Open Discussion · Research hypothesisPre-review pathway

Are we identifying the oxygen-delivery problem early enough?

A 2026 prehospital transfusion study shows how difficult it remains to identify which trauma patients will require emergent blood transfusion. The broader question for discussion is whether prehospital medicine can identify clinically meaningful oxygen-delivery failure earlier than severe hemodynamic deterioration alone.

01 / What the study measured

Simple physiological criteria. Limited predictive precision.

Warren and colleagues retrospectively evaluated proposed prehospital blood transfusion criteria in 25,473 EMS-transported trauma patients. The criteria were systolic blood pressure below 70 mmHg, systolic blood pressure below 90 mmHg with heart rate at least 110 beats per minute, or EMS-witnessed traumatic arrest.

25,473trauma patients in the retrospective cohort
52%of patients meeting at least one criterion received blood within four hours
56%highest positive predictive value, for SBP <90 mmHg + HR ≥110 bpm
02 / The question for discussion

Blood pressure and arrest describe hemodynamic deterioration. What about the oxygen deficit developing before that?

The study did not include direct tissue-oxygenation or tissue-ischemia measurements in its patient-selection criteria. Severe hypotension and traumatic arrest are clinically critical signals, but tissue oxygen delivery may already be becoming inadequate before those endpoints are reached.

The question is not only who will later receive blood. It is also who is entering a clinically meaningful oxygen-delivery deficit now.

03 / BHOC research hypothesis

Define the patient before defining the protocol.

For BHOC, the opportunity is not to replace donor blood or to assume that every hypotensive trauma patient requires an oxygen carrier. The development task is to work with emergency physicians, trauma specialists and EMS medical directors to define a broader, clinically defensible patient-selection framework.

That framework could combine symptoms, mechanism of injury, conventional physiology and validated perfusion or oxygenation markers. The exact variables must be established prospectively with clinicians rather than assumed from theory.

04 / Protocol concept to investigate

From recognizing shock to preserving oxygen delivery during transport.

1 / IdentifyTrauma, bleeding risk and clinical deterioration
2 / AssessPhysiology plus validated perfusion and oxygenation signals
3 / DefineClinically meaningful oxygen-delivery deficit or high-risk window
4 / InvestigateBHOC as an early oxygen-delivery bridge in eligible patients
5 / TransferMaintain life and organ viability until definitive hospital care

The clinical endpoint cannot simply be “product given.” A development program would need to test whether earlier oxygen-delivery support improves clinically meaningful outcomes such as organ injury, physiological recovery, transfusion requirements, complications, survival or other endpoints agreed with emergency and trauma specialists.

05 / Questions for emergency clinicians

This is where the hypothesis needs challenge.

Which patient?Which combination of injury pattern, physiology, perfusion and oxygenation signals identifies a clinically meaningful treatment window?
Which marker?Which validated bedside measures can detect oxygen-delivery failure early enough to change management without creating unnecessary treatment?
Which endpoint?Should studies prioritize organ injury, physiological recovery, transfusion requirement, survival, transport stability or a composite endpoint?
06 / Why this matters

The first task of emergency care is to preserve the patient until definitive treatment is available.

In severe hemorrhage and trauma, time is not only measured in minutes to hospital arrival. It is also measured in how long organs and tissues remain adequately perfused and oxygenated. A future BHOC prehospital protocol should therefore be built around the clinical window in which oxygen-delivery support can be justified, measured and tested.

If such a protocol demonstrates better outcomes prospectively, it could potentially evolve from an exceptional rescue concept into a standardized prehospital procedure for a defined patient population.

Evidence boundary: this page is an open research discussion, not a clinical recommendation. Warren et al. did not evaluate BHOC/HBOC therapy and the study does not establish that earlier BHOC administration improves outcomes. Any clinical use would require product-specific evidence, safety assessment, prospective trials and appropriate regulatory authorization.