Pulmonary Microbiota Changes and Clinical Outcomes in Neurosurgical ICU Patients With Artificial Airways

After neurosurgery, many patients need to stay in the intensive care unit (ICU) and use a breathing machine (mechanical ventilation) because of issues like decreased consciousness, weak breathing, or poor airway protection. During this period, the natural balance of bacteria in the lungs-known as the lung microbiota-can be disturbed by surgery, antibiotics, and airway procedures. This may reduce healthy bacteria and allow harmful bacteria to grow, increasing the risk of lung infections such as ventilator-associated pneumonia (VAP). This study will follow 220 postoperative neurosurgical ICU patients at three centers: Beijing Tiantan Hospital, Beijing Shijitan Hospital, and Beijing Anzhen Hospital from August 2025 to August 2026. These patients will include those undergoing surgery for brain tumors, brain hemorrhage, or traumatic brain injury. Airway secretion samples (tracheal aspirates) will be collected shortly after surgery and at several subsequent time points to assess how lung bacteria change over time while patients are using a breathing machine. Using advanced laboratory methods, the investigators will measure both the amount and types of bacteria in the lungs. The aim is to determine how these changes are related to patient outcomes, such as the occurrence of lung infections. The results of this study may contribute to earlier detection of lung infections and the development of personalized treatment plans to improve recovery in ICU patients after neurosurgery.