LETTER TO EDITOR
Year : 2013 | Volume
: 29 | Issue : 2 | Page : 272--274
Post-operative unmasked bilateral vocal cord palsy attributed to pre-operative radiotherapy
PM Singh, Anuradha Borle, Anjan Trikha
Department of Anaesthesia, All India Institute of Medical Sciences, New Delhi, India
P M Singh
Department of Anaesthesia, All India Institute of Medical Sciences, New Delhi
|How to cite this article:|
Singh P M, Borle A, Trikha A. Post-operative unmasked bilateral vocal cord palsy attributed to pre-operative radiotherapy.J Anaesthesiol Clin Pharmacol 2013;29:272-274
|How to cite this URL:|
Singh P M, Borle A, Trikha A. Post-operative unmasked bilateral vocal cord palsy attributed to pre-operative radiotherapy. J Anaesthesiol Clin Pharmacol [serial online] 2013 [cited 2019 Nov 15 ];29:272-274
Available from: http://www.joacp.org/text.asp?2013/29/2/272/111736
Radiotherapy used in head and neck cancers is capable of causing vocal cord palsy.  Any associated surgical damage to other vocal cord can cause severe obstruction in the post-operative period. Pre-operatively, unilateral vocal cord palsy may only present as minor voice change, and this symptom is often attributed to primary pathology, for which patient received radiotherapy.
A 40-kg, 38-year-old man was scheduled for right-sided radical neck dissection for non-keratinizing carcinoma of nasopharynx [T 2 N 3 M 0 ]. He had received 3 cycles of chemotherapy followed by radiotherapy (70 Gy in 30 fractions) 6 months earlier. Pre-operatively, he reported upper respiratory tract infection with mucopurulent sputum 6 weeks ago, which resolved after antibiotics and anti-histamines. There was no history of any other systemic illness. Systemic and airway examination was unremarkable.
Anesthesia was induced as per routine protocols, and no gross abnormality was noted in vocal cord position during laryngoscopy. Surgery lasted for 4.5 hours, after which neuromuscular blockade was reversed, and trachea was extubated at a Train of Four ratio of 0.9. Within 2 minutes of extubation, patient developed respiratory distress with tachycardia and desaturation. Respiratory distress continued to worsen with time, and the oxygen saturation (SpO 2 ) dropped to 82% despite administering 100% oxygen. The patient was fully awake with no signs suggestive of residual opioid effects or neuro-muscular blockade. The patient's trachea was re-intubated; subsequently, oxygen saturation rose to 100% on IPPV. He was shifted to the intensive care unit for further management.
As he could generate adequate tidal volume, he was allowed to breathe spontaneously with a continuous positive airway pressure of 5 cm of H 2 O on a 0.5 inspired oxygen fraction. Overnight elective ventilation was planned; his biochemical, hematological investigations, and chest X-ray were normal. After tracheal extubation the next day, he again developed labored breathing, chest retractions, was unable to vocalize, and SpO 2 fell to 90% in 10 minutes despite oxygen supplementation. Fiberoptic bronchoscopy showed bilateral vocal cord palsy without any apparent edema. The surgical team denied any possibility of surgical damage to left cord, as surgery was limited to right side only. A tracheostomy was done.
Pre-operatively, patient had no history suggestive of vocal cord paralysis, although such a condition can be present without any symptoms.  Neoplasms of nasopharynx can cause vocal cord palsy due to anatomical involvement of Vagus nerve of same side. The incidence of cranial nerve palsies after radiotherapy of the head and neck region is around 3%. , Delayed recurrent laryngeal nerve involvement due to radiotherapy [>12 month] has already been reported. ,
Bilateral vocal cord palsies can also occur after prolonged intubation though unilateral palsy is more common but is unlikely after only 4.5 hours of intubation.  Idiopathic vocal cord paralysis is also seen after herpes infections and can remain asymptomatic with minor voice change.  Our patient had history of recent upper respiratory tract infection bacterial (muco-purulent) but did not have its sequelae. It is likely that our patient developed unilateral vocal cord paralysis following radiotherapy, and the surgical trauma lead to paralysis of the right vocal cord, which resulted in respiratory distress in the post-operative period.
We recommend that a routine pre-operative indirect laryngoscopy to be done in patients for neck surgery receiving radiotherapy in the head and neck region. This small intervention can avoid catastrophic post-operative obstruction. Both the surgeon and anesthesiologist can later be blamed to have caused the palsy.
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