Alleviating Venous Ulcer Pain
Pain is one of the most dreaded and least understood complications of chronic and acute wounds. Through the years research has confirmed that that moisture-retentive topical primary wound dressings can alleviate pain compared to gauze dressings in chronic venous1 or pressure2 ulcers and in acute burns3 surgical excisions4 or traumatic wounds.5 A recent Cochrane review concluded that a topical eutectic mixture (at lowest possible temperature of solidification) of 2.5% each of the two local anesthetics lidocaine and prilocaine (LP cream) reduced pain during venous ulcer debridement.6 The World Health Organization (WHO)7 has proposed a three-step ladder of systemic pain relief for cancer patients recommending oral non-opioids, such as aspirin and paracetamol, to address basic pain plus additional “adjuvants” to manage anxiety if needed. As pain increases to mild or moderate levels, the second step on the pain ladder adds a mild opioid such as codeine. The third step calls for a stronger opioid such as morphine as pain becomes moderate or severe. The right drug or combination is given every 3–6 hours to maintain freedom from cancer pain. How would the WHO pain ladder work for venous ulcer patients? Would chronic morphine use delay healing?8 Two studies summarized below suggest a different set of analgesic principles to achieve safe and effective venous ulcer pain relief.
Topical Cream or Inhaled Nitrous Oxide for Debridement Pain
Reference: Claeys A, Gaudy-Marqueste C, Pauly V, et al. Management of pain associated with debridement of leg ulcers: a randomized, multicentre, pilot study comparing nitrous oxide-oxygen mixture inhalation and lidocaine-prilocaine cream. J Eur Acad Dermatol Venereol. 2010 Jun 21. [Epub ahead of print]
Rationale: Pain is a limiting factor in debriding fibrin or necrotic tissue from venous or arterial leg ulcers.
Objective: Compare analgesic safety and efficacy of inhaling a mixture of nitrous oxide with oxygen (NOO) or topical LP Cream during repeated mechanical debridement of venous and/or arterial leg ulcers.
Methods: This multicenter open-label RCT pilot study compared analgesic efficacy of 9-12 L/min inhalation of NOO started 3 minutes pre-debridement (n = 20) to a maximum of 10 g of topical LP Cream applied under an occlusive plastic film dressing 30 minutes pre-debridement (n = 21). Randomized block assignment was stratified across six French centers between 2004 and 2007. Non-neuropathic patients over 18 years of age, without severely impaired mental function as indicated by a Mini-Mental State Examination score (MMS)
Results: At baseline, the groups were comparable in ulcer etiology, pain and characteristics, pain and patient vital signs, and demographics. Twenty NOO patients underwent 95 debridements; 21 LP Cream patients had 114 debridements, with similar study withdrawal frequencies and reasons: 15 NOO and 14 LP Cream patients completed the study. Pain VAS and ratings increased after each debridement session for both groups (P P P
Authors’ Conclusions: There was a significant analgesic advantage of LP Cream. Both analgesics were tolerated well. Their different mechanisms of action and relative safety warrant future tests in combination.
Optimal Compression for Venous Leg Ulcers
Reference: Amsler F, Willenberg T, Blättler W. In search of optimal compression therapy for venous leg ulcers: A meta-analysis of studies comparing divers bandages with specifically designed stockings. J Vasc Surg. 2009;50(3):668–674.
Rationale: Compression is considered the most important conservative intervention for venous leg ulcers. High, multi-layer compression appears to improve outcomes more than low or one-layer compression. Advantages of medical compression stockings (CS) remain to be evaluated.
Objective: Compare effectiveness of CS with compression bandages (CB) in a systematic review and meta-analysis.
Methods: The authors searched MEDLINE, Current Contents, EMBASE, and the Cochrane Library for relevant combinations of the terms: venous insufficiency, leg, pain, edema, ulcer, compression therapy, bandages, stockings, hosiery, and randomized trials and requested related evidence from EUROCOM, the scientific arm of the coalition of European compression stocking manufacturers. All CS RCTs published in English, German, or French plus derivative references with a CS intervention in a RCT were included in a systematic review and meta-analysis of healing and pain. Outcomes were percentage of subjects with the target ulcer completely healed in 12–16 weeks (primary), measured pain during CS or CB wear, and time to complete ulcer healing. The meta-analysis used Cochrane Collaboration Review Manager 4.2.
Results: Eight prospective open-label RCTs on 342 CS subjects and 346 CB subjects with open venous ulcers met the search criteria. All subjects were randomized to parallel-groups except in one crossover study. Most studies excluded non-venous ulcer etiology, infection, an ankle/brachial systolic blood pressure ratio P P
Authors’ Conclusions:Compression stockings (CS) support a higher rate of healing and are better tolerated than compression bandages (CB).
These studies alert us to important possibilities for minimizing venous ulcer pain. Could there be a different pain ladder for each wound etiology? Evidence suggests that steps on the venous ulcer pain ladder may include: 1) reducing edema pain with compression, elevation, and calf muscle pump exercise9; 2) reducing compression bandage-associated pain10 by using CS appropriately instead of CB (Amsler et al study); 3) providing a moist wound environment1; 4) reducing frequency of painful dressing changes11; 5) using autolytic debridement12 to reduce the need for painful surgical debridement; 6) and when surgical debridement is absolutely necessary, using topical LP Cream instead of inhaled NOO to improve analgesia (Claeys et al study). These are only example steps and references to alleviate venous ulcer pain. Imagine how far we could advance with evidence at hand if we really “got serious”!
Amsler et al question the traditional view that compression stockings should be reserved for use on small or short-duration venous ulcers or to prevent recurrence once healed. The authors point out that the reasons for faster healing and less pain with stockings compared to bandages were not explored. Adherence to protocol, patient preferences, and other patient-oriented advantages or disadvantages of CS and CB were not addressed in their study because experienced staff at wound centers applied all compression interventions. Among patients randomized to CS in three studies reporting subject capacity to don their own stockings, 6.5% of were unable to do so. The authors recommend further testing in “real world” settings, where this percentage may be higher. They add that blind assignment and metrics were not used and that patients with more severe venous insufficiency may have been excluded from study for fear that they might not do well. It gives one pause to realize that such widely held fears persist despite such evidence.