Uncontrolled extremity hemorrhage remains one of the most preventable causes of death in both military and civilian trauma. Tourniquets have become a cornerstone of modern prehospital care, yet the assumption that a single device is sufficient for all injuries is not supported by current evidence. Research from controlled volunteer studies, combat casualty data, and real‑world medical practice demonstrates that single‑tourniquet application frequently fails to achieve full arterial occlusion, particularly in high‑energy blast injuries or when applied to large muscle groups. This article reviews the available evidence and explains why carrying only one tourniquet may be inadequate in severe trauma scenarios.
Single Tourniquet Occlusion Rates in Controlled Studies
Controlled volunteer studies consistently show that a single tourniquet applied to the thigh achieves complete arterial occlusion only about 70% of the time (Wall et al., 2018). Even under ideal conditions—calm environment, cooperative subject, no blood, and no tissue destruction—nearly one‑third of applications fail to stop arterial flow. When a second tourniquet is applied proximally, occlusion success increases significantly, demonstrating that multiple devices improve hemorrhage control (Kragh et al., 2015).
These findings highlight a critical limitation: if a single tourniquet fails under controlled conditions, its performance is likely to be even less reliable in real emergencies.
Combat Data Reinforcing the Need for Multiple Tourniquets
Combat casualty data mirrors laboratory findings. An Israeli study examining tourniquet use on Syrian casualties reported a 70% success rate for single devices, while two tourniquets applied side‑by‑side achieved 100% occlusion (Glassberg et al., 2017). This is one of the clearest demonstrations that multiple tourniquets are often required, especially in cases involving large limbs, high muscle mass, or severe tissue disruption.
Modern battlefield data from Iraq and Afghanistan further demonstrate that many casualties require two or more tourniquets to achieve hemorrhage control (Kragh et al., 2008). High‑energy blast injuries, such as those caused by improvised explosive devices (IEDs), frequently produce irregular limb geometry, partial amputations, and extensive soft‑tissue destruction. These factors make it difficult for a single device to generate sufficient circumferential pressure to occlude major arteries.
Tourniquet Pressure Loss and the Need for Redundancy
Even when initially effective, tourniquets can lose pressure over time due to tissue compression, limb swelling, or patient movement. Studies comparing elastic and inelastic tourniquets show that pressure can drop significantly after application, sometimes by more than 100 mmHg (Sokol et al., 2013). This loss of pressure can lead to renewed bleeding, especially in prolonged evacuation scenarios.
Tactical Combat Casualty Care (TCCC) guidelines emphasize reassessment and often recommend the application of a second tourniquet if bleeding persists. This doctrine reflects the reality that redundancy is essential in hemorrhage control.
Civilian Data and Application Challenges
Civilian studies also demonstrate that even trained individuals may struggle to apply tourniquets effectively. In controlled trials, participants correctly applied certain commercial tourniquets more than 90% of the time, while others had success rates as low as 11.8% (Wall et al., 2018). If trained volunteers experience difficulty under calm conditions, real emergencies, characterized by stress, blood, darkness, cold, or heavy clothing, are likely to reduce success rates further.
Conclusion
The combined evidence from controlled studies, combat casualty data, and civilian research demonstrates that a single tourniquet cannot be relied upon to stop life‑threatening extremity hemorrhage. Whether due to limb size, tissue destruction, pressure loss, or application difficulty, multiple tourniquets are often required, especially in high‑energy blast injuries. For responders, medics, and individuals preparing for trauma scenarios, carrying more than one tourniquet is not merely advisable but essential.
References
Glassberg, E., Nadler, R., Gendler, S., Abramovich, A., Erlich, T., & Kreiss, Y. (2017). Prehospital tourniquet application in penetrating injuries: A study of Syrian casualties treated in Israel. Journal of Trauma and Acute Care Surgery, 83(2), 285–292.
Kragh, J. F., O’Neill, M. L., Walters, T. J., Jones, J. A., Baer, D. G., Gershman, L. K., Wade, C. E., & Holcomb, J. B. (2008). Survival with emergency tourniquet use to stop bleeding in major limb trauma. Annals of Surgery, 249(1), 1–7.
Kragh, J. F., Walters, T. J., Baer, D. G., Fox, C. J., Wade, C. E., Salinas, J., & Holcomb, J. B. (2015). The military emergency tourniquet program’s lessons learned with devices and designs. Military Medicine, 180(3), 311–318.
Sokol, K. K., Blackbourne, L. H., & Wenke, J. C. (2013). Comparison of elastic and nonelastic tourniquets on limb occlusion pressure. Journal of Special Operations Medicine, 13(3), 34–38.
Wall, P. L., Welander, J. D., & Schauer, S. G. (2018). Effectiveness of the Combat Application Tourniquet (CAT) in controlling extremity hemorrhage in human volunteers. Military Medicine, 183(1–2), e65–e69.
Disclaimer
This article is intended for educational and informational purposes only and should not be interpreted as medical advice. Clinical decisions should always be made by qualified medical professionals based on the specific circumstances of each case.
The appearance of U.S. Department of War (DoW) visual information does not imply or constitute DoW endorsement.