Anaesthesia mumps presenting as an airway emergency requiring tracheal intubation

Anaesthesia mumps is a rare postoperative complication of anaesthesia. The clinical presentation of the condition can range from acute transient swelling of the salivary glands to severe airway swelling requiring tracheal intubation.

A 49‐year‐old man who had undergone a small bowel transplant presented for repair of an enterocutaneous fistula. He received intrathecal morphine followed by induction of general anaesthesia and uneventful intubation of his trachea. He had a pre‐existing peripherally inserted central catheter in his right cephalic vein, which was used for parenteral nutrition. A central venous catheter was inserted into the left internal jugular vein. The surgery was uneventful. He remained stable until 11 hours postoperatively when he was found to have significant symmetrical neck swelling and voice changes (Fig. 1a). There was no stridor or evidence of respiratory distress.

Figure 1.

(a) Neck swelling immediately prior to intubation; (b) Computed tomography imaging (sagittal section) showing bilateral submandibular gland swelling and soft tissue swelling with complete loss of air space surrounding the reinforced tracheal tube.

Due to progressive neck swelling despite adrenaline nebulisation, awake re‐intubation of the patient's trachea via the oral route was performed. There was evidence of soft tissue swelling and external compression of the pharynx laterally.

Computed tomography of the neck immediately after tracheal re‐intubation showed bilateral enlarged submandibular and parotid glands along with swelling of the surrounding soft tissues, causing a complete loss of air gap around the tracheal tube (Fig. 1b). The central line position was correct and there was no evidence of enlarged veins. He was nursed head up and was given dexamethasone. The neck swelling improved by the following morning. His trachea was extubated and he was discharged to the ward.

The main differential diagnoses for postoperative airway swelling include allergic reaction, haematoma, subcutaneous emphysema and superior vena cava (SVC) obstruction. Although this patient had a history of long‐term central venous access, the absence of venous dilatation excluded superior vena cava obstruction. The radiological evidence of enlarged salivary glands suggests sialadenitis as the likely cause.

The occurrence of acute transient sialadenitis has been described after gastroscopy, bronchoscopy and non‐shared airway procedures [1]. Anaesthesia mumps has also been reported following laryngeal mask insertion [2], neuraxial anaesthesia [3] and in the paediatric population [4]. The typical presentation includes acute unilateral or bilateral neck swelling, neck pain, voice changes or upper airway obstruction. Hyperacute presentation requiring immediate tracheostomy is one of the rare and catastrophic presentations [5].

The pathophysiology of anaesthesia mumps is poorly understood. Possible mechanisms include the obstruction of the salivary gland duct from the stasis of thick saliva secondary to dehydration augmented by anaesthetic factors such as mask ventilation, upper airway manipulation, and cough or gag reflex around the time of tracheal extubation. In cases where sialadenitis developed after spinal anaesthesia, dehydration combined with the use of vasopressors is hypothesised to be a cause. Trendelenburg and lateral positions are also associated with the condition.

Management of airway swelling requires careful assessment and individualised decision‐making. When neck swelling is progressive, there is a risk of venous and lymphatic drainage obstruction which can further worsen the airway swelling. Patients should therefore be monitored carefully as soon as any neck or airway swelling is suspected. It is important to consider human factors in these situations and balance the risk of impending airway obstruction with the benefit of tracheal intubation by an experienced anaesthetist.