RESUMEN
Objective: To observe the effects of neuromuscular blockade after combining atracurium (ATC) with veeuronium (VEC). Method: Fifty-four patients undergoing elective abdominal surgery(ASA grade Ⅰ-Ⅱ) were allocated randomly into 3 groups. After induction with intravenous midazolam-etomidate-fentanyl, neuromuscular blockade was measured with the train of four (TOF) to the ulnar nerve by monitoring the contraction of musculus adductor pollicis. The onset time and the peak effect were observed. According to the dose-effect relationships of the combination of ATC and VEC and that of either ATC or VEC given alone,the ED_(50) and ED_(95) were caeulated. The isogram and algebraic methods were used to analyse interaction between them. Result: The fraction ED_(50) values of ATC and VEC in combination were 52.26 and 11.71?g/kg respectively, The algebraic subtotal of combinations was 0.75