Poster 9: An Intermittent “Blown Pupil” in a Severe Traumatic Brain-Injured Patient Undergoing Rehabilitation: A Case Report

Abstract

Setting: Inpatient rehabilitation unit. Patient: A 16-year-old male undergoing rehabilitation after severe traumatic brain injury. Case Description: The patient was transferred to the rehabilitation unit 4 months after a motor vehicle accident in which he sustained a splenic rupture, bilateral femoral, tibial, and multiple cranial fractures with a right cranial nerve VII injury. His previous hospital course was complicated by intracranial and subdural hematoma, multiple infections, bilateral pneumothoraces, hydrocephalus, and several ventriculoperitoneal (VP) shunt revisions and shunt-related complications. On admission to the rehabilitation unit the patient was unable to communicate or follow directions due to the severity of his brain injury. On the third day of rehabilitation the on-call resident was called to investigate the concerns of the nurse and parents about a new right “blown pupil.” Examination confirmed an extremely dilated and unresponsive right pupil. A stat computerized tomography (CT) of the head showed no significant changes when compared with previous CTs. No other mental status or neurologic changes were noted on exam, although he was severely cognitively impaired from his accident. Neurosurgery suggested close monitoring. 6 hours later his pupils were again symmetric. The next morning the rehabilitation residents were called again to the bedside for a right “blown pupil;” it was at this time that the cause of the intermittent mydriasis was identified. Assessment/Results: The patient's intermittent unilateral mydriasis, or “blown pupil,” was induced by the ipratropium contained in his nebulizer administered by a loose-fitting face mask. Due to a right sided seventh cranial nerve injury the patient was unable to blink his right eye (lagophthalmos), which then led to the this unilateral exposure to the nebulized anticholinergic. The nebulizers were discontinued and his pupils remained symmetric during the remainder of his rehabilitation. Conclusions: Once serious complications, such as VP shunt complication, are excluded, it is important to consider medications and other iatrogenic causes of new symptoms. To our knowledge, this is the first reported case of mydriasis from nebulized ipratropium.