BACKGROUND: Ulinastatin is a protease inhibitor derived from human urine. The effects of ulinastatin on muscle relaxants have been attributed to its capacities to cause increase in liver circulation, diuresis and possibly increased acetylcholine release. Rocuronium is mainly eliminated via the liver and kidneys whereas cisatracurium is mainly cleared via Hofmann elimination which is organ independent. The effects of ulinastatin on cisatracurium have not been assessed before. Moreover the effects of ulinastatin on the recovery period of rocuronium have not been adequately studied before. In this study, the effects of ulinastatin on cisatracurium are compared with the effects of ulinastatin on rocuronium. This is done by contrasting the ulinastatin induced changes in onset time, clinical duration and recovery duration for rocuronium with those for cisatracurium.~METHODS: 80 patients will be enrolled in this study and assigned randomly into 4 equal groups. The ROC-ULI group received ulinastatin 5000U/kg followed by rocuronium 0.6 mg/kg, the ROC-NS (control) group received normal saline 0.1ml/kg followed by rocuronium 0.6 mg/kg, the CIS-ULI group received ulinastatin 5000U/kg followed by cisatracurium 0.1 mg/kg and the CIS-NS (control) group received normal saline 0.1ml/kg followed by cisatracurium 0.1 mg/kg. The time lag between either ulinastatin or normal saline administration and muscle relaxant injection is 2 minutes. Acceleromyography using response to TOF (train of four) stimulation is used to assess neuromuscular function. The site of stimulation and response assessment are the ulnar nerve and the adductor pollicis muscle respectively. The time parameters assessed in each group are the onset time, the times to return of the first, second, third and fourth response to TOF stimulation (RT1, RT2, RT3 and RT4 respectively), the duration of moderate neuromuscular block (RT1-RT4), the duration 25% (clinical duration), the duration 50%, the recovery TOF 0.7 period and the duration TOF 0.7. Anesthesia is induced and maintained with propofol using target controlled infusion. Analgesia is achieved with an initial bolus of sufentanil followed by remifentanil infusion. Depth of anesthesia is monitored using the Narcotrend™ index. p < 0.05 is considered as statistically significant.
The aim of this research was to determine the influence of ulinastatin on nondepolarising muscle relaxants Rocuronium and Cisatracurium.