Unexpected Difficult Airway in a Patient with a Known Difficult Airway
A 45-year-old woman with a history of previous difficult intubation (Cormack-Lehane grade 3) and a BMI of 35 kg/m² presents for elective thyroidectomy. She has a large goitre causing tracheal deviation and mild stridor when supine. She is otherwise well. You plan an awake fibreoptic intubation. After topicalisation and sedation with midazolam and fentanyl, you attempt awake fibreoptic intubation. The view is obscured by secretions and the patient becomes uncooperative, desaturating to 88% on 4 L/min nasal oxygen. You abandon the technique and decide to induce general anaesthesia with a plan for video laryngoscopy. After induction with propofol and rocuronium, you attempt video laryngoscopy but cannot see the glottis (Cormack-Lehane grade 3). Oxygen saturation is 92% and falling. You have a supraglottic airway (SGA) and a fibreoptic scope available.
1. What are your immediate next steps? Prioritise them.
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The priority is oxygenation. Immediately call for help and declare a difficult airway. Attempt ventilation with a supraglottic airway (SGA) while maintaining oxygen delivery. If SGA ventilation is successful, consider fibreoptic intubation through the SGA. If SGA fails, perform face-mask ventilation with an oropharyngeal airway and two-person technique. If oxygenation cannot be maintained, proceed to emergency front-of-neck access (eFONA) with a scalpel-bougie-tube technique. Since rocuronium was given, consider sugammadex 16 mg/kg for rapid reversal if eFONA is not immediately possible and the patient is not yet hypoxic. However, in a cannot-intubate-cannot-oxygenate situation, eFONA takes precedence. Ensure continuous monitoring and documentation. The patient's goitre and obesity increase the risk of airway obstruction, so early eFONA should be considered if ventilation is inadequate.
2. What factors in this case contributed to the failure of the initial plan, and how would you modify your approach in a future anaesthetic?
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Contributing factors: inadequate topicalisation and patient cooperation led to failure of awake fibreoptic intubation; secretions obscured the view; the patient's obesity and goitre increased airway difficulty; the decision to induce general anaesthesia without a clear backup plan for failed intubation may have been premature. For future anaesthetics: optimise the patient's condition (e.g., treat any respiratory infection, consider CPAP for OSA), involve a senior anaesthetist and ENT surgeon from the outset, and consider an awake tracheostomy under local anaesthetic as a primary plan if the airway is deemed critically compromised. Use a high-flow nasal oxygen and better topicalisation with antisialagogues (e.g., glycopyrrolate) to reduce secretions. Have a clear difficult airway algorithm and ensure all equipment is immediately available. Consider performing an awake video laryngoscopy as a first step. Document the difficulty and provide the patient with a difficult airway letter.