Special to OWM: The Cochrane Collaboration

Intermittent pneumatic compression for treating venous leg ulcers (Cochrane Review Abstract)

R Mani, K Vowden, and EA Nelson

   Background: Intermittent pneumatic compression (IPC) is a mechanical method of delivering compression to swollen limbs. This technique has been used to treat venous leg ulcers and limb swelling due to lymphedema. The effectiveness of IPC and the appropriate duration and frequency of IPC therapy are unknown, as are the differences between various types of IPC. This review analyses the evidence for the effectiveness of IPC as a treatment for venous leg ulcers.

   Objectives: To determine whether IPC increases the healing of venous leg ulcers. To determine the effects of IPC on health related quality of life of venous leg ulcer patients.

   Search strategy: The Cochrane Wound Group Trials Register was searched for RCTs of intermittent pneumatic compression in February 2001. Journals and relevant conference proceedings were searched by hand. Companies were also contacted for relevant unpublished data or ongoing studies.

   Selection criteria: Randomized controlled studies either comparing IPC with control (sham IPC or no IPC) or comparisons between IPC treatment regimens, in venous ulcer management were included.

   Data collection and analysis: Data extraction and assessment of study quality were undertaken by two reviewers independently.

   Main results: Four randomized controlled trials were identified. One small trial (45 people) found increased ulcer healing with IPC plus compression than with compression alone (relative risk for healing 11.4, 95% Confidence Interval 1.6 to 82). Two small trials with a total of 75 people found no evidence of a benefit for IPC plus compression compared with compression alone. One small trial (16 people) found no difference between IPC (without additional compression) and compression bandages alone.

   Reviewers' conclusions: Further trials are required to determine whether IPC increases the healing of venous leg ulcers.

   Citation: Mani R, Vowden K, Nelson EA. Intermittent pneumatic compression for treating venous leg ulcers (Cochrane Review). In: The Cochrane Library, 1, 2002. Oxford: Update Software.
(A substantive amendment to this systematic review was last made on 01 July 2001. Cochrane reviews are regularly checked and updated if necessary.)

Patient education for preventing diabetic foot ulceration (Cochrane Review Abstract)

GD Valk, DMW Kriegsman, and WJJ Assendelft
   Background: Ulceration of the feet, which can result in loss of limbs and even death, is one of the major health problems for people with diabetes mellitus.

   Objectives: To assess the effectiveness of patient education on the prevention of foot ulcers in patients with diabetes mellitus.

   Search strategy: Eligible studies were identified by searching the Wounds Group Specialized Trials Register, which is compiled from regular searches of the major health care databases including MEDLINE, Cinahl and EMBASE, hand searching of wound care journals and relevant conference proceedings. For this review the Register was searched up to March 2001.

   Selection criteria: Prospective randomized controlled trials (RCTs) which evaluated educational programs for the prevention of foot ulcers in people with diabetes mellitus. There was no restriction on language of the publications.

   Data collection and analysis: Data extraction and assessment of study quality were undertaken by two reviewers independently.

   Main results: The methodological quality of the eight included RCTs was poor. The internal validity score (range 0 - 10) of individual RCTs ranged from 2 to 4.
Four trials compared the effect of intensive with brief educational interventions; two of these reported clinical endpoints. One study involving high-risk patients reported a reduction in ulcer incidence (Peto odd ratio (OR): 0.28 (95% CI 0.13,0.59)) and amputation rate (Peto OR: 0.32 (0.14,0.71)) after 1 year. The other RCT did not find an effect at seven years follow-up. Participants' foot care knowledge significantly improved with education in 2 trials. In one trial, foot care knowledge was significantly worse at 6 months, although foot care behavior improved significantly. Noncalcaneal callus was significantly reduced by education in one trial.

   One RCT did not find that patient foot care education, as part of a general diabetes education program reduced foot ulceration compared with usual care. Patient education as part of a complex intervention targeted at both people with diabetes and doctors reduced the number of serious foot lesions at one year, in one RCT (OR: 0.41(0.16-1.00)) and improved foot care behavior.

   Evidence from 2 RCTs comparing the effect of patient-tailored education in addition to usual care was conflicting.

   Reviewers conclusions: Radomized controlled trials evaluating education for people with diabetes, aimed at preventing diabetic foot ulceration, are mostly of poor methodological quality. Existing data suggests that patient education may reduce foot ulceration and amputations, especially in high-risk patients. Foot care knowledge and behavior of patients seem positively influenced by patient education in the short term.

   Because of conflicting results and the methodological shortcomings more RCTs are needed.
   Citation: Valk GD, Kriegsman DMW, Assendelft WJJ. Patient education for preventing diabetic foot ulceration (Cochrane Review). In: The Cochrane Library, 1, 2002. Oxford: Update Software.

Pentoxifylline for treating venous leg ulcers (Cochrane Review Abstract)

AB Jull, J Waters, and B Arroll
   Background: Healing of venous leg ulcers is improved by the use of compression bandaging but some venous ulcers remain unhealed, and some people are unsuitable for compression therapy. Pentoxifylline, a drug which helps blood flow, has been used to treat venous leg ulcers but to date there has been no systematic review.

   Objectives: To assess the effects of pentoxifylline (oxpentifylline or Trental 400) for treating venous leg ulcers, compared with placebo, or other therapies, in the presence or absence of compression therapy.

   Search strategy: We searched the Cochrane Peripheral Vascular Diseases and Wounds Groups specialized registers (date of last search was May 2001), and reference lists of relevant articles. We hand searched relevant journals and conference proceedings, and contacted Hoechst (the manufacturer of the drug) and experts in the field.

   Selection criteria: Randomized trials comparing pentoxifylline with placebo or other therapy in the presence or absence of compression, in patients with venous leg ulcers.

   Data collection and analysis: Details from eligible trials were extracted and summarized by one reviewer using a coding sheet. Data extraction was independently verified by one other reviewer.

   Main results: Nine trials involving 572 adults were included. The quality of trials was variable. Eight trials compared pentoxifylline with placebo; in five of these trials, patients received compression therapy. In one trial, pentoxifylline was compared with defibrotide in patients who also received compression. Combining eight trials that compared pentoxifylline with placebo (with or without compression) demonstrated that pentoxifylline is more effective than placebo in terms of complete ulcer healing or significant improvement (relative risk of healing with pentoxifylline compared with placebo 1.41, 95% confidence interval 1.19 -1.66). Pentoxifylline plus compression is more effective than placebo plus compression (relative risk of healing with pentoxifylline 1.30, 95% confidence interval 1.10-1.54). A comparison between pentoxifylline and defibrotide found no difference in healing rates.

   More adverse effects were reported in patients receiving pentoxifylline, although this was not statistically significant (relative risk of adverse effects with pentoxifylline 1.25, 95% confidence interval 0.87-1.80). Nearly half of the reported adverse effects were gastrointestinal.

   Reviewers' conclusions: Pentoxifylline appears to be an effective adjunct to compression bandaging for treating venous ulcers. There was no cost effectiveness data available and healthcare commissioners may therefore conclude that it not be considered a routine adjunct. Pentoxifylline in the absence of compression may be effective for treating venous leg ulcers, although the evidence should be cautiously interpreted. The majority of adverse effects are gastrointestinal disturbances (indigestion, diarrhea, and nausea).

   Citation Jull AB, Waters J, Arroll B. Pentoxifylline for treating venous leg ulcers (Cochrane Review). In: The Cochrane Library, 1, 2002. Oxford: Update Software.
(A substantive amendment to this systematic review was last made on 01 September 2001. Cochrane reviews are regularly checked and updated if necessary.)

Topical negative pressure for treating chronic wounds (Cochrane Review Abstract)

D, L, and L Evans
   Background: Chronic wounds mainly affect the elderly and those with multiple health problems. Despite the use of modern dressings, some of these wounds take a long time to heal, fail to heal, or recur, causing significant pain and discomfort to the person and cost to health services. Topical negative pressure is used to promote healing of surgical wounds by using suction to drain excess fluid from wounds.

   Objectives: To assess the effectiveness of topical negative pressure (TNP) in treating people with chronic wounds and to identify an optimum TNP regimen.

   Search strategy: The Cochrane Wounds Group Specialized Trials Register was searched until July 2000. Experts in the field and relevant companies were contacted to enquire about ongoing and recently completed relevant trials. In addition citations within obtained papers were scrutinized to identify additional studies.

   Selection criteria: All randomized controlled trials which evaluated the effectiveness of TNP in treating chronic wounds were considered.

   Data collection and analysis: Eligibility for inclusion, data extraction and details of trial quality was conducted by two reviewers independently. A narrative synthesis of results was undertaken as only two small trials fulfilled the selection criteria and they used different outcome measures.

   Main results: Two small trials with a total of 34 participants evaluated the effectiveness of TNP on chronic wound healing. Trial 1 considered patients with any type of chronic wound; Trial 2 considered patients with diabetic foot ulcers only. The trials compared TNP (as open cell foam dressing with continuous suction) for the first 48 hours with saline gauze dressings. Trial 1 reported a statistically significant reduction in wound volume at 6 weeks in favor of TNP. Trial 2 (continuous suction, followed by intermittent suction after 48 hours) reported a reduction in the number of days to healing and a reduction in wound surface area at 2 weeks in favor of TNP, although no statistical analysis was reported.

   Reviewers' conclusions: The two small trials provide weak evidence suggesting that TNP may be superior to saline gauze dressings in healing chronic human wounds. However, due to the small sample sizes and methodological limitations of these trials, the findings must be interpreted with extreme caution. The effect of TNP on cost, quality of life, pain and comfort was not reported. It was not possible to determine which was the optimum TNP regimen.

   Citation: Evans D, L and L. Topical negative pressure for treating chronic wounds (Cochrane Review). In: The Cochrane Library, 1, 2002. Oxford: Update Software.
(A substantive amendment to this systematic review was last made on 14 November 2000. Cochrane reviews are regularly checked and updated if necessary.)