Effects Of Magnesium Sulfate Combined With Rocuronium On Muscle Relaxation In Patients With Thymoma Resection

Objective: Patients with thymoma are often associated with myasthenia gravis.Thoracoscopic thymoma resection,under general anesthesia,may be one of an effective treatment for such patients.These patients are very sensitive to muscle relaxants.Thus,a reasonable muscle relaxant used to reduce perioperative muscle relaxation is extremely urgent.Magnesium sulfate plays a role in muscle relaxation and vasodilation,which has been widely used in the field of anesthesia and analgesia.Whether magnesium sulfate can reduce muscle relaxants dose in thymoma surgery is not clear.This study was designed to investigate the effect of magnesium sulfate on intraoperative rocuronium in patients with thymoma,hopping to provide a reference for future clinical applications.Methods: Forty patients underwent thoracoscopic thymoma resection under general anesthesia,ASA grade Ⅰ~Ⅰ were randomly divided into magnesium sulfate group(group A)and normal saline group(group B),20 cases in each group.Patients were treated with fentanyl 4 ug / kg intravenous injection,and the propofol TCI target control(Marsh effect model)was used to maintain the BIS at 40-60 for 5 minutes.Group A magnesium sulfate 60 mg / Kg diluted with normal saline to 50 ml,intravenous infusion in 5 minutes.Group B 50 ml saline intravenous infusion in 5 minutes.TOF was observed,if the minimum value of TOF <10 then the tracheal was intubated.Otherwise when TOF > 10,rocuronium 0.05 mg / Kg was intravenously administrated until the TOF value <10 before tracheal intubation.Intraoperative propofol and remifentanil(2-4 ng / ml)TCI was used to maintain anesthesia.Parecoxib sodium 40 mg was administrated during surgery.0.5% ropivacaine was infiltrated after procedure completed.The TOF,heart rate,BIS,systolic blood pressure,dose of propofol,intubating time,time of TOF recovery to 90%,extubating time after surgery,agitation score,VAS score were recorded.Results: 1.In the group(group A),3 cases had a TOF value of <10 within 5 minutes after intravenous infusion of magnesium sulfate,while two cases had no significant change in TOF value before and after magnesium sulfate infusion.The TOFs of other 15 cases was significantly lower after administration of magnesium sulfate infusion.There was no significant difference in TOF in group B after saline infusion.The dose of rocuronium in group A was lower than group B.The dose of propofol in group A was lower than group B.The variation of heart rate and systolic blood pressure before and after tracheal intubation were smaller in group A.The duration of TOF recovery to 90% of group A was shorter than group B.There was no significant difference between the two groups in the time of tracheal extubation.There was no significant difference between visual analogue pain score(VAS)and agitation score.Conclusion: Magnesium sulfate can reduce the TOF of patients with thoracoscopic thymoma,and the dose of rocuronium for tracheal intubation,and can reduce the dose of propofol.