The initial proposal by Rozycki et al., in 1993 on the focused assessment with sonography for trauma (FAST) exam was a novel and systematic approach for the utilization of point-of-care ultrasound (POCUS) during the initial trauma survey.⁴ Although ultrasound was first described in the 1970s, this algorithm provided the framework for an integral component of our current trauma evaluation, largely replacing the need for diagnostic peritoneal lavage for the diagnosis of intraperitoneal hemorrhage.^1–3 It was not until 2004 that Kirkpatrick et al., published in the Journal of Trauma the protocol of the extended focused assessment with sonography for trauma (eFAST) exam incorporating the thorax in addition to the heart and abdomen assessment.⁴

Emergency physicians have been champions for implementing and teaching this invaluable tool into the culture of trauma care, altering the clinical care pathway for numerous critically ill trauma patients. After our nearly two decades of experience performing and interpreting the eFAST exam at a Level I trauma center, we believe that this durable bedside examination can benefit from a further nuanced conceptualization and approach.

Incorporating the eFAST Exam

Compared to when POCUS was first implemented for the assessment of trauma, computed tomography (CT) scanners have become faster (and more accurate), resuscitation theory has advanced, and the literature’s approach to traumatic injuries has changed.^5,6 In response to these changes, emergency physicians must determine the optimal ways of incorporating the eFAST exam. The goal of the eFAST examination for emergency physicians is not to replace CT imaging, but to complement modern trauma care in an evidence-based and practical manner.

Although emergency physicians have successfully incorporated the eFAST examination into the evaluation of patients with both blunt and penetrating trauma, we feel that the following recommendations can further enhance bedside decision making during your next critically-ill trauma resuscitation.

1. The “Three Box Concept”

FIGURE 1: A representation of the “three box concept” indicating the locations that need to be interrogated during an eFAST examination. (Click to enlarge)

When evaluating the acutely injured trauma patient, emergency physicians should be aware of the “three box concept” (See Figure 1). The thorax, heart, and abdomen comprise the three “boxes” that should be sonographically interrogated in order to determine whether an emergent intervention is warranted in the trauma bay, further imaging should be pursued, or the patient needs to proceed directly to the operating room (OR). In our experience, the order in which these “boxes’’ are evaluated as part of the eFAST should be based on the mechanism of injury as well as the patient’s clinical status. For example, patients with penetrating injuries to the chest should be initially evaluated for the presence or absence of pericardial effusion, pneumothorax, and hemothorax. A massive hemothorax/pneumothorax or a hemopericardium that is causing hemodynamic compromise may force the emergency physician to perform stabilization measures at the bedside (e.g., tube thoracostomy, pericardiocentesis, ED thoracotomy) without further imaging, or prompt the trauma surgeon to take the patient directly to the OR. If sonographic evaluation of these two boxes fails to reveal emergent pathology, evaluate the abdomen for the presence or absence of free fluid. Presence of hemoperitoneum in a hemodynamically unstable trauma patient classically leads to a direct need for operative intervention.