Case Report
A 78-yr-old woman (65 kg) with a 4 month history of dysphonia and dysphagia presented for an elective panendoscopy and left-sided tonsillectomy. She denied any symptoms of orthopnoea or stridor, and otherwise her medical history was unremarkable. Airway assessment revealed a Mallampati score of 3, with a 4 cm mouth opening, thyromental distance of 7 cm, and full dentition. Nasendoscopy performed by a consultant head and neck surgeon 2 weeks previously had revealed a swelling in the left tonsil with oedematous uvula which partially obscured the view of the pharynx, but the vocal cords and larynx appeared normal. A CT scan performed the day before surgery reported a large enhancing mass lesion in the region of the left palatine tonsil with significant bilateral cervical lymph nodes and narrowed airway at the level of the hyoid.
The discrepancy between the findings of the nasendoscopy and CT scan was discussed between two experienced consultant anaesthetists and a consultant head and neck surgeon in order to formulate plans for securing tracheal intubation. An awake fibreoptic intubation was considered. Intubation was anticipated to be difficult, although mask ventilation was anticipated to be possible. A stepwise plan for intubation was agreed. The initial plan was, therefore, induction of general anaesthesia with direct laryngoscopy, with a secondary plan of the use of an alternative blade, videolaryngoscope (Glidescope−; Verathon Inc., WA, USA), or a fibreoptic bronchoscope, depending on the difficulty encountered. The tertiary plan was to wake the patient up, reversing the rocuronium-induced neuromuscular block with sugammadex. The sugammadex was brought into the anaesthetic room and a 16 mg kg dose was calculated but not drawn up. In the event of failed oxygenation, a cricothyroid puncture was planned and a Ravussin needle (VBM Medizintechnik, Sulz, Germany) and Manujet (VBM Medizintechnik) were immediately available. The placement of a Ravussin needle pre-induction was not deemed necessary, given that ventilation was anticipated to be possible. All of the equipment required for each of the plans was prepared in the anaesthetic room. As is usual, the theatre nursing team were also alerted to the anticipated difficulty with intubation, management plans discussed, and they prepared a tracheostomy kit as a precaution.
The patient was pre-oxygenated for 4 min and then anaesthesia induced with fentanyl 75 μg administered i.v. followed by propofol 160 mg. This was followed immediately with rocuronium bromide 40 mg (0.61 mg kg) to achieve muscle relaxation. Bag-mask ventilation was easily achieved and the lungs were ventilated with oxygen at an
of 1.0 and sevoflurane at an end-tidal concentration of 1.9%. After 2 min, gentle direct laryngoscopy was performed with a Macintosh size 3 blade. On laryngoscopy, the anatomy was unidentifiable because of a large, rigid, fungating mass in the oropharynx and obliterating any view of the larynx or epiglottis. Direct laryngoscopy was abandoned and bag-mask ventilation successfully recommenced. Indirect laryngoscopy with the Glidescope was attempted to try and bypass the mass. This did not improve laryngoscopy and contact bleeding had commenced, so bag-mask ventilation was successfully re-instigated. A second consultant anaesthetist performed direct laryngoscopy with a size 4 Macintosh blade which was also unsuccessful. Bag-mask ventilation had now become increasingly difficult, despite the use of a Guedel airway and two-person mask ventilation. A size 3 laryngeal mask airway (LMA Unique−, Intavent Orthofix, Berks, UK) was inserted; however, ventilation was not possible and so it was removed.
A CICV scenario was now recognized and the decision made to awaken the patient. Oxygen saturation levels remained at 98%. The volatile agent was turned off, and sugammadex 1 g (15.4 mg kg) administered given i.v. within 30 s of the decision to awaken the patient being made. This was ~6 min after the administration of rocuronium. A nerve stimulator was attached to the patient. Further attempts at ventilation continued unsuccessfully. After 60 s, spontaneous chest wall movement was observed with the patient beginning to make respiratory effort and moving her upper limbs. Train-of-four nerve stimulation showed no evidence of fade. An obstructed pattern of breathing was witnessed with no capnography trace or movement of the reservoir bag. Oxygen saturations had now decreased to 92%, so an adult Ravussin cannula was inserted through the cricothyroid membrane to achieve rescue oxygenation. Placement was confirmed with aspiration of air and evidence of carbon dioxide on capnography, followed by oxygenation with the Manujet− set to an initial pressure of 0.5 bar and a rate of 5 bpm. Adequate inhalation and exhalation was confirmed by the rise and fall of the anterior chest wall, with upper airway manoeuvres being used to maintain a route for exhalation. The driving pressure was subsequently increased to 1 bar to achieve adequate tidal volumes and oxygen saturation levels increased to 98%.
An emergency tracheostomy was performed between the first and second tracheal rings by the surgical team with anaesthesia maintained using i.v. propofol. A 7.0 mm cuffed tracheostomy tube was inserted and conventional ventilation achieved followed by a panendoscopy and tonsillar biopsy. After the procedure, anaesthesia was discontinued and the patient woken up. She was nursed on the high dependency unit overnight, before returning to the ward. There was no neurological deficit. Histology showed a squamous cell carcinoma and a tracheostomy remained in situ while the patient underwent treatment for the tongue base tumour.