Cascadia Rising: thoughts on a Seattle earthquake disaster exercise

Review of the requirements for effective mass casualty preparedness for trauma systems. A disaster waiting to happen?

Mass casualty incidents (MCIs) are diverse, unpredictable, and increasing in frequency, but preparation is possible and necessary. The nature of MCIs requires a trauma response but also requires effective and tested disaster preparedness planning. From an international perspective, the aims of this narrative review are to describe the key components necessary for optimisation of trauma system preparedness for MCIs, whether trauma systems and centres meet these components and areas for improvement of trauma system response. Many of the principles necessary for response to MCIs are embedded in trauma system design and trauma centre function. These include robust communication networks, established triage systems, and capacity to secure centres from threats to safety and quality of care. However, evidence from the current literature indicates the need to strengthen trauma system preparedness for MCIs through greater trauma leader representation at all levels of disaster preparedness planning, enhanced training of staff and simulated disaster training, expanded surge capacity planning, improved staff management and support during the MCI and in the post-disaster recovery phase, clear provision for the treatment of paediatric patients in disaster plans, and diversified and pre-agreed systems for essential supplies and services continuity. Mass casualty preparedness is a complex, iterative process that requires an integrated, multidisciplinary, and tiered approach. Through effective preparedness planning, trauma systems should be well-placed to deliver an optimal response when faced with MCIs.

Blood transfusions in mass casualty events: recent trends

BACKGROUND AND OBJECTIVES

The US AABB disaster task force recommends estimating 3 RBC units per admission (UPA) for mass casualty events (MCEs). In a previous analysis, median MCE UPA were 2·7 RBCs, 1·2 plasmas and 0·27 platelet doses (Vox Sang 2017; 112:648). Additional recent data were sought from the current era of balanced massive transfusion protocols (bMTPs).

MATERIALS AND METHODS

Publications in English from 1980 to 2020 were reviewed for MCEs using ≥50 RBCs/event and with numbers of admissions available. MCE reports were stratified by era and event-wide or trauma-centre source. The bMTP era included all MCEs since 2010 plus a 2008 bMTP military report.

STATISTICS

Mann-Whitney test.

RESULTS

Thirty-two MCEs met analysis criteria. Event-wide reports used medians [interquartile ranges] of 1·8 [1·2-3·9] RBC, 0·6 [0·3-0·9] plasma and 0·14 [0·06-0·26] platelet-dose UPA. Trauma centres transfused 3·4 [2·7-6·3] RBC, 2·4 [1·3-4·1] plasma and 0·41 [0·34-0·50] platelet-dose UPA, all P < 0·05 vs event-wide. Same-event median post-day-1 transfusions were 50% of day-1 use for RBC, 28% for plasma and 16% for platelets. Compared to prior years, the median plasma/RBC transfusion ratio rose from 0·28 to 0·67 in the bMTP era (P < 0·01). In recent mass shootings, trauma centres transfused up to 42 platelets (range 0·45-0·57 UPA) on day 1.

CONCLUSION

Based on available mass casualty data, we recommend planning for 3 RBC, 1 plasma and one-fourth platelet-dose units per admission for blood centres (event-wide), and 6, 4 and one-half UPA, respectively, for trauma centres, which have seen rising plasma usage and large mass-shooting platelet needs.