January 24, 2008 — Drinkable tap water applied topically is as effective as normal saline for cleansing a wound, according to a Cochrane review published in the January 23 issue of the Cochrane Database Systematic Reviews.

"Various solutions have been recommended for cleansing wounds, however normal saline is favoured as it is an isotonic solution and does not interfere with the normal healing process," write Ritin Fernandez, RN, MN, and Rhonda D. Griffiths. MSc, DrPH, from the University of Western Sydney in New South Wales, Australia. "Tap water is commonly used in the community for cleansing wounds because it is easily accessible, efficient and cost effective, however, there is an unresolved debate about its use."

The objective of this review was to compare the effects of water vs other solutions used for wound cleansing. The investigators performed electronic searches of Cochrane Wounds Group Specialised Register (June 2007), MEDLINE (1996 - 2007), EMBASE (1980 - 2007), CINAHL (1982 - 2007), and the Cochrane Controlled Trials Register (Issue 3; 2007). They also searched reference lists from included trials and contacted lead authors, company representatives, and content experts to identify other eligible studies.

Inclusion criteria for studies were randomized and quasi-randomized controlled trials that compared water with other solutions in efficacy and safety for wound cleansing, with outcome measures including objective or subjective measures of wound infection or healing.

Two authors independently selected trials, extracted data, and evaluated the quality of the included studies. These procedures were checked by a third author, and differences in opinion were settled by discussion. A random effects model was used to pool some of the data.

Of 11 included trials, 7 compared rates of infection and healing in wounds cleansed with water vs normal saline, 3 trials compared cleansing vs no cleansing, and 1 trial compared procaine spirit vs water. Procaine spirit is a mixture of procaine HCl 2% with spirit 70% and is commonly prescribed for wound cleansing following surgery. Ability to pool the data was limited because there were no standard criteria across the trials for evaluating wound infection. The predominant comparisons were water vs normal saline and tap water vs no cleansing.

When chronic wounds were cleansed with tap water vs normal saline, the relative risk (RR) of developing an infection was 0.16 (95% confidence interval [CI], 0.01 - 2.96). Compared with saline, tap water was more effective in reducing the infection rate in adults with acute wounds (RR, 0.63; 95% CI, 0.40 - 0.99). In children, the use of tap water to cleanse acute wounds was not associated with a statistically significant difference in infection vs saline (RR, 1.07; 95% CI, 0.43 - 2.64).

When wounds were cleansed with tap water or not cleansed at all, there was no statistically significant difference in infection rates (RR, 1.06; 95% CI, 0.07 - 16.50). In a similar fashion, episiotomy wounds cleansed with water or with procaine spirit did not differ in infection rate. For cleansing open fractures, use of isotonic saline, distilled water, and boiled water was not statistically significantly different in the number of fractures that became infected.

"There is no evidence that using tap water to cleanse acute wounds in adults increases infection and some evidence that it reduces it," the review authors write. "However there is not strong evidence that cleansing wounds per se increases healing or reduces infection. In the absence of potable tap water, boiled and cooled water as well as distilled water can be used as wound cleansing agents. . . . The decision to use tap water to cleanse wounds should take into account the quality of water, nature of wounds and the patient's general condition, including the presence of comorbid conditions."

Methodologic limitations of the included trials are absence of details concerning the method of randomization of patients to treatment groups, selection bias, overall poor quality, lack of replication of most comparisons, poorly defined eligibility criteria in some cases, lack of consistency in the criteria used to assess wound infection, variance data for the healing outcomes not reported in the study that compared tap water with procaine spirit, failure to measure other outcomes such as patient comfort and satisfaction, and meta-analysis restricted to trials of the same intervention that evaluated the same outcome.

"While the findings of this review do not indicate adverse effects from the use of tap water, practitioners and health service managers should interpret the findings with caution as most of the comparisons were based on single trials, some of which do not report the methodology in sufficient detail to enable assessment of quality," the review authors conclude. "The availability and cost of resources may also determine which solution is used for cleansing wounds in different settings."

The review authors conducted 1 of the trials included in the review, but the authors did not receive from any commercial entity any payments or other benefits that were related in any way to the subject of the work. The University of Western Sydney and the South Western Sydney Area Health Service Australia supported this work.

Cochrane Database Syst Rev. 2008;00:000-000.

Clinical Context

Study Highlights

• The reviewers conducted electronic searches of Cochrane Wounds Group Specialised Register (June 2007), MEDLINE (1996 - 2007), EMBASE (1980 - 2007), CINAHL (1982 - 2007), and the Cochrane Controlled Trials Register (Issue 3; 2007).
• The reviewers also searched reference lists from included trials and contacted lead authors, company representatives, and content experts to identify other eligible studies.
• Studies included in the review were randomized and quasi-randomized controlled trials comparing water with other solutions for wound cleansing, with outcome measures being objective or subjective measures of wound infection or healing.
• 2 authors independently selected trials, extracted data, and evaluated the quality of the included studies. These procedures were checked by a third author, and differences in opinion were settled by discussion.
• A random effects model was used to pool some of the data.
• Of 11 included trials, 7 compared rates of infection and healing in wounds cleansed with water vs normal saline, 3 compared cleansing vs no cleansing, and 1 compared procaine spirit vs water.
• Lack of standard criteria across the trials for evaluating wound infection prevented pooling most of the data.
• For chronic wounds cleansed with tap water vs saline, the RR for infection was 0.16 (95% CI, 0.01 - 2.96).
• Tap water vs saline was more effective in reducing the infection rate in adults with acute wounds (RR, 0.63; 95% CI, 0.40 - 0.99).
• For children with acute wounds, infection rates were not statistically significantly different with tap water vs saline (RR, 1.07; 95% CI, 0.43 - 2.64).
• Wounds cleansed with tap water vs wounds not cleansed at all did not differ in infection rates (RR, 1.06; 95% CI, 0.07 - 16.50).
• Episiotomy wounds cleansed with water or with procaine spirit did not differ in infection rate.
• Infection rate for open fractures was not statistically significantly different for cleansing with isotonic saline, distilled water, or boiled water.
• Based on these findings, the authors concluded that there was no evidence that using tap water to cleanse acute wounds in adults increases infection and some evidence that it reduces it, but evidence is not strong that cleansing wounds per se increases healing or reduces infection.
• When potable tap water is not available, boiled and cooled water or distilled water may be used for wound cleansing.
• Factors affecting the decision to use tap water to cleanse wounds include water quality, nature of the wound, the patient's general condition, and comorbidities.
• Methodologic limitations of included trials are lack of details concerning method of randomization, selection bias, overall poor quality, lack of replication of most comparisons, poorly defined eligibility criteria, lack of consistency in criteria used to assess wound infection, failure to measure patient comfort and satisfaction, and meta-analysis restricted to trials of the same intervention that evaluated the same outcome.

Pearls for Practice

• This Cochrane review identified no evidence that using tap water to cleanse acute wounds in adults increases infection and some evidence that it reduces it. For chronic wounds cleansed with tap water vs saline, the RR for infection was 0.16. Tap water vs saline was more effective in reducing the infection rate in adults with acute wounds. For children with acute wounds, infection rates were not statistically significantly different with tap water vs saline. Infection rate for open fractures was not statistically significantly different for cleansing with isotonic saline, distilled water, or boiled water.
• Wounds cleansed with tap water vs wounds not cleansed at all did not differ in infection rates, and episiotomy wounds cleansed with water or with procaine spirit did not differ in infection rate.

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