Protecting the lungs during surgery is important because mechanical ventilation can sometimes cause lung injury, Newer approaches focus on adjusting ventilation to suit individual patients. Electrical impedance tomography is a safe, noninvasive method that allows real time monitoring of how air is distributed in different parts of the lungs without radiation.

Neurosurgical patients are especially vulnerable to changes in lung function during surgery due to long operating times, mechanical ventilation, fluid shifts and interactions between the brain and lungs. Neurosurgical procedures require patients to be placed in different positions such as supine, lateral or prone, which can significantly affect breathing and oxygen levels.

Previous studies show that body position influences how evenly air is distributed in the lungs. Prone positioning often improves ventilation in the posterior parts of the lungs and reduces lung collapse, but it may overstretch other lung areas. The effects of lateral positioning vary between patients. There is limited information on these position related changes specifically in neurosurgical patients.

There is also uncertainty about the best ventilation mode and pressure settings during neurosurgery. While moderate positive end pressure can improve lung expansion and reduce collapse, higher pressures may affect brain blood flow and pressure inside the skull. Studies using electrical impedance tomography suggest that moderate pressure improves ventilation distribution, but optimal settings differ between patients and positions.

This study aims to monitor and compare changes in lung ventilation in adult neurosurgical patients operated in different body positions using electrical impedance tomography. The findings may help guide personalised ventilation strategies and reduce the risk of lung injury during surgery.