Objective: The study hypothesis was that irrigation with tap water is as efficacious as irrigation with sterile saline in removing bacteria from simple lacerations in preparation for wound closure.
Methods: The study was conducted in a laboratory rat model previously described in the literature for evaluating wound irrigation techniques. The study used a randomized, blinded crossover design using 10 animals. Two full-thickness skin lacerations were made on each animal and each wound was inoculated with standardized concentrations of a Staphylococcus aureus broth. Wounds were irrigated for 4 minutes with normal saline from a syringe or 4 minutes with tap water from a faucet. Tissue specimens were sampled from each laceration prior to and following irrigation. Bacterial counts per gram of tissue were determined for each specimen and compared pre- and postirrigation.
Results: Preirrigation bacterial counts were not significantly different for saline vs tap water specimens. The wounds irrigated with saline had a mean reduction in bacterial count of 54.7% (SD=+/-28%), while the wounds irrigated with tap water had a mean reduction in bacterial count of 80.6% (SD=+/-20%) (p < 0.05, 2-tailed, paired t-test).
Conclusions: In this animal model, bacterial decontamination of simple lacerations was not compromised, and was actually improved using tap water irrigation. This is most likely due to the mechanical differences in the types of irrigation. In certain instances, such as with upper-extremity lacerations, tap water irrigation would likely be cheaper and less labor-intensive than irrigation with normal saline from a syringe.