Aim: SECURE aims to define the perceived indications for, specific techniques used in and the immediate complications of RSIs in current UK in-hospital practice across anaesthesia, critical care and emergency medicine. Specific objectives • Describe what specific equipment, protocols and training related to RSI are in place in different clinical areas across different UK acute hospital sites. • Describe, through the use of clinical vignettes, practitioner self reported RSI practice in the UK. • Describe, through observational study, current RSI practice in the UK, across different specialties and in different clinical areas. • Identify if observed practice is in line with practitioner self-reported practice, or if a “say-do gap” exists. • Compare self reported practice, observed practice, and site provision of equipment/protocols/training with international recommendations on RSI practice (PUMA guidelines - Project for Universal Management of the Airway) • Describe incidence of pre-specified complications associated with RSI, and identify specific components of practice and/or patient factors associated with these through case reviews.