A blood loss amount can be heard by Kobushi, and a simple and epoch-making blood loss estimation method "MAR method" which may be useful when it is useful

Photo by David Shankbone

Estimating the amount of blood lost due to trauma on-site is very important for proper treatment and sometimes is a matter of life. When a large number of injured people need rapid rescue activities due to a large-scale disaster, estimation of blood loss is also a criterion of who should treat and deliver the highest priority.

However, a highly accurate blood loss estimation method has not been established so far,Emergency life-saving personMedical professionals such as medical professionals must rely on "visual inspection" to estimate the amount of blood loss, and the estimated estimated blood loss is sometimes quite uncertain. there,New Jersey Medical and Dental UniversityRobert Wood Johnson Medical SchoolDoctors and others developed "MAR method"It is expected that the method using the fist called the fist will greatly increase the accuracy of estimating the amount of blood loss.

I do not want to encounter the opportunity to look at the flowing blood and estimate that amount, but it is very simple and it is a method that anyone can do so it may not be damaging.

Details are as below.Physicians Develop Method Using Fist To Estimate Blood Loss At Scene Of Trauma

New Jersey Medical Dental College Robert Wood Johnson Medical School Emergency Medicine and Pediatric Associate Professor Mark Merlin and colleagues developed a method for estimating blood loss using the fist 'MAR method' and confirmed its accuracy by experiment. Thesis isAmerican Journal of Emergency MedicineIt is published in the magazine.

"MAR method" is to remember that "the blood pool of the area hidden by a fist is about 20 ml of blood" and calculate estimated blood loss by counting how many fists are needed to conceal the flowing blood How to do. The surface area of ​​the sample of human whole blood and the area hidden behind the fist on the palm side of the fist were compared in various amounts of blood and the number 20 ml was derived as the average of "blood volume per fist".

When estimating the amount of blood loss, compare this with the palm side of the fist down.


Of course there are limits to the accuracy because various factors such as the state of the ground and floor · the momentum of bleeding · individual difference of the fist size are involved, but the experimental result that it can estimate far more accurately than the visual estimation It has come out.

In the experiments, 74 subjects first estimated their volumes by "visual inspection" about 75 ml and 750 ml of blood densities, then estimate once again after receiving a 1 minute explanation on "MAR method", "estimate MAR method We compare errors from the actual blood volume of estimated blood volume before and after taught.

As a result, the estimated blood volume due to "visual observation" of 74 people had an average error of 120% (average of absolute values ​​of errors) from the actual value in the 750 ml model and an average error of 73% in the 75 ml model However, the average error from the average value decreased by 76% in the 75 ml model by the "MAR method", 40% in the 750 ml model,Quartile rangeIt is said that it decreased by 60% in the 75 ml model and by 45% in 750 ml. It seems that somehow complicated things are said,Not only was the estimated value approached the actual value (accuracy increased) by the "MAR method" but also the variance among 74 estimated values ​​decreased (the accuracy increased)It seems to be good to think.

"Over the years several institutions have been searching for simple formulas that quickly, precisely and precisely estimate the blood loss.This method uses multiple subjects and it is the first time we have evaluated individual differences of chestnut rushing It is a successful example of, "Associate Professor Merlin says.

I do not know how much the number "20 ml with a fist 20" will differ with different viscosity liquids, but those who do not have the opportunity to estimate the amount of blood can estimate their volume when spilling milk, It might be a good idea to show off as a tasteful knowledge when someone spills alcohol at a party such as a year-end party.