Abstract: Objective To investigate the effect of different carbon dioxide pneumoperitoneum pressures on coagulation and gastrointestinal function in elderly patients with laparoscopic cholecystectomy. Methods Two hundred and fifty-eight patients over 68 years old undergoing laparoscopic cholecystectomy in our hospital were selected from June 2016 to June 2018,and they were divided into high pressure group,medium pressure group and low pressure group according to pneumoperitoneum pressure,with 86 cases in each group.During laparoscopic cholecystectomy,the operating time,carbon dioxide pneumoperitoneum time and anesthesia recovery time of the three groups were recorded.The blood oxygen partial pressure,arterial carbon dioxide partial pressure and PH value of the three groups were recorded at 6 hours before operation,1 hour before establishment of pneumoperitoneum,1 hour after pneumoperitoneum and 3 hours after pneumoperitoneum.The plasma prothrombin time,activated partial thromboplastin time,fibrinogen and plasma D-dimer of the three groups was measured at 6 hours before operation,1 hour after operation and 24 hours after operation.The serum D-lactic acid was measured at 6 hours before operation and 6 hours after operation.The time to passing gas,time to taking food and time to passing stool were observed and recorded. Results There was no significant difference in baseline data between the three groups (P>0.05).After establishment of pneumoperitoneum,no significant difference was observed in blood oxygen partial pressure and PH among the three groups (all P>0.05);The arterial partial pressure of carbon dioxide,activated partial thromboplastin time,fibrinogen,D-dimer and serum D-lactic acid in the low-pressure group were significantly lower than those in the high-pressure group and the medium-pressure group (all P<0.05).And the time to passing gas,time to taking food,and time to passing stool in the low pressure group were significantly less than those in the high-pressure group and the medium-pressure group (P<0.05). Conclusion Low-pressure carbon dioxide pneumoperitoneum has less influence on arterial partial pressure of carbon dioxide,coagulation and fibrinolysis function,gastrointestinal function in elderly patients,which is beneficial to rapid recovery after operation.