Background: In emergencies when commercially designed tourniquets are unavailable, hemorrhage may need to be controlled with improvised tourniquets. In the aftermath of the Boston Marathon bombing, no improvised strap-and-windlass tourniquets were used to treat casualties; tourniquets without windlasses were used. The purpose of the present study is to determine the effectiveness of improvised tourniquets with and without a windlass to better understand the role of the windlass in tightening the tourniquet strap.
Methods: An experiment was designed to test the effectiveness of improvised strap-and-windlass tourniquets fashioned out of a tee shirt on a manikin thigh. Two users conducted 40 tests each with and without the use of a windlass.
Results: Without a windlass, improvised tourniquets failed to stop bleeding in 99% of tests (79 of 80 tests). With a windlass, improvised tourniquets failed to stop bleeding in 32% of tests (p < .0001). In tests with no windlass, attempts to stop the pulse completely failed (100%, 80 of 80 tests). With a windlass, however, attempts to stop the pulse failed 31% of the time (25 of 80 tests); the difference in proportions was significant (p < .0001).
Conclusions: Improvised strap-and-windlass tourniquets were more effective than those with no windlass, as a windlass allowed the user to gain mechanical advantage. However, improvised strap-and-windlass tourniquets failed to control hemorrhage in 32% of tests.
2015.