Technology and product reviews Page Points 1. Larval therapy has been used to treat
most types of infected, sloughy or necrotic wound, irrespective of aetiology
2. Larval therapy is available in a number of forms, including free range and net pouch applications
3. As larvae ingest necrotic tissue they also ingest any bacteria present
liquid form can pass through the net mesh without impediment. This form of dressing is applied to the wound for up to five days. The dressing can be exported as long as it
reaches the destination by the following day and is used immediately.
SECONDARY DRESSING REQUIREMENTS Most larval delivery systems require daily removal and replacement of secondary dressings due to the build up of exudate. Larvae can also perish inside the dressing as a result of either dehydration or suffocation, therefore, secondary dressings must be air-permeable and if the dressing is applied to an area vulnerable to pressure, such as the sacrum, then care should be taken to avoid suffocation of the larvae by ensuring there is no prolonged pressure on the larvae for the duration of the treatment (3–5 days). Specifically, the free range larvae dressing requires a fresh layer of moistened gauze applied directly over the retention net during these daily dressing changes (the net pouch application does not need any moisture added as the foam cubes provide this).
Figure 1: Diabetic leg ulcer pre-larval therapy (top) and following five-day application of larvae.
form of patent. Use of bagged or netted larvae is subject to patent in certain parts of the world, particularly Europe and the US.
References 16. Courtenay CM, Church JC,
Ryan TJ. Larva therapy in wound management. J R Soc Med 2000; 93: 72–74.
17. Church J. Maggot intervention in the chronic wound. EWMA Journal 2001; 1(2): 10–13.
18. Johnson S. Using larval therapy to debride an ischaemic toe. Nurs Times 2001; 97(16): 39–40.
19. Brocklesby S. MRSA,
macrophages and maggots. Diabetic Foot 2002; 5(1): 16–24.
20. Dunn C, Raghavan U, Pfleiderer AG. The use of larvae in head and neck necrotising fasciitis. J Laryngol Otol 2002; 116: 70–72.
21. Lodge A, Jones M, Thomas S. Maggots ‘n’ chips: a novel approach to the treatment of
diabetic ulcers. Br J Community Nurs 2007; 11(12): 23–26.
Free range larvae Typically, free range larvae are applied directly to the wound. They can be contained in situ through the use of a retention net and sleek tape but will have freedom of movement in the area of the wound bounded by the net and tape. This type of application stays on the wound for up to three days.
Net pouch application An alternative form of larval therapy is the netted bag or pouch. This comprises a net pouch containing the larvae and hydrophilic polyurethane foam cubes, which retain moisture and prevent the pouch dressing from drying out as larvae need moisture to survive. The pouch containing the larvae and the foam is placed on to the wound and restricts the larvae to a particular area. The proteolytic enzymes that are secreted by the larvae and that break down devitalised tissue into a semi-
25 Wounds International Vol 2 | Issue 4 | ©Wounds International 2011
Discontinuation On removal, the wound should be reassessed to ascertain if a further application is required or whether a change to an alternative, conventional therapy is indicated. If debridement is complete, then no further application of larvae is needed. Larvae are classed as Grade A clinical waste that need to be incinerated and disposal should follow local policy.
CONCLUSION With an ageing population, the potential for patients to develop chronic wounds due to conditions such as diabetes mellitus and peripheral vascular disease will inevitably increase. This will have a significant impact on global healthcare systems, which will require more resources due to the level of care required, inevitably increasing costs. Larval therapy can bring significant clinical benefits to patients as well as potentially delivering financial savings as one application of larvae in place for 3–5 days is usually successful in debriding most wounds.
AUTHOR DETAILS Viv Pyatt, Bsc(Hons), RGN, PGCE, PGCMS, is a Clinical Nurse Advisor, Biomonde Ltd.
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53