A 25-year-old man was brought to the ED after a motor vehicle collision. He was reportedly restrained, but his car was significantly damaged.
He reported chest and back pain and seemed confused. Some superficial abrasions were noted on his left arm, but otherwise no external evidence of trauma was seen.
His initial vital signs were a blood pressure of 110/70 mm Hg, a heart rate of 115 bpm, and a SpO2 of 99% on room air.
A FAST exam was performed, and the cardiac view is shown. What does it show?
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This parasternal long axis view revealed a hemopericardium. Pericardial effusions are difficult to identify clinically. The classic Beck triad of hypotension, muffled heart tones, and distended neck veins are present in less than half of all presentations. Ultrasound is a sensitive modality to identify effusions, but pitfalls are important to recognize.
The eye looks for an anechoic fluid collection between the myocardium and pericardium when evaluating the pericardium. In trauma patients, clotting or clotted blood is frequently present within the sac, causing a more hypoechoic (gray) appearance. This can be easily overlooked if the landmarks are not carefully identified.
The heart is easy to identify, but the pericardium is more difficult. (Image.) It is the bright white border near the bottom left of the image. The effusion can then be identified between the two. Its appearance identifies it as likely composed of clotted blood because it does not have the typical black appearance. (Watch a video of this injury at http://bit.ly/VideosSound.)
Other findings typically sought when evaluating patients with effusions are signs of tamponade or impending tamponade. It is critical to note that these signs (such as right atrial or ventricular collapse) may not be present when effusions accumulate rapidly, such as after trauma. Waiting for these signs to develop can result in a crashing patient. Being vigilant and acting quickly are key in evaluating and treating these patients.
Patients with penetrating cardiac trauma that results in effusion typically should undergo operative exploration as soon as it is identified, but evidence is limited for what to do with effusions resulting from blunt trauma. These are rarely encountered in the ED, and many of these patients will die of severe cardiac trauma before arrival. No consensus guidelines exist, although several recent articles argue for a wait-and-see approach in stable patients. (Am J Emerg Med. 2018;36 9:1655; https://bit.ly/3WpJbim; Injury. 2018:49:20; https://bit.ly/3J3Q1GZ.)
This patient had injuries in addition to the pericardial effusion and initially responded well to resuscitation. Two days later, he had a syncopal event while getting out of bed and subsequently underwent pericardial window with evacuation of clotted blood.
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Dr. Buttsis the director of the division of emergency ultrasound and a clinical assistant professor of emergency medicine at Louisiana State University at New Orleans. Follow her on Twitter@EMNSpeedofSound, and read her past columns athttp://bit.ly/EMN-SpeedofSound.