EUROPEAN  TISSUE  REPAIR  SOCIETY

NUGGETS FROM THE WEB, UK
Website address:  http://www.nurseminerva.co.uk/wound.htm

Flanagan, M, 1997

Is there any evidence for the use of hydrogen peroxide as a debriding agent in sloughylnecrotic wounds?
27th June 1999

(Debride: to remove all foreign material and injured, infected, or dead tissue from a wound.) Hydrogen peroxide is less used now as a debriding agent than in the past. when hydrogen peroxide is applied to a wound it combines with catalase produced in the tissues and decomposes into oxygen and water, producing effervescence (Potter and Perry, 1993). The rationale was that this helps to loosen materials that might hinder wound recovery and enables them to be washed off more readily. Six-percent w/v hydrogen peroxide (known as ‘20 volume’ solution) liberates twenty times its own volume of oxygen upon decomposition (Thomas, 1990a), and is generally diluted 1 in 3 for the irrigation of wounds. The release of oxygen also kills some anaerobic bacteria such as the tetanus bacillus or Escherichia coli that might otherwise infect the wound. This anti-microbial action of hydrogen peroxide can be amplified 100-fold by the addition of L-cysteine (Berglin, et al, 1982).

The problem with hydrogen peroxide and some other traditional debriding agents is that they also damage the healthy cells (keratinocytes and fibroblasts) that are needed for wound healing and inhibit their necessary migration into the damaged area (Tatnall, Leigh and Gibson, 1990; Tatnall, Leigh and Gibson, 1991; O’Toole, Goel and Wood-ley, 1996). In current practice the emphasis has moved away from the use of cytotoxic materials to those which promote healing, including the use of natural signalling molecules such as platelet-derived growth factor (Higgins and Ashry, 1995). In the British National Formulary (1996) hydrogen peroxide is now listed under ‘Astringents, oxi-disers and dyes’, and not as a desloughing agent.

The application of hydrogen peroxide has been replaced with the use of saline wash, substances such as Debrisan and Intrasite Gel for the removal of necrotic tissue, and the application of hydrogel dressings such as Granuflex. Varidase is a desloughing agent with wound cleansing properties, and contains streptokinase and streptodornase (Thomas, 1990b).

References:

• Berglin, E.H., Edlund, M.B., Nyberg, G.K. and Carlsson, J. (1982) Potentiation by L-cysteine of the bactericidal effect of hydrogen peroxide in Escheri-chia coli. J of Bacteriology, 152(1), 81–88 (Oct).
• British National Formulary (1996) 13.11.6 Astringents, oxidisers and dyes: hydrogen peroxide. Joint publi-cation of the British Medical Association and the Royal Pharmaceutical Society of Great Britain (492).
• Higgins, K.R. and Ashry, H.R. (1995) Wound dressings and topical agents. Clin Podiatr Med Surg, 12(1), 31–40 (Jan).
• O’Toole, E.A., Goel, M. and Woodley, D.T. (1996) Hydrogen peroxide inhibits human keratinocyte migration. Dermatol Surg, 22(6), 525–529 (Jun).
• Potter, P.A. and Perry, A.G. (1993) Fundamentals of nursing: concepts, process and practice (3rd edition). St. Louis: Mosby-Year Book, Inc (p.1666).
• Tatnall, F.M., Leigh, I.M. and Gibson, J.R. (1990) Comparative study of antiseptic toxicity on basal keratinocytes, transformed human keratinocytes and fibroblasts. Skin Pharmacology, 3(3), 157–163.
• Tatnall, F.M., Leigh, I.M., and Gibson, J.R. (1991) Assay of antiseptic agents in cell culture: conditions affecting cytotoxicity. J of Hospital Infections, 17(4), 287–296 (Apr).
• Thomas, S. (1990a) Wound cleansing agents. In: Wound Management Dressings. The Pharmaceutical Press (Chapter 11, p.76).
• Thomas, 5. (1990b) ibid, p.78.

Suggested further reading:
Flanagan, M. (1997) Wound Management – access to clinical education. Edinburgh: Churchill Livingstone (Section 3: Managing wounds, p. 60).

We should like to thank Mrs C. Knowles, Tissue Viability Clinical Nurse Specialist, Royal Devon and Exeter Healthcare NHS Trust, Wonford, Exeter, Devon, for her contribution towards this response.

Papaya (also called pawpaw) has long been used as a treatment for skin wounds in a variety of countries blessed with a warm climate where the Car/ca papaya plant flourishes, for example in African countries (Starley, et al, 1999), Ceylon (Wimalawansa, 1981), and the Carribean (Hewitt, et al, 2000). Where health care resources are very limited the low cost of papaya combined with its effectiveness have encouraged its use in the treatment of skin ulcers and burns.

Usually the pulp of a relatively unripe fruit is chosen, mashed, and placed thickly over the wound on a daily basis. It appears that the papaya pulp enzymatically removes the dead and dying tissue on the surface of chronic ulcers, reduces any pre-existing infection, and encourages healing (Starley, et al, 1999; Hewitt, et al, 2000). It is worth noting that some patients experience a burning sensation when the papaya extract is applied.

There can be difficulties in preparing the fruit consistently and of course it is a non-sterile material when used in this traditional way, but interestingly, in the Jamaican study, there were no reports of infection being introduced by the treatment (Hewitt, et al, 2000). Presumably the Australian product that you have mentioned, but about which we do not yet have any information, will provide reasonable standardisation and perhaps reduce the risk of inadvertently introducing infection into the ulcer. As you suggest, the proteolytic enzymes papain and chymopapain present in papaya seem to be involved in the facilitation of wound-healing, probably helping to deslough the wound area, and there appears to be a protective antimicrobial activity too. Detailed analyses of the constituents of papaya have been made (Katague and Kirch, 1965; Baines, Stuchbury, and Brocklehurst, 1978).

References:

• Baines, B.S., Stuchbury, T. and Brocklehurst, K. (1978) Preparation and characterization of enzymes from spray-dried papaya (Car/ca papaya) latex. Biochemical Society Transactions, 6(1), 255–258.
• Colombetti, G. (1965) On local treatment of tropical phagedenic ulcer with papaya pulp. [Article in Italian] Minerva Medica, 56 (96), 4200–1 (Dec 1).
• Hewitt, H., Whittle, S., Lopez, S., Bailey, E. and Weaver, 5. (2000) Topical use of papaya in chronic skin ulcer therapy in Jamaica. West Indian Medical Journal, 49(1), 32–33 (Mar).
• Katague, D.B. and Kirch, E.R. (1965) Chromatographic analysis of the volatile components of papaya fruit. J of Pharmaceutical Sciences, 54(6), 891–894 (Jun).
• Laidet, B. and Letourneur, M. (1993) Enzymatic debridement of leg ulcers using papain. [Article in French] Annales de Dermatologie et de Venereologie, 120(3), 248.
• Otuka, E.S., Pedrazzani, E.S. and Pioto, M.P. (1996) The use of papain in plantar ulcers. [Article in Portugese] Revista Brasileira de En ferma gem, 49(2), 207–214 (Apr–Jun).
• Starley, I.F., Mohammed, P., Schneider, G. and Bickler, S.W. (1999) The treatment of paediatric burns using topical papaya. Burns, 25(7), 636–639 (Nov).
• Wimalawansa, S.J. (1981) Papaya in the treatment of chronic infected ulcers. Ceylon Medical Journal, 26(3), 129–132 (Sep).