1. Smart, Hiske MA, RN, PGDipWHTR, IIWCC

Article Content

The use of soaks in wound care is widely known, especially in day-to-day practice to help in wound bed cleansing. Compresses are not as widely used but also have scientific merit in modern wound care practice. The practices of removing fluid from wounds (absorption) or donating fluid to a dirty wound bed to clean it (soaking) are classic remedies when dealing with broken skin, as are poultices or cataplasms (using filled material to transfer heat or cold). Compresses were documented by Paulus Aegineta (607-690 BC): "[horizontal ellipsis]the use of a sponge or unscoured wool squeezed out in wine to act as an astringent."1 Compresses (especially vinegar or sweet wine-soaked compresses) were used to help wounds heal up through the 18th and 19th centuries. Even today, wound cleansing includes wound bed washing, scrubbing, rinsing with running water, and rinsing under pressure (via syringe) to remove surface debris and wound exudate. However, compresses have been seen as old-fashioned and fallen out of favor as a modality for wound management.


With the rise of moist wound healing principles and atraumatic wound dressings and procedures, the compress has now regained its place in wound care practice. Its mechanism is simple. Layering absorbent material (cloth) to form a small stack, dipping it into cleansing fluid (lukewarm or body temperature), and wringing it out to release all of the fluid again generate capillary action: the movement of a liquid along the surface of a solid caused by the attraction of molecules of the liquid to the molecules of the solid.2 It occurs when layers of slightly damp material are positioned on an area with a higher concentration of fluid present, changing the layers of material into an absorbent structure. Fluid clings to the sides of the material fibers, turning the meniscus upward and creating a directional flow against gravity.3 The movement of fluid directly into the damp material's layers continues against gravity until all fibers in the cloth layers are saturated. Once the flow direction is established, it will not reverse before equilibrium between the fluid content of the two surfaces (wound bed and compress) is reached. At that point, the capillary action mechanism slows until it is deactivated by oversaturation. Once that critical point is reached, fluid is let back into the area (a mechanism called soaking) because of reversal of the meniscus and loss of capillary action.


Why damp compresses as opposed to dry ones? Imagine a dry mop when put on a floor with a water spill present. It will at first spread the water over the floor before absorbing it via capillary action. By using a wrung-out (damp) compress, the capillary mechanism is preactivated and established, allowing immediate capillary flow to take place.




Layers of highly absorbent cloth material saturated with lukewarm fluid are positioned on the wound bed for 3 to 5 minutes, allowing fluid to seep via gravitational pull from the cloth layers into the wound bed. These soaks will donate moisture to the area on which they rest, clean the wound bed by diluting existing moisture or bacterial load on that surface, and rinse the wound bed without friction until all fluid has drained out of the cloth layers.



Layers of highly absorbent cloth material saturated with lukewarm fluid are wrung out until slightly damp and positioned on a wound bed for 3 to 5 minutes, generating a fluid shift against gravity from the wound bed into the material layers. Compresses remove moisture from the area on which they rest by creating a net fluid movement away from the wound bed into the absorbent cloth material layers via a diffusion gradient that can work against gravity, pulling and trapping fluid until the saturation point of the layered cloth material is reached.



The need for moisture donation or absorption is dependent on the healability category of a wound and the desired outcomes.4 In using wound soaks and compresses as clinical modalities, there are no hard and fast rules about when or how to use either. However, the condition of the wound bed and the healability of the wound are the two easiest markers to guide bedside care (Table).

Table. WHEN TO USE A... - Click to enlarge in new windowTable. WHEN TO USE A SOAK, COMPRESS, OR BOTH

Sometimes only one modality is used per procedure; at other times, a combination of the two can be implemented sequentially to achieve the needed outcomes and/or wound bed stabilization. The choice depends on the condition of the wound bed, the exudate in the wound bed, the fluid of choice, and the preference of the clinician doing the procedure.


Fluid choice for soaks or compresses is at the discretion of the clinician. It is important to note that potable water is hypotonic and may cause excessive moisture donation and subsequent edema to the underlying tissue when used as a soak. Isotonic saline (most common) is neutral, allowing physical forces (gravity or capillary action) to work. Hypertonic solutions may dehydrate a wound bed if used in a compress for excessive periods because of the steep diffusion curve present between the fluid concentration of the wound bed and the solution. Antiseptic solutions with bactericidal function can either directly target the surface of the wound bed (soak) or affect microorganisms trapped in the material cloth layers after bacteria are transported away from the wound bed (compress).


Although soaking will help to clean the superficial wound bed, the additional diffusion gradient and capillary action of a compress may aid in slightly deeper wound bed cleansing action and can remove exudate just below the visible wound bed. Both modalities have sufficient rationale to achieve atraumatic wound bed cleansing/preparation and may serve as valuable additions to the toolkit of the modern-day wound care practitioner.




1. Forrest RD. Early history of wound treatment. J R Soc Med 1982;75(3):198-205. [Context Link]


2. Capillary action. Last accessed April 5, 2021. [Context Link]


3. US Geological Survey. Capillary action and water. Last accessed April 5, 2021. [Context Link]


4. Sibbald RG, Elliott JA, Persaud-Jaimangal R, et al. Wound bed preparation 2021. Adv Skin Wound Care 2021;34(4):183-95. [Context Link]