Effects Of Neoadjuvant Chemotherapy On 50% Effective Plasma Concentration Of Propofol For Loss Of Consciousness In Breast Cancer Patients

Objective: To investigate the effect of neoadjuvant chemotherapy on 50% plasma effective concentration(EC50)of propofol for loss of consciousness in breast cancer patients by target-controlled infusion(TCI),and to provide reference for clinical application.Methods: Fifty female patients diagnosed with breast cancer were selected.According to neoadjuvant chemotherapy,they were divided into chemotherapy group(Group C)and non-chemotherapy group(Group NC),twenty-five patients in each group.Group C received EC(epirubicin + cyclophosphamide)sequential T solution for 8 cycles two weeks before surgery.Anesthesia was conducted with a TCI of propofol.The initial target plasma-site propofol concentration was 4.0ug/ml and was estimated by Dixon's up-and-down method.The target plasma-site concentration of propofol for patients was determined by the response(consciousness or unconsciousness)of the previous patient in each group,using increment or decrement of 0.5ug/ml.No response to tapping the shoulder was used as a symbol of unconsciousness.When the patient was unconsciousness or target-controlled infused for fifteen minutes,the test was terminated.Mean arterial pressure(MAP)and heart rate(HR)were recorded before anesthesia induction(T0),the plasma concentration reached the target concentration(T1),the effect-site concentration and target plasma concentration was balanced(T2),the patient lost consciousness(T3).The heart rate,hemoglobin(HB)and albumin(ALB)of patients were recorded in the group C before neoadjuvant chemotherapy.The heart rate,albumin and hemoglobin of patients in two groups before operation,and the adverse effects(cough,injection pain,et al)during the test were recorded.Results: 1?General state of patients: There was no statistical difference in age,weight and body mass index(P>0.05).HR and ALB were no statistical difference between two groups before operation,but HB were statistical difference between two groups.Compared to the situation before chemotherapy,preoperative heart rate increased significantly,and preoperative hemoglobin decreased significantly,while preoperative albumin didn't change significantly in group C.2?MAP at T0 was not significantly different between two groups,but HR at T0 in group C was significantly faster than group NC.There were 13 persons lost consciousness in both two groups.Both MAP and HR at T3 were significantly decreased compared to T0 of all those people who lost consciousness.MAP and HR at T3 were no statistical difference between two groups.3?In group C,the EC50 of propofol for loss of consciousness was 3.558ug/ml,and 95% confidence interval was 3.275~3.843ug/ml.The EC50 of propofol in group NC was 3.638ug/ml,and 95% confidence interval was 3.347~3.926ug/ml.The EC50 of propofol for loss of consciousness in two groups had no significant difference.4 ? There was no significant difference in adverse effects(cough,injection pain,etc)during the test.Conclusion: Neoadjuvant chemotherapy had no effect on EC50 of propofol for loss of consciousness by plasma target-controlled infusion in breast cancer patients.