Hysteroscopic surgery time is as follows: 1. single polyps: 5-10 minutes of electrodesiccation time and preparation time; 2. severe uterine adhesions: laparoscopic-assisted supervision is required, which takes 30-60 minutes; 3. multiple uterine fibroids: for submucosal fibroids of type 0, type I, type II, and even type III. Type III takes >1 hour and is technically demanding and not suitable for beginners. The pressure of the dilated uterus during the operation causes fluid to enter the blood through the open blood vessels and dilute the blood, which is prone to water intoxication, i.e. hyponatremia. The anesthesiologist should always be reminded to monitor electrolytes and perform blood gas analysis during prolonged surgery in order to detect and deal with problems in time to prevent complications, and to terminate the operation in time if they occur.