The Effects Of Neostigmine Antagonizing Residual Neuromuscular Blockade Induced By Cisatracurium In Elderly Patients

Background and Objective:Cisatracurium is the 1R cis-1'-R cis isomer of atracurim.Cisatracurium is metabolized by Hofmann elimination and is unaffected by age.Cisatracurium is belongs to intermediate-acting muscule relaxants.It is approximately four times as potent as atracurium,and unlike atracurium.it does not cause histamine release in the clinical dose range.It is now widely used in elderly patients.Good evidence-based practice dictates that clinicans should always quantitate the exent of neuromuscular blockade using objective monitoring.If sufficient recovery (train-of-four rate TOF≥0.9)has not been documented objectively at the end of surgical procedure,the neuromuscular block should be antagonized.For all long-time acting and intermediate-acting muscule relaxants,because of the inability to detect subtle neuromuscular blocks clinically and persistence at the end of surgical procedure.The reversal by anticholinesterase drugs should be routine.Since specific changes in the pathophysiology of elderly patients,recommendations regarding the timing and dose of administration of neositigmine remain unclear.The purpose of this experiment is to explore more proper timing and dose of neostigmine by observing the effect of different doses of neostigmine using at different time on antagonizing residual neuromuscular blockade induced by cisatracurium in elderly patients, to make fo the smooth recovery from anesthesia in elderly patients and to provide theoretical basis for the proper use of the neuromuscular blockade antagonists in clinical practice.Method:90 patients scheduled for surgery included 44 males and 46 females, aged 65-75 years with the normal BMI range(18～25kg/m2) and ASAⅠ～Ⅱ. They were randomly divided into 2 groups with 45 cases each and given with neostigmine when T1 had recovered to 10%(T1a group) or 25%(T1b group) respectively. In each group, three subgroup (15 cases each) were given neostigmine 20μg/kg(T1aN20, T1bN20), 35μg/kg(T1aN35, T1bN35), or 50μg/kg (T1aN50, T1bN50) respectively. The cases in six groups were treated with the same anesthetic and anesthesia method.Neostigmine and atropine were administered for the six groups(The ratio of neostigmine and atropine is 1:2,when the surgery was finished, the MAP and HR were recorded at the time before using neostigmine as well as 1 min,3min,5min,7min, 10min,15min after neostigmine respectively. And the time were recorded when TOF had recovered to75% and 90%.Results:1. The patients showed significantly no differences in gender, age, BMI, and the MAP,HR before treated with neostigmine(p>0.05).2. There was no statistical difference in the MAP,HR before all the cases were treated with neostigmine(p>0.05).In the two group T1a and T1b, the HR, MAP were higher than the basic value at the time lmin and 3min after they were given neostigmine.The HR, MAP were higher in the subgroup of 20μg/kg (T1aN20, T1bN20),35μg/kg(T1aN35,T1bN35), but there was no statistical difference in the MAP,HR compared to the level before the cases were treated with neostigmine (p>0.05); And the MAP, HR changes in the subgroup of 50μg/kg showed significantly differences compared to the level before the cases were treated with neostigmine(p<0.05). 3. The comparison of the recovery index of TOF intra-group comparison: Compared to the group of T1aN20, the time of TOF recovering to75% and 90% were shortened in the group of T1aN50 and T1aN35, and there were statistical differences(p<0.05). The time of TOF recovering to 75% and 90% were shorter in the group of T1aN50 than the group of T1aN35, but the changes had no significance; Group comparison:Compared to the group of T1aN2o, TlaN35 and T1aN50, the time of TOF recovering to75% and 90% were shortened in the group of T1bN20, T1bN35 and T1bN50 respectively, and there were all statistical differences(p<0.05).Conclusion:1. The recommend appropriate dose of neostigmine antagonizing residual neuromuscular blockade induced by cisatracurium is 35μg/kg in the elderly patients (the atropine were used compatiblely with neostigmine and the ratio of neostigmine/atropine is 1/2), which could induce the better recovery index of TOF as well as more stable hemodynamic changes.2. The more proper timing to give neostigmine antagonizing residual neuromuscular blockade induced by cisatracurium was the time when T1 had recovered to 25% in the elderly patients.