Optic Nerve Sheath Diameter and Postoperative Cognitive Disfunction at Laparoscopic Surgery

Evaluation of Optic Nerve Sheath Diameter, Cerebral Oxygen Saturation and Cognitive Functions in Patients Undergoing Laparoscopic Abdominal Surgeries; Prospective Observational Study

Purpose:

Pneumoperitoneum during laparoscopic abdominal surgery increases intra-abdominal pressure (IAP), potentially altering intracranial pressure (ICP) and cerebral oxygenation, with unclear implications for early postoperative cognitive dysfunction (POCD). Optic nerve sheath diameter (ONSD) via ultrasonography and near-infrared spectroscopy (NIRS) based cerebral oximetry offer non-invasive monitoring tools to assess these changes.

In this prospective observational study, fifty ASA I-III patients (20-60 years) undergoing elective laparoscopic abdominal surgery under general anesthesia were enrolled. Serial measurements of bilateral ONSD and regional cerebral oxygen saturation (rSO2, NIRS) were obtained at five perioperative time points: before induction (T0), 5 minutes post-induction (T1), 5 minutes after CO2 pneumoperitoneum (T2), 30 minutes after pneumoperitoneum (T3), and 5 minutes post-desufflation (T4). IAP was measured both intravesically and via insufflator readings. Cognitive function was assessed using the Mini-Mental State Examination (MMSE) preoperatively and at 24 hours postoperatively. Hemodynamic parameters and airway pressures were recorded concurrently.

Inclusion Criteria:

• Aged 20-60 years;
• American Society of Anesthesiologists [ASA] I-III)
• scheduled for elective laparoscopic abdominal surgery (e.g., cholecystectomy, appendectomy, hernia repair) under general anesthesia

Exclusion Criteria:

• pregnancy,
• known neurological or ocular disease,
• prior ocular surgery,
• significant cardiovascular disease (moderate to severe),
• chronic obstructive pulmonary disease (COPD),
• conversion from laparoscopy to open laparo-tomy.