Feras Khan, MD, is a Clinical Assistant Professor of Emergency Medicine. His research interests include critical care in the emergency department, specifically the use of noninvasive ventilation. He is also interested in the use of lung ultrasound for ARDS and pulmonary edema and the understanding of biomarkers for bacterial infection. He is participating in the Procalcitonin Antibiotic Prospective Trial (the ProACT study) based at the University of Pittsburgh. The goal of this project is to assess whether procalcitonin levels can guide antibiotic use for lower respiratory tract infections in the ED.