1. Faculty of Medicine, McGill University, Montreal, Canada
2. Department of Anesthesia, McGill University Health Centre, Montreal, Canada
3. Department of Otolaryngology - Head and Neck Surgery, McGill University Health Centre, Montreal, Canada
4. Department of Pediatric Surgery, Montreal Children's Hospital, 1001 Decarie Blvd, H4A 3J1, Montreal, QC, Canada