Lessons in planning from mass casualty events in UK.

Mass casualty events are a global phenomenon, but the NHS in England has faced an unprecedented number of major incidents this year: the Westminster Bridge terrorist attack (22 March), the Manchester Arena bombing (22 May), the London Bridge attack (3 June), the Grenfell Tower fire (14 June), and terrorist attacks at Finsbury Park mosque (19 June) and Parsons Green underground station (15 September). These events have tested the country’s major trauma systems. Each incident posed new challenges in differing environments, with different threats, resulting in different injuries.System learning is critical: debriefing and sharing information so that lessons learnt can be rapidly incorporated into future plans. In England, “hot” debriefs took place within two weeks and “cold” multiagency debriefs after four weeks, with post-incident reporting beyond six weeks. Here, we share some of that new learning. Emergency planning, resilience, and response commonly gives primacy to the initial stages of managing a major incident—first response, treatment on scene, triage, distribution of casualties, hospital reception, repeat triage, resuscitation, primary management, and command and control structures. These are rehearsed in desktop and simulation exercises, and both the Manchester and London teams report that these exercises, coincidentally undertaken shortly before the first attacks, were valuable in testing plans and informing policy and practice during the incidents. A similar benefit was reported in Paris in November 2015. However, it has become increasingly clear that the effect on hospitals and staff endures well beyond the first 24 hours. Longer term demands