Proposed mechanism of action for a hydroconductive dressing, Drawtex, for the treatment of wounds: In vitro experiment and clinical evidence

Abstract

Background. The mechanism of action of the Drawtex dressing is described as having three components: capillary, hydroconductive and electrostatic.

Objective. To find a more complete explanation of Drawtex’s mechanism of action, from in vitro research and clinical observations.

Method. Ten 1 Å~ 1 cm sections of Drawtex dressing were cut off, and some trypan blue was dripped onto one side of each using a pipette. The pieces were then examined macroscopically and under a light microscope (LM), on all sides and surfaces (superficial and deep surfaces, as well as the edges), to assess fluid movement.

Results. Three fibres (cotton, viscose and polyester) of different diameters and different directions were visible under the LM. Fluid could also be seen surrounding the fibres in which the trypan blue was absorbed. Macroscopic examination of Drawtex removed from sloughy wounds showed that slough was stuck to the dressing, and mechanical action also played a role.

Conclusion. Based on our observations, the following explanation of the mechanism of action of the dressing seemed easier to grasp: (i) absorption within the fibres; (ii) absorption between the fibres resulting from the Venturi effect, diffusion gradient and buoyant forces; (iii) the effect of the diffusion gradient; (iv) evaporation; (v) dehydration; and (vi) adsorption and mechanical slough removal. The physics of fluid movement is complex, and likely not fully understood.