Focused cardiac ultrasound is emerging as a useful tool in preoperative evaluation and crisis management. Focused cardiac ultrasound’s scope of practice includes screening for the presence/absence of pericardial effusion.1 Thus, practitioners of focused cardiac ultrasound should be able to differentiate a pericardial effusion from conditions that can mimic it, especially in an emergency. These focused cardiac ultrasound images were obtained in a patient who presented with hypotension and was found to have a trace pericardial effusion along with two other conditions that are often misdiagnosed as pericardial effusion.2,3
Fluid collections on ultrasound appear as anechoic/hypoechoic (dark) spaces with posterior acoustic enhancement (brightness deep to the effusion). In this parasternal long-axis view (PSLAX), two such fluid collections are seen posterior to the heart. In any parasternal long-axis view, fluid that dissects into the plane between the heart and descending aorta is pericardial whereas fluid deep to the heart unable to dissect into this plane is classically a left pleural effusion.3 Thus, this parasternal long-axis view shows a trace pericardial effusion and a large left pleural effusion containing atelectatic lung (Supplemental Digital Content 1, https://links.lww.com/ALN/C91).
In the subcostal four-chamber view (SC4C), two fluid collections appear superficial to the heart. In any subcostal four-chamber view, circumferential pericardial fluid follows the contours of the heart. In contrast, ascites fails to follow the contours of the heart and additionally contains an undulating falciform ligament2 (Supplemental Digital Content 2, https://links.lww.com/ALN/C92). Thus, this image shows the patient’s trace pericardial effusion and also prominent ascites.
The authors declare no competing interests.