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ABSTRACT Objective: To determine the factors related to quadriceps weakness, to evaluate electromyo-graphic changes in the quadriceps and to attempt to determine the neuromuscular restoration period after anterior cruciate ligament (ACL) repair. Methods: A total of 30 patients (28 males and 2 females) who underwent surgery conducted by two surgeons were reviewed prospectively. All ACLs were reconstructed arthroscopically with anterior tibial tendon allograft, using an anteromedial portal. The patients' quadriceps muscles' neuromuscular activity was determined with electromyography at early and late periods (1-3 months and 6-12 months, respectively). Results: A significant difference was observed (p < 0.01) in the quadriceps circumference between the operated extremities (average, 48.4 cm) and the healthy limbs (average, 50.6 cm), according to measurements obtained on the sixth month after surgery. The tourniquet time was greater than 50 minutes in patients with quadriceps atrophy. A significant elongation was observed in the motor unit potential duration of the operated ipsilateral side, compared to the contralateral side (p < 0.001) at the early-term period. Differences were observed between the ipsilateral MUP amplitude and the durations of early- and late-term patients, but were not significant. Conclusion: Our study demonstrated that atrophies are significantly overcome in the first year after surgery. The electromyographic examinations indicated that tourniquet use not only caused functional harm in the quadriceps muscle but it also caused structural damage. However, these structural injuries did not result in negative effects on the clinical success.
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Objective To study any changes in the surface electromyography of the paraspinal muscles before and after surgery in patients with degenerative lumbar kyphosis.Methods Thirty patients with lumbar degenerative kyphosis (LDK) were enrolled and underwent pedicle subtraction osteotomy.Surface electromyograms were recorded before the operation and 3 months afterward to observe the myoelectric activity of the paraspinal muscles.The electromyograms were also compared with those of healthy counterparts.Results The preoperative average EMG (AEMG) values in the LDK group in static standing were significantly higher than those of the control group.After the operation the values had decreased significantly,but were still significantly higher than in the control group.The preoperative AEMG values of the LDK group from the L1-2 segment during torso stretching were significantly lower than those of the control group.They increased significantly after the operation and were no longer significantly different from the control groups' readings.The pre-and post-operative AEMG values from the L4-5 segment were not significantly different and remained significantly lower than in the control group.During lifting and holding the mean power frequency slopes of the LDK group were significantly lower than those of the controls both before and after the operation,though the postoperative slopes were significantly higher than the preoperative ones.Conclusion Patients with lumbar degenerative kyphosis have obvious paraspinal muscle weakness and severe fatigue.Early pedicle subtraction osteotomy can significantly improve the functional status of the paravertebral muscles in the short term.
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Objective To observe the effects of autologous myoblast transplantation on endplate regeneration and neuromuscular function restoration following direct nerve implantation (DNI) in rats so as to offer experimental basis for the use of myoblasts in neural regeneration area and further lay foundation for the research using myoblasts as transgenic carriers. Methods A total of 20 male SD rats were randomly divided into experimental group and control group,with 10 rats in each group.Models of DNI in rat gastrocnemius were established.The experimental group was injected with primarily cultured autologous myoblasts to the DNI location,while the control group was injected with isometric medium without autologous myoblasts.The effects of myoblasts on the neuromuscular function recovery following DNI were studied by detecting the tibial functional index (FTI),neuro-electrophysiology and pathohistology.Results The experimental group displayed faster tibial nerve function recovery than the control group (P ＜ 0.01 ).The peak to peak value (PPV) of gastrocnemius neuro-electrophysiology,area under the curve and regenerated endplate number of the experimental group had statistical significances as compared with the control group ( P ＜ 0.01 ). Conclusion Myoblast autotransplantation accelerates the recoveryof neuromuscular function after rat DNI and increases the number of the regenerated endplates.
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BACKGROUND: Inexperienced anesthesiologists are frequently unclear as to whether to stimulate the ulnar or median nerve to monitor the adductor pollicis. The primary purpose of this study was to determine whether monitoring the adductor pollicis by positioning the stimulating electrodes over the median nerve is an acceptable alternative to applying electrodes over the ulnar nerve. METHODS: In 20 patients anesthetized with propofol and remifentanil, one pair of stimulating electrodes was positioned over the ulnar nerve. A second pair was placed over the median nerve on the other hand. The acceleromyographic response was monitored on both hands. Rocuronium 0.6 mg/kg was administered. Single twitch (ST) and train-of-four (TOF) stimulations were applied alternatively to both sites. RESULTS: None of the patients showed a twitch response at either site after injection of rocuronium. There were no differences in the mean supramaximal threshold, mean initial TOF ratio, or mean initial ST ratio between the two sites. Bland-Altman analysis revealed a bias (limit of agreement) in the TOF and ST ratios over the median nerve of 7% (+/- 31%) and 26% (+/- 73%), respectively, as compared with the ulnar nerve. The median nerve TOF ratio was overestimated by 16.2%, as compared with that of the ulnar nerve value, and the median nerve ST ratio was overestimated by 72.9%, as compared to that of the ulnar nerve. CONCLUSIONS: The ulnar and median nerves cannot be used interchangeably for accurate neuromuscular monitoring.
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Humans , Androstanols , Bias , Electrodes , Hand , Median Nerve , Neuromuscular Monitoring , Organothiophosphorus Compounds , Piperidines , Propofol , Relaxation , Ulnar NerveABSTRACT
BACKGROUND: The aim of study is to investigate the initial functional changes of muscle in rats induced to have myasthenia gravis, experimental autoimmune myasthenia gravis (EAMG). The authors investigated the functional changes of muscle evaluated by mechanomyography (MMG) and the expression of acetylcholine receptors (AChRs). METHODS: After the institutional approval, 39 male Lewis rats were randomly allocated into study. 26 animals were immunized to induce EAMG by Torpedo AChR (T-AChR) emulsified with complete Freund's adjuvant (CFA) and phosphate buffer saline (PBS)/bovine serum albumin (BSA) 0.01% at the base of tail, and received booster immunizations twice by T-AChR with incomplete Freund's adjuvant (IFA) and PBS/BSA 0.01% at all different site on the upper back. 13 animals were sham immunized as control group by the same method of EAMG except T-AChR. Clinical EAMG scores were examined. Anti T-AChR and anti rat-AChR (R-AChR) antibodies (Ab) were compared by using (125)I-alpha-bungarotoxin ((125)I-alpha-BuTx) radioimmunoassay. Under the anesthesia, neuromuscular functions were monitored by MMG using single twitch (ST) and TOF. AChRs were quantitated using (125)I-alpha-BuTx. RESULTS: Overall weight gain and final body mass, muscle force (ST), specific muscle force of ST, TOF fade ratio and AChRs were reduced in EAMG score 3 compared to control (P < 0.0001). Anti T-AChR Ab and anti R-AChR Ab were increased in score 3 EAMG (P < 0.0001). CONCLUSIONS: EAMG score 3 rats showed characteristic neuromuscular functions as depressed initial ST and its specific force, initial TOF fade and increased anti AChR Abs. Those above characteristics had significant correlations with the clinical EAMG scores. AChRs were significantly down-regulated according to their functional characteristics and clinical EAMG scores.
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Animals , Humans , Male , Rats , Acetylcholine , Anesthesia , Antibodies , Freund's Adjuvant , Immunization, Secondary , Myasthenia Gravis , Myasthenia Gravis, Autoimmune, Experimental , Radioimmunoassay , Receptors, Cholinergic , Serum Albumin , Tail , Torpedo , Weight GainABSTRACT
[Objective] The purpose of this study was to determine whether icing treatment has an effect on muscle reaction time and functional performance of a sprained ankle. [Methods] Subjects were six persons (healthy group) and six persons who had an acute ankle sprain (patient group) . Anterior talar translation and talar tilt of the six patient group were evaluated by the stress X-ray measure. Ice treatment was applied for 20 minutes. [Results] The following points were clarified : 1) Reaction times of peroneus longus (PL) and peroneus brevis (PB) for the sprained ankle group (SA) were significantly longer than those for the non-sprained ankle group (NA) (p<0.05) . Length of time of standing on one leg with closed eyes for SA was significantly shorter than for NA (p<0.05) . 2) After icing treatment, reaction time of PL for SA tended to be shorter. Furthermore, PB significantly decreased after icing treatment (p<0.05) . Side-steps for SA were significantly increased after icing treatment (p<0.05) . 3) Reaction times of PL and PB for NA significantly increased after icing treatment (p<0.05) . Standing on one leg with closed eyes for NA significantly decreased after icing treatment (p<0.05) . [Conclusion] It was shown that icing treatment of a sprained ankle leads to a shorter muscle reaction time and an increase in the number of side-steps. Therefore, it was concluded that icing treatment of a sprained ankle might be able to improve incapacitated neuromuscular function and functional performance by acute trauma.
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BACKGROUND: The purpose of this study was to investigate whether the effects of mivacurium on onset and recovery were affected by the duration of more than 2 weeks after injury of the lower motor neuron in rabbits. METHODS: The animals were divided into five groups. The control group was without lower motor neuron injury. In the experimental groups, the lower motor neuron injury was made by denervating with a 75 - 80% lesion on the common peroneal nerve to the right anterior tibialis muscle. The experimental groups were subdivided as 1, 2, 3 and 4 week groups (named group 1 wk, 2, 3 and 4 wks) according to the duration of the denervation of the common peroneal nerve. The response relationship of mivacurium on the muscle twitches induced by TOF (train of four) stimulation (supramaximal stimulus of 0.2 ms duration, square-wave pulses, 2 Hz rate and 10 mA, repeated every 10 seconds) was studied in the anterior tibialis muscles and compared between all groups. Neuromuscular responses (onset, recovery time to T1(1), T1(25), T1(75), T1(95) and recovery index) of muscle twitches to intravenous mivacurium (0.18 mg/kg) were studied. After recording the muscle twitches, macroscopic findings were observed. RESULTS: The recovery time, T1(1) of group 4 wks was significantly longer than those of group 1, 2 and 3 wks (P < 0.05), but not different from the control group. The recovery time, T1(25), T1(75) and T1(95) of group 4 wks was significantly longer than those of all other groups (P < 0.05), but the onset times of all groups were not significantly different. The recovery index of group 4 wks was significantly higher than that of the control group (P < 0.05), but those of groups 1, 2 and 3 wks were not significantly different from that of the control group. The mass of the anterior tibialis muscle was significantly decreased at 4 weeks after the lower motor neuron injury (P < 0.05). CONCLUSIONS: Our results therefore suggest that the neuromuscular response to intravenous mivacurium on recovery in rabbits becomes prolonged according to the durations of the denervation and represents sensitivity at 4 weeks after the lower motor neuron injury.
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Animals , Rabbits , Denervation , Motor Neurons , Muscles , Peroneal NerveABSTRACT
BACKGROUND: Sometimes hypoxemia occurs in the postoperative recovery room because of postoperative residual curarization (PORC). Some reports show that postoperative residual curarization is common. PORC occurs after the use of the long-acting muscle relaxants. It has been recommended to use intermediate-acting muscle relaxants and a TOF monitor to decrease PORC. The purpose of this study was to examine whether the use of the TOF monitor during propofol anesthesia affects the incidence of postoperative residual curarization. METHODS: 38 ASA I or II patients were divided randomly into two groups of 19 each. They received propofol-fentanyl-nitrous oxide for anesthesia. Pancuronium (80 100 microgram/kg) was used to facilitate tracheal intubation and additional doses were used to maintain surgical relaxation. The requirement for incremental doses of pancuronium and adequacy of recovery following reversal were assessed, either with (control group:n = 19) or without (experimental group:n = 19) TOF monitoring. Fifteen minutes after the arrival at the recovery room, neuromuscular function was assessed clinically and by using TOF. RESULTS: There were no statistical differences in body weight, age, or duration of operation between the two groups. There was no statistical difference in the total dose of pancuronium and total dose of pancuronium relative to body weight and duration of operation. There were statistical differences in TOF ratio in the recovery room (0.73 vs. 0.86). The incidence of PORC was 47% in the control group and 5% in the experimental group. CONCLUSIONS: Though the monitoring of TOF did not effect the dose of muscle relaxant, it may have reduced the incidence of PORC. However, the PORC had no clinical significance because the mean TOF ratio in the two groups was over 0.7 and there were no clinical signs of residual muscle weakness.
Subject(s)
Humans , Anesthesia , Hypoxia , Body Weight , Incidence , Intubation , Muscle Weakness , Pancuronium , Propofol , Recovery Room , RelaxationABSTRACT
BACKGROUND: Ideal condition of endotracheal intubation after administration of non-depolarizing muscle relaxants like vecuronium is the time when the diaphragm and upper airway muscles are completely relaxed. But these muscles are difficult to determine the degree of relaxation. Neuromuscular response of these muscles are similar to that of orbicularis oculi (OO), but adductor pollicis (AP) is different. However, it is sometimes difficult to monitor OO response. The purpose of this study was to monitor the upper airway muscle relaxation using AP other than OO. METHODS: Fourty-four adult patients of ASA class 1 schaduled for elective surgery under general anesthesia were examined. Anesthesia was induced with fentanyl 2 mcg/kg, and 2 minutes later followed by thiopental sodium 5 mg/kg. After supramaximal stimulation for control twitch height, vecuronium 0.1 mg/kg was intravenously injected and applied continuous train-of-four (TOF) facial nerve stimuli. The TOF response of OO was closely observed with examiner's naked eyes. When complete relaxation of OO achieved, TOF ratio of AP and the time after vecuronium injection were recorded. Thereafter, tracheal intubation was performed and the intubating condition scores was recorded. Ulnar nerve stimuli were continuously applied until complete relaxation of AP was achieved. The time of complete relaxation of AP after vecuronium injection was also recorded. RESULTS: The onset time of complete relaxation was significantly faster in OO (181.3+/- 47.4 secs) as compared with that of AP (265.0+/-67.8 secs). The average TOF ratio of AP was 47.3+/-17.2% and the condition of intubation performed after complete relaxation of OO was satisfied. CONCLUSION: The optimal time for endotracheal intubation was about 3 min after vecuronium 0.1 mg/kg injection, when TOF ratio of AP was about 50%.
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Adult , Humans , Anesthesia , Anesthesia, General , Diaphragm , Facial Nerve , Fentanyl , Intubation , Intubation, Intratracheal , Muscle Relaxation , Muscles , Neuromuscular Nondepolarizing Agents , Relaxation , Thiopental , Ulnar Nerve , Vecuronium BromideABSTRACT
BACKGROUND: The timing of administration may be an important factor in order to obtain maximal antagonizing effect of anticholinesterase on neuromuscular blockade. The objective of this study is to seek for the optimal administration time of pyridostigmine for reducing the recovery time of vecuronium. METHODS:Thirty patients were devided into three groups,who were receiving intravenously pyridostigmine (0.2 mg/kg) at 10% (group 1), 20% (group 2) and 25% (group 3) recovery of T1. The recovery indices (RI: time taken for T1 to recover from 25 to 75% of control) and recovery time (time taken for T1 to recover from 5% to 20, 25, 50 & 75%) in vecuronium (0.1 mg/kg) neuromuscular blockade were checked and compared between 3 groups using train of four stimulation with Relaxograph(Datex co., Finland). RESULTS: The recovery time (T5-20, T5-25, T5-50, T5-75) was significantly faster in the group 1 than the group 3. But there were no significant differences in recovery indices (RI) between 3 groups. CONCLUSIONS: Provided there is a slightest evidence of spontaneous recovery, early administration of anticholinesterse will reduce the recovery time of nondepolarizing neuromuscular block. But it can not affect the dissociation rate of vecuronium (KD) and there were no significant differences in recovery indices.
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Humans , Neuromuscular Blockade , Pyridostigmine Bromide , Vecuronium BromideABSTRACT
BACKGROUND: The interactions between furosemide and muscle relaxants is controversial. In this study, the effects of furosemide on the recovery from neuromuscular blockade induced by vecuronium were investigated in thirty ASA class 1 or 2 adult patients undergoning elective orthopedic surgery under the general aneshtesia with O2-N2O-enflurane. METHODS: Furosemide was administered intravenously at 20% spontaneous recovery of first twitch height of TOF(T1) under the neuromuscular monitoring using Relaxograph?(Datex Co. Finland) as follows: placebo in control group, 5mg in group 1 and 20mg in group 2. Recovery index(RI) defined as the time from 25% to 75% recovery of T1, urinary output during this period and serum K+ levels at 10% and 75% recovery of T1 were measured. RESULTS: RI was shortened significantly in group 1 (11.2+/-3.4 min.) and group 2 (14.9+/-2.7 min.) compared with control group (19.3+/-4.0 min.)(P<0.05). The urinary output was significantly greater in the groups received furosemide than that in the control group(P<0.05), but serum K+ levels were not significantly changed after administration of furosemide. CONCLUSIONS: Furosemide facilitates recovery of neuromuscular blockade induced by vecuronium.
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Adult , Humans , Furosemide , Neuromuscular Blockade , Neuromuscular Monitoring , Orthopedics , Vecuronium BromideABSTRACT
The methods commonly used for monitoring neuromusculsr transmission do not allow evaluation of an intense neuromuscular blockade. Viby-Mogensen et al. introduced posttetanic count by which an intense nondepolarizing neuromuscular blockade can be evaluated, Our study was designed to evaluate whether the application of a tetanic stimulation (50 Hz for 5 sec.) every 6 to 10 minutes influences the recovery of neuromuscular transmission. 26 adult patients (ASA class I or II) were studied. They ranged in age from 20 to 71 years (mean 39.7 years). Anesthesia was induced with 0.1 mg/kg vecuronium and 4-5 mg/kg thiopental sodium and maintained with nitrous oxide and halothane. TOF group was stimulated with TOF stimulation only while PTC group with the pattern of stimulation introduced by Viby-Mogensen et al. In our results, the recovery time of PTC group was shorter than that of the TOF group. Therefore, our results indicate that intermittent tetanic stimulation (50 Hz for 5 sec.) every 6 to 10 minutes during intense non depolarizing neuromuscular blockade influences the time to the first response to TOF nerve stimulation.