Diabetes: foot ulcers and amputations

Diabetes: foot ulcers and amputations
Dereck Hunt
Clinical Evidence

Summary
Ulcer healing

Debridement with hydrogel compared with standard care Debridement with hydrogel may increase ulcer healing rates after 12–20 weeks compared with standard care ( low-quality evidence).

Surgical debridement compared with usual care Surgical debridement may be no more effective than usual care at promoting ulcer healing (low-quality evidence).

Debridement with larvae compared with debridement with hydrogel Debridement with larvae may be as effective as debridement with hydrogel at promoting ulcer healing ( very low-quality evidence).

Wound dressings compared with each other All wound dressings other than dimethyl sulfoxide may be as effective as each other at promoting ulcer healing after 4–12 weeks (low-quality evidence).

Dimethyl sulfoxide dressing compared with conventional treatment Dimethyl sulfoxide may increase ulcer healing rates compared with conventional treatment after 15 weeks ( moderate-quality evidence).
For GRADE evaluation of interventions for foot ulcers and amputations in diabetes, see table.

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Benefits
Debridement:

We found one systematic review (search date 2005, 5 RCTs, 418 people). [43] The review found that debridement using hydrogel significantly increased healing at 12–20 weeks compared with gauze dressing or standard wound care (3 RCTs, 198 people; RR 1.84, 95% CI 1.30 to 2.61; ARI 23%, 95% CI 10% to 26%; NNT 5, 95% 2 to 10). The review also found no significant difference in complete healing between debridement with larvae compared with hydrogel (1 RCT, 140 people: 5/70 (7%) with larvae v 2/70 (3%) with hydrogel; RR 2.5, 95% CI 0.5 to 12.4; published in abstract form only; duration of follow up was unclear). The review also found no significant difference in ulcer healing between surgical debridement (surgical excision, eventual debridement or removal of bone segments underlying the lesion and surgical closure) compared with conventional management (pressure relief and regular dressings; the type of dressing was not reported) (1 RCT, 42 people; 19/24 [79%] with conservative care v 21/22 [95%] with surgical debridement; RR 1.21, 95% CI 0.96 to 1.51; P=0.1).
Wound dressings:

We found two systematic reviews [44] [45] and one subsequent RCT. [46] The first systematic review (search date 2005) found no RCTs on silver-based dressings for foot ulcers in people with diabetes. [44] The second systematic review (search date 1998, 9 RCTs, number of people unclear) did not perform a meta-analysis, but reported by specific wound dressing comparisons. [45] We have reported the comparisons here where the RCTs found fitted our inclusion critieria of greater than 20 people per study. The review found no significant difference between hydrocellular dressing compared with alginate-based dressings in complete healing rates (2 RCTs, 40 people; OR 2.44, 95% CI 0.78 to 7.57). The review found no significant difference between an adhesive “hydroactive” polyurethane gel dressing compared with a hydrocellular dressing in time to healing or reduction in wound size at 4 weeks (1 RCT, 40 people with neuropathic foot ulceration; time to healing: WMD +4.76 days, 95% CI -7.41 days to +16.93 days; reduction in would size: WMD -1.1mm 2, 95% CI -41.7mm 2 to +39.5mm 2 ). The review found no significant difference between a collagen-alginate dressing versus saline moistened gauze in either complete healing or mean time to complete healing (1 RCT, 75 people with nonischaemic noninfected diabetic foot ulcers; complete healing: OR 1.07, 95% CI 0.35 to 3.25; mean time to complete healing: WMD +2.80 days, 95% CI -8.8 days to +14.4 days). The review found that significantly more ulcers were healed at 15 weeks with dimethyl sulfoxide compared with conventional treatment (not described) (1 RCT, 40 people with diabetic foot ulceration; OR 11.44, 95% CI 3.28 to 39.92). The review found no significant difference between cadexomer iodine ointment compared with standard dressings (not described) at 12 weeks (1 RCT, 35 people with diabetes and “cavity” ulcers of the foot; OR 3.04, 95% CI 0.59 to 15.56). One subsequent RCT (39 people) compared moist (calcium alginate) versus dry (fine mesh gauze) wound dressings applied daily for up to 4 weeks. [46] The RCT found no significant difference in healing between wet versus dry dressings (OR 1.2, 95% CI 0.3 to 4.9; P=0.8).
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Harms
Debridement:

The systematic review found that there were significantly fewer adverse effects with hydrogel compared with good wound care (total of 22 events with hydrogel v 36 with good wound care; RR 0.60, 95% CI 0.38 to 0.95). [43] The review also found that significantly more people because infected with conservative treatment compared with surgical debridement (3/24 [13%] v 1/22 [5%]; RR 0.33, 95% CI 0.03 to 3.47).
Wound dressings:

The systematic review and subsequent RCT gave no information on adverse effects. [45] [46]
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Comment

In the systematic review on debridement, the trials were generally small and of poor methodological quality.
Clinical guide:

We have included debridement and wound dressings together in the same option as the exact mechanism of the treatment can be unclear (e.g. hydrogel). Hydrogel functions by increasing the moisture of the wound environment and that this effect may be more significant than its effect on debridement.
References

43. Smith J. Debridement of diabetic foot ulcers. Cochrane Database of Systematic Reviews 2002, Issue 4. Art. No.: CD003556. DOI: 10.1002/14651858.CD003556. Search date 2005; primary sources Cochrane Wounds Group Specialised Register, Cochrane Central Register of Controlled Trials, hand searches of journals, reference lists, and writing to recognised experts in the field.
44. Bergin SM, Wraight P. Silver based wound dressings and topical agents for treating diabetic foot ulcers. Cochrane Database of Systematic Reviews 2006, Issue 1. Search date 2005; primary sources Cochrane Wounds Group Specialised Register, Cochrane Central Register of Controlled Trials, Medline, Embase, Cinahl, hand searching of The Journal of Wound Care, contact with manufacturers, researchers, and wound groups.
45. O'Meara S, Cullum N, Majid N, Sheldon T. Systematic reviews of wound care management: (3) antimicrobial agents for chronic wounds; (4) diabetic foot ulceration. Health Technol Assess 2000;4(21)
46. Ahroni JH, Boyko EJ, Pecoraro RE. Diabetic foot ulcer healing: Extrinsic vs. intrinsic factors. Wounds 1993; 5:245–255.