Succinylcholine has long been the neuromuscular blockade agent of choice for the emergency physician for rapid sequence intubation because of its rapid onset and relatively brief duration of action. However, it has many known life-threatening side effects and contraindications including allergy, histamine release, dysrhythmias, hyperkalaemia, and malignant hyperthermia.¹ It has also been known to cause significant masseter spasm in children when used in conjunction with volatile anaesthetics such as halothane.^2–5 In adults, succinylcholine can also produce transient masseter spasm that resolves when fasciculation stops. This potentially deadly side effect has been noted in other specialties but the incidence in adults is unknown.^6,7 The generally agreed upon treatment is to stop the anaesthetic and reschedule the procedure at a later date with different agents and evaluation for malignant hyperthermia.⁴ However, in the emergency department that management option is not available to the emergency physician. Knowledge of the potential side effects of this commonly used medication is paramount to successful airway management.

We present a case of succinylcholine induced masseter spasm in the emergency department requiring surgical cricothyroidotomy for airway control. We believe that this is the only reported case of masseter spasm resulting in a failed airway requiring surgical cricothyroidotomy during rapid sequence intubation.

CASE REPORT

The patient was a 56 year old man brought in by ambulance for altered mental status and hypotension. His vital signs in the field were: blood pressure 97/58 mm Hg; heart rate 135; respiratory rate 19; and SAo₂ 98% on 100% oxygen. Finger stick whole blood glucose was normal. The ambulance team reported that the patient’s apartment was covered with bloody vomitus and melaena, and the patient was noted in the field to be covered in what appeared to be old blood and stool. He presented complaining only of …