In Summary, for those who received tap water irrigation:

Benefits in NNT

  • 97.2% saw no benefit
  • 2.8% were helped by preventing an infection
  • 1 in 36 were helped (infection prevented)

Harms in NNT

  • None were harmed
  • None were harmed

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Source: Fernandez R, Griffiths R. Water for wound cleansing. Cochrane Database Syst Rev. 2012 Feb 15;2:CD003861. doi: 10.1002/14651858.CD003861.pub3. Review. PubMed PMID: 22336796.
Weiss EA, Oldham G, Lin M, Foster T, Quinn JV. Water is a safe and effective alternative to sterile normal saline for wound irrigation prior to suturing: a prospective, double-blind, randomised, controlled clinical trial. BMJ Open. 2013.

Efficacy Endpoints: Wound infection

Harm Endpoints: None identified

Narrative: Various solutions are available for wound irrigation. It has been suggested that normal saline may be preferable due to its isotonicity and sterility. This review examines tap water as an alternative to normal saline in its use for wound cleansing and prevention of subsequent infection.

The Cochrane Collaboration reviewed three studies in adult populations and two in pediatric populations comparing the rates of acute wound infection from the use of these two solutions for acute wound cleansing. In adults (1138 participants) there was a slight decrease in wound infection in the tap water group (NNT 36 RR .6, 95% CI .40-.99). In the pediatric population (535 participants) there was a non-significant increase in wound infections in tap water group (NNT 500, RR 1.07, 95% CI .43-2.64).

A randomized controlled double-blind trial published since this Cochrane review found similar results. In the 663 participants studied there was no difference between those irrigated with tap water versus normal saline, with a trend towards decreased infections in the tap water group.

Given the lack of adverse events and affordability, tap water should be considered a safe alternative to normal saline for cleansing of acute wounds.

Caveats: In the Cochrane Review studies there was no standardization for wound infection diagnosis across the pooled data. In the case of chronic wounds, a small study found a similar decrease in infection in the tap water group as compared to the normal saline group (NNT 9).1

Interestingly, two studies comparing the use of tap water for cleansing versus no cleansing, one enrolling patients with acute head wounds and the other enrolling post-operative hernia patients caring for their wounds at home, found no difference in infection rates.2 3 However, these studies were small, of moderate quality, and further investigations would be needed before these findings could be generalized to a broader group.

Author: Christina Chao, MD and Dan Runde, MD

Published/Updated: February 20, 2013

  1. The Title Bar

    The title bar is color-coded with our overall recommendation.

    • Green: Benefits outweigh risks.
    • Yellow: Unclear risk/benefit profile.
    • Red: Benefits do not outweigh risks.
    • Black: Obvious harms, no clear benefits.
  2. Tip content...