Eric J. Koch, DO; Michael Andersen, MD; George A. Barbee, DSc, EM PA-C; Antonio Boyd, Submarine IDC; Cyril Clayton, EMT-P; Christopher W. Hewitt, DO; John C. Maitha, MPAS, APA, PA-C; Michael A. Remley, NRP, ATP; Alexandre Nguyen, MD; Joseph Kaleiohi, PA; Harold Montgomery, ATP; Travis Deaton, MD; Frank Butler, MD; Jennifer Gurney, MD
Journal of Special Operations Medicine
Operational experience from the Russo-Ukrainian War revealed frequent use of tourniquets that were not medically indicated and an increase in ischemic complications from prolonged tourniquet application as a consequence of extended evacuation times. In response to this, the Committee on Tactical Combat Casualty Care (CoTCCC) convened a working group to evaluate whether tourniquet reassessment and conversion practices should extend to the All Service Member (ASM) level. With input from NATO and partner nations, the Working Group developed a standardized, time-based algorithm that provides plain language guidance for reassessment, repositioning, and conversion. The proposed change replaces the term replacement with repositioning, affirms a reassessment window within 2 hours for nonmedical personnel, and limits conversion beyond 2 hours to medical personnel. These updates will expand lifesaving capability to nonmedical responders, reduce preventable morbidity and mortality from tourniquet use, and align TCCC principles with current operational realities.
The update incorporates lessons from recent conflicts, particularly the Russo-Ukrainian War, where delayed evacuation and prolonged tourniquet use—sometimes lasting hours to days—have led to increased morbidity and mortality. Extended tourniquet times have been associated with prolonged tourniquet application syndrome (PTAS), including ischemic limb damage, compartment syndrome, amputation, metabolic acidosis, hyperkalemia, acute kidney injury, and death.
The proposed changes aim to:
The Working Group found that inconsistent and overly complex tourniquet terminology creates confusion, particularly for nonmedical personnel learning TCCC. To improve clarity and standardization, simplified definitions were recommended for all TCCC education and doctrine:
The term “replacement” should be eliminated to reduce ambiguity and improve communication across all TCCC provider levels.
The group also concluded that tourniquet reassessment and limited conversion should extend to the All Service Member (ASM) level within clearly defined boundaries. This reflects modern operational realities where delayed evacuation and limited medical access require nonmedical personnel to sustain casualty care for prolonged periods. Guided reassessment can reduce preventable complications, improve limb preservation, and restore perfusion when appropriate. Expanding reassessment authority to ASM supports survivability, responder autonomy, and the TCCC principle that all servicemembers play a role in sustaining life until higher care is available.
Tourniquet conversion timing should be guided by ischemic risk and provider capability, with reassessment occurring as soon as tactically feasible and ideally within the first 2 hours after application. Evidence supports a time-based risk model in which tourniquet use under 2 hours carries the lowest risk, 2–6 hours represents increasing caution, and beyond 6 hours carries significant danger for ischemic and reperfusion complications.
Recommended time cutoffs by TCCC tier are:
These time points are intended as practical risk-management boundaries rather than absolute physiologic limits, recognizing that patient response varies based on injury, environment, and operational conditions.
A failed tourniquet conversion attempt does not reset or extend ischemic time limits. Ischemic risk should be tracked continuously from the moment the tourniquet is first applied until it is permanently removed. Brief loosening, intermittent reperfusion, or re-tightening does not create a new timing window and should not alter the original 2-hour reassessment or 2–6-hour conversion thresholds.
If conversion fails—meaning bleeding recurs and the tourniquet must be re-tightened—the original application time still governs decision-making. Near upper time limits, the safest approach is generally to leave the tourniquet in place until higher-level monitored care is available. All reassessment and failed conversion attempts should be documented, including timing, re-tightening, and clinical findings.
Yes. Because shock recognition is already taught in ASM and CLS TCCC training, it should continue to be used as a contraindication to tourniquet conversion. ASMs are trained to recognize simple signs of shock—such as rapid breathing, altered focus, pale or clammy skin—while CLS personnel receive additional instruction in assessing perfusion and mental status.
The Working Group supports reinforcing these existing observation-based skills rather than adding complex medical assessment requirements. Teaching shock recognition more deliberately for tourniquet decision-making also improves triage, evacuation prioritization, and overall casualty assessment, supporting the broader TCCC principle that all servicemembers should recognize physiologic deterioration and intervene appropriately.
Implementing tourniquet reassessment and conversion at the ASM level would not require a full redesign of TCCC curricula. Instead, it could be added through a focused supplemental training module that builds on skills ASMs already learn, such as bleeding control and shock recognition.
The Working Group recommends a concise 2–3 hour module covering:
This training could be integrated into existing TCCC education platforms, including the Joint Trauma System and Deployed Medicine ecosystem, which already supports standardized, scalable instruction using modern learning technologies and simulation methods.
Implementation may require updates to trainer qualification standards and Service-level policies to ensure safe, consistent instruction. Overall, the change is viewed as achievable within existing training architecture while improving readiness for prolonged casualty care environments.
The tourniquet reassessment algorithm was developed to provide nonmedical personnel with a simple, standardized framework for safe decision-making in prolonged casualty care environments. It was adapted from a NATO STO HFM Specialist Team model and modified to align with U.S. TCCC doctrine, military training tiers, and operational realities.
Development drew from:
The algorithm incorporates time-based risk categories (<2 hours, 2–6 hours, >6 hours) using a color-coded “Tourniquet Traffic Light” concept. It provides tier-specific guidance for reassessment, repositioning, and conversion, along with documentation requirements and escalation points such as telemedicine consultation.
The final product is an evidence-informed, plain-language decision aid designed to improve consistency, safety, and interoperability while enabling servicemembers to manage tourniquets across delayed evacuation and prolonged care scenarios.
The TCCC Tourniquet Reassessment Working Group evaluated whether tourniquet reassessment and conversion should extend to the All Service Member (ASM) level and created a standardized framework for all TCCC tiers. Lessons from recent conflicts showed that prolonged or unnecessary tourniquet use—especially in delayed evacuation and limited-medical-support environments—can lead to preventable complications.
To address this, the group developed a time-based reassessment algorithm using clear, plain-language guidance for reassessment, repositioning, and conversion. The approach is intended to help nonmedical personnel make safe decisions while reducing ischemic injury and systemic complications.
Key updates include:
The group acknowledges that evidence on prolonged tourniquet use and reperfusion risk remains incomplete. Therefore, the recommendations are designed as operational decision-support guidance rather than absolute clinical rules, emphasizing judgment, simplicity, and adaptability as future evidence emerges.