Effect Of Cerebral Blood Flow Volume Change On Postoperative Nausea And Vomiting In Laparoscopic Gynaecological Surgery Patients

Objective:This study intends to monitor the cerebral blood flow volume（CBFV）in patients with laparoscopic gynaecological surgery,and to explore its relationship to the incidence of postoperative nausea and vomiting（PONV）.Methods:120 patients undergoing elective surgeries under general anesthesia were selected for the research and divided into four groups.Group A,laparoscopic gynecological surgery patients（N=30）;Group B,female laparoscopic Cholecys-tectomy patients（N=30）;Group C,abdominal gynecological surgery patients（N=30）;Group D,laparoscopic gynecological surgery patients who were administered intravenously0.5g/kg of mannitol 30 minutes before the surgery（N=30）.The diameter（D）,Angle-corrected time-averaged flow velocity（Vm）as well as resistance index（RI）of internal carotid arteries and the vertebral arteries were recorded through Doppler ultrasound at the time of 5 minutes after getting into operating room（T₁）,5 minutes after insertion a laryngeal mask（T₂）,immediately carbon dioxide pneumoperitoneum and Trendelenburg position（T₃）,30 minutes after pneumoperitoneum and Trendelenburg position（T₄）,immediately termination of pneumoperitoneum and recovery of horizontal position（T₅）,10 minutes after termination of pneumoperitoneum and recovery of horizontal position（T₆）.And then,all subjects’CBFV at these 6 time points were calculated and the incidence of PONV within 48 hours after surgery were recorded.Results:There were no significant difference in age,body mass index,preoperative content of hemoglobin,operative time and the volume of fluid transfusion between four groups（P>0.05）.However,the amout of intraoperative urine in group D was more than group A,group B and group C significantly（P<0.05）.The differences of CBFV at T₁,T₂,T₅ and T₆ in four groups were not significant（P>0.05）;CBFV at T₃ in group A and D were significant increased as compared with group B and C（P<0.05）;CBFV in group D was significant increased compared with group A,B and C at T₄（P<0.05）,while there were no significant difference in group A,B and C at the same time point（P>0.05）.RI of internal carotid arteries and the vertebral arteries in group A and D were increased significantly as compared with group B and C at T₃（P<0.05）.RI of internal carotid arteries and the vertebral arteries in group A was increased significantly compared with the other three groups at T₄（P<0.05）,and RI of internal carotid arteries and the vertebral arteries in group D was significant higher than group B and C at the same time point（P<0.05）.RI of internal carotid arteries and the vertebral arteries in group A was significantly increased as compared with group B,C and D at T₅ and T₆（P<0.05）,while there no difference in four groups at T₁ and T₂（P>0.05）.The occurrence rate of PONV of group A,B,C and D was 56.67%,26.67%,23.33%and 30.00%respectively,the incidence of PONV in group A was significantly higher and more severity than other three groups（P=0.026）.Conclusion:Obstruction of cerebral venous blood reflux under the effect of Trendelenburg position increased the incidence of PONV in laparoscopic gynaecological surgery patients,while the change of CBFV seemed to not associated with the high incidence of PONV in laparoscopic gynaecological surgery patients.And a small dose of mannitol was administered intravenously prior to surgery could reduce the incidence of PONV in gynecological laparoscopic surgery patients.