Reduction in critical mortality in urban mass casualty incidents: analysis of triage, surge, and resource use after the London bombings on July 7, 2005.

BACKGROUND: The terrorist bombings in London on July 7, 2005, produced the largest mass casualty event in the UK since World War 2. The aim of this study was to analyse the prehospital and in-hospital response to the incident and identify system processes that optimise resource use and reduce critical mortality.
METHODS: This study was a retrospective analysis of the London-wide prehospital response and the in-hospital response of one academic trauma centre. Data for injuries, outcome, triage, patient flow, and resource use were obtained by the review of emergency services and hospital records.
FINDINGS: There were 775 casualties and 56 deaths, 53 at scene. 55 patients were triaged to priority dispatch and 20 patients were critically injured. Critical mortality was low at 15% and not due to poor availability of resources. Over-triage rates were reduced where advanced prehospital teams did initial scene triage. The Royal London Hospital received 194 casualties, 27 arrived as seriously injured. Maximum surge rate was 18 seriously injured patients per hour and resuscitation room capacity was reached within 15 min. 17 patients needed surgery and 264 units of blood products were used in the first 15 h, close to the hospital's routine daily blood use.
INTERPRETATION: Critical mortality was reduced by rapid advanced major incident management and seems unrelated to over-triage. Hospital surge capacity can be maintained by repeated effective triage and implementing a hospital-wide damage control philosophy, keeping investigations to a minimum, and transferring patients rapidly to definitive care.