Spinal Myoclonus Leading to Endotracheal Tube Biting and Cardiac Arrest

Abstract

INTRODUCTION: Endotracheal (ET) tube biting is a common problem with oropharyngeal intubation, though is usually treatable with patient redirection or sedation. Here we present a rare case of cardiac arrest from ET tube biting.CASE PRESENTATION: A 27-year-old man with hyper IgE syndrome and cervical syringomyelia was admitted to the intensive care unit for planned intubation in the setting of chronic progressive hypercarbic respiratory failure. He had undergone bilateral lower lobectomies as a child for recurrent pneumonias, and the combination of neuromuscular weakness and severe kyphoscoliosis caused him to have restrictive lung physiology. The plan of care was for intubation, subsequent tracheostomy, and neurosurgical intervention on his syrinx. On the day of admission to the ICU, intubation went smoothly, and post-intubation the patient required low dose fentanyl infusion to maintain a Richmond Agitation Sedation Scale (RASS) of zero. He was alert and oriented. Overnight the same day, the patient was observed to be strongly biting his ET tube which obstructed airflow from the ventilator. Attempts to redirect patient were not successful, and he was given boluses of fentanyl and midazolam without resolution of biting. He then sustained hypoxic PEA cardiac arrest with return of spontaneous circulation achieved after 8 minutes of CPR. Post arrest, his mental status was poor and there was concern for status epilepticus, so propofol infusion was started and levetiracetam was given. Subsequent workup immediately post arrest including 5 days of continuous video EEG in the ICU did not demonstrate any seizure activity. Computed tomography angiogram of his head and neck vessels did not demonstrate any vascular occlusion or hemorrhage. After targeted temperature management and weaning of sedation, his mental status returned to normal. A bite guard was placed to prevent further ET tube obstruction. Tracheostomy was then performed. Within the next month the patient developed bilateral jerking movements of his lower extremities as well as tongue biting during his sleep. He underwent multiple video EEG studies which demonstrated these events without EEG correlate for seizure. Neurology diagnosed the patient with spinal segmental myoclonus, and he was initiated on clonazepam for treatment.DISCUSSION: ET tube biting is a known complication of oropharyngeal intubation. However, previous reports of major complications related to ET tube biting have come from damage to the tube itself (1-3). To our knowledge, this is the first case reported of a patient biting on the ET tube for long enough to arrest from hypoxemia. His diagnosis of spinal myoclonus is the most likely explanation for this event.CONCLUSIONS: In patients with a history of myoclonus, it may be prudent to prophylactically apply bite guard devices to prevent this rare complication of mechanical ventilation.