Abstract: Objective: To compare the effects of laparoscopic surgery under different pneumoperitoneum pressure on the patient's respiratory and circulatory systems.Methods: Seventy-two patients treated with laparoscopic cholecystectomy were randomly divided into high pneumoperitoneum pressure group(HP group,2.0 kPa) and low pneumoperitoneum pressure group(LP group,1.33 kPa).The indicators of respiratory and circulatory systems before and after pneumoperitoneum and postoperative complications between two groups were analyzed.Results: Compared with before pneumoperitoneum,the airway pressure,partial pressure of CO₂ in end expiratory,heart rate,systolic blood pressure and mean arterial pressure in two groups significantly increased after pneumoperitoneum(P< 0.01),and the rise degree of which in HP group was significantly higher than that in LP group(P< 0.01).Compared with before pneumoperitoneum,the indicators in LP group came back to normal level(P >0.05),but for the HP group these were still high after 5 min of deflation(P< 0.01).Compared with before pneumoperitoneum,the thoracic compliance in two groups significantly decreased(P< 0.01),and the decline degree of which in HP group was obviously after pneumoperitoneum.Compared with before pneumoperitoneum,the thoracic compliance in LP group improved to normal level(P >0.05),but for the HP group it was still low after 5 min of deflation(P< 0.01).The complications in 5 cases of the HP group were found.Conclusions: The effects of high pneumoperitoneum pressure on the patient's respiratory circulatory systems are great.The laparoscopic surgery should be implemented under low pneumoperitoneum pressure,and the indicators of respiratory and circulatory systems should be dynamically monitored to prevent complications.