1. Department of Pediatrics, Division of Pediatric Emergency Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
2. Department of Pediatrics, Division of Pulmonary Medicine and the Center for Asthma Research, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
3. Department of Surgery, Division of Trauma and Surgical Critical Care, Vanderbilt University Medical Center, Nashville, Tennessee, USA
4. Department of Emergency Medicine, Division of Emergency Medical Services, Vanderbilt University Medical Center, Nashville, Tennessee, USA