The development of actively
hemostatic wound dressings for use in severe trauma remains a major public-health and military goal. But, although some manufacturers claim that existing dressings activate
platelets and/or
blood coagulation, mechanistic evidence is often lacking. We describe a method for assessing the active
hemostatic properties of dressings in vitro, entailing measurement of the
flow of recalcified platelet-rich plasma (PRP) through a dressing sample. If the dressing is hemostatically active,
flow is reduced. This
flow is then compared with the flow-through of PRP in which both
platelet and
coagulation function are blocked with
EDTA. The ratio of the two generates a
hemostatic index that ranges from 1.0 (no active
hemostasis) to 0 (highly potent). The method is applicable to porous or semiporous dressings, whether fabric, sponge,
fleece, or granules. For an active dressing, the test is easily modified to differentiate between the contributions of
platelet and
coagulation to overall
hemostasis. The method is illustrated for fabrics, over-the-counter gauze and sponge dressings, collagen-based sheets, and an absorbent granule dressing. One active
collagen dressing is used to illustrate discrimination between
platelet and
coagulation function. The ability to assess
hemostatic properties may significantly enhance the development of advanced active dressings.
