Comparison of Different Dosages of Rocuronium on Abdominal Wound Closure / 昆明医科大学学报

Objective To evaluate the effects of different dosages of rocuronium on abdominal wound closure under general anesthesia.Methods Ninety ASA class I or II patients scheduled for elective abdominal surgery under general anesthesia were randomized into three groups with 30 cases each.Each group received rocuronium 1 time of ED95 (0.3 mg/kg),0.5 time of ED95 (0.15 mg/kg),0.2 time of ED95 (0.06 mg/kg) respectively when closing the abdominal wall.TOF recovered to 25%, 75%, 90%, time of eye-opening on command, time of head-lift for more than 5 seconds,extubation time, the rate of upper airways obstruction after extubation and the satisfaction score for the muscle relaxation to general surgeons were recorded.Results TOF values had no significantly different among the three groups before abdominal wound closure (P＞0.05).Compared with group A and group B,time of TOF in group C was significangtly increased after administration of rocuronium (P＜0.05) . Time of TOF recovery to 25%, 75%, 90%in group C were significangtly decreased (P＜0.01).Compared with group A and group B, time of eye-opening on command ,head-lift for more than 5 seconds and extubation time were significantly shorter in group C.There were 8,4,0 patients undwent upper airways obstruction among each group respectively after extubation (P＜0.05).The satisfaction score for muscle relaxation among three groups had no significant difference.Conclusion An additional administration of 0.2 time of ED95 (0.06 mg/kg) rocuronium before abdominal wound closure in abdominal surgery can achieve satisfactory muscle relaxation for surgeons.

The study of proper depth of muscle relaxant in posterior fossa surgery under total intravenous anesthesia / 临床麻醉学杂志

Objective To investigate the proper depth of muscle relaxant without affecting elec-trophysiological monitoring in patients undergoing posterior fossa surgery under total intravenous an-esthesia (TIVA).Methods Forty patients selected for posterior fossa surgery were randomly divided into two groups A and B.Group A:no muscle relaxants were administered after anesthesia induction until the EMG was completed.Group B:muscle relaxants maintained in range of TOF 2%-25% dur-ing electrophysiological monitor.TIVA were used to all patients and BIS was maintained in range of 40-60.Two electrophysiological data were applied during the electrophysiological monitoring:sponta-neity EMG and evoked EMG.EMG amplitude was recorded at different TOF value.Operation time and the dosages of propofol,sufentanil,rocuronium bromide were recorded.Also,the SBP,DBP,HR at perioperational period and facial nerve function before surgery,one week and six months after sur-gery were recorded.Results The electrophysiological monitoring completed successfully in all pa-tients.The total amount of propofol in group A significantly increased than those in group B(P <0.05).Three patients in group A had body movement during the operation.Four cases in group B couldn??t perform electrophysiological monitor when the TOF had three signals.There were no differ-ence between the two groups in SBP,DBP,HR and facial nerve function.Conclusion Maintaining TOF value in range of 2%-25% under non-depolarizing muscle relaxant during CPA surgery doesn??t affect intraoperative nerve electrophysiological monitor and prevent body movement,total dose of sed-ative anesthetics is also decresed.

Neuromuscular Blocking Action of Neostigmine Methylsulfate / 대한마취과학회지

BACKGROUND: Although the neuromuscular blocking properties of neostigmine have been known for many years, few assessment of this effect has been described in man. The aim of this study is to determine the effect of neostigmine on neuromuscular transmission in the absence of muscle relaxants. METHODS: ASA I, twenty unpremedicated patients who had given their informed consent were administered neostigmine 2.0 mg and atropine 0.5 mg under propofol, fentanyl, and O2-N2O(67%) anesthesia. Train-of-four responses were measured electromyographically using 0.2 msec, 2 Hz of supramaximal ulnar nerve stimulation every 20 sec. RESULTS: There was no alteration in the train-of-four ratio, but the first twitch height decreased significantly after administration of neostigmine(P<0.05). Fasciculations were noted in the face and arms. Heart rate was decreased significantly to compare with preinjection value(P<0.05) while mean arterial pressure was not changed. CONCLUSIONS: It is concluded that even in clinical doses neostigmine may produce a depolarizing neuromuscular blockade, probably from the consequence of excessive accumulation of acetylcholine in the neuromuscular junction.

The Train-of-Four Ratio Profile During Onset and Offset Following Administration of Neuromuscular Blocking Agents / 대한마취과학회지

BACKGROUND: The train of four (TOF) stimulation is valuable to study pharmacodynamics associated with the interaction between muscle relaxants and receptors in the neuromuscular junction. TOF fade expresses presynaptic effect diminished output of transmitters. The aim of this study was to examine differences in presynaptic effects of different relaxants by measuring the TOF ratio during the onset and offset of block. METHODS: Eighty four healthy adult patients of ASA grades I or II were included in the study. The muscle relaxants studied were vecuronium (0.08 mg/kg), atracurium (0.5 mg/kg), mivacurium (0.15 mg/kg), rocuronium (0.6 mg/kg) and succinylcholine (1.0 mg/kg, 0.1 mg/kg, 0.2 mg/kg, 0.4 mg/kg). The TOF ratios were measured at approximate height of first response in the TOF (T1) of 75, 50 and 25% during onset and offset. Especially its ratios were measured at first depress of T1 during onset and its corresponding T1 during offset following administration of subclinical doses of succinylcholine. RESULTS: In the non-depolarizing muscle relaxants, TOF fade is more evident during offset than onset (p<0.05). The extent of fade varies between muscle relaxants. The greatest TOF fade has been shown in rocuronium during onset. In the succinylcholine, the TOF fade is apparent during onset and related to doses given (p<0.05). However the significant TOF fade is not seen during offset. CONCLUSIONS: All muscle relaxants, including both depolarizing and nondepolarizing agent, have predominantly postsynaptic and presynaptic effects. Furthermore, the fact that moderate TOF fade after subclinical doses of succinylcholine occurred obviously during onset of block is possibly indicating a greater presynaptic receptor blocking action.