Department of Psychology, Old Dominion University, Norfolk, VA, United States of America.
Department of Computer and Information Science, Linköping University, Linköping, Sweden.
PLoS One. 2020 Nov 12;15(11):e0242096. doi: 10.1371/journal.pone.0242096. eCollection 2020.
A severe hemorrhage can result in death within minutes, before professional first responders have time to arrive. Thus, intervention by bystanders, who may lack medical training, may be necessary to save a victim's life in situations with bleeding injuries. Proper intervention requires that bystanders accurately assess the severity of the injury and respond appropriately. As many bystanders lack tools and training, they are limited in terms of the information they can use in their evaluative process. In hemorrhage situations, visible blood loss may serve as a dominant cue to action. Therefore, understanding how medically untrained bystanders (i.e., laypeople) perceive hemorrhage is important. The purpose of the current study was to investigate the ability of laypeople to visually assess blood loss and to examine factors that may impact accuracy and the classification of injury severity. A total of 125 laypeople watched 78 short videos each of individuals experiencing a hemorrhage. Victim gender, volume of blood lost, and camera perspective were systematically manipulated in the videos. The results revealed that laypeople overestimated small volumes of blood loss (from 50 to 200 ml), and underestimated larger volumes (from 400 to 1900 ml). Larger volumes of blood loss were associated with larger estimation errors. Further, blood loss was underestimated more for female victims than male victims and their hemorrhages were less likely to be classified as life-threatening. These results have implications for training and intervention design.
严重出血可能在几分钟内导致死亡，而专业的急救人员还来不及赶到。因此，在出血受伤的情况下，可能需要缺乏医疗培训的旁观者进行干预，以挽救受害者的生命。正确的干预措施要求旁观者准确评估伤害的严重程度，并做出适当的反应。由于许多旁观者缺乏工具和培训，他们在评估过程中所能使用的信息有限。在出血情况下，可见的失血可能是采取行动的主要线索。因此，了解未经医学培训的旁观者（即普通民众）如何感知出血非常重要。本研究的目的是调查非专业人员通过视觉评估失血的能力，并研究可能影响准确性和伤害严重程度分类的因素。共有 125 名非专业人员观看了 78 段个体出血的短视频。在视频中系统地操纵了受害者的性别、失血量和摄像机视角。结果表明，非专业人员高估了小量失血（50 至 200 毫升），而低估了大量失血（400 至 1900 毫升）。较大的失血量与较大的估计误差有关。此外，女性受害者的失血量被低估得更多，她们的出血也不太可能被归类为危及生命。这些结果对培训和干预设计具有启示意义。
