Abstract

Background
Each year millions of Americans venture to the backcountry to enjoy the outdoors. Lacerations and abrasions are some of the most common injuries encountered. Previous research shows that the best treatment to limit infection in contaminated wounds is irrigation of the wound with pressures between 6 and 15 pounds per square inch (psi).
Methods
We took 4 of the most popular water purifications units available to the consumer and measured the impact pressures of each to see if they would consistently produce the required 6 psi necessary for adequate wound irrigation. Impact pressures were calculated by directing the stream onto a metal bending beam that allowed measurement of force. PSI was then calculated by dividing the force of the stream by its surface area.
Results
Using 3 separate measurements added together and divided for 1 average the following psi were calculated. Katadyn Hiker Pro, 1.38 psi; MSR Sweetwater microfilter, 3.68 psi; First need deluxe water purifier, 1.84 psi; and MSR Miniworks EX microfilter, 0.82 psi.
Conclusions
While any type of irrigation and cleansing of a contaminated wound is better than nothing, none of the 4 water purification units reached the suggested 6 psi necessary for wound irrigation. It is suggested that a 35- to 50-mL syringe with an 18-gauge needle be added to your first aid kit to be used with the filtered water from your unit.
