CPR评分解释了

我们知道良好的CPR可以给出更高的生存率，而得分的想法是反映出表现的出色for the patient.

Previously, CPR feedback has been given with a strict approved/non-approved result. Over the last 10 years, Laerdal and our partners have created an algorithm providing a more detailed and granular CPR score. Let’s illustrate with an example:

例子：Meet Julie, a top CPR performer who failed the CPR test

Julie is an emergency nurse in a UK hospital. She is physically fit, and able to provide solid depth of more than 50mm in every compression - all fully released and with absolutely no interruptions. She is one of the best CPR performers we’ve ever seen. Still, after the session, the binary CPR feedback said she had failed. Why?

她的压缩速度是每分钟一致的122次压缩。在临床上很棒，但在指南中的魔术100-120限制之外只是一点点。告诉她她失败了吗？不。如果您的生活在线，您希望朱莉能对您进行心肺复苏术。

We saw these results all the time when using the old, binary scoring, and this is one of the reasons we made a new algorithm for scoring CPR.

尽管其他CPR评分的提供者仅使用二进制数字，但Laerdal使用非二进制方法来提出更现实和救生的性能审查。简单的原因是，尽管49毫米和25毫米压缩深度都超出了指南阈值，但无疑是49，而到目前为止，迄今为止的性能更加多。

• 二进制评分：只是通过或失败。在介绍性的示例中，学习者1在50-60 mm的正确范围内具有94％的压缩。其余的压缩不在准则之外。例如25毫米和49毫米之间没有区别。他们俩都是“不足的”。
• 非二进制数：The bigger the deviation, the bigger the score reduction. In other words, 49 mm compression depth gives a far better score than 25 mm.

Fig 1. Non-binary scoring.
学习者1and 2 have equal amount of compressions inside and outside of the guideline threshold. But Learner 2 get the higher score since compressions outside the thresholds are closer to the guideline.所有其他CPR技能都使用相同的原则。（数字不扩展，仅出于说明目的）

The algorithm which makes up the QCPR score is made by Laerdal Medical in close collaboration with members of the AHA ECC Subcommittees and co-authors of the 2013 AHA Consensus Statement on CPR Quality. Based on input from these specialist members, we created mathematical models for each sub-skill in CPR performance, like compression depth, leaning, ventilation volume, etc.

每个压缩和通风都会单独跟踪和评分，并在整体得分中求和。即使平均率之类的数字可能很有趣，但平均值也不用于计算总分。同样，二进制数不会直接影响分数计算。

减法评分模型
The scoring algorithm use a subtractive scoring model where we start off on a perfect score and, if the learners do something wrong, the score is reduced. If you are within the guidelines you will always get a 100% score. If you deviate, the score is reduced.

沿着S曲线绘制，我们可以看到，小偏差会减少整体得分，而大偏差会导致CPR分数大幅下降：

图2：X轴的压缩率，并在Y轴上得分。
We see that the CPR score deteriorates quickly on both sides of the guideline thresholds. (graph not to scale, for illustrative purposes only)

QCPR Manikins的一个流行功能是QCPR竞赛，其中最多六名学习者可以参加一场比赛，以查看哪一个表现最好的CPR。

有时我们看到,当一个参与者achieves the best score on binary sub-metrics (like adequate depth percentage), another participant will be crowned the winner of the race. The binary sub-metrics (like percentage of adequate depth) will not always help explain the CPR score.

示例1-低二进制指标的高分：

Two learner perform 100 compressions. Learner 2 gets a better overall score than learner 1, even though learner 1 had better compression depth if you only look at the binary metrics.

原因是学习者2是closerto the guidelines during the 10 compressions that were not fully "adequate", and learner 1 was very far away from the guidelines during the 8 compressions that were not "adequate".

示例2-超过限制的通风：

In another example, both learners provide too much air in ventilation and miss the ventilation sub-metric.

Let's say learner 2 gave 610 ml of air (which is clinically OK) and learner 1 provided 2000ml of air, which indeed can compromise the clinical outcome. In binary terms, these results are the same, simply "not adequate". However, in clinical terms, and therefore also in scoring terms, they are very different. Learner 2 was much closer to the guidelines and receives a higher score.

有时,特别是for 'Compressions Only' sessions - the total score is unexpectedly low, even though compression rate, depth, and release are all perfect (see image below).

The score reduction for many of those sessions comes from the chest compression fraction. If your compressions are interrupted, there will be a reduction in the score - longer interruptions give larger score reductions.

同样值得注意的是，如果您仅进行“仅压缩”会话，则预期的胸部压缩分数为100％，因为您没有充分的理由停止压缩。因此，如果存在中断，则分数会严格降低。

插图，仅压缩会话：速率，深度和释放都是完美的。但是，总分出乎意料地低。罪魁祸首是胸部压缩分数参数。

The number of parameters scored depends on which manikin or simulator you use, and which software or application you use.

用于计算QCPR分数的10个参数：

• Compression depth
• 压缩率
• Incomplete release
• Hand position
• 每个周期的压缩
• Chest compression fraction (also known as flow fraction)
• 通风量
• Ventilation rate
• Number of pre-ventilations
• 灵感时间