Written by Michael Stocker
Trauma patients attended to by helicopter EMS (HEMS) survived more often than predicted by national risk models, with the greatest gains among moderately severe injuries. Prehospital emergency anaesthesia (PHEA—basically rapid sequence intubation) was independently associated with improved survival.
Elevating outcomes in trauma transport
Determining which transport strategy best serves trauma patients is critical for both systems design and bedside decision-making. This retrospective study compared observed 30-day survival among HEMS-attended trauma patients, with expected survival derived from the UK Trauma Audit & Research Network (TARN) probability-of-survival model, using case-mix-adjusted W-statistics. In short: “Did these patients survive more often than predicted based on externally validated risk models?” The primary outcome was observed-to-expected survival, stratified by predicted survival bands. Case-mix adjustments weighted patients with moderate survival probability (think “sick but salvageable”) more heavily, while deemphasizing those with very low or very high predicted survival.
HEMS-attended patients demonstrated 5.23 excess survivors per 100 compared with TARN predictions, with the largest effect in patients with 25–45% predicted survival. Age and GCS were the strongest mortality predictors, while PHEA was independently associated with improved survival. Patients presenting in traumatic circulatory arrest (TCA) were analyzed separately, with 356 (27.1%) achieving ROSC sustained to hospital arrival, of which 46 survived to 30 days. 93% of TCA patients received at least one critical advanced intervention, with plasma transfusion, endotracheal intubation, and pelvic binders independently associated with ROSC. The physician-staffed UK HEMS model may limit generalizability to most US systems.
How will this change my practice?
As a HEMS doc, this reinforces my bias in favor of HEMS for severe trauma. That said, I would find it more compelling if HEMS patients were directly compared with similarly injured ground-transported patients, rather than against predicted outcomes alone. Without a non-HEMS comparator, the question we face daily—“Will this patient do just as well by ground or do they need air transport?”—remains unclear.
Source
Helicopter Emergency Medical Services attendance is associated with favourable survival outcomes in major trauma: derivation and internal validation of prediction models in a regional trauma system. Emerg Med J. 2026 Feb 3:emermed-2025-215451. doi: 10.1136/emermed-2025-215451. Epub ahead of print. PMID: 41633812.
