1. Department of Otolaryngology – Head and Neck Surgery University of Texas Southwestern Medical Center Dallas Texas U.S.A.
2. Department of Pediatric Otolaryngology Children's Medical Center Dallas Dallas Texas U.S.A.
3. Department of Anesthesiology and Critical Care Medicine Children's Hospital of Philadelphia Philadelphia Pennsylvania U.S.A.
4. Department of Anesthesiology & Critical Care Perelman School of Medicine at the University of Pennsylvania Philadelphia Pennsylvania U.S.A.
5. Division of Otolaryngology Children's Hospital of Philadelphia Philadelphia Pennsylvania U.S.A.
6. Department of Otorhinolaryngology ‐ Head and Neck Surgery Perelman School of Medicine at the University of Pennsylvania Philadelphia Pennsylvania U.S.A.