Overview
This prospective observational study aims to evaluate the relationship between changes in respiratory mechanics and cerebral oxygenation in adult patients undergoing elective lumbar disc surgery in the prone position under general anesthesia.
Cerebral regional oxygen saturation will be monitored using bilateral frontal near-infrared spectroscopy (NIRS), while respiratory parameters including tidal volume, respiratory rate, peak airway pressure, plateau pressure, positive end-expiratory pressure, and dynamic compliance will be recorded from the anesthesia ventilator. Measurements will be obtained at predefined time points before and after positioning the patient prone and after returning to the supine position at the end of surgery.
No changes will be made to anesthesia, ventilation, medication doses, or surgical management for research purposes. All clinical care will be provided according to routine practice by the responsible anesthesia team. The study will investigate whether changes in respiratory mechanics during prone positioning are associated with changes in cerebral regional oxygen saturation.
Description
This prospective observational study will evaluate the relationship between respiratory mechanics and cerebral regional oxygen saturation in patients undergoing elective lumbar disc surgery in the prone position under general anesthesia.
Bilateral frontal cerebral oxygen saturation will be monitored using near-infrared spectroscopy (NIRS), and respiratory parameters including tidal volume, respiratory rate, Ppeak, Pplat, PEEP, and dynamic compliance will be recorded at predefined intraoperative time points. No intervention will be made to routine anesthesia, ventilation, medication, or surgical management for research purposes.
Eligibility
Inclusion Criteria:
- Age 18-75 years
- Written informed consent
- Scheduled for elective lumbar disc herniation surgery
- ASA physical status I-III
- Volume-controlled ventilation
Exclusion Criteria:
- History of increased intracranial pressure
- Conditions preventing placement of cerebral NIRS probes
- Development of severe intraoperative complications
- Significant hemodynamic instability
- Known cerebrovascular disease or severe carotid artery disease
- Hemoglobin \<10 g/dL or anticipated major bleeding
- Severe heart failure (EF \<40%)
- Advanced COPD or restrictive lung disease
- Orthopedic or neurological conditions preventing tolerance of the prone position
