July 10, 2018 by Agnes Usoro
It’s a busy Monday afternoon ED shift and you get a box call from EMS. 25-year-old restrained driver was involved in an MVC collision going about 40 miles per hour. She self extricated, denies loss of consciousness and was ambulatory on the scene. Vitals are notable for tachycardia to the 130s, BP 135/75, RR 20, 99% on room air. Upon arrival to the ED, primary and secondary surveys were unremarkable for any gross injuries but do reveal bruising to the anterior chest wall overlying the sternum. Chest x-ray was negative for a pneumothorax, hemothorax or bony fracture and Chest CT did not reveal any visceral pulmonary injuries, bony fractures or vascular injuries. Labs were notable for a negative troponin and her EKG revealed sinus tachycardia without any arrhythmias. You wonder if there is any additional work up needed to rule out a blunt cardiac injury, such as a cardiac contusion? And if this patient is safe for discharge?
Blunt Cardiac Injury (BCI) should be suspected in any patient presenting after blunt chest trauma. BCI has varying presentations from subtle chest pain and difficulty breathing to hemodynamic instability from fulminant heart failure and even death. There lacks a gold standard to confirm or exclude BCI but various diagnostic modalities can be used to predict the likelihood of cardiac injury in the setting of trauma.
Here we will discuss the 2012 recommendations by the Eastern Association for the Surgery of Trauma regarding screening for Blunt Cardiac Injury as well as alternative recommendations to these guidelines:
- For all patients presenting to the Emergency Department with blunt chest trauma, they should receive an electrocardiogram (ECG) – Level 1 Recommendation
- If there are any ECG abnormalities, new from the patient’s baseline ECG, the patient must be admitted for continuous ECG monitoring.
- If the ECG abnormality remains persistent on serial ECGs, a transthoracic echocardiogram should be obtained.
- For all patients presenting to the Emergency Department with blunt chest trauma, they should have a troponin I level measured – Level 2 Recommendation
- If the troponin I level is elevated, the patient must be admitted for continuous ECG monitoring and serial troponins.
- Troponin though can be elevated in the setting of catecholamine release or reperfusion injury from hypovolemic shock and may not be indicative of blunt cardiac injury. Therefore, alternative recommendations by an Emergency Medicine systematic review recommends against obtaining a screening troponin unless you have an abnormal ECG.
- For individuals with an abnormal ECG or positive troponin, you can consider Cardiac computed tomography (CT) or Cardiac magnetic resonance imaging (MRI) to differentiate blunt cardiac injury from an acute myocardial infarction – Level 3 Recommendation.
- Cardiac contusion is only associated with 2.4% of sternal fractures. Hence, with a normal ECG and negative troponin, additional work up is not required even if a patient has a sternal fracture.
Overall if BCI is highly suspected despite a normal ECG and negative troponin, you can consider performing a bedside point-of-care echocardiogram to evaluate for regional wall motion abnormalities or evidence of a reduced ejection fraction. But even with a normal bedside ultrasound, if the suspicion for BCI remains high, particularly in a patient with ongoing chest pain, the patient should be monitored for a minimum of 24-48 hours. The treatment of BCI is primarily supportive but can involve electrolyte repletion, utilization of inotropic agents, and become as invasive as an intra-aortic balloon pump, angiography, or even surgery.
Our trauma patient had a normal ECG and negative troponin. Her tachycardia resolved with fluids and she was observed for 4 hours. She was ultimately cleared for discharge by the trauma service and suffered no long-term sequelae from her blunt chest trauma.
Bernardin B., Troquet, J. Initial management and resuscitation of severe chest trauma. Emerg Med Clin North Am. 30(2):377-400, 2012.
Eastern Association for the Surgery of Trauma. Blunt cardiac injury, screening for. J Trauma. 73(5):S301-S306, November 2012. Obtained from: https://www.east.org/education/practice-management-guidelines/blunt-cardiac-injury,-screening-for
Morley, E.J., et al. Emergency department evaluation and management of blunt chest and lung trauma. Emergency Medicine Practice, 18(6), June 2016. Obtained from: ebmedicine.net