Comparison of Various Methods of Electromyographic Monitoring of the Recurrent Laryngeal Nerve in Thyroid Surgery

2002 ◽  
Vol 111 (9) ◽  
pp. 811-816 ◽  
Author(s):  
Kurt P. Tschopp ◽  
Christine Gottardo

In the present study, 3 types of electrodes for recurrent laryngeal nerve (RLN) monitoring are compared: 1) intralaryngeal surface electrodes attached to a conventional endotracheal tube, 2) monopolar needle electrodes placed on the vocal cords by direct laryngoscopy, and 3) bipolar needle electrodes inserted intraoperatively through the cricothyroid ligament. Data were collected from stimulation of 21 RLNs in 16 patients undergoing thyroid surgery. The reliability in terms of distinct electromyographic (EMG) potentials following stimulation of the RLN was 100% with monopolar and bipolar needle electrodes and 76% with intralaryngeal surface electrodes. The mean (±SD) amplitudes of the EMG potentials were 1.61 ± 1.6 mV, 2.37 ± 1.8 mV, and 0.35 ± 0.4 mV for the monopolar endolaryngeal, bipolar transligament, and intralaryngeal surface electrodes, respectively. The advantages and disadvantages of each type of electrode are discussed.

2021 ◽  
pp. 3-6
Author(s):  
Devesh Kumar Gupta ◽  
Shinu Kaur ◽  
Deepti Gupta

Introduction: Fibreoptic Intubation (FOI) is the gold standard for managing difcult airways. There are various approaches such as: Nebulization with lidocaine; 'Spray as you go'(SAYGO); Airway nerve block - blocking superior laryngeal nerve & recurrent laryngeal nerve & sedation. The present study aims to compare 'airway nerve block' (NB) and 'spray as you go'(SA) method for awake exible bronchoscopic intubation used in combination with conscious sedation. Methods: 60 patients of age group 18 – 65 years with difcult airway undergoing general anaesthesia with nasotracheal intubation, were randomly allocated into two groups. After premedication & nasal preparation, all patients received injection dexmedetomidine at a dose of 1µg/kg in 100ml of 0.9% NS over 10 minutes. In Group SA, 2ml lignocaine 4% was sprayed above and below the cords after visibility of glottic opening via working channel of the bronchoscope and 2 ml lignocaine 4% within trachea before insertion of endotracheal tube. In Group NB, bilateral superior laryngeal nerves & recurrent laryngeal nerve was blocked. Then a exible breoptic bronchoscope preloaded with a exometallic endotracheal tube of appropriate size was then inserted via nasal route. Results: The mean intubation time for Group NB [87.27 ± 7.58 sec] was shorter than that for Group SA [190.33 ± 9.14] (p<0.0001). Conclusion: Awake exible bronchoscopic intubation under sedation with airway nerve block provides better intubating conditions compared to SAYGO


Author(s):  
Nitika Gupta ◽  
Rohan Gupta ◽  
Inderpal Singh ◽  
Sunil Kotwal

<p class="abstract"><strong>Background:</strong> Galen first described the recurrent laryngeal nerve (RLN) as a nerve that descended from the brain to the heart, then reversed the course and ascended to the larynx and caused the vocal cords to move. Tracheoesophageal groove is useful for identifying the RLN. In the present study we studied the course of RLN in tracheoesophageal groove and its anatomical position, in patients undergoing thyroid surgery.</p><p class="abstract"><strong>Methods:</strong> The study was conducted in the Department of ENT and Head and Neck Surgery, SMGS Hospital, for a period of two years, on the patients who underwent thyroid surgeries. Tracheoesophageal groove was considered first landmark to identify RLN position and only after meticulous dissection in the groove, the nerve could be identified. The nerve was carefully dissected and its position evaluated in relation with trachea and esophagus.  </p><p class="abstract"><strong>Results:</strong> Trajectory of the nerves studied in the patients was mostly in the tracheoesophageal groove (TEG), seen in 113 (69.75%) nerves. 16.05% of the nerves were seen in the posterior half of the trachea while 4.94% of the nerves were seen to travel from TEG to anterior half of trachea and 1.85% from TEG to posterior half of trachea. 6.17% of nerves travelled from oesophagus to the TEG.</p><p class="abstract"><strong>Conclusions:</strong> A uniform dissection procedure should be followed and the recurrent laryngeal nerve must be first looked for in the TEG, which serves as important landmark and later any deviation must be considered.</p><p class="abstract"> </p>


2014 ◽  
Vol 96 (2) ◽  
pp. 130-135 ◽  
Author(s):  
J Smith ◽  
J Douglas ◽  
B Smith ◽  
T Dougherty ◽  
C Ayshford

Introduction There is disparity in the reported incidence of temporary and permanent recurrent laryngeal nerve (RLN) palsy following thyroidectomy. Much of the disparity is due to the method of assessing vocal cord function. We sought to identify the incidence and natural history of temporary and permanent vocal cord palsy following thyroid surgery. The authors wanted to establish whether intraoperative nerve monitoring and stimulation aids in prognosis when managing vocal cord palsy. Methods Prospective data on consecutive thyroid operations were collected. Intraoperative nerve monitoring and stimulation, using an endotracheal tube mounted device, was performed in all cases. Endoscopic examination of the larynx was performed on the first postoperative day and at three weeks. Results Data on 102 patients and 123 nerves were collated. Temporary and permanent RLN palsy rates were 6.1% and 1.7%. Most RLN palsies were identified on the first postoperative day with all recognised at the three-week review. No preoperative clinical risk factors were identified. Although dysphonia at the three-week follow-up visit was the only significant predictor of vocal cord palsy, only two-thirds of patients with cord palsies were dysphonic. Intraoperative nerve monitoring and stimulation did not predict outcome in terms of vocal cord function. Conclusions Temporary nerve palsy rates were consistent with other series where direct laryngoscopy is used to assess laryngeal function. Direct laryngoscopy is the only reliable measure of cord function, with intraoperative monitoring being neither a reliable predictor of cord function nor a predictor of eventual laryngeal function. The fact that all temporary palsies recovered within four months has implications for staged procedures.


2019 ◽  
Vol 130 (6) ◽  
pp. 1583-1589 ◽  
Author(s):  
Evan Jon Propst ◽  
Jonah Gorodensky ◽  
Jonathan Daniel Wasserman ◽  
Ethan Forde Glazman ◽  
Leona Ariel Tilis ◽  
...  

2011 ◽  
Vol 27 (3) ◽  
pp. 96-101 ◽  
Author(s):  
Cheng-Jing Tsai ◽  
Kuang-Yi Tseng ◽  
Fu-Yuan Wang ◽  
I-Cheng Lu ◽  
Hsun-Mo Wang ◽  
...  

2020 ◽  
pp. 1098612X2096788
Author(s):  
Teela L Jones ◽  
Kyrissa Boyer ◽  
Kelly Chapman ◽  
Brea Craigen ◽  
Anderson da Cunha ◽  
...  

Objectives The objective of this study was to evaluate the time to decreased reactivity of the arytenoid cartilages in cats after application of topical lidocaine. Methods One hundred and ten mixed-breed cats were randomly assigned to one of five groups based on the time between application of lidocaine and stimulation of the larynx: 5 (T5), 15 (T15), 30 (T30), 45 (T45) or 60 (T60) s. Cats were premedicated with dexmedetomidine, ketamine and buprenorphine. Anesthesia was induced with propofol to effect. Lidocaine 2% (2 mg/kg) was applied topically to the vocal cords using a catheter attached to a syringe under direct laryngoscopy. After lidocaine application, the designated time elapsed and the vocal cords were stimulated with the patient end of an endotracheal tube. Severity of reaction was reported as none, mild, moderate or severe. All cats were intubated after the reactivity score was recorded. Anesthesia was maintained with isoflurane and 100% oxygen while cats were spayed or neutered. Cats were monitored in recovery for signs of respiratory complications and pain. Results There was a significant difference in overall reactivity score between T5 and T45 ( P = 0.0038). Also, there was a significant difference in the number of cats with no reaction compared with cats with any reaction between T5 and T30 ( P = 0.03), as well as between T5 and T45 ( P = 0.0028). No cat had a severe reactivity score at T45 or T60. All cats were successfully intubated. There were no complications during intubation, maintenance of anesthesia or recovery. Conclusions and relevance As the lowest overall reactivity score occurred at T45, it is recommended to wait at least 45 s after application of topical lidocaine before attempting tracheal intubation.


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