Rail bombing with 30 casualties and two theatres — primary sieve choice, secondary Sort limits, and the index operation boundary

Model answer

• Doctrine frame: triage early and dynamic by severity, necessity and urgency for the greatest good — declare early, sort fast, re-sort continuously.^[11]
• Primary tool: BCD Sieve 70.4% sensitive with 70.9% over-triage beats NARU 44.9% with 56.4% over — BCD supersedes NARU as the UK primary tool; sieve by walk, respiratory rate, heart rate or capillary refill, military version adds consciousness.^[1][6]
• MPTT alternative: lowest under-triage at 42.4% with undertriaged mortality 5.7% and fewer thorax/head injuries missed than either sieve — the validated alternative when physiology plus mechanism is available.^[4]
• Elderly boundary: all tools perform poorly past 65 — assume undertriage in the older casualty, never argue it away.^[1]
• Sort limits: the Sort finds 15.7% of LSI need with 84.3% undertriage at 98.7% specificity — a P2 Sort label never reassures; its secondary use should be reviewed.^[3]
• Shock-index alternative: Sort 58.6%/88.7% against shock index above 0.75 at 70.0%/74.7% across 345 traumas — use it, but civilian translation is unproven.^[16]
• Re-triage rule: door accuracy runs 61% with 18% of life-threats missed and re-triage used in 4% — re-triage every arrival, especially Sort negatives.^[3]
• Paediatric choice: SPTT 92.2% sensitive at 75.0% over-triage beats tape 34.1% and JumpSTART 45.0% — sieve the teenager with the paediatric tool and accept the over-triage.^[18]
• Index operation: first arrivals bleed uncontrollably from trunk and cavities — stop the bleeding and control the contamination, nothing more; TASC serves the situation where damage control serves the patient.^[12]