Hindawi BioMed Research International Volume 2021, Article ID 5655061, 11 pages https://doi.org/10.1155/2021/5655061
Research Article Facial Nerve Monitoring under Different Levels of Neuromuscular Blockade with Cisatracurium Besilate in Parotid Tumour Surgery
Huimin Huang, Hong Jiang , Jinxing Liu, Jie Chen , Lin Qiu, Jiayi Wang, Wenhui Liu, and Huan Chen
Department of Anesthesiology, Shanghai 9th People’s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
Correspondence should be addressed to Hong Jiang; [email protected] and Jie Chen; [email protected]
Received 1 May 2021; Revised 13 June 2021; Accepted 23 June 2021; Published 13 July 2021
Academic Editor: Yuzhen Xu
Copyright © 2021 Huimin Huang et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Background. Anaesthesia can alter neuronal excitability and vascular reactivity and ultimately lead to neurovascular coupling. Precise control of the skeletal muscle relaxant doses is the key in reducing anaesthetic damage. Methods. A total of 102 patients with the normal functioning preoperative facial nerve who required parotid tumour resection were included in this study. Facial nerve monitoring was conducted intraoperatively. The surgeon stimulated the facial nerve at different myorelaxation intervals at TOF% (T4/T1) and T1% (T1/T0) and recorded the responses and the amplitude of electromyogram (EMG). Body movements (BM) or patient-ventilator asynchrony (PVA) was recorded intraoperatively. Results. In parotid tumour resection, T1% should be maintained at a range of 30 to 60% while TOF% should be maintained at a range of 20 to 30%. Analysis of the decision tree model for facial nerve monitoring suggests a partial muscle relaxation level of 30% 1. Introduction need to increase the dose of intraoperative analgesics and sedative drugs. However, this may increase the risk of Anaesthesia can alter neuronal excitability and vascular reac- anaesthesia-related complications such as neurovascular tivity and ultimately lead to neurovascular coupling [1]. Skel- injury, intraoperative circulatory depression, and delayed etal muscle relaxants are widely used in anaesthesia. However, postoperative awakening. numerous studies have linked skeletal muscle relaxants to neu- In this study, nondepolarizing skeletal muscle relaxant, ff rovascular side e ects [2, 3]. Therefore, precise control of the Cisatracurium besilate, was used in total intravenous anaes- skeletal muscle relaxants dose is the key in reducing anaes- thesia during parotid tumour resection requiring facial nerve thetic damage [4]. monitoring. The study is aimed at determining the appropri- Facial nerve injury is a relatively common and major ate level of muscular relaxation and providing a reference for complication of parotidectomy that is disheartening to sur- general anaesthetic procedures requiring facial nerve moni- geons and the patients. Intraoperative facial nerve monitor- toring by exploring the feasibility of facial nerve monitoring fi ing can signi cantly reduce postoperative facial nerve injury under partial muscular relaxation. [5–8]. It is traditionally held that skeletal muscle relaxants should be avoided in general anaesthetic procedures requir- 2. Materials and Methods ing neuromonitoring. However, general anaesthesia without the use of skeletal muscle relaxants may aggravate anaesthetic 2.1. Basic Characteristics. This was a prospective study done damage and lead to intraoperative BM and PVA, affecting the between 2019 and 2020 at the Ninth People’s Hospital. The surgical process [9]. To avoid BM/PVA, anaesthetists often study was approved by the Ethics Committee of the Clinical 2 BioMed Research International 60 60 40 Count 40 20 Count 20 0 0 369 369 T1% T1% Movement Ventilation.confrontation No No Yes Yes (a) (b) 100 Count 50 0 2.5 5.0 7.5 10.0 048 Estimated T1% of patients T1% P < 0.001 EMG.reaction Yes No MRVC No Yes (c) (d) 0.0 2.5 5.0 7.5 10.0 Estimated T1% of patients P < 0.001 EMG.reaction No Yes (e) Figure 1: Relationship between T1% and the degree of muscle relaxation with skeletal muscle relaxants in facial nerve monitoring: (a) T1% and body movement score relationship; (b) T1% and patient-ventilator asynchrony relationship; (c) estimated T1% with/without BM/PVA; (d) T1% and positive facial nerve EMG reaction relationship; (e) comparison of estimated T1% between positive EMG reaction and negative EMG reaction. BioMed Research International 3 100 75 Count 50 100 75 25 50 Count 25 0 0 048 048 TOF% TOF% Movement Ventilation.confrontation No No Yes Yes (a) (b) 150 100 Count 50 0 0.0 2.5 5.0 7.5 10.0 048 Estimated TOF% of patients TOF% P < 0.001 EMG.reaction Yes No MRVC No Yes (c) (d) Figure 2: Continued. 4 BioMed Research International 0.0 2.5 5.0 7.5 10.0 Estimated TOF% of patients P < 0.001 EMG.reaction No Yes (e) Figure 2: Relationship between TOF% and the cut-off value for the effect of facial nerve anaesthesia for muscle relaxation: (a) the relationship between TOF% and body movement score; (b) the relationship between TOF% and patient-ventilator asynchrony; (c) comparison of estimated TOF% with/without BM/PVA; (d) the relationship between TOF% and positive EMG reaction of the facial nerve; (e) comparison of estimated TOF% between positive EMG reaction and negative EMG reaction. Trial Center of the Ninth People’s Hospital of Shanghai Jiao tion current were determined. Cisatracurium besilate 0.15 Tong University (Ethics No. 2017-405-T302). Patients mg/kg (3 × ED95) was then administered intravenously, requiring parotid tumour resection who were classified under and the tracheal tube was inserted. The BIS electrodes were American Society of Anesthesiologists (ASA) grade I to II connected to monitor the depth of anaesthesia. For the main- (n = 102) were selected for the inclusion to the study. Exclu- tenance of general anaesthesia, continuous propofol 2-10 sion criteria are comprised of patients with Cisatracurium mg/(kg·h) and remifentanil 0.1-2 μg/(kg·min) were adminis- besilate allergy, facial palsy, or other neuromuscular diseases, tered with real-time regulation to maintain intraoperative history of diabetes mellitus, epilepsy, and craniotomy that vital signs, BIS between 40 and 60, and End-Tidal Carbon ff may a ect neuromonitoring. Anaesthesia was intravenously Dioxide (ETCO2) between 35 and 45. Single additional doses administered, with routine ECG monitoring, bispectral index of Cisatracurium besilate 0.025 mg/kg (0:5 × ED95) were also (BIS) monitoring for the depth of anaesthesia, facial nerve given intraoperatively to maintain partial muscle relaxation EMG, and muscle relaxation monitoring (TOF%, T1%) car- in the following cases: (a) patients developed BM/PVA, (b) ried out. Cisatracurium besilate was used intermittently dur- intraoperative electrokinetic stimulation of the patient’s ing the operation. The surgeon recorded the facial nerve muscle twitching was too pronounced to interfere with the EMG at different levels of myorelaxation while stimulating procedure, and (c) patients’ TOF% or T1% was >91%. the facial nerve or adjacent tissues to the operative area dur- ing the excision of the parotid tumour. BM and PVA were 2.3. Facial Nerve Monitoring. A Medtronic NIM-Neuro 3.0 also recorded intraoperatively. neuromonitor (Medtronic Xomed, Inc., USA) was used to record the facial nerve EMG upon induction of general 2.2. General Anaesthesia and Muscle Relaxation Monitoring. anaesthesia. Stimulating electrodes were inserted into the Patients admitted to the operating room underwent routine frontalis, orbicularis oculi, orbicularis orientalis, and chin cardiac monitoring and received preoperative medication muscles, while the grounding electrodes were inserted to 30 min before the surgery. Before induction of the general the thorax and then connected to the mainframe of the facial anaesthesia, the Veryark-TOF muscle relaxation monitor nerve monitor. The facial nerve or adjacent tissues were stim- (Willie’s Ark, China) was connected to the ulnar nerve on ulated with bipolar electrodes. To ensure accuracy of the the left upper forearm. The muscle tone sensor was placed facial nerve stimulation, the main trunk of the facial nerve at the tiger’s mouth of the hand while the temperature sensor or main branches, the mandibular margin branch and the was placed at the inner thumb muscle and secured with an temporal branch, was selected. Stimulation intensity was adhesive tape. The muscle relaxation monitoring was set up 0.20 mA, and the event threshold was 100 μV. Facial nerve in the train-of-four stimulation (TOF) mode with one- stimulation was considered positive at an EMG wave minute repetitive stimulation time, and the TOF% (T4/T1) amplitude > 100 μV and an abrupt rise in EMG changes. and T1% (T1/T0) values were recorded. In the induction of general anaesthesia, patients were sedated by intravenous 2.4. Observation Parameters. Patients’ facial nerve EMG administration of midazolam 0.05 mg/kg, fentanyl 2 μg/kg, responses and specific wave amplitude values were recorded and propofol 2 mg/kg. T0 value and the appropriate stimula- at different muscle relaxation intervals. The TOF% (T4/T1) BioMed Research International 5 Movement or ventilation confrontation 100 80 60 AUC 40 Sensitivity (%) TOF : 89.5720 T1 : 94.6680 20 0 100 80 60 40 20 0 Specifcity (%) (a) EMG.reaction 100 80 60 AUC 40 TOF : 90.8765 Sensitivity (%) T1 : 89.6961 20 0 100 80 60 40 20 0 Specifcity (%) (b) Figure 3: Continued. 6 BioMed Research International 2500 2000 1500 1000 500 0 0246810 EMG TOF EMG T1 (c) Figure 3: ROC curves of TOF% and T1% for predicting the effect of facial nerve anaesthesia on muscle relaxation: (a) ROC curve of TOF% and T1% for body movement or patient-ventilator asynchrony; (b) ROC curve of TOF% and T1% for body movement or positive EMG reaction of the facial nerve; (c) correlation of EMG values with TOF% and T1%. and T1% (T1/T0) were divided into eleven different muscle resection were included in this study. All patients included in relaxation intervals, such as 0%, 1-10%, 11-20%, 21-30%, the study were in ASA classification grade I to II. Patients had 31-40%, 41-50%, 51-60%, 61-70%, 71-80%, 81-90%, and a mean age of 44:49 ± 13:02 years, weight of 65:54 ± 13:51 kg, 91-100%. Patients were continuously monitored for muscle and height of 167:21 ± 8:62 cm. relaxation. The facial nerve was stimulated intraoperatively at different intervals of TOF% and T1%, and the response 3.2. T1% Relationship to the Optimal Dose of the to facial nerve monitoring was recorded and the wave Neuromuscular Relaxant. A histogram of BM/PVA and amplitude of the EMG was recorded when there was a pos- T1% is shown in Figures 1(a) and 1(b). The chi-square test fi itive reaction. Patients were continuously observed for limb revealed a signi cant correlation between T1% and BM/PVA P : fi and swallowing movements, under different levels of mus- ( <0001) (Figure 1(c)). Patients experienced signi cantly % ≥ % cle relaxation. The BM score was calculated by dividing elevated BM/PVA at T1 60 . The correlation between dif- stimulus with BM by stimulus without BM. The presence ferent intraoperative muscle relaxation conditions (T1%) and of autonomic respiratory waveform on the monitor and positive EMG reaction of the facial nerve was shown to be sig- fi P : anaesthetic machine was recorded under different levels of ni cant using chi-square analysis ( <0001)(Figures1(d) muscle relaxation. and 1(e)). As shown in Figure 1(d), EMG monitoring of the facial nerve was largely unaffected at T1% >30% when the 2.5. Statistical Analysis. Statistical analyses were done using R muscle relaxation was maintained with Cisatracurium besilate software (version 3.6.0). Visualization of the decision tree in TIVA. This suggests that T1% should be controlled at a was done with the treeheater package, as described in a pre- range of between 30 and 60% in parotidectomy. vious study [10]. The receiver operating characteristic curve (ROC) was used to assess the predictive accuracy of T1% 3.3. TOF% Relationship to Neuromuscular Blockade Levels in and TOF% [11]. Nomogram was used to construct predictive Facial Nerve Monitoring. A histogram of BM/PVA and models to assess the risk of BM/PVA. The calibration curve TOF% is shown in Figures 2(a) and 2(b). The relationship ff and C-index were further used to assess the predictive power between di erent intraoperative muscle relaxation levels of the nomogram [12, 13]. One-way ANOVA or two-tailed t (TOF%) and the occurrence of BM/PVA was calculated fi -test was used to determine significance between groups. using the chi-square test, which revealed a signi cant corre- P : Values of P <0:05 were considered statistically significant. lation ( <0001) (Figure 2(c)). Patients were shown to expe- rience significantly elevated BM/PVA when TOF% ≥ 30%. 3. Results The correlation between different intraoperative muscle relaxation levels (TOF%) and positive EMG reaction of the 3.1. Demographic and Clinical Characteristics. A total of 102 facial nerve using chi-square analysis was shown to be signif- patients (48 males and 54 females) undergoing parotid mass icant (P <0:001) (Figures 2(d) and 2(e)). As seen in BioMed Research International 7 T1 ≤ 8 > 8 T1 TOF ≤ 7 T1 > 7 ≤ 6 > 6 ≤ 5 > 5 NO NO NO NO YES MRVC ASA TOF% T1% (a) T1 ≤ 2 > 2 T1 T1 > 3 Sex ≤ 1 > 1 ≤ 3 Female Male NO NO YES YES YES EMG T1% Sex NA Female Male (b) Figure 4: Visualization of the decision tree. (a) A decision tree-heat map for predicting the occurrence of BM or PVA during surgery. MRVC: movement or ventilation confrontation has occurred; ASA: American Society of Anesthesiologists. (b) A decision tree-heat map for predicting a positive EMG response of the facial nerve during surgery. EMG: electromyogram. Note: the heat map colours present the relative value of a sample compared to the rest of the group. Figure 2(d), EMG monitoring of the facial nerve was largely of facial nerve monitoring. It is worth noting that the magni- unaffected at TOF% >20% when muscle relaxation was tude of facial nerve EMG values did not correlate linearly maintained with Cisatracurium besilate in TIVA. This sug- with TOF% and T1%. EMG amplitude values in most gests that TOF% should be controlled at a range of 20 to patients were below 1000 μV and did not increase as the mus- 30% in parotidectomy. cle relaxation lessened (Figure 3(c)). 3.4. ROC Curves of TOF% and T1% for Predicting the Effect of 3.5. Visualization of the Decision Tree. Decision trees were Facial Nerve Anaesthesia on Muscle Relaxation. As shown in drawn to guide visualization for better clinical application. Figure 3(a), the ROC curve had an AUC of 0.896 for TOF% As shown in Figure 4(a), the decision tree-heat map for pre- and 0.947 for T1%, both close to 1. It can be concluded that dicting BM/PVA occurrence during surgery reflects that T1 the different intervals of TOF% and T1% values are ideal % ≤ 50% does not result in BM/PVA, while TOF% >60% is for determining the presence of BM/PVA, with T1% being a high-risk factor for BM/PVA occurrence. Therefore, in par- relatively better than TOF%. Figure 3(b) shows a ROC curve otidectomy, T1% should be maintained ≤50% and TOF ≤ plotted against the facial nerve EMG showing an AUC of 60%. As shown in Figure 4(b), a decision tree-heat map for 0.909 for TOF% and 0.897 for T1%, which were also close predicting the incidence of a positive EMG response of the to 1. It can be concluded that the different intervals of facial nerve during surgery revealed a good positive EMG TOF% and T1% values are ideal for determining effectiveness reaction of the facial nerve at T1% >30%. Women were seen 8 BioMed Research International Points 0 20406080100 Female Sex Male Age (year) 80 60 02040 BMI 3035 2025 15 ⁎⁎ TOF% 0246810 ⁎⁎⁎ T1% 12345678910 Total−points−to−outcome nomogram : Total points 140 160 180 200 220 240 260 280 300 320 340 Pr (status) 5e – 04 0.001 0.002 0.004 0.008 0.02 0.04 0.08 0.15 0.3 0.5 0.7 0.85 0.92 0.96 (a) 0.8 0.6 0.4 Proportion 0.2 Mean absolute error = 0.018 Mean squared error = 7e-04 0.0 Quantile of absolute error = 0.048 0.0 0.2 0.4 0.6 0.8 Probability of adverse neuromuscular blockade efect Apparent Bias−corrected Ideal (b) Figure 5: A visual nomogram prediction model. (a) Nomogram prediction model for predicting the occurrence of BM or PVA during surgery. (b) Calibration curve of the BM/PVA model for predicting the occurrence of BM/PVA during surgery. The closer the solid line to the dashed line, the better the predictive power. to be less likely to have a negative EMG reaction of the facial such as sex, age, BMI, TOF%, and T1% (Figure 5(a)). The nerve compared to men. In conclusion, 30% Table 1: Chart showing the prediction factors. delayed postoperative awakening, hypothermia, and other anaesthetic complications. The use of a higher dose of the Prediction model analgesic, remifentanil, under general anaesthesia was shown Variable β P Odds ratio (95% CI) value to decrease the incidence of intraoperative BM from 44 to Intercept 0.034 0.001 (0-0.119) 0.007 20%. However, the highest dose of remifentanil (0.21 TOF% -0.059 1.396 (1.123-1.768) 0.004 mg/kg·min) did not completely prevent BM and was associ- T1% -0.678 2.633 (1.909-3.888) P <0:001 ated with increased intraoperative hypotension and brady- Sex (male) 2.189 0.657 (0.203-2.053) 0.472 cardia and circulatory depression [16]. Maintaining partial muscle relaxation in general anaesthesia has been shown to Age (years) -2.003 0.983 (0.944-1.022) 0.391 be a more effective strategy. In recent years, skeletal muscle BMI -0.001 0.88 (0.723-1.048) 0.172 relaxants have been used during general anaesthesia in a vari- Note: β is the regression coefficient. ety of procedures requiring neuromonitoring to induce a par- tially muscle relaxed state [17–21]. Table 2: C-index of the nomogram prediction model. In this study, the nondepolarizing skeletal muscular fi relaxant, Cisatracurium besilate, was used. The study Features C-index (95% con dence interval) revealed that facial nerve monitoring could be effectively per- Entire cohort 0.959 (0.935-0.982) formed under partial muscle relaxation. The suitable range of Train set 0.977 (0.957-0.997) partial muscle relaxation was determined as TOF% between Validation set 0.905 (0.84-0.97) 20 and 30% or T1% between 30 and 50%. Noteworthily, the TOF% value is considered a classical indicator of the degree of muscle relaxation. In this study, a positive EMG reaction during surgery, and patients should be anaesthetized at an in facial nerve monitoring was seen in some patients in mus- increased depth. cle relaxation recovery with a TOF% of 0 and a partial recov- ery at T1%. There was no reaction to facial nerve stimulation 4. Discussion in all patients when T1% was 0. T1% was more sensitive in facial nerve monitoring during the initial phase of myosin In this study, we explored the optimal cut-off value for neu- recovery which is consistent with the findings of Chung rovascular anaesthesia on muscle relaxation in local surgery et al. Chung et al. recommended using T1% as the control involving parotid tumour resection. 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