Irrigation of simple lacerations with tap water or sterile saline in the emergency department did not differ for wound infections
Q In patients presenting to the emergency department (ED) with simple lacerations, is wound irrigation with tap water equivalent to irrigation with sterile saline for wound infections?
randomised controlled trial.
blinded (outcome assessors).
5–14 days after wound closure.
2 urban trauma centres and 1 suburban community hospital in the US.
713 patients >17 years of age who presented to the ED with acute uncomplicated skin lacerations requiring staples or sutures. Exclusion criteria were puncture or bite wounds; self inflicted wounds; grossly contaminated wounds; wounds >8 hours old; wounds involving tendon, joint, or bone; diabetes; significant peripheral vascular disease; HIV or immunocompromised conditions; use of antibiotics or corticosteroids; or pregnancy.
339 patients were allocated to tap water irrigation. Patients with upper extremity wounds were instructed to irrigate their wounds for ⩾2 minutes under tap water from an unmodified tap in a steel sink. Patients with wounds in other locations used a non-sterile, single use, approximately 1-metre length of clear plastic tubing connected to the tap to facilitate irrigation. 374 patients were allocated to sterile saline irrigation. Wounds were irrigated by providers, using ⩾200 ml sterile saline administered with a sterile 35 ml syringe. Wound care after irrigation, including method of closure, was at the provider’s discretion in both groups. All patients were instructed to return to the ED in 5–14 days for suture or staple removal and wound evaluation.
wound infection (wounds that required a significant change in treatment course after closure, specifically, debridement, antibiotics, or early suture or staple removal). Equivalence between groups would be accepted if the tap water group had a wound infection rate <10%. A sample size of 1000 was calculated to provide 80% power to detect a 5% absolute difference in wound infection rates with α = 0.05 and 15% attrition.
89% were included in the analysis (64% with upper extremity wounds).
The tap water and sterile saline groups did not differ for wound infection rates (table); the trial was underpowered to detect a difference between groups.
In patients presenting to the emergency department with simple lacerations, wound irrigation with tap water did not differ from irrigation with sterile saline for wound infections.
- Mary Cooke, RGN, PhD
The relative efficacy of solutions used for wound cleansing remains unclear despite several studies and a review.1 In previous trials comparing isotonic saline with tap water,2,3 neither was found to have significant benefit over the other, and no trials have answered the question of whether there is a clinically significant increase in infection rates with tap water rather than sterile saline.
In emergency care, wound closure materials include glue, “steri-strips,” sutures, or clips. Moscati et al did not discuss these or other key variables such as skin preparation, patient age or comorbidities, or the variable quality of tap water. The definition of infection is valid (ie, patients with such reactions would need to seek advice). The authors concluded that the study was underpowered to detect a doubling in infection rates between saline and water, although the lower costs recorded with tap water could outweigh a potential change in infection rates that includes a halving with tap water to 1.65% or an increase to 8.9%. Other methodological limitations of the study include loss of >10% of the patients despite a $10 stipend (although this loss was equal across both groups), failure to do an intention-to-treat analysis, and the use of rough estimates to calculate costs.
The study by Moscati et al confirms the findings of previous studies that using tap water instead of saline does not increase infection rates, but larger studies or a meta-analysis are needed to exclude the possibility of a type 2 error (ie, concluding there is no difference when one actually exists).
For correspondence: Dr R M Moscati, State University of New York at Buffalo, Buffalo, NY, USA.
Sources of funding: in part, Federal Highway Administration through the Center for Transportation Injury Research and Calspan University at Buffalo Research Center.