Detemine The Minimum Alveolar Concentration Of Sevoflurane In Hysteroscopic Surgery

Objective:To determine the minimum alveolar concentration of sevoflurane in hysteroscopic surgery.Methods:The subjects were selected according to the inclusion criteria.Married women of childbearing age,ASA class?-?,age 20-45 years old?not postmenopausal patients?,BMI 20-25 kg/m²,no respiratory tract infection within two weeks prior to surgery,no sevoflurane anesthesia in half a year.Before the induction of anesthesia,oxygen flow was given 5L/min for3min.The method was induced by sevoflurane induction,until the eyelash reflex disappeared.The up-and-down method was adopted.The end tidal sevoflurane concentration of the first patient was set at 3%,and the operation could begin after the concentration reached the standard and stabilized for15min.If the physical activity was negative,the concentration of sevoflurane in the next patient was reduced by 0.2%.If the physical activity of the patient was positive,the concentration of sevoflurane was increased by 0.2%in the next patient.The midpoint from negative response to positive response was set as a balance point.When there are six balance point,the study concludes.All the data were analysed.Results:The ED₅₀0 of the end tidal sevoflurane concentration for blunting the responses to hysteroscopic surgery was 2.04%,the ED₉₅ was 2.28%?95%confidence interval 2.15%-4.17%?;the minimum alveolar concentration of sevoflurane in hysteroscopic surgery was?2.07±0.18?%.Conclusion:The minimum alveolar concentration of sevoflurane in hysteroscopic surgery was 2.07%.