Being in even the most benign car accident imaginable, can be stressful for patients. Inherently, if they have any chest pain they’re going to be convinced that they’ve sheared their aorta right off its hinges. While that may be of concern to them, we are pretty certain that their aorta is still intact if they still are alive, but did they sustain a cardiac contusion? How do we figure out if they had one? And what the heck do we do with them if they did in fact have a cardiac contusion?
1) What are we concerned about in blunt chest trauma?
There are many clinically significant injuries possible in the setting of blunt chest trauma. One that comes to mind is the nebulus diagnosis of “cardiac contusion.” A lot of the controversy and uncertainty comes from the unclear definition of cardiac contusion which seems to encompass things like myocardial rupture, valvular injury, arrhythmias, cardiac dysfunction, etc. In my mind these types of patients would be more clinically apparent so we’ll focus on the patients who may appear well or relatively so.
2) Do we need to get a troponin in blunt chest trauma?
The answer is yes and no. There is a “guideline” answer and a practical one.
The guideline answer is yes. The 2012 EAST practice guideline for blunt trauma recommends BOTH an EKG and troponin. They state based on their references that a normal EKG in blunt chest trauma has a NPV of 95%. This increases to 100% with a normal troponin. There are several studies that support the use of troponin in this setting and there are instances when EKGs may be normal with a positive troponin. One recent study showed a troponin at 24 hours had 100% NPV for severe cardiac injury.
But the practical answer may be no. There are other studies that are less optimistic regarding the sensitivity and specificity and discourage the use of troponin as a gold standard for diagnosing cardiac contusion from blunt trauma. Another study showed that positive troponins were not a strong predictor of abnormalities on echocardiogram. So getting a troponin may not even matter. However other studies suggested that a positive troponin may be indicative of cardiac contusion or underlying cardiac issue, which brings us to our next question.
3) What do we do with a positive troponin in blunt chest trauma?
One of the arguments against getting a troponin is not knowing what to do with it. If it is negative can they go home? If it’s positive do they need to stay? A 2013 prospective study out of Iran does not recommend troponin as a gold standard in cardiac injury but does encourage intensive cardiac monitoring if an elevated troponin is found. Another study showed that elevated troponin was linked to arrythmias during the patients stay. So this would suggest admission and tele monitoring for a patient that may have otherwise gone home.
4) Does this change the patients outcome?
Probably not. Three older studies looked at outcomes of patients with cardiac contusions and they really have no long term sequelae and do well.
What’s the bottom line?
Being in a trauma center I would follow the trauma guidelines of getting both an EKG and troponin in the setting of blunt chest trauma. If this is negative with a negative EKG and the patient appears well clinically then likely discharge. However if they have an isolated positive troponin then I would consider admission for 24 hour monitoring for arrythmias with a consideration for inpatient echocardiogram with a reassuring knowledge that they will almost absolutely do well long term.
Post by: Dr. Jordan Jeong, DO (@jeongjom)