Effect Of Low And Standard Pneumoperitoneum Pressure On The Prognosis Of Optic Nerve Sheath And Nervous System In Elderly Patients With Colorectal Cancer

Objective:Colorectal cancer is one of the cancers with the highest incidence in the world.In recent years,with the change of dietary habits and the improvement of awareness of early screening the incidence of patients over 60 years old shows a significant upward trend in China.Laparoscopic radical resection of colorectal cancer may lead to perioperative complications while treating primary disease,improving quality of life and survival rate.In this study,optic nerve sheath diameter was used as a non-invasive parameter to evaluate the effects of different pneumoperitoneum pressure combined with restrictive infusion strategies on intracranial pressure,postoperative short-term complications and cognitive function in elderly patients with laparoscopic colorectal cancer,so as to prevent the occurrence of postoperative nervous system complications in elderly patients.method:A total of 60 patients,aged 65 to 80 years and ASA grade I to II,who underwent laparoscopic colorectal cancer surgery in the First People’s Hospital of Jiujiang City were randomly divided into two groups（n=30）:standard pneumoperitoneum pressure group（H-pneumoperitoneum pressure 12～14 mm Hg）and low pneumoperitoneum pressure group（L-pneumoperitoneum pressure 9～11 mm Hg）.Restrictive intraoperative fluid therapy was used during perioperative period,and ONSD was measured by ultrasound to reflect intracranial pressure.Baseline ONSD（T₀）,5 min after successful anesthesia induction and endotracheal intubation（T₁）,15 min（T₂）,45 min（T₃）,1 h45 min（T₄）after pneumoperitoneum and head-down position,and 15 min after peritoneal defation and repositioning in the neutral position（T₅）.MAP,BP,Ppeak,Pplat,BIS,blood gas analysis of Pa CO₂and Pa O₂,ONSD of the right eye（the mean value of transverse and longitudinal meridian）,the time endotracheal tube was removed in the PACU,short-term postoperative neurological complications such as headache,nausea and vomiting,delirium were recorded,and record the day before anesthesia,after anesthesia to 24 h,48 h MMSE simple mental state examination score.result:Compared with T₁,Ppeak and Pplat of the two groups increased at T_2⁴.Compared with group H,Ppeak and Pplat in group L were significantly decreased at T_2⁴（P<0.05）.Compared with T₀,Pa CO₂in the two groups was significantly increased at T_3⁴,and that in group H was significantly higher than that in group L（P<0.05）.After anesthesia induction intubation,compared with T₀,ONSD increased in both groups at T₁,but there was no significant difference between Group H and Group L（P>0.05）.With the passage of time,the ONSD of the two groups was significantly higher than that of the T₀group and the T_2⁵group,and the ONSD of the H group was significantly higher than that of the L group at T_3⁴（P<0.05）.At T₅,ONSD returned to T₁level in both groups.Compared with preoperative,the MMSE scores of the two groups at 24h after surgery were all decreased;The MMSE score at 24h after operation in group L was significantly higher than that in group H（P<0.05）.conclusion:The strategy of low pneumoperitoneum pressure combined with restricted infusion can alleviate the increase of ONSD in elderly patients with colorectal cancer during perioperative period,which may be beneficial to improve the perioperative safety of elderly patients with long-term pneumoperitoneum and head-down position.