# Investigation of the Acute Effects of Two Different Preoxygenation Methods on Neurodegenerative Biomarkers in Laparoscopic Cholecystectomy Surgery

## TL;DR

This study compares two preoxygenation methods during surgery and finds that one causes more stress on brain cells and increases neurodegenerative markers.

## Contribution

The study reveals that standard preoxygenation with 100% FiO2 increases neurodegenerative biomarkers compared to a rapid method.

## Key findings

- Standard preoxygenation (100% FiO2) significantly increased pTau, S100B, NSE, and GFAP levels, indicating neuronal and glial stress.
- Rapid preoxygenation (eight deep breaths) showed lower levels of acute neurotoxicity and oxidative stress.
- Hemodynamic stress was higher in the standard preoxygenation group during and after the procedure.

## Abstract

Background and Objectives: Oxygen is essential for all living organisms and plays a critical role in anesthesia and intensive care practices. However, the notion that unlimited oxygen therapy is harmless is a misconception. Our study investigates the acute effects of different preoxygenation methods on hemodynamic parameters and neurodegenerative biomarkers in patients undergoing laparoscopic cholecystectomy surgery. Materials and Methods: This prospective, randomized, controlled study included 52 patients undergoing elective laparoscopic cholecystectomy under general anesthesia. Patients were divided into two groups: Group I received standard preoxygenation (100% FiO2 for 3 min), while Group II underwent rapid preoxygenation (eight deep breaths over 30 s to 1 min). Hemodynamic parameters (SAP, DAP, MAP, and SpO2) and neurodegenerative biomarkers (pTau, S100B, NSE, NfL, GFAP) were measured after preoxygenation, after intubation, and at the end of surgery. Results: Group I exhibited a significant increase in levels of pTau, S100B, NSE, and GFAP, indicating higher neuronal and glial cell stress compared to Group II (p < 0.001). No significant increase in NfL levels was observed in either group. Hemodynamic parameters (HR, SAP, DAP, MAP) were significantly higher during and after preoxygenation in Group I, suggesting an increased stress response. Group II showed lower levels of acute neurotoxicity and oxidative stress. Conclusions: Our findings indicate that preoxygenation with 100% FiO2 induces stress in neuronal cells, axons, and glial cells, leading to an increase in neurodegenerative biomarkers. Optimizing preoxygenation strategies is crucial to reduce oxidative stress and improve neurological outcomes for surgical patients.