In 2011, then Oregon Health & Science University surgeon Martin Schreiber, M D, received support from the National Trauma Institute to explore a straightforward idea with big implications. Instead of protecting every trauma patient from blood clots with the same standard dose of enoxaparin, why not measure a patient’s real time coagulation and tune the dose to the individual? The study proposed using thrombelastography, often shortened to TEG, to guide dosing and compare outcomes with a fixed regimen. The goal was simple. Reduce preventable clots in the highest risk patients without increasing bleeding.
This article highlights the project and then shows how the field has evolved. The story begins with a question that still matters. Are we dosing the patient in front of us, or the average patient on a protocol?
The challenge that inspired the work
After major injury, deep vein thrombosis and pulmonary embolism remain common causes of harm in the intensive care unit. Immobility, inflammation, and tissue injury all increase clot risk. For years, many services relied on a fixed dose of low molecular weight heparin because fixed dosing is easy to standardize. Yet the same dose can protect one patient and leave another underdosed, especially in patients with obesity or complex physiology.
Schreiber’s team proposed a different path. Use a whole blood test that tracks how a clot forms, strengthens, and breaks down. Then use that information to decide whether a patient needs a different dose than the default.
The proposed solution
TEG records a curve of clotting performance in real time. It reflects the joint work of platelets, fibrinogen, and fibrinolysis rather than a single lab value. In the study design, one patient group would receive the usual enoxaparin dose and another would receive a dose adjusted by TEG results, with careful monitoring for both clots and bleeding. The National Trauma Institute awarded funding to move the concept from idea to bedside testing as part of a broader push for practical trauma research.
The investigator behind the idea
By that time, Dr Schreiber was serving as chief of trauma, critical care, and acute care surgery at OHSU and as a professor of surgery. His background spans both civilian and military medicine. As a U S Army reservist, he deployed to Iraq and Afghanistan and served as the Joint Theater Trauma System Director, a role centered on turning evidence into daily practice in austere settings. At OHSU, he led a trauma research laboratory with long-standing federal support, focused on hemostasis, resuscitation, and the body’s response to injury. His work has a consistent theme. Measure what matters, translate data into decisions at the bedside, and build protocols that busy teams can use.
Why the study mattered for healthcare
Precision for patients who need it most
Fixed dosing is convenient, yet the burden of clotting falls heaviest on patients with severe injuries, high body mass, or prolonged immobilization. These same patients are the likeliest to be subtherapeutic on a standard regimen. A physiologic readout such as TEG creates a path to dose for the person, not the protocol.
Outcomes over convenience
Convenience is not a clinical endpoint. If a simple measurement can safely lower clot events, hospitals have a strong reason to rework pathways and training.
Better resource use
Clots extend stays, prompt imaging and interventions, and can cause long term disability. Even modest reductions yield meaningful savings and, more importantly, fewer life altering complications.
A common language for the team
Trauma care depends on surgeons, intensivists, pharmacists, and nurses. A shared physiologic target improves coordination. Saying that a tracing shows increased clot strength is more actionable than saying the patient seems at risk.
Lessons that travel
If individualized prevention works in trauma, the concept can inform surgical intensive care units, burn care, and other settings where physiology shifts quickly.
A simple bridge to today
This research pushed trauma services toward a clear idea. Measure relevant signals for each patient and tailor the dose to fit. In the years since, hospitals embraced that idea at scale through weight based dosing and anti Xa monitoring to confirm protection. The tool may differ from the original TEG concept, yet the destination is the same. Routine practice now treats clot prevention as a personalized decision rather than a fixed default.
Now in 2025: What has changed
Guidelines and hospital playbooks have moved steadily away from one fixed dose for all adults. Contemporary algorithms recommend earlier pharmacologic prophylaxis when bleeding risk is controlled, a higher default dose for many patients, and dose confirmation in higher risk cohorts using anti-Xa levels. Many centers begin with enoxaparin forty milligrams twice daily as an initial approach for most adults, while traumatic brain and spine injury often begin at thirty milligrams twice daily with close imaging and clinical review.
Hospitals have translated that guidance into practical playbooks. Weight-based dosing is common, with tiered initial doses and explicit anti-Xa targets, and pharmacist-driven titration in the intensive care unit. One example protocol begins most patients on weight-stratified enoxaparin and requires anti-Xa monitoring for patients over ninety kilograms, for very high body weights, and in other high-risk categories.
Why the change? A large share of critically injured patients do not reach target anti Xa levels with traditional thirty milligrams twice daily dosing. Protocols that escalate by weight and adjust to an anti-Xa goal improve the proportion of patients who achieve protective exposure, and comparative studies link anti-Xa guided dosing to lower venous thromboembolism without a rise in bleeding.
What about TEG as the dosing compass? Reviews over the last decade have not shown consistent superiority for TEG-guided low molecular weight heparin dosing over strategies that use weight and anti-Xa levels. Modern summaries describe trials where TEG did not reduce venous thromboembolism rates compared with fixed dosing, and they place TEG’s strongest role in resuscitation and transfusion decision making rather than routine clot prevention dosing.
Trauma teams have also clarified timing in difficult scenarios. For patients with traumatic brain injury, consensus work favors earlier prophylaxis once imaging shows stability, since delays raise clot risk and many patients tolerate carefully timed starts without lesion progression. This approach continues to evolve with updated best practice guidance.
A snapshot of a typical pathway today
Start early when safe. After injury and initial imaging, begin pharmacologic prophylaxis as soon as bleeding risk is controlled, with forty milligrams of enoxaparin twice daily as a common adult starting point outside of brain or spine injury, and with thirty milligrams twice daily for those populations alongside careful reassessment.
Escalate by weight. Use tiered starting doses for heavier patients, and plan targeted anti-Xa checks in high-risk cohorts.
Measure exposure. Draw anti-Xa levels at steady state, titrate by small increments to reach prophylactic targets, and recheck after changes.
Extend when indicated. Continue prophylaxis after discharge in selected high risk patients who remain at elevated risk after leaving the hospital.
Two clear takeaways
Personalization is now routine. The field widely adopted the spirit of Schreiber’s question. Dose the patient, not the average. The everyday tools are weight-based starts and anti-Xa monitoring rather than TEG for prophylaxis.
Guidelines and local protocols align more than ever. Services converge on low molecular weight heparin over unfractionated heparin, earlier starts when safe, higher initial doses for many adults, and anti-Xa guided adjustments for patients at the highest risk of being underprotected.
What this evolution means in practice
The 2011 study highlights an important pivot point. It asked teams to replace a blunt instrument with a tuned approach. In the years since, trauma programs have kept the same guiding idea while choosing the most reproducible tools. Many centers still use TEG for resuscitation and transfusion choices, where whole blood viscoelastic testing offers insights that routine labs can miss. For clot prevention dosing, services now rely on weight and anti-Xa levels because those tools are easier to standardize, scale across units, and audit for safety and effectiveness.
The practical benefits are easy to see. More patients reach protective exposure without increased bleeding risk. Fewer patients suffer preventable clots. Teams speak a common language about timing, targets, and risk. The emphasis on measurement has also strengthened related pathways, including protocols for early prophylaxis in stable traumatic brain injury and for pharmacist-driven titration in the intensive care unit.
Closing perspective
The 2011 research by Martin Schreiber helped push trauma care toward individualized prevention. The core lesson endures. When teams measure the right signals and adjust in real time, prevention becomes precise and patients are safer. In 2025, weight and anti-Xa guided enoxaparin dosing has become the everyday expression of that lesson, while TEG continues to inform bleeding and transfusion decisions where a whole blood view adds the most value. The fixed dose that once defined prophylaxis is no longer the default. The patient in front of you is.
