Determining blood loss at the scene of trauma can be critical to successful patient treatment. Healthcare workers have used visual estimation, which can be highly inaccurate, to determine volumes of blood loss. A simple method developed by University of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School may drastically improve their accuracy.
A team led by Mark Merlin, DO, assistant professor of emergency medicine and pediatrics at the UMDNJ-Robert Wood Johnson Medical School and medical director of emergency medical services at Robert Wood Johnson University Hospital, has developed the MAR Method, which relies upon a persons fist to determine external blood loss.
In a clinical trial, increments of human whole blood were measured. The researchers compared the anterior (palm side) surface of the fist to the surface area of blood present and created a formula averaging blood per fist. They determined that a fist covers a surface area of blood that equals roughly 20 mL.
Then two scenarios were staged using 75 and 750 mL of blood. Seventy-eight study participants were asked to estimate blood volumes before and after being taught the MAR Method.
After less than one minute of instruction, participants were able to determine blood volumes with improved accuracy and precision, the researchers report in an article in the American Journal of Emergency Medicine.
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