Effect of Various Modes of Mechanical Ventilation in Laparoscopic Cholecystectomies on Optic Nerve Sheath Diameter and Cognitive Functions

Aim: In this study, we aim at investigating the effects of volume-controlled ventilation (VCV) and pressure-controlled ventilation (PCV) modes on changes in the optic nerve diameter and cognitive functions in laparoscopic cholecystectomy operations. Materials and Methods: Sixty patients who underwent laparoscopic cholecystectomy were randomly divided into two groups based on the mode of mechanical ventilation provided: Group P; PCV, Group V; VCV. Optic nerve sheath diameter was measured when the patient was awake (T0), in the 10th minute after induction (T1), in the 10th minute after the initiation of gas insufflation (T2), when maximum gas pressure was reached in the reverse-Trendelenburg position (T3), and pre-extubation (T4). Partial oxygen saturation (PaO₂), PCO₂, end-tidal carbon dioxide (ETCO₂), and peak airway pressure (pPEAK) were also recorded. A Mini-Mental State Examination (MMSE) was conducted on patients preoperatively and in the postoperative third month. Results: Between the groups, a statistically significant difference was found in Group P compared with Group V in terms of optic nerve diameter at measurement times T1 (P < .05). In the intragroup comparison, a significant difference was found in the initial values in all measurements except for measurement times T0 and T4 in both Group P and Group V (P < .05). pPEAK values were identified to be statistically significantly lower in Group P than Group V at all measurement times (P < .05). No difference was identified in the MMSE scores in the intergroup and intragroup comparisons. Conclusion: Laparoscopic cholecystectomy increases the optic nerve diameter due to the mechanical and systemic effects of the operation, and the PCV mode can be preferred. Clinical Trial Number: NCT04413903.