使用 MAR 法估计外部失血量。

External blood loss estimation using the MAR Method.

机构信息

University of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School Department of Emergency Medicine, New Brunswick, NJ 08901, USA.

出版信息

Am J Emerg Med. 2009 Nov;27(9):1085-90. doi: 10.1016/j.ajem.2008.07.039.

DOI:10.1016/j.ajem.2008.07.039

PMID:19931755

Abstract

BACKGROUND

An element lacking in medical education is training to estimate blood volumes. Therefore, health care workers currently use visual estimation as their only means of determining blood volumes, which has shown to be highly inaccurate. This study proposes and tests a new method using one's fist to determine external blood loss.

METHODS

Increments of human whole blood were measured and used to compare fist size to surface area of blood present. A formula was created averaging blood per fist, hereafter known as the MAR Method. Two scenarios were staged using set quantities of blood (75 and 750 mL). Participants estimated blood volumes before and after being taught the MAR Method in a 1-minute session. Errors in estimation before and after using the MAR Method were compared.

RESULTS

The MAR Method was created using a fist to cover a surface area of blood that equals 20 mL. A total of 74 participants had errors of 120% and 73% for visualization of the small and large pools, respectively. For the smaller volume, the average error from the mean decreased by 76% (P < .0001), and the interquartile range of errors decreased by 60%. For the larger volume, the average error from the mean reduced by 40% (P < .0001), and the interquartile range of errors reduced by 45%.

CONCLUSION

Use of the MAR Method improves blood volume estimations. After less than 1 minute of instruction, participants were able to determine blood volumes with improved accuracy and precision.

摘要

背景

医学教育中缺乏的一个元素是估算血量的培训。因此，医护人员目前仅使用目视估计作为确定血量的唯一手段，但事实证明这种方法非常不准确。本研究提出并测试了一种使用拳头来确定外部失血的新方法。

方法

测量人体全血的增量，并将拳头大小与存在的血液表面积进行比较。创建了一个平均每拳血量的公式，以下称为 MAR 方法。使用设定量的血液（75 和 750 毫升）进行了两个场景的模拟。参与者在 1 分钟的会议中接受了 MAR 方法的教学后，分别对血液量进行了估计。比较了使用 MAR 方法前后的估计误差。

结果

MAR 方法是使用拳头覆盖血液表面积为 20 毫升来创建的。共有 74 名参与者在可视化小池和大池时的错误率分别为 120%和 73%。对于较小的体积，平均误差从平均值减少了 76%（P<0.0001），误差的四分位距减少了 60%。对于较大的体积，平均误差从平均值减少了 40%（P<0.0001），误差的四分位距减少了 45%。