Objective To evaluate mivacurium-induced release of histamine in the patients undergoing general anesthesia.Methods Eighty patients of both sexes,aged 19-58 yr,weighing 42-75 kg,of ASA physical status Ⅰ or Ⅱ,undergoing ureteroscopy under general anesthesia,were randomly divided into 2 groups (n =40 each) using a random number table:rocuronium group (group R) and mivacurium group (group M).Anesthesia was induced with iv midazolam 0.04 mg/kg,fentanyl 3 μg/kg,etomidate 0.3 mg/kg,and mivacurium 0.20 mg/kg (group M) or rocuronium 0.75 mg/kg (group R).Streamlined liner of the pharynx airway (SLIPA) was inserted for mechanical ventilation.PET CO2 was maintained at 35-40 mmHg.Anesthesia was maintained with fentanyl and propofol.Before muscle relaxant administration,at 3 min after muscle relaxant administration and at 5 min after insertion of SLIPA,venous blood samples were collected for determination of plasma histamine concentrations (by HPLC) and the histamine release was classified.Results Compared with group R,the plasma histamine concentration and histamine release were increased at 3 min after muscle relaxant administration in group M.No fatal responses caused by histamine release were found in the two groups.Conclusion Although mivacurium induces release of histamine,it can still be safely used for the patients undergoing ureteroscopy under general anesthesia.

Objective:To explore the clinical efficacy of internal fixation with a reduction plate assisted by our self-designed lower extremity fracture traction reduction device for tibial plateau fractures of Schatzker type Ⅵ.Methods:A retrospective study was conducted of the 32 patients with tibial plateau fracture of Schatzker type Ⅵ who had been treated at Orthopaedic Department, Mindong Hospital Affiliated to Fujian Medical University from April 2018 to July 2021. Depending on their treatments, they were divided into 2 groups. In the control group of 16 cases subjected to open reduction and internal fixation with manual traction, there were 9 males and 7 females with an age of 50.0±11.7 years; in the observation group of 16 cases subjected to internal fixation with a reduction plate assisted by our self-designed lower extremity fracture traction reduction device, there were 8 males and 8 females with an age of 54.6±11.1 years. The operation time, fracture reduction time, total incision length, intraoperative blood loss, Rasmussen knee function score and maximum active range of knee motion were compared between the 2 groups.Results:There was no significant difference in the preoperative general data between the 2 groups, showing comparability between the groups ( P>0.05). The operation time [(158.6±26.0) min], fracture reduction time [(61.6±9.6) min], and total incision length [16.0 (13.3, 17.0) cm] in the observation group were significantly shorter than those in the control group [(199.9±60.9) min, (73.8±17.2) min, and 20.0 (17.0, 21.8) cm]; the intraoperative blood loss [175.0 (100.0, 200.0) mL] in the observation group was significantly less than that in the control group [200.0 (162.5, 387.5) mL]; the maximum active ranges of knee motion at one week and one month in the observation group were 94.9°±12.0° and 113.8°±14.1°, significantly larger than those in the control group (78.3°±14.6° and 96.8°±11.4°) (all P<0.05). Fractures achieved bony union at one year after operation in both groups. At 12 months after operation, there was no significant difference in the maximum active range of knee motion or the Rasmussen knee function score between the 2 groups ( P>0.05). Conclusion:In the treatment of Schatzker type Ⅵ tibial plateau fractures, compared with manual traction and open reduction, internal fixation with a reduction plate assisted by our self-designed lower extremity fracture traction reduction device can shorten operation time and total incision length, reduce intraoperative blood loss, and facilitate postoperative functional recovery of the knee for the patients.