Objective To evaluate the effect of hemorrhagic shock factor on the pharmacokinetics of rocuronium in pigs.Methods Sixteen pathogen-free Bama miniature pigs of both sexes,aged 3-5 months,weighing 22-25 kg,were divided into 2 groups (n=8 each) using a random number table:control group (group C) and hemorrhagic shock group (group HS).In group C,rocuronium 3.78 mg/kg was injected via the auricular vein.In group HS,the animals were subjected to volume-controlled hemorrhage,about 40％ of blood volume was withdrawn from the left femoral artery over 15 min (30 ml/kg),and rocuronium 3.78 mg/kg was injected via the auricular vein after the model was successfully established.At 0,2,4,7,10,15,20,30,60,120,180,240,300,360 and 420 min after rocuronium injection,blood samples were collected from the internal jugular vein for determination of the plasma concentration of rocuronium by high-performance liquid chromatography-tandem mass spectrometry.The pharmacokinetic parameters of rocuronium were calculated.Results Compared with group C,the plasma concentration of rocuronium was significantly increased at 20 and 60-420 min after rocuronium injection,the elimination half-life and mean residence time were prolonged,and the plasma effect-site equilibration rate constant was decreased in group HS (P＜0.05).There was no significant difference in the maximal concentration and area under the concentration-time curve between the two groups (P＞ 0.05).Conclusion The elimination of rocuronium is slower in a pig model of hemorrhagic shock.