Just some of the questions many first-time or novice clinicians may ask when faced with a complex instance of wound care.
The guiding principles of wound care have always been focused around defining the wound, identifying any associated factors that may influence the healing process, then selecting the appropriate wound dressing or treatment device to meet the aim and aid the healing process.
A structured approach is essential, as the most common error in wound care management is rushing in to select the latest and greatest new wound dressings without actually giving thought to wound aetiology, tissue type and immediate aim.
If best patient outcomes are to be achieved, applying evidence-based wound management knowledge and skills is essential.
This wound and dressings guide will identify some of the most common wound types and guide you in setting your aim of care and selecting the best dressing or product to achieve that aim.
Descriptors used to identify the tissue found in wounds are:
Poor quality granulation
Ideally the quickest (and often safest) way to remove necrotic tissue is to involve a surgeon who will then surgically debride the offending tissue.
If this is not possible, then a skilled clinician may be able to conservatively sharp debride the tissue to just above the viable base.
If this is not possible, then dressings known to aid autolytic debridement should be selected and used according to manufacturer's instructions. An important aspect to consider is that when debriding wounds autolytically the wound may appear deeper as the necrotic debris is removed revealing the true depth of the wound.
Important: Without a doubt, removal of necrotic tissue and management of infective tissue are two priorities in wound care.
Granulation tissue (firm, beefy red tissue) requires some exudate management and protection.
A dressing that maintains a minimally moist environment and protects the tissue, is generally required.
This soft, gelatinous, highly exuding tissue requires specific treatment. Some clinicians believe the use of silver nitrate (burning the tissue back) is the best option.
(It has been my experience that an approach to bacterial load, direct pressure and dressings that will manage moisture are more acceptable.)
Infective tissue is best removed when possible by employing the same methods as with necrotic tissue. Antibiotics need to be prescribed when the wound is causing systemic infection. Be aware that caution is exercised when debriding infected necrotic tissue as bleeding may occur.
However, if the wound is locally infected, the clinician may choose to manage the infective tissue with debridement and topical antimicrobials (not topical antibiotics) (Lipsky & Hoey 2009). Topical antibiotics may be used in specific circumstances - for more information, refer to Wound Infection in Clinical Practice: Principles of Best Practice.
Another consideration if colonisation is of concern, is to use generalised body skin-antiseptic cleansers to reduce the possibility of bacteria colonising from one area to another.
The pale, pink/mauve tissue usually found at the edges of wounds, healing by secondary intention, requires protection. If the wound is superficial/partial thickness then islands of epithelium may also be found sprouting up from skin appendages.
This tissue responds poorly to too much moisture and in most cases a dressing that protects this tissue from the effects of moisture is used. The use of barrier agents ensures this.
Poor Quality Granulation (Agranular)
The term used to describe pale, grey/brown/red granulation tissue.
The general approach is to use an antimicrobial and exudate-management dressing, reviewing blood profiles and concentrating on nutrition to help grow stronger better-quality tissue.
The term used to describe pale, grey/brown/red granulation tissue.
With the above information, it is now time to undertake wound care specific to the type of wound.
Dressing Surgical Wounds
Most surgery can be categorised into two groups: elective ('clean') and emergency (this is often referred to as 'dirty').
A surgical wound of the latter category has a higher incidence of dehiscence or complications.
Dehiscence is defined as:
'Separation of the layers of a surgical wound, it may be partial or only superficial, or complete with separation of all layers and total disruption.'
(Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health 2003)
There are a number of well-identified risk factors that can lead to wound dehiscence, including being overweight, increasing/advanced age, poor nutrition, diabetes, smoking and having had radiation therapy previously in the area.
The elective case has the opportunity to correct some of these risk factors, however the emergency case may not have such an opportunity.
The simple, straightforward suture line is generally treated with a dressing that will manage a small amount of anticipated, early inflammatory exudate and provide a waterproof covering.
All surgical wounds do require support and this is an important factor both for reducing oedema and ensuring patient comfort.
This type of dressing is generally left intact for five to seven days and then removed for inspection of the suture line, with the view to remove the staples or sutures as prescribed.
Suggested dressings to achieve the aims for simple suture lines include: Opsite™ and Mepore Pro™.
Uses: Surgical wounds, cuts, abrasions, low to moderately exuding wounds.
Examples:Opsite™, Mepore Pro™.
Care of this simple suture line then involves continued support and hydration. For this, some surgeons prefer supportive adhesive flexible tape for ongoing scar hydration, such as Fixomull™ and Mefix™.
Type: Adhesive flexible tape.
Features: cut to size, adhesive, flexible, allows hydration.
Uses: fixing primary dressings, catheters and tubes.
Dehisced Surgical Wound
The dehisced surgical wound requires a thorough assessment of cavities or structures involved, as well as presence of foreign bodies, infection and/or necrotic tissue. Once these parameters have been considered, an aim can be set.
Removal of necrotic tissue and management of infection is paramount to move on to the wound healing phase.
Surgical debridement may leave large cavities or areas of raw tissue which can ideally be managed with a Topical Negative Pressure Device. This wound care ‘vacuum cleaner’ will remove excess exudate and contain it in a canister, away from the wound surface.
Due to the negative pressure, the wound edges are drawn in, helping to promptly reduce wound surface. This also reduces oedema, an important aspect to consider in all instances of wound care.
These wounds are generally acute and in most circumstances go on to heal almost regardless of what is done. Simple abrasions in particular, if not managed by a health professional, form a scab which eventually will drop off, revealing a healed area beneath.
The issue here however, is that this type of healing is slow and can result in an unacceptable scar.
The best management of an abrasion is to stop the bleeding, give the area a good clean with an antiseptic and then apply a mesh dressing that will protect the superficial raw area and allow new tissue to form quickly without being damaged when the first dressing is attended. Mesh dressings for this purpose include: Mepitel™, Urgotul™, or Hydrotul™.
Type: Mesh contact layer.
Features: low-adherence, supportive, allows exudate to pass through, transparent.
Uses: abrasions, skin tears, lacerations, ulcers.
Examples:Mepitel™, Urgotul™, Hydrotul™.
The secondary dressing on this mesh is generally a light absorbent adhesive pad, such as Cutiplast Steril™ or Primapore™.
A secondary waterproof dressing is generally not recommended for this first dressing due to the risk of infection – the excessive heat and moisture will create an environment conducive to bacterial growth.
At the next dressing change, if there are no signs of infection, then a waterproof dressing can be used as the secondary dressing, provided all environmental considerations have been made.
After a thorough assessment, a small, simple laceration is generally managed with antiseptic cleansing, Steri-Strips™ and either a waterproof, light, absorbent dressing or a non-waterproof, light, absorbent, adhesive dressing, using the principles mentioned earlier about risk of infection.
All layers of skin are intact, with no redness, blemishes or maceration.
Intact skin with non-blanchable redness of a localised area, usually over a boney prominence.
A stage one pressure injury is an intact area of damage, so protection of the tissue and providing an environment for recovery is the aim.
Adhesive foams can be employed if moisturising the area on each shift is not possible. Examples of adhesive foam include Mepilex Border™ and Allevyn Life™.
Partial thickness loss of dermis presenting as a shallow, open- wound with a red/pink wound bed, without slough or bruising. May also present as an intact or ruptured serum-filled blister. Shiny or dry.
Stage two pressure injuries are relatively clean, superficial, partial-thickness injuries. Once again, protection is important, however due to the break in the integument, the chosen dressing must also have some absorbent capabilities.
Adhesive foams are generally appropriate here, unless the wound is located very close to the anus, in which case a thick barrier cream is often used. Conveen Critic Barrier Cream™ is one appropriate example.
Full thickness tissue loss, subcutaneous fat may be visible, slough may be present.
Stage three injuries involve damage through to the subcutaneous tissue, with the presence of slough and soft, tenacious necrotic tissue, which will require debridement.
Debridement can be as previously mentioned: managed by a surgeon, a skilled clinician, or using dressings to aid autolytic processes. Dressings that aid this autolysis include: Flaminal Hydro or Forte™, Prontosan Gel™, Mesalt™ and Iodosorb™ powder or ointment.
Whilst the autolytic process is taking place, the wound exudate will be higher in volume, so super absorbent pads will be required as the secondary dressing, for example Zetuvit Plus™.
Full thickness tissue loss with exposed bone, tendon or muscle. Slough or eschar may be present.
Stage Four implies that the area of damage extends down through muscle and bone may be exposed or palpable. These injuries are generally necrotic and malodourous. Managing odour becomes the priority.
Metronidazole Gel™ will typically reduce odour in a few days. HydroClean Plus™ is a preloaded pack of PHMB, that slowly drips into the wound, aiding autolytic debridement, and can safely be used with Metronidazole Gel™.
If the patient is in otherwise good health, then surgery and Topical Negative Pressure devices would be used.
Unstageable (Depth Unknown)
Unstageable pressure injury (depth unknown): full thickness tissue loss, base is covered by slough and/or eschar (yellow / brown/ black) in the injury bed.
The aim here is to remove the necrotic tissue until viable tissue is reached and the wound can begin to heal from the base up.
Debriding products previously mentioned can be used on this category.
Suspected Deep Tissue Injury (Depth Unknown)
Suspected deep tissue injury (depth unknown): purple/maroon localised area of discoloration of intact skin or blood-filled blister. May develop thin blister or eschar over dark wound bed.
The aim here is to preserve the tissue intact for as long as possible and await what the body can do if the pressure is removed. Most clinicians take a -watch and wait approach. Dressings that seal the area off can sometimes create more moisture and heat making the tissue more vulnerable to further damage.
Although there are many types of leg ulcers, the most common are venous, followed by arterial, and then mixed venous arterial.
Ulceration of lower legs is often complex as the diagnosis may not have been made.
Venous ulcers can heal with compression therapy, however conversely some arterial ulcers may deteriorate if compression is used.
Therefore having a knowledge of the characteristics of venous and arterial ulcers is imperative to ensure appropriate decision-making regarding management of these wounds.
Venous ulcers are located in the lower third of the lower-leg and generally are superficial and weeping.
The priority of care is managing the oedema and encouraging the epithelium to grow across the superficial break.
Zinc paste bandages and compression bandages are the mainstay of treatment to achieve these goals. The zinc paste bandages may include products like Viscopaste™ or Varicex™.
If the wound has been present for a considerable length of time, then some bacterial involvement is likely, and so an antimicrobial is suggested such as Iodosorb Powder™ or Sorbact compress™. This could then be combined with a super absorbent pad such as Zetuvit Plus™.
Compression therapy selection is complex and must be tailored to the patient. A safe and effective system from which to start, however, is the use of straight, elasticated tubular bandages, for example Tubigrip™ or Tubular Form™.
These must be applied from toes to knee after selecting the appropriate size according to the manufacturers guide. Commence with one layer, if tolerated then add another second layer but extending to only 2/3 of the lower leg and finally if tolerance is maintained then add another 1/3. This is known as 3 layers straight elasticated tubular bandage-allowing removal of the upper layers for sleeping then re-apply next morning.
When it comes to managing arterial ulceration, a vascular surgeon is best to consult as ideally some surgery can be performed to restore perfusion to the limb. It then becomes the attending clinician’s role to prevent infection.
Generally the rule is: if the tissue is dry and ischaemic, then keep it dry. So Betadine™ lotion is used to achieve this and keep the eschar dry.
If the tissue in the arterial wound is offensive, infected or malodourous, then a silver or cadexomer iodine may be used, such as Aquacel Ag™ or Iodosorb™ ointment/powder.
Keep your formulary up to date with what is considered best practice and review the wound regularly to ensure progress.
Recognising and assessing a wound is an important part of providing healthcare.
Ultimately, however, the overall aim - for you, and for the patient - is to completely and successfully heal the wound.
The Healing Process
Most wounds go on to heal in the normal pathway of:
Maturation / Contraction
As there are many factors to consider when trying to manage a complex, slow-to-heal wound, the following factors are not an exhaustive list, and not necessarily presented in order of priority, however it is generally considered that nutrition is paramount in order to achieve healing.
Cellular growth is dependent on adequate intake of protein, vitamin C, zinc and iron. There are other nutrients required that also play an important role, but these four are often considered vital.
The formula to calculate a normal protein intake for a healthy adult woman is 0.75g per kilogram of bodyweight per day, and 0.84g per kilogram of bodyweight per day for healthy adult men. However, when a chronic non-healing wound is present or the individual is pregnant, breastfeeding, or over the age of 70 years, it increases to approximately 1-2g per kilogram of bodyweight per day (National Health and Medical Research Council 2014).
The recommended dietary intake (RDI) of vitamin C for a normal healthy adult is 45mg per day, however in an individual with a chronic wound, this increases to approximately 100-200mg per day (National Health and Medical Research Council 2014).
Normal RDI of zinc is 8mg in healthy adult women, and 14mg per day for adult men. However, as with protein and vitamin C, this increases to an RDI of 15-25mg per day in individuals with a complex, slow-healing wound.
Iron intake is also necessary for wound healing. The RDI of iron is greater in women during the menstrual years, with 18mg per day advised to support healthy functioning. For women greater than 51 years of age, and all healthy adult men, the intake is recommended to be 8mg per day. To boost wound healing however, and in women who are pregnant, the RDI for iron can be as high as 30mg per day.
There is no doubt that a healthy, balanced diet of fresh fruit, vegetables, meat, fish and chicken is invaluable to keep the body functioning well.
Issues can arise in older adults who fail to fulfil the RDIs for the required nutrients, and this is when wounds in older adults may fail to heal due to lack of appropriate nutrients.
Additional factors that may influence healing include:
General health status
If the patient has declining health, then it is unlikely any amount of therapy will influence wound healing.
Older adults heal more slowly than younger people.
Being too thin or obese, will delay healing. Obesity may raise concerns about skin fold infections and repeated colonisation.
Mechanical stress on the tissues
Shear, friction and pressure will all affect the wound tissue and periwound condition.
Presence of debris in the wound
Debris will promote the risk of infection and slow the growth of epithelial cells. Debris must be removed before healthy tissue can regrow.
Temperature of the wound area
For example, leukocyte cells need to be maintained at approximately 37 degrees Celsius, so keeping the wound warm and using warmed solutions helps to maintain the functioning of leukocytes. Socks should also be worn to keep the peripheries warm and dilate vessels as much as possible.
Desiccation and maceration of the tissue
Both of these processes will affect new cellular growth and hence must be addressed.
Both local and systemic infection will hinder wound healing, and it is imperative to be able to recognise infected tissue in order to effectively manage wounds.
There is a misconception regarding the use of antiseptics in wound care, and health professionals need to be educated on best practice policies in relation to chemical management of infected wounds. If the wound is infected, then cleansing with an antiseptic solution and rinsing this off after 2 minutes will assist in reducing bacterial load. There re now also many proven safe cleansers such as -ProntosanTM, MicrodaycnTM, OctenilinTM.
Active or passive exposure to cigarettes will inhibit or delay wound healing.
A study has shown that people suffering from depression have slower rates of wound healing. The exact cellular implication of this is not known but it is believed that people who are depressed fail to consume a healthy diet or engage in other activities that promote health which in turn leads to poor wound healing.
Some medications are known to delay healing and increase lower leg oedema. If you think this may be a concern for one of your patients, it is best to ask the pharmacist to check medications for any that could impact healing.
For a chronic wound to progress to the healing phase, health professionals must be able to clean the wound as thoroughly as possible without causing further pain to the patient.
The words 'cleansing' and 'debridement' are often used interchangeably, however they are two distinct terms to describe different management processes:
The application of a fluid that is then wiped across the wound area with gentle strokes to aid in the removal of any loose, unwanted product or agent.
The removal of dead or devitalised tissue, particulate matter, and foreign bodies from a wound bed. Debridement is generally accepted as a necessary precursor to the formation of new tissue.
There are many methods of wound debridement; some are readily accessible to the majority of clinical staff, however others require specialist training or application and may only be found in specialty clinics or acute care facilities.
Types of Debridement
The most common method of removing necrotic tissue from a wound is using the body’s own naturally occurring enzymes and fluid. This is referred to as autolysis. Moist wound therapy assists in this process, although some moist agents can increase the risk of maceration.
Wound care dressing products that assist in aiding autolytic debridement include:
Tea tree oil dressings
Biological debridement uses specifically-bred larvae to phagocytose the necrotic tissue and aid in its removal. This process is not commonly used as patients are generally not comfortable with having maggots put on their wounds.
Chemical agents for debridement are no longer available in Australia. Whilst there are some being used overseas, none of these have yet been approved for use in Australia.
There are a few enzyme products available around the world but the only one currently available in Australia is FlaminalTM. This product is a mixture of calcium alginate and two naturally occurring enzymes found in saliva-lactose peroxidase and glucose oxidase.
Mechanical debridement can involve several different methods. Sharp surgical is the gold standard of mechanical debridement, and involves having a surgeon remove all of the necrotic tissue so that the vascular bleeding wound bed is exposed.
Conservative sharp wound debridement is the next best option, and is usually carried out by a skilled clinician such as a wound consultant or podiatrist.
Another mechanical method of debridement includes using a high pressure irrigation device, which literally blows off the necrotic tissue.
By performing excellent gentle wound cleansing and debridement, health professionals can assist with wound healing by removing any necrotic tissue which may be impacting the treatment goals.
Simple debridement that can be undertaken by all health professionals involves gentle circular movements over the wound with dry gauze, which may lift some debris.
Using forceps to gently scrape the tissue may also help lift debris off the wound.
Naturally, all of these aforementioned methods require a thorough assessment of the patient and their pain both during and after the dressing procedure.
When managing a complex, slow-healing wound, it is important to remember that there are occasions when wound debridement is not appropriate, and symptom control is more suitable.
For example, dry eschar does not always need to be removed – in some cases it acts as its own dressing.
Should the body decide to separate the eschar from the tissue below it, the eschar then usually provides a well-demarcated edge from which to work.
It is imperative to ensure that the correct dressing, and dressing regime, has been chosen to optimise wound healing.
When your assessment reveals that the wound is heavily soiled, necrotic tissue is present, and/or there is the potential of bacterial colonisation, then more regular dressings will be required.
In many cases, these heavily colonised wounds will require daily dressing changes, with empasis on peri-wound protection.
If the decision has been made to change a dressing daily, then consideration on product choice becomes imperative as costs will rise unless less expensive dressings are selected.
Once the necrotic tissue has been removed and healthy granulation tissue is present, the aim dramatically changes to one of protection.
The goal here is to disturb the tissue as little as possible, in order to allow the body to heal itself.
Products chosen at this time can remain in situ for four to five days, or even as long as seven days, depending on the absorbent capacity and nature of the wound interface material.
Foam dressings are usually the best product to achieve these parameters.
One of the crucial aspects of a dressing regime is assessment and re-assessment.
Assessment at each dressing change involves looking for changes in tissue type and exudate volume and type, any reduction in odour, changes in wound size, and reduction of pain.
These will not occur simultaneously, so deciding which parameter to check each week will be left to the attending clinician. However, the most important signs to measure wound healing include improvements in tissue quality, and reduction of odour and exudate volume.
With continued best practice interventions, these signs indicate that the wound will most likely go on to heal.
In evaluating the effectiveness of a treatment regime, the health professional should be able to clearly state the wound type and what the treatment aims were.
Without establishing these factors, the aim/s and product selection are random and not based on best practice recommendations.
Wounds that generally do not heal unless surgical/medical intervention is possible include arterial ulcers, skin cancers and tumours, and wounds as a result of an autoimmune disorder.
Dressings play a less significant role in the management of these wounds, and healing is almost totally dependent on managing the overarching problem.
Words by Jan RicePublished 11 November 2019Last Reviewed 11 November 2019