Is the chest x-ray an appropriate screening exam for ER patients with AMS?

Emergency department patients with altered mental status (AMS) regularly undergo a routine chest radiograph at our institution. While there are many causes of chest pathology seen on the chest radiograph that may cause an altered mental status, it is not clear that a routine chest radiograph for these patients affects management. The goal of this study is to determine if a chest radiograph is an appropriate screening examination for AMS. This is a retrospective review of 100 consecutive patients who underwent head computed tomography for altered mental status in the emergency department and had a chest radiograph during the same visit. Of 100 patients undergoing a routine chest radiograph for AMS, 17 had findings which altered patient care, 15 of those had signs/symptoms which clearly indicated that a chest radiograph was needed, and the other two had leukocytosis. The routine performance of a chest radiograph in the setting of a patient presenting to the emergency department with altered mental status affected medical management in 17%, a modest benefit. The positive predictive value of a chest x-ray in these patients may be improved if certain symptomatologies are present.