Evaluation of intracranial pressure changes using ultrasonographic measurement of optic nerve sheath diameter during laparoscopic surgeries

Abstract

Background & objective: Laparoscopic surgery, while minimally invasive, presents physiological challenges due to pneumoperitoneum and a Trendelenburg positioning, which may impact intracranial pressure (ICP). Optic nerve sheath diameter (ONSD) is a non-invasive marker of ICP changes, but its role in laparoscopic procedures remains underexplored. This study evaluates ONSD variations in patients undergoing laparoscopic surgery and its correlation with perioperative hemodynamic parameters and postoperative neurological symptoms.

Methodology: This prospective, observational study included 20 adult patients (ASA I-II), scheduled for elective laparoscopic surgery. ONSD was measured using ultrasonography at baseline (pre-induction), 10 min post-pneumoperitoneum, 30 min post-pneumoperitoneum, 60 min post-pneumoperitoneum, and 10 min post-extubation. Hemodynamic parameters, including mean arterial pressure (MAP), heart rate (HR), and end-tidal CO₂ (EtCO₂), were recorded at the same time points. Postoperative neurological symptoms were assessed at 6 and 24 hours post-surgery.

Results: ONSD increased significantly during pneumoperitoneum and Trendelenburg positioning, peaking at 60 min post-insufflation (P < 0.05). The highest mean ONSD recorded was 5.60 ± 0.41 mm, compared to a baseline of 4.80 ± 0.36 mm. MAP and EtCO₂ remained stable, with no significant correlation with ONSD changes (P > 0.05). However, ONSD showed a strong correlation with MAP (r = 0.768, P < 0.001). Postoperatively, headache (100%), altered consciousness (95%), and lethargy (80%) were the most common symptoms, suggesting transient ICP elevation.

Conclusions: ONSD significantly increases during laparoscopic surgery, reflecting transient ICP elevation, though hemodynamic parameters remain stable. These findings highlight the importance of intraoperative ICP monitoring, particularly in patients with predisposing neurological risks. Further studies with larger sample sizes are needed to validate these observations and optimize perioperative management strategies.

Abbreviations: EtCO₂: end-tidal CO₂, HR: Heart rate, IAP: intra-abdominal pressure, ICP: intracranial pressure, MAP: mean arterial pressure, ONSD: Optic nerve sheath diameter

Keywords: Laparoscopic surgery; Intracranial pressure; Optic nerve sheath diameter; Pneumoperitoneum; Trendelenburg position; Hemodynamics

Citation: Caleb AJ, Kabilan AA, Thilaak P, Brindha R, Choudhay AK, Periasamy P. Evaluation of intracranial pressure changes using ultrasonographic measurement of optic nerve sheath diameter during laparoscopic surgeries. Anaesth. pain intensive care 2025;29(5):309-316. DOI: 10.35975/apic.v29i5.2854

Received: May 09, 2024; Reviewed: October 26, 2024; Accepted: January 01, 2025