关键词: Trendelenburg体位, 瑞马唑仑, 七氟醚, 视神经鞘直径, 颅内压

Abstract:

Objective To explore the impacts of remimazolam on intraoperative intracranial pressure （ICP） and cerebral oxygenation in patients undergoing laparoscopic lower abdominal and pelvic surgery under CO₂ pneumoperitoneum combined with Trendelenburg position. Methods Eighty-eight patients scheduled to undergo laparoscopic lower abdominal and pelvic surgery were randomly assigned to the remimazolam group （n = 44） and the sevoflurane group （n = 44）. In the remimazolam group， continuous infusion of remimazolam at a rate of 1 mg/（kg·h） was administered for anesthesia maintenance. In contrast， the sevoflurane group inhaled 2% sevoflurane. Heart rate （HR）， mean arterial pressure （MAP）， peak airway pressure （Peak）， plateau airway pressure （Plat）， end-tidal CO₂ （P_ETCO₂）， regional cerebral oxygen saturation （rSO₂）， and optic nerve sheath diameter （ONSD）of both eyes were measured and recorded at the following time points： prior to anesthesia induction （T₀）， 5 minutes after induction （T₁）， 10 minutes （T₂）， 30 minutes （T₃）， and 60 minutes （T₄） after the establishment of pneumoperitoneum in Trendelenburg position， as well as 30 minutes after deflation in the supine position （T₅）. Results No significant intergroup differences were detected in HR， MAP， Peak， Plat， or P_ETCO₂ at any time point （P > 0.05）. In both groups， Peak and Plat values were significantly higher at T₂-T₄ compared to T₁ （P < 0.05）. Regarding the ONSD） no intergroup differences were noted at T₀ and T₁ （P > 0.05）. From T₂ to T₅， ONSD in both groups increased significantly relative to T_0.. It gradually rose with the prolongation of pneumoperitoneum and Trendelenburg positioning and showed a slight decrease at T₅ （P < 0.05）. Specifically， at T₃ and T₄， the remimazolam group exhibited significantly smaller ONSD values than the sevoflurane group （P < 0.05）. Throughout the study， no intergroup differences in rSO₂ were observed （P > 0.05）. Conclusion In laparoscopic lower abdominal and pelvic surgeries performed in the Trendelenburg position， intravenous anesthesia with remimazolam may be more effective in mitigating the elevation of intracranial pressure compared to sevoflurane inhalation.

Key words: trendelenburg position, remimazolam, sevoflurane, optic nerve sheath diameter, intracranial pressure