation in patients receiving magnesium sulfate compared with control.	From induction of anesthesia to the end of one-lung ventilation (approximately 2-3 hours).
Dynamic Lung Compliance and Airway Resistance (Raw)	Dynamic compliance (Cdyn) will be recorded at predefined intraoperative time points to evaluate changes in pulmonary mechanics associated with magnesium sulfate administration.Airway resistance (Raw) will be measured at predefined intraoperative time points using ventilator-derived data. Raw will be compared between patients receiving magnesium sulfate and those in the control group to assess the effect of magnesium sulfate on airway resistance during one-lung ventilation.	Intraoperative period (approximately 2-3 hours).
Postoperative Arterial Oxygen Partial Pressure (PaO₂) on Room Air	Arterial oxygen partial pressure (PaO₂) will be measured in the postoperative period while patients are breathing room air. This outcome will be used to assess whether intraoperative magnesium sulfate administration has an effect on early postoperative oxygenation following one-lung ventilation.	Within the first postoperative hour while breathing room air.

Collaborators and Investigators

• Sponsor: Marmara University
• Investigators: Study Chair: Meliha ORHON ERGÜN, Marmara University Faculty of Medicine, Department of Anesthesiology and Reanimation; Principal Investigator: İlayda AKARSU KAYA, Marmara University Faculty of Medicine, Department of Anesthesiology and Reanimation

Study record dates

Study Major Dates

• Study Start (Actual): December 1, 2025
• Primary Completion (Estimated): July 15, 2026
• Study Completion (Estimated): November 28, 2026

Study Registration Dates

• First Submitted: December 24, 2025
• First Submitted That Met QC Criteria: December 24, 2025
• First Posted (Actual): January 8, 2026

Study Record Updates

• Last Update Posted (Actual): January 8, 2026
• Last Update Submitted That Met QC Criteria: December 24, 2025
• Last Verified: December 1, 2025

More Information

Terms related to this study

• Keywords: Oxygenation; Magnesium Sulfate; One-Lung Ventilation; Lung Mechanics; Airway Pressure
• Other Study ID Numbers: 09.2025.463

Plan for Individual participant data (IPD)

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

Drug and device information, study documents

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