Comparison of onset of neuromuscular blockade with electromyographic and acceleromyographic monitoring: a prospective clinical trial

Abstract Background Reliable devices that quantitatively monitor the level of neuromuscular blockade after neuromuscular blocking agents' administration are crucial. Electromyography and acceleromyography are two monitoring modalities commonly used in clinical practice. The primary outcome of this study is to compare the onset of neuromuscular blockade, defined as a Train-Of-Four Count (TOFC) equal to 0, as measured by an electromyography-based device (TetraGraph) and an acceleromyography-based device (TOFscan). The secondary outcome was to compare intubating conditions when one of these two devices reached a TOFC equal to 0. Methods One hundred adult patients scheduled for elective surgery requiring neuromuscular blockade were enrolled. Prior to induction of anesthesia, TetraGraph electrodes were placed over the forearm of patients' dominant/non-dominant hand based on randomization and TOFscan electrodes placed on the contralateral forearm. Intraoperative neuromuscular blocking agent dose was standardized to 0.5 mg.kg−1 of rocuronium. After baseline values were obtained, objective measurements were recorded every 20 seconds and intubation was performed using video laryngoscopy once either device displayed a TOFC = 0. The anesthesia provider was then surveyed about intubating conditions. Results Baseline TetraGraph train-of-four ratios were higher than those obtained with TOFscan (Median: 1.02 [0.88, 1.20] vs. 1.00 [0.64, 1.01], respectively, p < 0.001). The time to reach a TOFC = 0 was significantly longer when measured with TetraGraph compared to TOFscan (Median: 160 [40, 900] vs. 120 [60, 300] seconds, respectively, p < 0.001). There was no significant difference in intubating conditions when either device was used to determine the timing of endotracheal intubation. Conclusions The onset of neuromuscular blockade was longer when measured with TetraGraph than TOFscan, and a train-of-four count of zero in either device was a useful indicator for adequate intubating conditions. Clinical trial number and registry URL NCT05120999, https://clinicaltrials.gov/ct2/show/NCT05120999.

The application of intraoperative neurophysiological monitoring in selective dorsal neurotomy for primary premature ejaculation: a prospective single-center study / 亚洲男科学杂志(英文版)

Selective dorsal neurotomy (SDN) is a surgical treatment for primary premature ejaculation (PE), but there is still no standard surgical procedure for selecting the branches of the dorsal penile nerves to be removed. We performed this study to explore the value of intraoperative neurophysiological monitoring (IONM) of the penile sensory-evoked potential (PSEP) for standard surgical procedures in SDN. One hundred and twenty primary PE patients undergoing SDN were selected as the PE group and 120 non-PE patients were selected as the normal group. The PSEP was monitored and compared between the two groups under both natural and general anesthesia (GA) states. In addition, patients in the PE group were randomly divided into the IONM group and the non-IONM group. During SDN surgery, PSEP parameters of the IONM group were recorded and analyzed. The differences in PE-related outcome measurements between the perioperative period and 3 months' postoperation were compared for the PE patients, and the differences in effectiveness and complications between the IONM group and the non-IONM group were compared. The results showed that the average latency of the PSEP in the PE group was shorter than that in the normal group under both natural and GA states (P < 0.001). Three months after surgery, the significant effective rates in the IONM and non-IONM groups were 63.6% and 34.0%, respectively (P < 0.01), and the difference in complications between the two groups was significant (P < 0.05). IONM might be useful in improving the short-term therapeutic effectiveness and reducing the complications of SDN.

Somatosensory evoked potentials in clinical practice: a review / Potenciais evocados somatossensitivos na prática clínica: uma revisão

Abstract The authors present a review of the current use of somatosensory evoked potentials (SSEPs) in neurological practice as a non-invasive neurophysiological technique. For this purpose we have reviewed articles published in English or Portuguese in the PubMed and LILACS databases. In this review, we address the role of SSEPs in neurological diseases that affect the central nervous system and the peripheral nervous system, especially in demyelinating diseases, for monitoring coma, trauma and the functioning of sensory pathways during surgical procedures. The latter, along with new areas of research, has become one of the most important applications of SSEPs.

Resumo Os autores apresentam uma revisão do uso atual do potencial evocado somatossensitivo (PESS) na prática neurológica como uma técnica neurofisiológica não invasiva. Revisamos artigos publicados em Inglês ou Português nas bases de dados PubMed e LILACS. Nesta revisão abordamos o papel do PESS nas doenças neurológicas que atingem o sistema nervoso central e o sistema nervoso periférico, especialmente, nas doenças desmielinizantes, no monitoramento do coma, do trauma e da função das vias sensitivas durante os procedimentos cirúrgicos, que se tornou uma de suas aplicações mais importantes, assim como novas áreas de pesquisa.

Relationship between intraoperative neurophysiological monitoring alert and postoperative walking ability / 中国组织工程研究

BACKGROUND: Intraoperative neurophysiological monitoring is popular in spinal surgery. However, a severe iatrogenic spinal cord injury cannot be completely eliminated. Is there a relationship between true positive intraoperative neurophysiological monitoring alert during particular surgical steps and postoperative neurological recovery? This topic is to improve the safety of spinal invasive procedures. OBJECTIVE: To determine the relationship between true positive intraoperative neurophysiological monitoring alert during particular surgical steps and postoperative walking ability. METHODS: A retrospective study of 2 249 patients undergoing intraoperative neurophysiological monitoring in Li Ka Shing Faculty of Medicine, the University of Hong Kong was conducted. Standard patient demographics, diagnosis and operative features and intraoperative neurophysiological monitoring data were collected. There were 10 cases of true positive intraoperative neurophysiological monitoring alert (4 males, 6 females, 14-88 years old), and the average follow-up time was 9.8 years. The patients were divided into two groups based on whether surgical steps triggering intraoperative neurophysiological monitoring alert impact the spinal cord or not. The study was performed in accordance with the ethical requirements of Li Ka Shing Faculty of Medicine, the University of Hong Kong, and the patients and their guardians signed the informed consents. RESULTS AND CONCLUSION: These alerts occurred during decompression (n=3), anterior disc release (n=1), finding the entering point of T3 pedicle (n= 1), screw insertion (n=1), reduction of fracture (n=2), insertion of wire (n= 1), and cement injection (n=1). Among these patients, 100% of spinal cord invasive procedure patients developed incompetence of walking, while 80% (4/5) of spine cord non-invasive patients were capable of walking (P < 0.05). After the alert was triggered, four patients continued with primary program, three patients underwent expanding decompression and three patients gave up surgery. If true positive intraoperative neurophysiological monitoring alert is reported during spinal invasive procedures, there should be a very high chance of postoperative walking disability. If any conditions occur, the surgery needs to be stopped, and instead, remedial measures such as surgery suspension, steroids injection, and additional decompression should be performed immediately.

Neuromonitorización intraoperatoria del nervio facial: a propósito de un caso / Intraoperative neuromonitoring of the facial nerve: a case report

Introdução: A preservação do nervo facial (NF) é uma das principais preocupações do cirurgião durante o tratamento aberto das fraturas mandibulares, uma vez que uma lesão nessa estrutura anatômica pode causar sequelas estéticas e funcionais permanentes. A existência de variações anatômicas (anastomoses e ramificações incomuns) aumenta o risco de danos no NF, mesmo nas mãos de cirurgiões experientes. O neuromonitoramento intraoperatório tem-se mostrado um grande aliado para evitar lesões nos ramos nervosos que podem estar envolvidos na área cirúrgica. Considerando a escassez desse assunto na literatura referente à cirurgia maxilo-facial, objetivamos demonstrar o uso da técnica de neuromonitoração do NF durante o acesso submandibular para o tratamento da fratura bilateral do ângulo mandibular. Relato de caso: No presente relato de caso, as abordagens cirúrgicas de ambos os lados não apresentaram danos permanentes ao NF. Esse resultado assim como a literatura sugerem que o neuromonitoramento intraoperatório proporciona maior segurança durante a realização de abordagens cirúrgicas, nas quais os ramos do nervo facial estão envolvidos, reduzindo, assim, o risco de sequelas nervosas. Considerações Finais: Esse recurso pode ser de grande auxílio no treinamento hospitalar ao longo do processo de formação de cirurgiões bucomaxilofaciais... (AU)

Introduction: Facial nerve (FN) preservation is one of the surgeon's major concerns during the open treatment of mandibular fractures since an injury to this anatomical structure can cause permanent aesthetic and functional sequelae. The existence of anatomical variations (anastomosis and unusual branching) increases the risk of FN damage even in the hands of experienced surgeons. Intraoperative neuromonitoring has proven to be a great ally to avoid injury to the nerve branches that may be involved in the surgical area. Considering the scarcity of this subject in the maxillofacial surgery literature, we aimed to demonstrate the use of the FN neuromonitoring technique during the submandibular approach for the treatment of bilateral mandibular angle fracture. Case report: In the present case report, the surgical approaches of both sides presented no permanent damage to the FN. Results: This result, as well as previous literature, suggests that intraoperative neuromonitoring provides greater safety during the performance of surgical approaches in which the facial nerve branches are involved and thus, reduces the risk of nerve sequelae. Final considerations: This resource can be of special assistance in teaching hospitals throughout the training process of maxillofacial surgeons... (AU)

Intraoperative Neurophysiological Monitoring during Microvascular Decompression Surgery for Hemifacial Spasm

Hemifacial spasm (HFS) is due to the vascular compression of the facial nerve at its root exit zone (REZ). Microvascular decompression (MVD) of the facial nerve near the REZ is an effective treatment for HFS. In MVD for HFS, intraoperative neurophysiological monitoring (INM) has two purposes. The first purpose is to prevent injury to neural structures such as the vestibulocochlear nerve and facial nerve during MVD surgery, which is possible through INM of brainstem auditory evoked potential and facial nerve electromyography (EMG). The second purpose is the unique feature of MVD for HFS, which is to assess and optimize the effectiveness of the vascular decompression. The purpose is achieved mainly through monitoring of abnormal facial nerve EMG that is called as lateral spread response (LSR) and is also partially possible through Z-L response, facial F-wave, and facial motor evoked potentials. Based on the information regarding INM mentioned above, MVD for HFS can be considered as a more safe and effective treatment.

Development of a Novel Intraoperative Neuromonitoring System Using a Surface Pressure Sensor to Detect Muscle Movement: A Rabbit Model Study

OBJECTIVES: False-negative or false-positive responses in intraoperative neuromonitoring (IONM) using electromyography (EMG) in thyroid surgery pose a challenge. Therefore, we developed a novel IONM system that uses a surface pressure sensor instead of EMG to detect muscle twitching. This study aimed to investigate the feasibility and safety of a new IONM system using a piezo-electric surface pressure sensor in an experimental animal model. METHODS: We developed the surface pressure sensor by modifying a commercial piezo-electric sensor. We evaluated the stimulus thresholds to detect muscle movement, as well as the amplitude and latency of the EMG and surface pressure sensor in six sciatic nerves of three rabbits, according to the stimulus intensity. RESULTS: The surface pressure sensor detected the muscle movements in response to a 0.1 mA stimulation of all six sciatic nerves. There were no differences in the thresholds of stimulus intensity between the surface pressure sensor and EMG recordings to detect muscle movements. CONCLUSION: It is possible to measure the change in surface pressure by using a piezo-electric surface pressure sensor instead of EMG to detect muscle movement induced by nerve stimulation. The application of IONM using a piezo-electric surface pressure sensor during surgery is noninvasive, safe, and feasible. Measuring muscle twitching to identify the state of the nerves using the novel IONM system can be an alternative to recording of EMG responses.

Efficacy of bilateral erector spinae plane block in improving intraoperative wake-up quality in patients undergoing thoracolumbar scoliosis correction with general anesthesia / 中华麻醉学杂志

Objective@#To evaluate the efficacy of bilateral erector spinae plane block (ESPB) in improving intraoperative wake-up quality in the patients undergoing thoracolumbar scoliosis correction with general anesthesia.@*Methods@#Forty American Society of Anesthesiologists physical status Ⅱor Ⅲ patients of both sexes, aged 18-60 yr, scheduled for elective posterior approach thoracolumbar scoliosis correction, were divided into 2 groups (n=20 each) using a random number table method: control group (C group) and bilateral ESPB group (E group). Bilateral ESPB was performed through injecting 0.375% ropivacaine 15-20 ml to each site in group E. Anesthesia was induced by intravenously injecting propofol, sufentanil and cisatracurium after dexmedetomidine was intravenously infused for 10 min.Anesthesia was maintained by intravenously infusing remifentanil, propofol and dexmedetomidine.Propofol infusion was stopped and the infusion rate of remifentanil and dexmedetomidine was decreased during intraoperative wake-up test.Wake-up test was performed every 30 s starting from 5 min after stopping propofol infusion.The wake-up time, occurrence of agitation and coughing, hemodynamic changes (△MAP and △HR, the difference between MAP while stopping administration before wake-up test and maximum MAP during wake-up test, the difference between HR while stopping administration before wake-up test and maximum HR during wake-up test) and blood loss were recorded.The wake-up quality was assessed during operation.@*Results@#Compared with C group, the wake-up time was significantly shortened, the incidence of agitation and coughing was decreased, blood loss was reduced, △MAP and △HR were decreased, and the wake-up quality was increased in E group (P<0.05).@*Conclusion@#Bilateral ESPB can increase the intraoperative wake-up quality in the patients undergoing thoracolumbar scoliosis correction with general anesthesia.

Intraoperative Neurophysiological Monitoring during Microvascular Decompression Surgery for Hemifacial Spasm

Hemifacial spasm (HFS) is due to the vascular compression of the facial nerve at its root exit zone (REZ). Microvascular decompression (MVD) of the facial nerve near the REZ is an effective treatment for HFS. In MVD for HFS, intraoperative neurophysiological monitoring (INM) has two purposes. The first purpose is to prevent injury to neural structures such as the vestibulocochlear nerve and facial nerve during MVD surgery, which is possible through INM of brainstem auditory evoked potential and facial nerve electromyography (EMG). The second purpose is the unique feature of MVD for HFS, which is to assess and optimize the effectiveness of the vascular decompression. The purpose is achieved mainly through monitoring of abnormal facial nerve EMG that is called as lateral spread response (LSR) and is also partially possible through Z-L response, facial F-wave, and facial motor evoked potentials. Based on the information regarding INM mentioned above, MVD for HFS can be considered as a more safe and effective treatment.

Efficacy of bilateral erector spinae plane block in improving intraoperative wake-up quality in patients undergoing thoracolumbar scoliosis correction with general anesthesia / 中华麻醉学杂志

Objective To evaluate the efficacy of bilateral erector spinae plane block (ESPB) in improving intraoperative wake-up quality in the patients undergoing thoracolumbar scoliosis correction with general anesthesia.Methods Forty American Society of Anesthesiologists physical status Ⅱ or Ⅲ patients of both sexes,aged 18-60 yr,scheduled for elective posterior approach thoracolumbar scoliosis correction,were divided into 2 groups (n=20 each) using a random number table method:control group (C group)and bilateral ESPB group (E group).Bilateral ESPB was performed through injecting 0.375％ ropivacaine 15-20 ml to each site in group E.Anesthesia was induced by intravenously injecting propofol,sufentanil and cisatracufium after dexmedetomidine was intravenously infused for 10 min.Anesthesia was maintained by intravenously infusing remifentanil,propofol and dexmedetomidine.Propofol infusion was stopped and the infusion rate of remifentanil and dexmedetomidine was decreased during intraoperative wake-up test.Wake-up test was performed every 30 s starting from 5 min after stopping propofol infusion.The wake-up time,occurrence of agitation and coughing,hemodynamic changes (△ MAP and △ HR,the difference between MAP while stopping administration before wake-up test and maximum MAP during wake-up test,the difference between HR while stopping administration before wake-up test and maximum HR during wake-up test) and blood loss were recorded.The wake-up quality was assessed during operation.Results Compared with C group,the wake-up time was significantly shortened,the incidence of agitation and coughing was decreased,blood loss was reduced,△ MAP and △ HR were decreased,and the wake-up quality was increased in E group (P＜ 0.05).Conclusion Bilateral ESPB can increase the intraoperative wake-up quality in the patients undergoing thoracolumbar scoliosis correction with general anesthesia.

Intraoperative Neurophysiologic Testing of the Perigastric Vagus Nerve Branches to Evaluate Viability and Signals along Nerve Pathways during Gastrectomy

PURPOSE: The perigastric vagus nerve may play an important role in preserving function after gastrectomy, and intraoperative neurophysiologic tests might represent a feasible method of evaluating the vagus nerve. The purpose of this study is to assess the feasibility of neurophysiologic evaluations of the function and viability of perigastric vagus nerve branches during gastrectomy. MATERIALS AND METHODS: Thirteen patients (1 open total gastrectomy, 1 laparoscopic total gastrectomy, and 11 laparoscopic distal gastrectomy) were prospectively enrolled. The hepatic and celiac branches of the vagus nerve were exposed, and grabbing type stimulation electrodes were applied as follows: 10–30 mA intensity, 4 trains, 1,000 µs/train, and 5× frequency. Visible myocontractile movement and electrical signals were monitored via needle probes before and after gastrectomy. Gastrointestinal symptoms were evaluated preoperatively and postoperatively at 3 weeks and 3 months, respectively. RESULTS: Responses were observed after stimulating the celiac branch in 10, 9, 10, and 6 patients in the antrum, pylorus, duodenum, and proximal jejunum, respectively. Ten patients responded to hepatic branch stimulation at the duodenum. After vagus-preserving distal gastrectomy, 2 patients lost responses to the celiac branch at the duodenum and jejunum (1 each), and 1 patient lost response to the hepatic branch at the duodenum. Significant procedure-related complications and meaningful postoperative diarrhea were not observed. CONCLUSIONS: Intraoperative neurophysiologic testing seems to be a feasible methodology for monitoring the perigastric vagus nerves. Innervation of the duodenum via the celiac branch and postoperative preservation of the function of the vagus nerves were confirmed in most patients. TRIAL REGISTRATION: Clinical Research Information Service Identifier: KCT0000823

Visual and electrophysiological identification of the external branch of superior laryngeal nerve in redo thyroid surgery compared with primary thyroid surgery

PURPOSE: Thyroid reoperations are surgically challenging because of significant anatomical variance. Visual and functional identification of the external branch of the superior laryngeal nerve (EBSLN) were studied in 2 groups of patients who underwent primary and redo thyroid surgery. METHODS: This study was conducted on 200 patients: 100 patients with redo and 100 patients with primary thyroid surgery. In addition to visual identification, nerve branches were functionally identified by intraoperative nerve monitoring (IONM). Visual, functional, and total identification rates of the EBSLN in both primary and redo surgery were determined and compared between the 2 groups. RESULTS: We attempted to identify 138 and 170 EBSLNs at risk in redo and primary surgery, respectively. Visual identification rates were 65.3% and 30.4% (P < 0.001) in primary and redo surgery groups, respectively. In total, 164 (96.5%) and 97 EBSLNs (70.3%) were identified in primary and redo surgery, respectively (P < 0.001), including the use of IONM. In primary surgery group, 53 nonvisualized EBSLNs of 164 identified nerves (32.3%) were determined by IONM alone. In redo surgery group, 55 of 97 identified nerves (56.7%) were determined by IONM alone (P < 0.001). CONCLUSION: Both visual and total identification rates of the EBSLN are significantly decreased in reoperative thyroidectomy. IONM increases the total identification rate of the EBSLN in primary and redo thyroid surgery. Electrophysiological monitoring makes a substantial contribution to the identification of the EBSLN both in primary and especially in redo thyroid surgery.

Surgical Outcomes of Thalamic Tumors in Children: The Importance of Diffusion Tensor Imaging, Neuro-Navigation and Intraoperative Neurophysiological Monitoring

BACKGROUND: Recently, modern technology such as diffusion tensor imaging (DTI), neuro-navigation and intraoperative neurophysiological monitoring (IOM) have been actively adopted for the treatment of thalamic tumors. We evaluated surgical outcomes and efficacy of the aforementioned technologies for the treatment of pediatric thalamic tumors. METHODS: We retrospectively reviewed clinical data from 37 children with thalamic tumors between 2004 and 2017. There were 44 operations (27 tumor resections, 17 biopsies). DTI was employed in 17 cases, neuro-navigation in 23 cases and IOM in 14 cases. All diagnoses were revised according to the 2016 World Health Organization Classification of Tumors of the Central Nervous System. Progression-free survival (PFS) and overall survival (OS) rates were calculated, and relevant prognostic factors were analyzed. The median follow-up duration was 19 months. RESULTS: Fifteen cases were gross total resections (GTR), 6 subtotal resections (STR), and 6 partial resections (PR). Neurological status did not worsen after 22 tumor resections. There were statistically significant differences in terms of the extent of resection between the groups with DTI, neuro-navigation and IOM (n=12, GTR or STR=12) and the group without at least one of the three techniques (n=15, GTR or STR=9, p=0.020). The mean PFS was 87.2±38.0 months, and the mean OS 90.7±36.1 months. The 5-year PFS was 37%, and the 5-year OS 47%. The histological grade (p≤0.001) and adjuvant therapy (done vs. not done, p=0.016) were significantly related to longer PFS. The histological grade (p=0.002) and the extent of removal (GTR/STR vs. PR/biopsy, p=0.047) were significantly related to longer OS. CONCLUSION: Maximal surgical resection was achieved with acceptable morbidity in children with thalamic tumors by employing DTI, neuro-navigation and IOM. Maximal tumor resection was a relevant clinical factor affecting OS; therefore, it should be considered the initial therapeutic option for pediatric thalamic tumors.

Intraoperative Neurophysiological Monitoring for Spinal Fusion

The surgical techniques of spinal fusion are frequently used in the treatment of many spine conditions. Apart from having anatomical knowledge, in order to perform those procedures safely, it is essential to utilize all the tools available to assure the appropriate positioning of the materials and avoid neural injury. The goal of this article is to review the literature on the use of intraoperative neurophysiological monitoring for spinal fusion procedures and to discuss the controversies regarding this issue.

As técnicas cirúrgicas de fusão espinhal são frequentemente utilizadas no tratamento de muitas condições da coluna vertebral. Além do conhecimento anatômico, para realizar esses procedimentos com segurança é essencial utilizar todas as ferramentas disponíveis para assegurar o posicionamento adequado dos materiais e evitar lesões neurais. O objetivo deste artigo é revisar a literatura sobre o uso de monitorização neurofisiológica intraoperatória para procedimentos de fusão espinhal e discutir as controvérsias relacionadas a essa questão.

Analysis of Abnormalities of Intraoperative Neurophysiological Monitoring in Spine and Spinal Cord Surgery under General Anesthesia / 中国康复理论与实践

@#Objective To analyze the factors related with intraoperative neurophysiological monitoring (IONM) in spine and spinal cord surgery under general anesthesia, in order to increase the effectiveness of IONM. Methods A retrospective study was performed on patients who received somatosensory-evoked potential (SEP) and motor-evoked potentials (MEP) in spine surgery under general anesthesia from Ju-ly, 2011 to January, 2016. Results Data from 104 patients were collected in which 18 cases had abnormal SEP and 17 cases had abnormal MEP. A single factor analysis indicated that abnormal SEP was related to concentration of inhalation anesthetic (CIA), hypothermia in peri-operative period (HTM), and type of anesthesia (χ2>6.219, P<0.05), whereas abnormal MEP was related to CIA, hypotension in periopera-tive period (HTN), and additional muscular relaxants (χ2>4.125, P<0.05). Logistic regression analysis indicated that abnormal SEP was relat-ed to CIA and HTM, whereas abnormal MEP was related to CIA and HTN (P<0.05). Conclusion CIA, HTM, and HTN were possible fac-tors related with IONM in spine surgery under general anesthesia.

Dual Monitoring with Stump Pressure and Electroencephalography During Carotid Endarterectomy

BACKGROUND: Intraoperative monitoring during carotid endarterectomy is crucial for cerebral protection. We investigated the results of carotid endarterectomy under dual monitoring with stump pressure and electroencephalography. METHODS: We retrospectively reviewed the medical records of 50 patients who underwent carotid endarterectomy between March 2010 and February 2016. We inserted a temporary shunt if the stump pressure was lower than 35 mm Hg or if any intraoperative change was observed on electroencephalography. RESULTS: Seventeen (34%) patients used a temporary shunt, and the mean stump pressure was 26.8 mm Hg in the shunt group and 46.5 mm Hg in the non-shunt group. No postoperative mortality or bleeding occurred. Postoperatively, there were 3 cases (6%) of minor stroke, all of which took place in the shunt group. A comparison of the preoperative and the intraoperative characteristics of the shunt group with those of the non-shunt group revealed no statistically significant difference between the 2 groups (p <0.01). CONCLUSION: Dual monitoring with stump pressure and electroencephalography was found to be a safe and reliable monitoring method with results comparable to those obtained using single monitoring. Further study should be performed to investigate the precise role of each monitoring method.

Comparing the effects of vecuronium and cisatracurium on electrophysiologic monitoring during neurosurgery: a randomized controlled study

BACKGROUND: The differences between neuromuscular blocking (NMB) drugs on the efficacy of intraoperative motor-evoked potential (MEP) monitoring have not been established through clinical study. We compared the effects of vecuronium and cisatracurium on the efficacy of intraoperative MEP monitoring. METHODS: We enrolled 72 patients who had undergone neurosurgery with MEP monitoring. We randomly allocated the subjects into one of two groups, in whom we maintained continuous intravenous vecuronium (Group V) or cisatracurium (Group C) infusion during the surgeries; the target partial NMB for maintenance was T1/Tc 50% (T1, first twitch of TOF response; Tc, control response of T1 before NMB drug injection). We compared the means and coefficients of variation (CV, %) of all measured MEP amplitudes and the frequencies of NMB drug dose changes. RESULTS: The means and CVs of MEP amplitude and latency in all four limbs did not differ significantly between the groups, although we did change the continuous NMB drug doses in group V significantly less often than in group C. CONCLUSIONS: There were no significant differences between vecuronium and cisatracurium on the MEP variability and mean amplitudes. However, cisatracurium needed more frequent dose changes to maintain T1/Tc 50%.

An Electrode Configuration for Recording Muscle Motor Evoked Potentials in the Upper Extremities during Intraoperative Neurophysiological Monitoring

OBJECTIVE: The main aim of the present study is to examine the electrode configurations used to record the muscle motor evoked potential (mMEP) in the upper extremities during surgery with the goal of producing a high and stable mMEP signal, in particular among the abductor pollicis brevis (APB), abductor digiti minimi (ADM), and across the APB-ADM muscles, which have been widely used for the mMEP in the upper extremities. METHODS: Thirty right-handed patients were recruited in this prospective study. No patients showed any adverse events in their mMEP signals of the upper extremities during surgery. The mMEPs were recorded independently from the signals for the APB and ADM and for those across the APB-ADM. RESULTS: The mMEP amplitude from across the APB-ADM was statistically higher than those recorded from the APB and ADM muscles. Moreover, the coefficient of variation of the mMEP amplitude from across the APB-ADM was smaller than those of mMEP amplitude recorded from the APB and ADM muscles. CONCLUSION: The mMEP from across the APB-ADM muscles showed a high yield with high stability compared to those in each case from the APB and ADM muscles. The configuration across the APB-ADM muscles would be best for mMEP recordings from the upper extremities for intraoperative neurophysiological monitoring purposes.

Intraoperative Neurophysiological Monitoring for Spinal Cord Tumor Surgery: Comparison of Motor and Somatosensory Evoked Potentials According to Tumor Types

OBJECTIVE: To identify which combination of motor evoked potentials (MEPs) and somatosensory evoked potentials (SEPs) is most reliable for postoperative motor deterioration during spinal cord tumor surgery, according to anatomical and pathologic type. METHODS: MEPs and SEPs were monitored in patients who underwent spinal cord tumor surgery between November 2012 and August 2016. Muscle strength was examined in all patients before surgery, within 48 hours postoperatively and 4 weeks later. We analyzed sensitivity, specificity, positive and negative predictive values of each significant change in SEPs and MEPs. RESULTS: The overall sensitivity and specificity of SEPs or MEPs were 100% and 61.3%, respectively. The intraoperative MEP monitoring alone showed both higher sensitivity (67.9%) and specificity (83.2%) than SEP monitoring alone for postoperative motor deterioration. Two patients with persistent motor deterioration had significant changes only in SEPs. There are no significant differences in reliabilities between anatomical types, except with hemangioma, where SEPs were more specific than MEPs for postoperative motor deterioration. Both overall positive and negative predictive values of MEPs were higher than the predictive values of SEPs. However, the positive predictive value was higher by the dual monitoring of MEPs and SEPs, compared to MEPs alone. CONCLUSION: For spinal cord tumor surgery, combined MEP and SEP monitoring showed the highest sensitivity for the postoperative motor deterioration. Although MEPs are more specific than SEPs in most types of spinal cord tumor surgery, SEPs should still be monitored, especially in hemangioma surgery.

Comparison of emergence characteristics between sevoflurane and propofol anesthesia under the guide of Narcotrend / 临床麻醉学杂志

Objective To compare the emergence characteristics between propofol total intrave-nous anesthesia (TIVA)and sevoflurane induction and maintenance anesthesia (VIMA)under the guidance of Narcotrend,and to see if the recovery of consciousness after different anesthesia regimen will be of identical Narcotrend index (NTI).Methods Sixty ASA Ⅰ or Ⅱ patients undergoing elective transsphenoid pituitary tumor resection were randomized to receive deep anaesthesia (D)or light anaesthsia (L)with propofol (P)/remifentail (group PD and group PL)or sevoflurane (S)/remifentanil (group SD and group SL).During surgery,anesthesia was maintained at a depth of NTI at 46-37 or 56-47 for deep or light anesthesia respectively.After surgery,group comparisons of the NTI at extubation,recovery time,and the time interval between NTI 80 and extubation (Tdelay )were performed by analysis of variance.Results The NTI at consciousness was significantly lower in group PD (84.2±2.7)and PL(84.9±2.5)compared with group SD (88.6 ±3.4)and group SL (89.9 ± 3.3)(P < 0.05 ).The Tdelay was significantly longer in group SD (9.4 ± 4.6 )min compared with group SL (4.7±2.4)min (P <0.05),but there was no difference between group PD and group PL. Compared with other groups,the recovery time was longer in group SD (P <0.05).Conclusion The results indicate that the NTI values at recovery of consciousness are not identical between patients re-ceived proposfol or sevoflurane anesthesia.