Monday, December 04, 2006

UK Nursing Magazine Outlines Evidence for Use of Honey in Wound Care

Honey Dressings in Wound Care
Nursing Times (UK), 2006 May 30-Jun 5;102(22):40-2

Irene Anderson outlines the evidence that is available to support the use of honey in wound care and provides practical points for clinical practice

Bees collect sugar solutions from plants and concentrate the solutions by allowing water to evaporate. The bees also add enzymes, one of which converts sucrose into glucose and fructose and another which converts some glucose into gluconic acid, so making the pH of honey too acidic for microbes to grow in it. This reaction also produces hydrogen peroxide (Molan, 2005). The type of honey from Leptospermum plant species (such as manuka) is known to have a broad spectrum of antimicrobial activity (Molan and Betts, 2004). A range of presentations of honey is available with a CE mark; some are available on the Drug Tariff. Indications and contraindications for using honey are listed in Boxes 1 and 2...

Antimicrobial effect

Honey is known to have a broad-spectrum antibacterial and antifungal effect. There are a number of reasons for this:

- Its osmotic effect: The high concentration of sugars draws water away from the organisms, so dehydrating them and causing cell death;

- Its acidity: this inhibits the growth of organisms;

- The action of hydrogen peroxide: this inhibits bacterial growth;

- The action of phytochemicals (plant chemicals), known as non-peroxide antibacterial factors (Cooper, 2005).

The antimicrobial effects of honey can vary. According to Molan and Betts (2004), honeys with median levels of hydrogen peroxide and manuka honey with median phytochemical levels are equally effective against bacteria, although it would appear that manuka has a greater effect on enterococci species.

Although hydrogen peroxide is present in honey, it is activated only when the honey is diluted. The level of hydrogen peroxide in honey is less than that in solutions used in the past as a wound cleansing solution. These solutions were found to have an adverse effect on healthy tissues and have been replaced by more effective and safer materials...

Anti-inflammatory effect

Honey is known to have anti-inflammatory properties and case studies have demonstrated its usefulness on non-healing wounds (Dunford, 2005; 2000). A laboratory study on the effect of honey on cells implicated in prolonged inflammation demonstrated that the honey was able to modulate the activity of monocytes to release growth factors and anti-inflammatory agents (Tonks et al, 2003), although how this is achieved is not yet understood.

Pain

Molan (2005) reports that pain associated with using honey may possibly be due to the acidity and/or the organic chemicals in it. In some instances, the pain or discomfort has been transitory (Dunford and Hanano, 2004). Interestingly, Molan (2005) reports that the incidence of pain may be particularly evident when wounds are inflamed, which should be borne in mind when considering the evidence for using honey in infected and acutely inflamed wounds. There are reports that honey has relieved wound pain, especially in a comparative study with saline-soaked gauze, and in comparison with a hydrocolloid (Misirlioglu et al, 2003).

Evidence

There are a limited number of randomised controlled trials involving the use of honey in wound care. Subrahmanyam compared honey with polyurethane film (1993), boiled potato skins (1996), and silver sulfadiazine (1998). It is not clear from the studies how wound healing was measured objectively, and there are few details in them about the control of wound types, size, and wound bed presentation. In one study, for instance, the use of honey was compared to using a polyurethane film dressing in the management of partial-thickness burns (Subrahmanyam, 1993). The healing time for those in the honey group was faster than for those who had the film dressing, but the film dressing appears to have been left on for up to eight days and it was changed only if leaking occurred. This is not in accordance with product instructions and does not take into account the higher exudate levels experienced in the early stages of acute burns (the treatment was begun within six hours of wounding)...

Conclusion

The above examples on the use of honey in wound care indicate that there is a growing collection of case study evidence on its usefulness (Van der Weyden, 2005; Dunford 2005, 2000; Kingsley, 2001), although some case studies demonstrate a more limited usefulness for specific treatment objectives (Kingsley, 2001).

Laboratory studies have demonstrated the mode of action of honey, especially in relation to the antimicrobial and anti-inflammatory effects of its hydrogen- and non-hydrogen peroxide components (Moore et al, 2001). What is missing is robust evidence of the use of honey compared to modern wound care products that also exert antimicrobial and anti-inflammatory effects.

-----

Box 1: Indications for Using Honey in Wound Care

* Acute and chronic wounds
* Non-healing wounds
* Wounds colonised with MRSA (local protocols must be adhered to where appropriate)
* Infected wounds (as long as appropriate management of the infection is also in place)
* Wounds that need debridement (see contraindications)
* Wounds that are moderately wet
* Painful wounds (see contraindications)
* Malodorous wounds
* Red, excoriated skin

Box 2: Contraindications for Using Honey in Wound Care

* Honey that is not indicated for use in wounds
* People sensitive to bee stings
* Dry, necrotic wounds (honey may cause further drying)
* Acute pain and inflammation (pain may increase for some people, therefore be prepared to reassess the patient and to select a different dressing)
* When the dressing cannot be changed within the specified time

-----

Table 1: Examples of Treatment Outcomes of Honey Use and the Assessment Required for Their Measurement

Positive anti-inflammatory effect
As it is known that honey has an anti-inflammatory effect, has there been a reduction in redness and swelling? Are there signs of positive changes in the condition of the wound?

Positive anti-microbial effect
Has the infection resolved? (Appropriate action should have been taken to treat clinical infection in addition to applying the honey dressing.) Have there been fewer episodes of clinical infection for this patient since the treatment was started?

Reduction in pain
Has the pain increased or reduced? Has any pain been a transient experience that the patient is willing to cope with or have the honey dressings been discontinued?...

-----

Using Honey Dressings: The Practical Considerations
Nursing Times, VOL 96, NO 36, 07 Dec 2000

Dressing the wound
The literature contains little on the methods used to dress wounds with honey, and where details are provided it is apparent that techniques vary widely. The following advice is based on clinical experience gained at the Honey Research Unit and that of associates working in the field.

Amount of honey
The amount of honey needed to treat a wound depends on the amount of exudate, because the beneficial effects are reduced or lost if small amounts of honey are diluted by large amounts of exudate. The deeper the infection, the more honey will be needed to achieve an effective level of antibacterial activity diffusing deep into the wound tissues. Typically, 20ml of honey (25-30g) should be used on a 10cm-square dressing.

Frequency of dressing changes
This depends on how rapidly the honey is diluted by exudate. Dressings are usually changed once a day, but with heavily exuding or infected wounds they may initially need to be changed up to three times a day...

Dressing application
Honey is runny and sticky, which can make it a difficult medium to handle, but this can be overcome by soaking it into an absorbent wound-contact material, such as gauze and cotton tissue. Wound-contact materials that have been preimpregnated with honey are the most convenient way to apply it to surface wounds. Preimpregnated pads, which use honey with a standardised level of antibacterial activity that has been sterilised by gamma irradiation, are available commercially in New Zealand...

No comments: