A Solution to Saving Lives: New Technology from the U.S. Army

The Facts:

1. Hemorrhage is the leading cause of death in survivable deaths from traumatic injuries in both the civilian and the military populations.  
2. Hemorrhage is responsible for 91% of the preventabledeathsin the military, and responsible for 612,000 deathsper year in the civilian population.  
3. Early intervention is one of the key solutions to decreasing survivable deaths caused by hemorrhage. 

The Problem:

 If the solution is as easy as early intervention, what is delaying treatment for these patients?  

1. When trauma occurs, the medical staff only has what is visually observed of the patient, and the patient’s standard vital signs to detect any signs of hemorrhagic shock.  This method does not detect hemorrhage early enough to intervene with life-saving interventions.   
2. Hemorrhage is not always visible, such as the case of internal bleeding.  A patient suffering from internal bleeding will most likely be treated after a patient with visible blood loss.  The problem here is that the internal blood loss could be worse than the visible blood loss, however there is almost no way for the medical team to be aware of this until it is too late.  
3. Using standard vital signs. The body is very good about compensating for blood loss.  The body will continue to maintain somewhat regular vital signs, until it can no longer compensate for the loss of blood, at which point the vital signs will show significant changes.  By the time the vital signs show changes, the body begins to shut down organs and it is almost too late for intervention. 

The Solution:

The possible solution to these problems is the Compensatory Reserve Index (CRI). The CRI is a device that has the ability to detect hemorrhage much sooner than vital signs, theoretically allowing for earlier intervention.  Here is how it works.   

The algorithm behind the CRI

The CRI is composed of brand new technology developed by the U.S. Army, and is generated from the patient’s arterial wavelengths.  These wavelengths represent the sum of all the compensatory mechanisms of the body.  Over many years, the U.S. Army built a database of arterial wavelengths recorded from volunteers and were recorded during different blood volumes.   

When the CRI device is placed on a patient, it records the patient’s arterial wavelengths within the first thirty heartbeats.  During that time, the CRI compares the patient’s wavelengths to the wavelengths it has stored in the database. It then predicts how close the patient is to decompensation (organ failure).  After the initial first thirty heartbeats, the CRI measures arterial wavelengths at every heartbeat, constantly updating the prediction.  The CRI scale is from 0-1. One is considered a ‘full tank’, and zero is the point of decomposition.  Numbers from 0-1 give an indication of how close the patient is to organ failure. 

The CRI in Comparison to Other Measures

            We know the problems - there is no current way to detect hemorrhage early enough for intervention.  We also now know how the CRI works.  Now, how do we apply the CRI to the current problems related to deaths caused by hemorrhage?  

             Research studies have been implementing the CRI in simulated hemorrhage settings and comparing it to vital signs for detecting hemorrhage. The CRI has outperformed vital signs in early detection of hemorrhage in all the studies.  In fact in most of the studies, as the central blood volume decreased in the volunteers, the CRI decreased accordingly. The standard vital signs did not have a significant enough change for the studies to even include a measurement.

The CRI doesn’t just detect hemorrhage in the earlier stages, it detects it in a timely manner.  It took medical professionals 10.7 minutesto detect instability (decompensation) in a patient when using the CRI monitor.  The medical professionals then tried detecting instability in a patient using a vital sign monitor.  Solely using vital signs, it took the medical team 18.3 minutes to detect instability. A 7.6 minute difference can be huge when trying to treat a patient with blood loss in an emergency situation.  

Not only can the CRI detect blood loss, it can also detect when intervention is working. In othe words, it can detect when the patient starts to become stable again.  A studythat observed this had participants that underwent red blood cell (RBC) transfusions with their CRI levels taken during the transfusion. The results showed that as the RBC count increased, the CRI levels of the patients also increased. 

  

That is a lot of science and studies, so the basic breakdown of the comparisons is this:

The Comparison	The outcome
Compared to vital signs, the CRI detects hemorrhage in earlier stages	More time for intervention
Compared to vital signs, the CRI is easier to read/use	More time for intervention
The CRI detects all changes to blood volume (decrease or increase in blood volume)	Knowing if treatment is effective/working

Future of Saving Lives

            While the CRI has proved itself against standard vital signs in early detection of hemorrhage during the simulated hemorrhage studies, there is still some research to be done before it ends up in the hands of medical professionals.  All of the studies were performed with healthy individuals in controlled environments. In real world scenarios, the CRI would be utilized in situations with real hemorrhage patients in stressful environments.  Further research would need to observe the CRI in these types of situations.  Also, while the simulated hemorrhage technique used in all the studies is provento be the best simulation for hemorrhage, there is no way to test the CRI in a real hemorrhage situation unless it is actually tested with real hemorrhage patients.  

 If the CRI can continue to prove it’s ability in future studies in real scenarios, the CRI has potential to land in the hands of medical professionals and could be the answer to decreasing survivable deaths from hemorrhagic shock.  

Meet the Author

My name is Nicole Buzzee, and I am a senior at Westfield State University studying Movement Science with a concentration in Sports Medicine.  I plan to attend graduate school to earn my Doctorate of Physical Therapy.  I would love to work with the military or veteran population while applying my passion for health.  

https://www.linkedin.com/in/nicole-buzzee/

References

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