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

Marmara University104 enrolled

Overview

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 Type

OBSERVATIONAL

Enrollment

104

Conditions

Intraoperative Oxygenation and Pulmonary Mechanics

Eligibility

Sex: ALLMin age: 18 YearsMax age: 80 Years

Medical Language ↔ Plain English

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

Outcomes

Primary Outcomes

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.

Time frame: From induction of anesthesia to the end of one-lung ventilation (approximately 2-3 hours)

Secondary Outcomes

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.

Time frame: 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.

Time frame: 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.

Time frame: Within the first postoperative hour while breathing room air.