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Enlarged thyroid gland with retrosternal extension has an increased incidence of difficult intubation, and it poses real airway challenge for the anesthesiologists. Here, we present a case of successful management of a difficult airway in a female patient of enlarged thyroid gland, planned for open reduction and internal fixation of the upper end of humerus. Endotracheal intubation was achieved after deliberate insertion of an endotracheal tube in esophagus. The patient was extubated over a ventilating bougie, with uneventful postoperative course.
Patients with thyroid enlargement have an increased risk of difficult tracheal intubation especially the ones which produce tracheal deviation or compression, or both, of the airway.[1,2] Preoperative detection of the difficult airway is very important, as failure to intubate can increase morbidity, especially in elderly uncontrolled patients. We should consider different options and plans keeping armamentarium of instruments and techniques in view; that can be applied for maintaining and securing airway. We describe here the successful management of a case of difficult airway due to enlarged thyroid swelling by deliberate insertion of an endotracheal tube (ETT) in the esophagus followed by endotracheal intubation.
Sixty-eight years old hypertensive female of American Society of Anesthesiologist Grade III, presented to the emergency department with a history of traumatic fracture of upper end of humerus for which open reduction and internal fixation was planned. She was a diagnosed case of multinodular goiter with hyperthyroidism for the last 10 years. She had a huge swelling in the neck which has gradually increased in size over the past few years, with progressive features of dyspnea, stridor, and insomnia in recumbent position. Ten days back she had one episode of atrial fibrillation for which no treatment was given. Her regular medication included tablet carbimazole 5 mg once daily (o.d.), tablet metoprolol 25 mg o.d. and tablet amlodipine 5 mg o.d.
Preoperative physical examination revealed a body mass index of 28 kg/m2 with a regular heart rate of 98 beats per minute and blood pressure (BP) of 160/80 mmHg. On examination of thyroid gland it was found that both the lobes were enlarged, with right (11 cm × 7 cm) more than the left (8 cm × 4 cm) and extending from lower jaw to below the sternal notch. It was occupying both the anterior and posterior triangles of the neck [Figure 1]. Airway examination revealed Mallampatti II score with restriction of neck movements both in flexion and extension. Thyromental distance and sternomental distance could not be measured due to enlarged thyroid gland. Neck and chest veins were not engorged. Rest of the general and physical examination was unremarkable.
On investigations, electrocardiogram had features of sinus tachycardia and echocardiography revealed diastolic dysfunction with ejection fraction of 65%. Thyroid function tests were suggestive of uncontrolled hyperthyroidism (thyroid stimulating hormone of 0.24 IU/L [0.35–5.50 IU/L], free T3 of 430 pg/dl [145–348 pg/dl] and free T4 of 2.4 ng/dl [0.7–1.9 ng/dl]). Radiological examination of the airway and upper chest revealed deviation of trachea to the right side with compression of the air column underneath and endothoracic goiter, respectively [Figure 2]. Indirect laryngoscopy by ENT surgeon showed long floppy overhanging epiglottis with nonvisualization of vocal cords.
After explaining risks associated with the procedure, informed consent was taken from the patient. In the operating room, difficult airway cart was kept ready. The airway was nebulized with 4 ml of 4% lignocaine 30 min before the procedure. On arrival in operating room, the patient had a heart rate of 140 bpm and BP of 180/99 mmHg. The patient was given injection midazolam 1 mg and kept in the head-up position with rolled sheets underneath the shoulders as she was having difficulty in breathing in the supine position. After preoxygenation for 5 min flexible intubation fiberscope (FIF) (Karl Storz, Tuttlingen, Germany) was introduced nasally in the spontaneously breathing awake patient. Only long floppy epiglottis was visible, and the glottic opening could not be appreciated in spite of instructions to the patient to take deep breaths to facilitate its identification. Then general anesthesia was induced with injection fentanyl 75 μg and sevoflurane 0.2–8% in 100% oxygen in graded fashion in spontaneously breathing patient. Bag and mask ventilation checked. FIF with preloaded 7.0 mm ETT was again tried under anesthesia and an assistant was instructed to support the lateral margins of the swelling and lift the swelling against the gravity with gentle pressure, i.e., antigravity lift technique, but in vain. Then direct laryngoscopy with Truview EVO2 laryngoscope (Truphatek) was chosen in lieu of difficult airway. Only tip of epiglottis was visible, and it was not possible even to pass a gum elastic bougie behind the epiglottis through the vocal cords due to the compressed and distorted airway anatomy. After repeated attempts using Truview EVO2 laryngoscope and antigravity lift technique, we decided to place an ETT of 6.5 mm deliberately in esophagus, which helped us in the successful placement of gum elastic ventilating bougie in the trachea. Then endotracheal intubation was done with 7.0 mm ETT using the railroad technique [Figure 3]. Confirmation of the ETT was done by capnography. Thereafter, anesthesia and surgery continued in a conventional manner except for an episode of atrial fibrillation perioperatively which reverted on its own without any medication. Before extubation leak test was performed which showed no evidence of tracheal collapse and patient was extubated over ventilating bougie. She was then shifted to Intensive Care Unit with bougie in place, which was taken out after 2 h [Figure 4]. Postoperative period went uneventful except for sore throat.
The problem of airway management is the main concern when a patient with goiter presents for any surgery. The anesthesiologist should, therefore, pay particular attention to history, preoperative assessment of the airway and should make a plan for securing the airway and to deal with acute airway complications. Abdel Rahim et al. proposed that preoperative risk factors in a patient with large and long-standing goiter (>3 years) are significant tracheal narrowing and/or deviation and retrosternal extension. Amathieu et al. concluded that classical predictive criteria such as mouth opening <35 mm, Mallampatti III or IV, limited neck movements <80° and thyromental distance are reliable predictors of difficult airway in enlarged thyroid gland patients too. Our case had most of the predictors of difficult airway which helped us in predicting the difficult airway and thus being prepared with the plans and preparation of difficult intubation.
In the present era of practice which is bounded by medicolegal aspects, general anesthesia with endotracheal intubation is the safest approach in patients with compromised airway. Laryngeal mask airway can be used as an option in the management of difficult airway but in our case, due to distorted upper airway anatomy it was not safe to rely on supraglottic airway devices. The biggest concern in this patient was that the possibility of performing an elective or emergency tracheostomy was very bleak and risky.
For airway assessment, Ambreesha et al. have recommended that an initial fiberoptic bronchoscopy be done to define the extent of retrosternal extension of the thyroid mass and obstruction of the airway; as was done in our case. However, probably because of the distorted airway anatomy FIF could not be negotiated beyond hypo-pharynx. Though Eldawlatly et al. and Srivastava and Dhiraaj have reported the successful management of difficult airway with fiberoptic bronchoscope. However, there are also reports of complete airway obstruction and loss of difficult airway during awake fiberoptic intubation by Shaw et al. and Crosby.
Considering our experience with the Truview EVO2 laryngoscope, we chose it over conventional Macintosh laryngoscope as it was an anticipated difficult airway. Few trial reports available so far with Truview EVO2 laryngoscope have shown improvement in laryngeal view especially in anticipated difficult airway situations and also have shown that it improves Cormack–Lehane score by at least one grade. In spite of the repeated attempts, we were not able to visualize glottis (Cormack–Lehane Grade III), and the only tip of the epiglottis was visible. This leads to our plan of deliberate insertion of ETT in esophagus. The tube placed in the esophagus not only acted as a guide but also offered some support to the posterior structures in the compressed airway. As it was supplemented with antigravity lift technique, it leads to the lifting of the weight of enlarged thyroid gland from the larynx anteriorly. Both the maneuvers helped us in the successful placement of ventilating bougie in glottis, followed by the endotracheal intubation. Memon and Ashraf also found that antigravity lift technique was helpful in securing the airway in a female patient of large goiter, where trachea was collapsed under the influence of relaxant and weight of swelling.
The patient was extubated after keeping the ventilating bougie in the trachea so that in the case of any airway emergency, oxygenation, and intubation can be accomplished using bougie as a guide.
Though such patients should be optimized and rendered euthyroid before taking up for surgery, as it decreases the morbidity especially in elderly age group, but considering the emergency nature of surgery we have to take our patient unprepared.
Our case report has reported a novel approach of successful endotracheal intubation after an ETT placed in esophagus in patients of the difficult airway with enlarged thyroid swelling (none was found on searching the literature). Although there is no evidence that any specific anesthetic technique, in particular, is best for patient with difficult airway, we believe that this case report will stimulate further research on alternative airway management modalities for patients with huge thyroid swelling and difficult airway who have to undergo surgery.
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There are no conflicts of interest.