CPR scoring explained

We know good CPR gives higher survival rates, and the idea about scoring is to reflect how good the performance really isfor the patient。

此前，CPR反馈已经提供了严格的批准/未经批准的结果。在过去的10年中，莱德尔和我们的合作伙伴创建了一种提供更详细和粒度CPR评分的算法。让我们用一个例子来说明：

Example:遇见朱莉，这是一个失败的CPR测试的CPR表演者

朱莉是英国医院的紧急护士。她身体健康，能够在每种压缩中提供超过50毫米的固体深度 - 全部释放，绝对没有中断。她是我们见过的最佳CPR表演者之一。仍然，在会议之后，二进制CPR反馈表示她失败了。为什么？

The rate of her compressions were a consistent 122 compressions per minute. Clinically superb, but just a tiny bit outside of the magic 100-120-limit in the guidelines. Was it fair to tell her she failed? No. If your life was on the line, you’d want Julie to perform CPR on you.

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.

而其他的提供者CPR得分只使用比娜ry numbers, Laerdal uses a non-binary approach to present a more realistic and lifesaving performance review. The simple reason is that while both 49 mm and 25 mm compression depth is outside of the guideline threshold, 49 is undoubtedly, and by far, a much more desired performance.

• Binary scoring:Simply passed or failed. In the introductory example, Learner 1 had 94% of the compression in the correct range of 50-60 mm. The remaining compressions were outside the guidelines. There is no distinction between for example 25 mm and 49 mm. They are both "inadequate".
• Non-binary numbers:偏差越大，减少得分越大。换句话说，49毫米压缩深度给出了比25毫米更好的得分。

图1.非二进制评分。
学习者1和2在指南阈值的内部和外部具有相同的压缩量。但是学习者2获得更高的分数，因为阈值外部的按压更接近指南。The same principle is used on all other CPR skills. (figure not to scale, for illustrative purposes only)

批发QCPR评分的算法是由劳埃尔医疗与2013年AHA CPR质量同意陈述的AHA ECC小组委员会和共同作者188体育直播比分的成员密切合作。基于这些专业成员的输入，我们为CPR性能的每个次技能创建了数学模型，如压缩深度，倾斜，通风量等。

Each compression and ventilation are tracked and scored individually and summed up in the overall score. Even though numbers like average rate can be interesting, averages are not used to calculate the overall score. Similarly, the binary numbers do not affect the score calculation directly.

Subtractive scoring model
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.

Plotted along an S-curve, we can see that small deviations give small reductions in the overall score, while large deviations result in large reductions in CPR scores:

Fig.2 : Compression rate on the x-axis, and score on the y-axis.
我们看到CPR评分在指南阈值的两侧迅速恶化。（图表不扩展，仅用于说明目的）

A popular feature of our QCPR manikins is the QCPR race where up to six learners can participate in a race to see which one performs the best 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.

Example 1 - high score with low binary metrics:

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.

The reason is that learner 2 was更近在10个压缩期间的指导方针，并没有完全“充足”，而学员1则在8个压缩期间远离指南，这些压缩不“充足”。

Example 2 - Ventilations over the limit:

在另一个例子中，两位学习者都提供了过多的通风空气，并错过了通风子度量。

让我们说学习者2给了610毫升的空气（临床上的OK），学习者1提供了2000ml的空气，这确实可以损害临床结果。在二进制术语中，这些结果是相同的，简单地“不足”。然而，在临床术语中，因此也在得分术语中，它们非常不同。学习者2更接近指南并获得更高的分数。

有时 - 特别是对于“只关注”会话 - 总分数竟然很低，即使压缩率，深度和释放都是完美的（见下图）。

许多会话的得分减少来自胸部压缩分数。如果您的压缩中断，则会减少得分 - 更长的中断会导致更大的分数减少。

Also worth noting, if you are running a ”Compression only” sessions, the expected chest compression fraction is 100%, as you have no good reasons to stop the compressions. So, if there are interruptions, the score is reduced rather strictly.

Illustration, Compression only session: Rate, depth, and release are all perfect. However, the total score is unexpectedly low. The culprit is the chest compression fraction parameter.

评分的参数数量取决于您使用的Manikin或模拟器，以及您使用的软件或应用程序。

10 parameters used to calculate QCPR score:

• 压缩深度
• Compression rate
• 不完整的释放
• 手势位置
• Compression per cycle
• 胸部压缩分数（也称为流量分数）
• Ventilation volume
• 通风率
• 通风前的数量
• Inspiration time in pre-ventilations