Safety and Efficacy of Wound Cleansers

Dear Readers:

The adage “Cleanliness is next to godliness” seems to apply to wounds as well as people. Wounds have been cleansed since recorded history to remove foreign or necrotic matter, reduce odor, or more recently, to reduce bacterial burden. The evidence on cleansing, irrigation, and wound disinfection has been ably reviewed elsewhere,¹ with appropriate techniques and cleansers described. Yet, we rarely know if we are doing more harm than good when cleansing a wound. Is it wise to wash away or dilute natural growth factors^2,3 and autolytic enzymes or cool a wound during cleansing? Do we consider patient pain during the cleansing process? I recall the burning pain of sterile distilled water, our standard control solution for maximal-pain, when applied to open cantharidin blister beds used to measure wound pain in response to topical formulations. Isotonic saline solution was a soothing, zeropain control. Which is safer? For those interested in safety and efficacy of wound cleansers, the 2 recent reviews summarized in this Evidence Corner bring some issues into clearer focus, but leave many of these questions unresolved.

Evidence Supports Use of Tap Water To Cleanse Wounds

Reference: Fernandez R, Griffiths R.Water for wound cleansing. Cochrane Database Syst Rev. 2008;23(1):CD003861.
Rationale: There is an unresolved debate about safety and efficacy of the usual community practice of cleansing wounds with tap water.Acute care and other environments with ready access to other sterile cleansing solutions seem to prefer them for wound cleansing.
Objective: Assess the effects of water compared with other solutions for cleansing wounds.
Methods: MEDLINE, EMBASE, CINAHL, and Cochrane databases were searched and authors and corporations were contacted to identify and retrieve randomized or quasi-randomized controlled studies comparing healing or infection effects of water to other solutions used in wound cleansing. Derivative references from included studies were also reviewed. Two independent authors selected the references, evaluated study quality and extracted data for analysis, pooled when appropriate, using a random effects model.
Results: Of 11 randomized controlled trials (RCTs) identified, 7 compared infection and/or healing of wounds cleansed using water or saline, 3 compared tap water cleansing with no cleansing, and 1 compared infection rates of episiotomy wounds cleansed with procaine spirit or water. Analyses showed that chronic wounds have a significantly lower risk of infection if cleansed with tap water than if cleansed with saline. No other infection differences were statistically significant for cleansing solutions on acute wounds in children, for open fractures cleansed with distilled water, boiled water, or isotonic saline, or for cleansing with tap water compared to not cleansing.
Authors’ Conclusions: There is no evidence that saline wound cleansing is more effective than tap water in reducing the likelihood of a wound infection or improving healing; some evidence suggests the opposite. The evidence is insufficient to support cleansing wounds with water or saline versus no cleansing at all.

Topical Antimicrobial May Improve Venous Ulcer Healing

Reference: O’Meara S, Al-Kurdi D, Ovington LG. Antibiotics and antiseptics for venous leg ulcers. Cochrane Database Syst Rev. 2008;23(1):CD003557.
Rationale: Venous ulcers affect up to 1% of individuals during their lifetime in some countries and are often heavily colonized. Applying topical antibiotics or antimicrobials to cleanse or treat wounds is believed to reduce wound bacterial burden, thus favoring healing.
Objective: Explore effects of systemic or topical antibiotics or topical antiseptics on venous ulcer healing.
Methods: MEDLINE,EMBASE, CINAHL, and Cochrane databases were searched for RCTs comparing effects of at least 1 systemic or topical antibiotic or topical antiseptic on at least 1 objective measure of venous ulcer healing. Study quality was assessed by 1 author according to standard criteria and data were extracted on a standardized form, with validity checked by a second author.
Results: Of 22 qualifying trials identified, 5 involved systemic antibiotics, with the rest of the trials studying topical preparations: 10 cadexomer iodine, 3 peroxidebased formulations, 2 povidone iodine, 1 ethacridine lactate, 1 mupirocin. The only benefit (P < 0.05) of a systemic antibiotic for venous ulcer healing was reported for levamisole, an antihelminthic agent, in a small trial. Cadexomer iodine was the only topical antimicrobial formulation significantly improving the percent of venous ulcers completely healed during 4–6 weeks of treatment. Other surrogate venous ulcer outcomes, such as reduced wound surface area, reportedly also improved in response to topical cadexomer iodine, mupirocin, or ethacridine lactate in some studies. Most trials were small with methodologic problems, such as unmatched groups at baseline.
Authors’ Conclusions: Presently, the evidence to support routine use of systemic antibiotics to improve venous ulcer healing is insufficient. Among topical antimicrobial cleansers or other formulations, some evidence supports topical use of cadexomer iodine on venous ulcers, but further high quality research is needed before drawing definitive conclusions.

Clinical Perspective
These reviews focused on infection rates and healing responses to wound cleansing; the first reminds us of the absence of strong evidence that cleansing wounds with any solution reduces wound infection rates. An earlier review of pressure ulcer healing outcomes⁴ led to a similar conclusion: there is “no good evidence” that cleansing pressure ulcers or using a particular solution helps healing—no change from the C-Level evidence supporting pressure ulcer cleansing in 1994.⁵ While it is comforting to know that if potable tap water is all one has for wound cleansing, it is at least as safe as normal saline, this makes one wonder whether we are engaging in superstitious behavior by cleaning wounds or simply in need of better controlled clinical studies to support it.
The second review suggests that topical cadexomer iodine may speed venous ulcer healing—presumably in patients not allergic to iodine. Rodeheaver and Ratliff¹ noted that most povidone iodine (PI) and cadexomer iodine (CI) studies investigating efficacy on wounds were inadequately controlled. In the only well-controlled study they found while comparing PI with saline⁶ that PI was no different from saline on pressure ulcers.They also note that absorbance of CI was not well matched in study controls supporting CI efficacy. It is difficult to tell whether effects of CI supported by O’Meara et al are due to its absorbance, iodine released or to some other factor such as increased inflammation,⁷ which can also lead to increased scarring.
Perhaps we need to consider why a wound is being cleansed before we choose a cleanser. If the goal of wound cleansing is to visualize the wound bed for diagnostic or intervention purposes and pain is not an issue, Fernandez et al tell us that tap water is a safe and effective option. Preclinical evidence supports the safety and efficacy of using nonionic surfactant solutions to remove wound surface contaminants with less force than is normally required with saline, if the goal is to gently remove loosely adherent debris, slough, or other material obscuring or contaminating the wound.¹
Neither review addressed patient-reported pain associated with wound cleansing. It remains unclear whether one should consider isotonic cleansers to minimize pain during wound cleansing. A MEDLINE search of combined terms “wound cleanser pain” found 1 uncontrolled study. It seems that there is more to question about wound cleansing than originally thought and minimal quality research to support the answers.