ABSTRACT
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.