10 Wound care
Of all the body’s organs none is more exposed to infection, disease and injury than the skin, and wound healing is a prime example of how the body can maintain homoeostasis. This process often needs assistance to prevent the formation of chronic and sometimes fatal wounds. In this chapter we explore evidence to show how efficient aromatherapy and natural base products can be when used in the process of wound healing. The chapter also covers the stages of wound healing, previous research, the pros and cons of aromatic wound healing, pressure sores, burns and positive case studies.
Wounds can be healed by primary intention, when the edges are brought together by stitches, staples or adhesive tape, e.g. following surgery or repaired lacerations; or by secondary intention, where the wound is left open and allowed to granulate. Very occasionally, owing to infection, wounds that are meant to heal by primary intention can break down and end up healing by secondary intention.
The classic model of wound healing is divided into several overlapping stages which normally progress in a predictable manner. If they do not, healing may not progress well, leading to a chronic wound. A good understanding of these stages is helpful in being able to provide effective aromatic treatment of wounds.
Following injury a plug is formed to prevent further bleeding and becomes the main support for the wound until it is replaced with granulatory tissue and then collagen. Inflammation at the wound site causes an increase in circulation, resulting in tissue swelling and the release of factors involved in the next (proliferative) stage.
Inflammation facilitates the entry of white cells into the wound site, clearing it of debris and bacteria, the damaged tissue being removed after a couple of days. This debridement or cleaning of the wound
Case study 10.1 Penetrating wound with infection risk
Marcel (49) had just sustained a penetrating, ragged wound, approximately 3.5 cm deep, 1.5 cm to the left of the anal margin, after accidentally sitting on a blunt-ended rusty metal spike while gardening.
First-aid intervention involved bathing and flushing the wound copiously with approximately 5 drops each of Lavandula latifolia [spike lavender] and Melaleuca alternifolia [tea tree] added to cool water. A tetanus booster was administered, but owing to the proximity of the wound to the anus and the consequent high infection risk, a decision was made not to suture. Instead, the wound was treated with essential oils and monitored closely.
The wound was irrigated daily (using a small syringe) with the above for 1 week, to ensure rapid healing of the deeper tissues and to prevent pockets of infection forming, which might occur if epithelialization took place too swiftly. A gauze pad was soaked in the same mixture to form a compress over the wound, being changed twice daily. The same blend was used also to lubricate the anus prior to a bowel movement (to avoid over-stretching and straining), followed by careful washing of the area afterwards. A high-fibre diet and increased fluids were taken to reduce the risk of constipation.
One week after the injury irrigation was no longer required as the wound was closed and looking healthy. Two formulations were prepared for ongoing treatment until the new skin over the wound was fully stable.
The immediate and lasting analgesic/local anaesthetic effect permitted Marcel to sit from the first day without discomfort. The speed of healing was equally remarkable, the wound diameter reducing by half in 3 days. There was also very little inflammation. On the first day the area was swollen and had a purplish appearance, and by day 2 it looked pink and healthy. At no point was there evidence of infection.
(Taken from the International Journal of Clinical Aromatherapy 3 (2b): 14–15)
stimulates the cells that create granulation tissue and inflammation plays an important role during the initial stages; while there is debris in the wound (dirt or other objects) the inflammatory stage can become extended, leading to a chronic wound.
After 2 or 3 days new blood vessels are formed within the wound. Special fibroblast cells grow, forming a new extracellular matrix (ECM) and granulation tissue. This activity requires oxygen and nutrients from the blood vessels, causing a typical red appearance of the tissue which is essential for further stages of healing to occur. The granulation tissue functions as rudimentary tissue, continuing to grow until the wound bed is covered. At the end of granulation, fibroblasts begin converting granulating tissue into collagen – important because it increases the strength of the wound. Too little oxygen will inhibit the growth of fibroblasts and the deposition of ECM, which can lead to excessive, fibrotic scarring. Thus the therapist needs to be aware that smokers and people with poor circulation can have reduced oxygen flow to the wound site, which may slow the healing process.
Once the wound is filled with granulation tissue, epithelial (skin) cells begin to advance across the wound until they meet in the middle. Epithelial cells only occur at the wound edges and require healthy tissue to migrate across, so if the wound is deep it must first be filled with granulation tissue. If this new membrane becomes damaged, re-epithelialization has to occur again from the wound margins. Therefore care must be taken during dressing changes not to destroy any part of the wound membrane; the more quickly migration of skin cells occurs, the less obvious the scar will be.
Contraction can last for several weeks and is a key stage of wound healing; if it continues too long, disfigurement and loss of function can occur. Special cells, similar to smooth muscle cells, pull the extracellular matrix within the body of the wound when they contract, reducing the wound size, whilst fibroblasts lay down the collagen to reinforce the wound.
This can last a year or longer, depending on the size of the wound and how it was left to heal. During maturation, type III collagen is replaced by type I collagen and slowly the strength of the wound increases.
Box 10.1 Factors inhibiting wound healing
(adapted from Harris 2006)
The presence of a slow-healing wound has significant physical, psychological, psychosocial and financial impact. The psychosocial impact is even greater if the wound is malodorous or on a visible part of the body. The longer a wound takes to heal, the greater the microbial load, with further risk of complications and delayed healing (Bowler et al. 2001). Thus the challenge is to find interventions that promote and accelerate normal wound healing without complications, as outlined in Box 10.1.
The choice and specification of dressing is very important to achieve the above objectives and wound healing agents should adhere to certain specifications (Leach 2008). Natural bases and essential oils can play numerous roles in promoting wound healing, providing a range of treatment options (Box 10.2).
(adapted from Harris 2006)
Few dressings satisfy all the criteria in Box 10.2, but it could be said that many plant extracts come close to being ideal wound-healing agents, e.g. aloe, calendula, hypericum and comfrey (Leach 2004), which leads to the question why are natural remedies, including aromatherapy, not used more widely in hospitals, hospices and the community? In 2002, John Kerr listed the following reasons:
Famous pioneer aromatherapists such as Gattefosse and Valnet were well aware of the healing effects of essential oils, but the first report in the aromatherapy literature of using essential oils for wound healing in hospital was by clinical aromatologist Alan Barker (1994). He explored the aromatic treatment of pressure sores based on his experience of working in the English National Health Service, suggesting the following:
Later, Ron Guba (1998/1999) used 10% of CO2 extracts and essential oils in a cream containing a range of fixed oils on a number of wound types (venous ulcers, pressure sores, skin tears and abrasions) in nursing homes in Australia. The essential oils used were Lavandula angustifolia [lavender], Artemisia vulgaris [mugwort] and Salvia officinalis [sage], plus CO2 extracts of Matricaria recutita [German chamomile] and Calendula officinalis [calendula]. The most significant results were obtained with chronic wounds.
Kerr (2002) reported the results of three years’ work using essential oils for a range of wounds in Australian nursing homes. The main finding was that a 9–12% concentration of essential oils yielded better results than much weaker doses, with no side effects. The essential oils used included Lavandula angustifolia, Matricaria recutita [German chamomile], Pogostemon patchouli, Commiphora myrrha [myrrh] and Melaleuca alternifolia [tea tree] in Aloe vera gel.
Two American practitioners (Hartman & Coetzee 2002) conducted a study using Lavandula angustifolia and Matricaria recutita essential oils diluted in grapeseed fixed oil for the treatment of chronic ulcers of several months’ duration and resistant to conventional treatments (the experimental group), comparing them with a control group who continued to receive conventional wound care. The results confirmed improved healing times in the experimental group. An important observation was that all wounds in the experimental group appeared to worsen initially for up to 2 weeks, with increased exudate and erythema, after which they showed signs of healing. A possible reason for this may be the increase in circulation and vascular permeability encouraged by the essential oil application – thereby accelerating angiogenesis. This observation has been confirmed in the author’s own practice.
Primmer (2002) successfully treated a skin tear in an elderly patient using a mix of Lavandula angustifolia, Eucalyptus radiata [narrow-leaved peppermint], Matricaria recutita and Boswellia carteri [frankincense] at 3% dilution in sweet almond oil. When applied to the wound twice daily, a significant improvement was seen within 24 hours and the wound healed totally in 4 weeks with very little scarring, the therapist using this blend successfully several times with other patients.
Diane Ames (a family nurse practitioner and clinical aromatherapist) is endeavouring to integrate the use of essential oils into the healthcare system in Milwaukee. The cases dealt with were numerous – deep-seated infections, boils and abscesses, venous ulcers, several grades of pressure sore and fungating tumours, and all had good results (Ames 2006).
In 2004, a team from Manchester Metropolitan University developed a dressing model for wounds to decolonize them from MRSA by vapour contact. This led to a phase 1 clinical trial on the effects of diffusion of essential oils to reduce infection risks. The study was carried out in the Burns Unit of Wythenshawe Hospital (Edwards-Jones et al. 2004) (see also Case 9.2 MRSA).
Concentrations of essential oil for wound healing formulas range from 1.5% to 25%, depending on each individual case and the expertise of the therapist. Always take an in-depth history and do a patch test. For direct application essential oils should be diluted in a suitable base or used on a dressing pad rather than straight on the wound.
With regard to the use of essential oils in wound healing, several are constantly mentioned in the research literature. What has not been properly researched is whether particular constituents are responsible for specific healing results – hence the use of the word ‘may’ when discussing this in the text.
Many aromatherapy texts cite myrrh as an effective wound healer from ancient times to the present (Price & Price 1999, Battaglia 1997, Kerr 2002), being specifically healing to bedsores, as it is highly antibacterial. It has an ability to increase the number of leukocytes in the blood (Bartram 1995) and is especially bacteriostatic against Staphylococcus aureus (one of the biggest bacterial wound invaders) and other Gram-positive bacteria (Price & Price 1999). The main constituents are sesquiterpenes, which may help decongest the wound and reduce inflammation (Price 1995). Myrrh can be bought as a resin but this should not be used for wounds – only distilled essential oil is safe for this purpose.
Canadian balsam is antiseptic against staphylococcus spp. and E. coli (Price & Price 2007), anti-inflammatory and cicatrizant, and is used by Native Americans for the treatment of burns, sores and cuts. It is high in monoterpenes (75–90%, mostly β-pinene), which may be why it is good for healing skin lesions and ulcerations. It is helpful for depression, nervous tension and stress-related conditions, all of which add healing properties on a different level. Non-toxic and non-irritating, it may be chosen instead of myrrh for its ease of use, being a much thinner solution (Fact sheet, Penny Price Aromatherapy (2010).
Lemon has been found to be the most effective oil for debriding and desloughing wounds (Penny Price 2003 personal communication). This may be due to the high monoterpene content (90–95%), which can be aggressive to skin and mucous surfaces (Price L 2003 personal communication). It has exceptional antibacterial qualities, having the ability to stimulate the body’s own white blood cells (Battaglia 1997). Lemon is useful in reducing wound odours and is both mentally and spiritually uplifting.