Introduction to Wound Dressings

Original Editor - Stacy Schiurring based on the course by Dana Palmer

Top Contributors - Stacy Schiurring and Jess Bell  

Wound Dressing Selection

The primary goals of wound dressings are to promote wound healing and prevent further tissue damage. To achieve these goals, wound dressings must perform the following functions: (1) maintain an appropriate level of moisture in the wound bed, (2) act as a barrier to bacteria and other contaminants, (3) provide thermal insulation, (4) facilitate debridement, (5) promote enzymatic and growth factor supplementation, (6) allow for adequate gas exchange with the external environment, and (7) pain management.

"The main purpose of wound dressing is: a) provide a temporary protective physical barrier, b) absorb wound drainage, and c) provide the moisture necessary to optimize re-epithelialization. The choice of dressing depends on the anatomical and pathophysiological characteristics of the wound." - Obagi et al., 2019

There are countless types of wound dressings available. Dressing selection begins with a detailed patient history and physical examination. Important factors for dressing selection include (1) the wound's age (acute versus chronic), (2) infection status, (3) the amount of drainage, (4) the depth and shape of the wound, and (5) the patient's overall health and level of function. Other important considerations when creating a wound dressing plan include (1) patient compliance, (2) cost and ease of dressing changes, (3) frequency of dressing changes, and (4) the need for additional antibiotics to treat underlying infection.

Wounds should be continuously reassessed with each dressing change, and wound care plans adjusted and changed as needed. Dressing changes should be performed as infrequently as possible while still maintaining the appropriate wound balance and bioburden management. Removing a wound dressing, cleansing the wound, and exposing it to the external environment will slow wound healing time by reducing the wound's temperature, altering its moisture content, and exposing it to bacteria.

If you would like to review the stages of expected wound healing, please see this article. For a list of wound care-related terminology and definitions, please refer to this article.

Dressing Categories

There are two main categories of wound dressings: primary and secondary dressings. Both categories of dressing can have therapeutic and / or protective functions as part of a wound care treatment plan.

Primary dressings (primary contact layer) are in direct contact with the wound (e.g. packing strips).

Secondary dressings are not in contact with the wound (e.g. ABD (abdominal) pads). They cover and contain the primary dressing. The secondary dressing must be compatible with the treatment goals of the primary dressing.

"Wound dressings have undergone an evolutionary process from natural materials that simply covered and concealed the wound, to materials that focused on moisture management, and more recently, to materials that either deliver active ingredients or interact directly with cells or specific chemicals in the local wound environment. Advances in dressings technology have led to a new proliferation of topical products that do more than just cover and conceal, but that also can facilitate the healing process as well as address specific issues in nonhealing wounds. Dressings may play an important adjunctive role in concert with overall efforts to manage the underlying causes of chronic nonhealing wounds." - Liza G. Ovington, PhD

Table 1. Wound dressing materials

	Description / action	Indications	Contraindications	Dressing examples
Alginates	Contain polysaccharide compounds derived from algae or kelp Absorb large amounts of moisture and drainage, up to 20 times their weight Provide moisture balance to wound bed Promote haemostasis Often require a secondary dressing	Moderate to heavily draining wounds Can be used on infected and noninflected wounds Can be found in sheet or cavity-filling (rope / ribbon) form Commonly changed every 2-3 days	Dry wounds Necrotic wounds Caution needed with wound packing to prevent the wound from drying out May cause lateral wicking and periwound maceration	Maxorb II Alginate Kaltostat Alginate Cutimed Alginate
Biological dressings	Provide scaffolding and support to healing wounds Stimulate host cell growth Provide moisture Can include growth factors, allograft dressings, honey, hyaluronic acid, collagen, alginates, and polymers enriched with polyhexamethylene biguanide, chitin, and chitosan derivatives	Dry to high draining wounds	Patients with a known allergy to source material	Puracol Skin Temp II Biopad (horse source) Regranix (growth factor) Grafix (human placental membrane) Apligraf (cow and human sources) Oasis (pig sources) Dermagraft (human fibroblast-derived)
Contact layer dressings	Single layer of woven or perforated material coated with a non-adherent substance such as petrolatum or silicone Maintain moisture in wound bed and protect wound surface from trauma during dressing removal			Petrolatum-impregnated gauze Telfa pad
Hydrogels	Water- or glycerine-based dressing Moisture donating to the wound bed Ideal for rehydrating a wound, balancing moisture in the wound bed, and providing a "cooling sensation" to the wound	Dry to moderately draining wounds Come in sheets or gel / liquid-type form Can be combined with silver dressings	Infected wounds Heavily draining wounds Can cause periwound maceration	Tegaderm Hydrogel AquaDerm Kendall Hydrogel
Hydrocolloids	Consist of three layers: an inner adhesive layer, a middle layer that absorbs fluid, an external layer that allows for limited gas exchange Moisture balancing Occlusive tendency of this dressing promotes autolytic debridement which produces a yellow "gel and smell" that can be mistaken for infection but is a benign process	Dry to moderately draining wounds Come in sheet form in various thicknesses, or gel form Can be combined with silver dressings Can be left in place for up to 7 days	Infected wounds Heavily draining wounds May cause hypersensitivity reaction (contact dermatitis) Can cause periwound maceration Can promote over-granulation	McKesson Hydrocolloid Tegaderm Hydrocolloid DynaDerm Hydrocolloid
Hydrofibres	Made of carboxymethylcellulose fibres Absorb large amounts of moisture and drainage, up to 30 times their weight Provide moisture balance to wound bed Often requires a secondary dressing	Moderate to heavily draining wounds Can be used on infected and noninflected wounds Can be found in sheet or cavity-filling form	Dry wounds Necrotic wounds Caution needed with wound packing to prevent the wound from drying out May cause lateral wicking and periwound maceration	Aquacel Melgisorb
Foams	Moisture absorbent dressing, different brands have different levels of absorptive capacity Semi-occlusive Can serve as a primary or secondary dressing Protect wound bed/healing epithelium from damage Antimicrobial Thermal insulation Do not adhere to wound surface Conform to uneven body surfaces	Use of moderate to heavily draining wounds Can be found in sheet or cavity-filling form Sheets are available with or without an adhesive border Can be combined with silver dressings	Dry to minimally draining wounds Necrotic wounds	CuraFoam Optifoam Allevyn McKesson Foam Dressing
Films	Transparent thin dressing Allow for visualisation of the wound Provide protection from bacteria or other contaminants Allow for gas exchange with the external environment	Primary dressing over superficial dry or low draining wounds Secondary dressing over alginate or hydrogel for rehydration of wound bed	Moderate to heavily draining wounds Patients with fragile or compromised periwound Skin sensitive to adhesive Infected wounds	Hydrofilm Kendall Transparent Film Tegaderm

Active (bioactive) agents can be added to various types of dressings. Bioactive agents include natural or synthetic materials, such as collagen, honey, iodine, and silver, and can impact the healing process of a wound. It is important that the treating wound care provider have a good understanding of how the chosen bioactive agent is expected to interact with a wound. They should also perform a thorough patient assessment before their use and continue with ongoing assessments during their use.

Bioactive dressings typically share a number of features. They are able to maintain a moist wound environment and can restore normal pH levels in the wound bed. They tend to be permeable to oxygen and can effectively manage wound drainage. They are biodegradable, compatible with biological systems and have antioxidant properties. In addition, they often require a secondary dressing.

Table 2. Bioactive dressings and dressing additives

	Action	Indications	Contraindications	Dressing examples
Activated charcoal or activated carbon	Antimicrobial action	Infected wounds Improves wound odour More effective when combined with silver	Bleeding wounds Dry wounds In cavity wounds, such as tunnels	CarboFlex
Antibiotic ointments	Antimicrobial action	Infected wounds	Should not be used prophylactically	Bacitracin Gentamicin Mupirocin Polysporin
Collagen	Essential for wound healing Anti-inflammatory actions Can be derived from cow, pig, or sheep sources	Granulating or epithelialising tissue Available in sheet, powder, or foam form May need to be wetted with sterile saline to activate product	Infected wounds	Puracol Skin Temp II
Honey	Medical grade honey is sterilised but maintains its enzymatic activity Antibiotic and anti-inflammatory actions Moisture balancing (can function as either moisture-absorbing or moisture-donating)	Research suggests the enzymatic properties of honey are superior to traditional enzymatic and autolytic debridement Integrated into other dressing types		MediHoney hydrogel MediHoney alginate
Iodine	Antimicrobial action	Infected wounds All levels of drainage Can be combined with many other dressing types Cadexomer iodine is not cytotoxic to healthy tissue, unlike povidone iodine	Patients with known sensitivity to iodine, including allergies to shellfish Patients with thyroid dysfunction Should not be combined with collagenase Dry or necrotic tissue	Iodoflex Iodoform
Methylene blue and gentian violet	Broad spectrum nonselective antimicrobial action, may be effective against biofilms (more research needed)	Must be wetted with sterile saline to activate the agents Provides slight negative pressure suction to draw fluid out of the wound Comes in foam form Non-adherent to wound bed when kept moist	Can cause wound edge epibole	Hydrofera Blue
Silver	Broad spectrum antimicrobial action	Infected wounds All levels of drainage Can be combined with many other dressing types	Known sensitivity to silver Reevaluation with use to ensure appropriate antimicrobial coverage is provided In general, limit use to approximately two weeks due to risk of silver toxicity Some silver products cannot be used with saline because it will decrease the product's effectiveness	Silvercel Biatain Silicon Ag Foam DermaGinate Ag Alginate Silver sulfadiazine (Silvadene)

Secondary dressings may require additional tapes, adhesives, or bandage wraps to secure the various layers of dressing. When using tape as part of a dressing treatment plan, it is important to consider why the tape is being used, will the tape stick to the patient's skin or only the dressing, and the characteristics of the tape (breathable, water / fluid resistant, flexible and able to conform to the body / dressing, and the typical wear time). Different categories of tape used in wound care include paper tape, cloth tape and transparent film.

Paper tape is a paper-backed adhesive. It is breathable and gentle on the skin. It is used for securing a dressing to itself or to the skin. Its main benefit is its ease of removal without typically causing pain or skin damage (skin tear). Dressing examples include Micropore and Hypafix.

Cloth tape is a cloth material with a strong adhesive. Due to its great adhesive properties, it should not be placed directly on the skin, but it can be used to secure secondary dressings to themselves. It is ideal for securing bandages or pressure wraps.

Transparent film is a type of adhesive often used to secure IV sites, but it can also be used as a secondary dressing to secure primary dressings in place.

Tubular dressings can also be used to secure layers of dressings. They provide circumferential support and are ideal for use around fingers, limbs, or the head. They are made of a solid elasticised fabric or netted material, and come in various sizes to fit a wide variety of body parts.

Clinical Resources

• Guideline: Wound Dressing Selection (British Columbia Provincial Nursing Skin & Wound Committee)
• Wound Care Algorithm (Cardinal Health)
• Wound Dressing Guide (Australian Institute of Health and Biomedical Innovation)
• Wound Dressing Selection Guide (Wounds Canada)
• Wound Identification and Dressing Selection Chart (Australian Government, Department of Veterans' Affairs)
• Product Information Sheet Look Up