Anaesthetic management of a patient with myasthenia gravis and tracheal stenosis

The combination of myasthenia gravis and tracheal obstruction presents a number of difficulties for anaesthetic management. This case illustrates the advantages of careful planning. A 66-yr-old man with myasthenia gravis required resection of a stenosis at the site of an old tracheostomy. The primary goal was to accomplish safe management of the airway, a task made more difficult because the airway was shared with the surgeon. Awake fibreoptic examination of the tracheal stenosis performed in the operating room provided useful information in planning the subsequent anaesthetic. From this examination, it was found that the trachea could be intubated by a normal endotracheal tube passed through the stenosis over the fibreoptic bronchoscope. Intraoperatively, the orotracheal tube was withdrawn temporarily and replaced with an endotracheal tube placed by the surgeon into the distal trachea. Extubation was carried out judiciously and a plan for reintubation prepared in advance. The anaesthetic plan was modified because of the myasthenia gravis. Following careful investigation of the extent of the patient's disease and its treatment, an assessment was made of the patient's need for postoperative ventilation. The anaesthetic plan included maintenance of anticholinergic medications until the time of surgery and their early resumption postoperatively, avoidance of neuromuscular blocking agents, and careful monitoring of neuromuscular function during the anaesthetic. Careful examination of the area of tracheal stenosis and a carefully considered plan for reintubation are prerequisites for this type of surgery. Clinically well controlled myasthenia gravis was managed successfully using familiar principles.