Cryopreservation does not begin when a patient reaches a storage facility. It begins after legal death, wherever the patient happens to be.
The first-response problem is therefore simple to state: reduce warm ischaemia, start cooling, and preserve vascular access for the procedure that follows.
Standby changes the starting conditions
When death is expected, a trained team can deploy before it occurs. No preservation procedure begins until legal death has been pronounced.
Being nearby does not guarantee a perfect case. It removes one avoidable source of delay.
Tomorrow.bio asks to be notified early because deployment, hospital coordination, equipment and local permissions all take time. Its current process is described on the official standby page.
Sudden or unattended death is different. The team can only respond after notification, so the period without circulation may already be substantial.
This is why Standby, Stabilisation and Transport should be evaluated as a response system, not merely as an ambulance.
What circulatory arrest changes
After the heart stops, blood no longer supplies oxygen or removes metabolic waste. The brain is especially vulnerable to this global ischaemia.
Damage is not controlled by elapsed time alone. Temperature, residual circulation, prior illness and the quality of cardiopulmonary support all matter.
Cooling slows many biochemical reactions, but there is no universal rule that converts every temperature drop into a precise amount of preserved brain structure.
A useful mental model is therefore directional: warm time is generally worse than cold time, but a clock cannot substitute for biological measurement.
What stabilisation actually does
Tomorrow.bio describes its stabilisation sequence as rapid external cooling, cardiopulmonary support, ventilation, and administration of anti-clotting and tissue-protective medications.
Mechanical chest compressions can produce some circulation and distribute cold and medications. They do not reproduce normal cardiac output, and their effectiveness varies.
An ice-water bath removes heat more effectively than placing isolated bags of ice on the body. Temperature probes are needed because surface temperature is not core temperature.
Anticoagulants may help preserve vascular patency when used promptly. They cannot reliably reverse clots that formed before the team arrived.
A 2024 peer-reviewed biostasis research roadmap treats these measures as plausible, protocol-dependent interventions whose effectiveness still needs better empirical validation.
The handoff criterion
Stabilisation is not the final preservation. It prepares the patient for blood washout and cryoprotective perfusion.
The useful record includes pronouncement time, team arrival, start of cooling, measured temperatures, cardiopulmonary-support periods, medications and complications.
Those data later inform the S-MIX estimate and the broader quality review.
The next phase is the perfusion and cryoprotection procedure. Its success partly depends on how much vascular function the first response preserved.
TL;DR: After legal death, standby teams begin cooling, circulation support and protective medication as quickly as possible. Their goal is to reduce ischemic damage before cryoprotective perfusion.
Estimate preservation quality
Explore how timing and circumstances can change the quality of a cryopreservation procedure.
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Further reading