Point-of-care ultrasound (POCUS) is designed to answer very specific questions in real time. Additionally, it can help expeditiously make life-saving diagnoses, while avoiding unnecessary or potentially costly testing or imaging [1]. An important POCUS application in the emergency and critical care settings is the focused cardiac examination. The primary goal of focused cardiac POCUS is to identify pericardial effusions, tamponade, and asystole. Overall, the use of cardiac POCUS is underutilized in the pediatric patient population. This is presumably because the overall incidence of acquired (non-congenital) cardiac pathology in pediatric populations is quite low when compared with adult patient populations. Nonetheless, the identification of cardiac pathology in children can be immediately life-saving.
There exists a tremendous body of literature that supports the use of cardiac POCUS in diagnosing pericardial effusions in adult patient populations. Mandavia et al. [2] studied bedside cardiac POCUS performed by emergency medicine physicians in patients at high risk for pericardial effusions, with an overall accuracy of 98%, sensitivity of 96% and specificity of 98%. In patients with penetrating chest trauma and traumatic pericardial effusions, Plummer et al. [3] showed that cardiac POCUS improved outcomes when compared to those who did not receive cardiac POCUS, with shorter time to diagnosis (15.5 versus 42.4 min) and better overall survival (100% versus 57%).
There is limited literature on focused cardiac POCUS in pediatric patient populations. The majority of studies involving cardiac POCUS to identify pericardial effusions and tamponade in the pediatric ED setting are limited to case reports [4, 5]. However, in a prospective observational study of 70 pediatric emergency department patients, the overall sensitivity and specificity of cardiac POCUS in detecting diminished LV function, pericardial effusions, and abnormal IVC collapsibility, when compared with comprehensive echocardiogram was 95% (95% CI 82–99%) and 83% (95% CI 64–93%), respectively [6].
Cardiac tamponade clinically presents as Beck’s triad: jugular venous distension, muffled heart tones and hypotension [7]. However, only one-third of patients with tamponade will have all three features and 10% will not have any of them. POCUS can readily identify both pericardial effusions and sonographic tamponade [8]. The diagnosis of sonographic cardiac tamponade can be made before a patient becomes hypotensive or has clinical signs of tamponade. Signs of sonographic tamponade include a circumferential pericardial effusion, accompanied by poor filling and/or diastolic collapse of the right ventricle (“scalloping”) due to increased intrapericardial pressure, which results in reduction of stroke volume and cardiac output [9, 10].
Pericardiocentesis is the definitive treatment for cardiac tamponade. Ultrasound-guidance for pericardiocentesis has been shown to improve success rates and decrease complications when compared with blind attempts [11]. Though it is a rare condition in the pediatric population, pericardiocentesis may be indicated after blunt or penetrating trauma, or after cardiac catheterization or cardiac surgery [12]. Tsang et al. showed that those pediatric patients who had ultrasound-guided pericardiocentesis, had a 99% success rate, with 93% on the first attempt, and 1% major and 3% minor complication rates [13].
The identification of cardiac masses is not the primary goal of POCUS. However, this may be an unexpected or incidental finding. Alternatively, in a child presenting with a widened mediastinum on chest radiograph, a focused cardiac POCUS may be expeditiously performed to evaluate for the presence of a mass at the bedside.