Effects of permissive hypercapnia on cognitive function and stress response in elderly patients undergoing laparoscopic radical resection for colorectal cancer

Zhang Bao; Jin Tao; Cui Jingjing; Zuo Shanshan; Wang Xue; Liu Qianqian; Zhou Yi; Liu Run

doi:10.11986/j.issn.1673-873X.2024.12.13

Abstract：Objective To explore the effects of permissive hypercapnia(PHC)on cognitive function and stress response in elderly cases undergoing laparoscopic radical resection for colorectal cancer.Methods 140 elderly cases undergoing laparo-scopic radical resection for colorectal cancer from May 2021 to December 2023 were randomly divided into routine group(n=70)and PHC group(n=70)by random number table method.Both groups of elderly patients underwent mechanical ven-tilation after induction of general anesthesia,and adjusted respiratory parameters.The partial pressure of arterial carbon di-oxide(PaCO2)in the conventional group was maintained at 35-45 mmHg,and the PaCO2 in the PHC group was main-tained at 46-60 mmHg.The operation conditions(pneumooperitoneum time,mechanical ventilation time,operation time,intraoperative blood loss),cognitive function[simple mental State Scale(MMSE)score,incidence of cognitive impairment(POCD)],stress response index[norepinephrine(NE),epinephrine(E),cortisol(Cor)]and hemodynamic index[heart rate(HR),mean arterial pressure(MAP)],the complications of the two groups were compared.Results The pneumoper-itoneum time,mechanical ventilation time,operation time and intraoperative blood loss between 2 groups were no significant differences(all P>0.05).The MMSE scores of both groups on the 1st,3rd and 7th day after surgery were lower than those before surgery,and the scores in conventional group were lower compared with PHC group(P<0.05).The rate of POCD in conventional group was higher than that in PHC group(P<0.05).The levels of NE,E and Cor in 2 groups 24h after op-eration were increased,and those in conventional group were higher compared with PHC group(P<0.05).The HR at T0 and T3 time points between the two groups was no significant difference(P>0.05).The HR at T1-T3 time points in PHC group was higher than that at T0 time points,and the HR at T1-T2 time points was higher than that in conventional group(P<0.05).The T0-T3 MAP between the two groups was no significant difference(P>0.05).The incidence of complica-tions between the two groups was no significant difference(P>0.05).Conclusion The application of PHC in the elderly patients with laparoscopic radical resection of colorectal cancer is significant,which can improve the cognitive function,re-duce postoperative cognitive dysfunction,and reduce the surgical stress reaction,and is worthy of clinical application.