1. Department of Otolaryngology-Head and Neck Surgery, University of Texas Southwestern Medical Center, Dallas, TX, United States
2. Divisions of Pediatric Otolaryngology, Department of Anesthesiology and Pain Management, University of Texas Southwestern, Dallas, TX, United States
3. Department of Anesthesiology and Pain Management, University of Texas Southwestern Medical Center, Dallas, TX, United States
4. Department of Anesthesiology, Children's Health Medical Center, Dallas, TX, United States
5. Outcome Research Consortium, Cleveland, OH, United States