Clinical Investigation of Key Parameter Range of AMG Muscle Relaxant Monitor / 中国医疗器械杂志

The accelerometry(AMG) muscle relaxant monitor is the most widely used quantitative muscle relaxant monitor to assess the degree of neuromuscular at present. In this study, the ulnar nerve was stimulated by using train of four stimulation(TOF) mode of the AMG muscle relaxant monitor, and the movement of the adductor pollicis muscle was monitored. In this way, the distribution range of key parameters (acceleration peak value, response time, and TOF ratio) of the adductor pollicis muscle during the use of muscle relaxant in clinical practice is analyzed and will provide a practical basis for the development and improvement of the muscle relaxant monitor.

The effect of pyridostigmine on bispectral index during recovery from sevoflurane anesthesia / 대한마취과학회지

BACKGROUND: There have been some conflicting reports showing that muscle relaxants and anticholinesterases affect the level of the bispectral index (BIS). The purpose of this study was to investigate whether pyridostigmine affects the level of the BIS during recovery from sevoflurane anesthesia. METHODS: Fifty-two adult patients scheduled for laparoscopic cholecystectomy and laparoscopic appendectomy. Anesthesia was induced with thiopental 4 mg/kg and rocuronium 0.6 mg/kg. The lung was mechanically ventilated with 1-3 vol% sevoflurane, 50% oxygen and 50% nitrous oxide. After a specimen was removed, the sevoflurane concentration was maintained at 1.5 vol%. When skin closure began, sevoflurane was stopped; however, 50% oxygen and 50% nitrous oxide were maintained. The patients then received either (1) a group that received an injection of glycopyrrolate 0.04 mg/kg and pyridostigmine 0.2 mg/kg (reverse (R) group, n = 26) or (2) a group that received normal saline (control (C) group, n = 26). Group assignment was random. Pyridostigmine, a reversible cholinesterase inhibitor, is a parasympathomimetic. End-tidal sevoflurane concentration, train of four (TOF) ratio, bispectral index (BIS), blood pressure and heart rate were measured from the end of the operation to 15 min after inject of pyridostigmine or placebo. RESULTS: There were no significant between group differences in the time dependent decrease in end-tidal sevoflurane concentration (P = 0.0642). There were significant differences between the two groups for the time course for increases in the TOF value (P < 0.0001). There were significant differences between the two groups for the time course for increases in the BIS value (P = 0.0107). There were no significant differences in the mean BIS value up to 10 minutes after administering drug, but 15 minutes after administrating the reverse drug or the control drug, the BIS value showed significantly different BIS values: 68.2 +/- 6.2 (Group R) and 63.2 +/- 6.2 (Group C) (P = 0.0058). CONCLUSIONS: The finding that pyridostigmine increases TOF and BIS suggests that pyridostigmine may enhance recovery during recovery from sevoflurane anesthesia.

The Influence of Patient Controlled Analgesia on the Recovery of Muscle Power and Respiratory Function following Intraoperative Muscle Relaxants / 대한마취과학회지

BACKGROUND: Residual muscle paralysis after anesthesia is reduced with the advent of intermediate-acting neuromuscular blocking drugs, yet the incidence is as high as about 10 percent. Opioids in patient-controlled analgesia (PCA) may cause respiratory depression and other problems after anesthesia. The purpose of this study is to evaluate the influence of PCA on the SPO2, TOF ratio, head-lift and tongue protrusion during recovery room stay following intraoperative muscle relaxants. METHODS: 120 patients aged from 20 to 65 in ASA class I and II were divided into control or PCA groups. All patients received rocuronium (0.9 mg/kg) or atracurium (0.5 mg/kg) for tracheal intubation, and maintenance of relaxation was done with atracurium 0.2 mg/kg/hr during inhalation anesthesia. Reversal of block was done with pyridostigmine 0.15 mg/kg and glycopyrrolate 0.2 mg. SpO2, TOF ratio, 5 sec-head lift, tongue protrusion tests were evaluated in the recovery room. RESULTS: IV-PCA did not influence the incidence of residual block, SPO2, TOF ratio during recovery room stay for 20 minutes, but influenced negatively 5 sec-head lift test, tongue protrusion test only immediately after arrival at the recovery room. CONCLUSIONS: Since IV-PCA decreased the ability to perform head-lift and tongue protrusion early postoperatively, it is recommended that patients with IV-PCA should be carefully managed against the risk of aspiration or upper respiratory obstruction during their early recovery room stay.

The Effect of Neostigmine on the Train-of-four Ratio during the Recovery from Vecuronium- or Atracurium-induced Neuromuscular Blockade / 대한마취과학회지

BACKGROUND: The train-of-four(TOF) fade known as expression of prejuntional receptor binding was useful for evaluating the residual neuromuscular blockade(NMB). The present study was undertaken to investigate the effect of the neostigmine(Neo) on TOF ratio during the recovery from vecuronium(V) or atracurium(A) induced NMB under the general anesthesia. METHODS: Forty healthy adult patients were randomly divided into 4 groups as follows; spontaneous recovery from V-induced NMB(V-C group) or A-induced NMB(A-C group), reversed recovery with Neo at 20% recovery of control first twitch height(T) from V-induced NMB(V-R group) or A-induced NMB(A-R group). TOF ratio at 25 and 75% recovery of T and recovery index(RI) defined as time from 25 to 75% recovery of T were measured. RESULTS: TOF ratios at 25 and 75% recovery of T were 3.7 & 35.8%(V-C group), 8.4 & 46.9%(A-C group), 3.7 & 48.7%(V-R group) and 15.2 & 55.6%(A-R group) respectively(P>0.05). RI were 19.2 min(V-C group), 19.5 min(A-C group), 3.5 min(V-R group), and 5.6 min(A-R group) respectively (P<0.05). CONCLUSIONS: RI were significantly shortened in reversed recovery groups with Neo than spontaneous recovery groups (P<0.05). However TOF ratio at 75% recovery of T1 were not significantly different between spontaneous recovery and reversed recovery groups.

The Comparison of the TOF Ratios between Electromyograph and Accelerograph following Vecuronium Administration / 대한마취과학회지

The present study was firstly undertaken in an attempt to compare simultaneously EMG(electromyography) and two new ACC(accelerography) reponses in the both hand following vecuronium administration in 26 ASA 1 or 2 adult patients undergoing general anesthesia. In the three NMT monitors, stimulating electrodes are applied similarly over the ulnar nerve on the volar side of the wrist, but the evoked EMG(Relaxograph, Datex Co.) responses obtained from the hypothenar muscles, TOFGUARD(Biometer Co.) responses from adductor pollicis and ParaGraph(Utah Med. Prod. Co.) responses from both muscles of hypothenar and thenar muscle of the hand respectively. Following induction of anesthesia with thiopental sodium(5 mg/kg) and vecuronium(0.08 mg/kg) intravenously, endotracheal intubation was facilitated and anesthesia was maintained with a mixture of enflurane(1~2%) and N2O(50%) . After loss of consciousness, the assessment of the neuromuscular blockade was started. We compared simultaneously TR(train-of-four ratio) responses of EMG at the one hand, and two new ACC named TOF-GUARD and ParaGraph at the other hand respectively during evoked recovery from vecuronium induced neuromuscular blockade. The result was the greater depression of TR response in TOF-GUARD and the lesser depression of TR response in ParaGraph than those in EMG. But test for parallelism did not show a statistically significant difference between the slope of these regression lines. Conclusively, the regression line for TR seems to be tend to give an impression that two new ACC named TOF-GUARD and ParaGraph would be suitable in the assessment of neuromuscular blockade in clinical anesthesia.

The Reversal Effects of Anticholinergics During Recovery from Vecuronium Induced Neuromuscular Blockade in Humans / 대한마취과학회지

Anticholinergics are commonly used to block undesirable musearinic effects of the anticholinesterase agents. The results observed in man and animal seem indicate that atropine may interfere with the neuromuscular junction. Our study investigate this role in clinical anesthesia, when anticholinergics are given at the beginning of recovery from vecuronium induced neuromuscular blockade. Forty-four ASA I-II adult anesthetized(tbiopental, enflurane, N, vecuronium) patients undergoing elective surgery were monitored with ParaGraph. The patients received intravenously 0.9% normal saline 2ml in control and atropine 0.5mg,atropine 1.0mg, or glycopyrrolate 0.4mg in study group when twitch height spontaneously was beginning to regain. After administration of atropine and glycopyrrolate,TOF ratio and DBS ratio were observed at every 6min intervals. On the other hand, vecumnium 0.8mg in 0.9% normal saline20ml(control) and vecuronium 0.8mg mixed atropine 0.25mg in 0.9% normal saline 20ml(study) were given I.V. each forearm of one patient with double isolation arm test under the normal twitch height. After tourniquet release, first twitch height and TOF ratio were observed at every 5min intervals, All results were no significant different between the control group and those study groups, for all the observed tests, but anticholinergics seem to be shown to enhance the recovery in clinical doses and to delay in large doses from neuromuscular blockade. The mechanism of action of antieholinergics, at the neuromuscular junction, are discussed with references, possibly by acting on muscarinic presynaptic inhibitory receptors, which are invalued in the negative feedback mechanism of transmitter release.