The potential role of dexmeditomidine during perioperative period in a hypertensive patient with Eagle syndrome.

Sir,

Anatomical variation in head and neck region always pose numerous anticipated and unanticipated challenges besides airway difficulties. Anesthetic techniques and strategies need meticulous attention during operative procedures on these lesions. Eagle syndrome or stylohyoid syndrome is a rare entity comprising 4% of population, in which there is elongation of styloid process or symptomatic calcification of stylohyoid ligament. The signs and symptoms include foreign body sensation in throat, pain in ear or on face, headaches, dysphagia, and sore throat or change in voice.[1] The syndrome is usually characterized by a female predominance and commonly it occurs after 30 years of age.[23]

We are reporting a 35-year-old female patient who presented in ear, nose, and throat (ENT) outpatient department with complaints of pain on the right side of face and neck, and foreign body sensation in the throat since last 1 year. She also complained of dysphagia and regurgitation for the last 3 months. Patient was operated for tonsillectomy under general anesthesia 1 year back with no postoperative complications. She was also diagnosed as hypertensive 6 months back and was prescribed tablet amlodipine 5 mg once daily which she was taking regularly.

Diagnosis of Eagle's syndrome was made by intraoral palpation using index finger in the tonsillar fossa[4] and was confirmed by X-ray skull lateral view for styloid process [Figure 1]. Patient was planned for bilateral styloidectomy procedure. During preanesthetic evaluation, patient's systemic examination was found to be normal and airway examination revealed Mallampatti grade I airway. Heart rate and blood pressure were within normal limits. Routine preoperative investigation including chest X-ray (CXR) and electrocardiogram (ECG) were normal and patient was accepted for surgery as American Society of Anesthesiologist physical grade II. Patient was advised to keep fasting overnight and was prescribed tablet amlodipine 5 mg along with tablet ranitidine 150 mg, metoclopramide 10 mg, and alprazolam at bedtime and at 6 am on day of surgery. Informed and written consent was taken.

Figure 1

Elongated styloid processes in X-ray lateral view skull

On the day of surgery, baseline parameters were recorded and were observed to be normal. Xylometazoline nasal drop were administered in both the nostrils and a good intravenous access was achieved with 18 G cannula. Standard monitoring included ECG, pulse oximetry and noninvasive blood pressure. As patient gave history of frequent regurgitation, she was planned for rapid sequence induction and intubation. Inj. glycopyrrolate 0.2 mg and inj. pentazocine 24 mg were administered before induction. Inj. dexmedetomidine 1 μg/kg was administered as infusion in 100 ml normal saline over 15 min. Preoxygenation was done for 4 min and induction of anesthesia was achieved with inj. 2.5% thiopentone sodium 5 mg/kg followed by inj. suxamethonium 2 mg/kg with a continued cricoid pressure during intermittent positive pressure ventilation with face mask and Bains circuit. Patient was intubated nasotracheally with 7.0 mm cuffed endotracheal tube and cricoid pressure was released after inflation of cuff of endotracheal tube. Throat was packed with roller gauge in a unique manner which we normally practice in our set up.[5] Anesthesia was maintained with halothane, oxygen in nitrous oxide in a ratio of 40:60, and muscle relaxation was achieved with inj. vecuronium bromide as and when required. Patient remained hemodynamically stable throughout the surgical procedure with a regular pulse rate (PR) in the range of 68-74/min and mean arterial pressure of 65-70 mmHg. Bilateral partial styloidectomy was done by intraoral approach. At the end of procedure after achieving hemostasis, reversal of neuromuscular blockade was achieved with inj. neostigmine 2.5 mg and inj. glycopyrrolate 0.5 mg. Throat pack was removed and trachea was extubated. Postoperatively patient was kept in recovery room for 3 h and the entire recovery period was uneventful.

The present case was interesting from literature point of view, as during induction precautions had to be exercised to prevent aspiration resulting from regurgitation. The preoperative medication included tablet metoclopramide for aspiration prophylaxis and rapid sequence induction and intubation was planned and carried out. Another remarkable feature in the present case included obtundation and attenuation of pressor response during induction and intubation. However, it had been cited in the literature that there were marked fluctuations during the excision of styloid processes, but we did not observe any such episode during intraoperative period. The possible explanation for this phenomenon can be explained on the basis of dexmedetomidine's ability to effectively attenuate pressor response when given as infusion 1 μg/kg over 15 min preoperatively.[6]

The pathophysiological mechanism for the pain in Eagle syndrome can be attributed to a number of factors which may include but are not limited to:

Compression of neural elements, glossopharyngeal nerve, lower branch of trigeminal nerve, and or chorda tympani by the elongated styloid process

Impingement on the carotid vessel by styloid process, producing irritation of the sympathetic nerves in the arterial sheath

Fracture of ossified stylohyoid ligament, followed by proliferation of granulation tissue

Stretching and fibrosis involving the 5th, 7th, and 10th cranial nerves in the post tonsillectomy period.[7]

All such factors can be easily controlled by a good analgesia and a sympatholytic agent. Dexmedetomidine possesses both these characteristics and is an upcoming drug in many such scenarios. Hence, role of dexmedetomidine as sympatholytic in anticipated transient rise of blood pressure (BP) during excision of styloid process (because of impingement on carotid vessels) contributed to the successful management of hypertensive patient in Eagle syndrome.