Multimodal perioperative monitoring of intracranial pressure surrogates and cerebral oxygenation during laparoscopic surgery: implications for early cognitive outcomes

This study aimed to evaluate perioperative changes in optic nerve sheath diameter (ONSD) and regional cerebral oxygen saturation (rSO₂) using noninvasive monitoring techniques during laparoscopic abdominal surgery, and to assess their association with postoperative cognitive dysfunction (POCD).

This prospective observational study included 50 ASA I–III patients aged 20–60 years undergoing laparoscopic abdominal surgery under general anesthesia. Bilateral ONSD and rSO₂ were measured at five time points: before induction (T0), 5 min after induction (T1), 5 min after CO₂ pneumoperitoneum (T2), 30 min after pneumoperitoneum (T3), and 5 min after desufflation (T4). IAP was assessed using intravesical measurements and insufflator readings. Cognitive function was evaluated with the Mini-Mental State Examination (MMSE) preoperatively and 24 h postoperatively. Hemodynamic and airway parameters were recorded concurrently.

ONSD increased significantly following pneumoperitoneum, peaking at 30 min, and returned toward baseline after desufflation. In contrast, rSO₂ demonstrated a non-synchronous pattern, increasing after induction, decreasing transiently after pneumoperitoneum, and subsequently recovering toward post-induction levels, suggesting preserved cerebral oxygenation despite intraoperative physiological changes. No significant correlation was observed between ONSD and rSO₂. Intravesical intra-abdominal pressure (IAP) measurements were consistently higher than insufflator-derived values. No significant differences were found between preoperative and postoperative MMSE scores.

CO₂ pneumoperitoneum induces transient increases in intracranial pressure (ICP) surrogates and reversible changes in cerebral oxygenation without affecting early postoperative cognitive function. These findings support the use of multimodal monitoring rather than reliance on single parameters.

The study was retrospectively registered at ClinicalTrials.gov.

ClinicalTrials.gov identifier: NCT07264764. Registered on 24 November 2025.