EMERGENCY ULTRASOUND

 

 

 

 

Ultrasound is a useful, nonradiated, noninvasive, real-time, dynamic, and inexpensive diagnostic modality for immediate assessment at emergency departments. It allows findings to be directly correlated with a patient’s clinical presentations, provides efficient diagnosis, and decreases medical errors. Additionally, it can be used repeatedly if the patient’s condition changes, like an “ultrasound stethoscope” [1,2].

 

Emergency ultrasound (EUS) has developed substantially in the past 20 years. In the history and development of this field, “point-of-care ultrasound”, “bedside ultrasound”, and “focused ultrasound” are the interchangeable terms for EUS that can describe its characteristics [3]. EUS is considered integral to the clinical practice of emergency medicine [4], involving multidiscipline and goal-directed scanning. However, some authors suggested that EUS was limited and less comprehensive, compared to other ultrasound subspecialties [5].

 

In the United States, the American College of Emergency Physicians has instructed comprehensive guidelines of EUS as a standard for residency training. The guidelines comprise 11 core applications: trauma, intrauterine pregnancy, abdominal aortic aneurysm, cardiac, biliary, urinary tract, deep vein thrombosis, soft tissue, thoracic, ocular, and procedural guidance; and five scopes: resuscitative, diagnostic, procedural guidance, symptom/sign based, and therapeutic [6]. Additionally, the registered diagnostic medical sonographer certification, through the American Registry for Diagnostic Medical Sonography, is available for emergency physicians. However, controversies exist because this certification does not ensure or measure a physician’s competency [4].

In Taiwan, the “Ultrasound Subcommittee” of the Taiwan Society of Emergency Medicine (TSEM) was set up in 2008. The first committee chairman was Professor Hsiu-Po Wang. He contributed to the integration of professional work, and established a communication platform between the TSEM and the Taiwan Society of Ultrasound in Medicine (TSUM). Due to his efforts, the trabasic and advanced courses for EUS have been worked out by the TSEM since 2008. The “Emergency Subcommittee” of the TSUM and the credentialing system for the EUS instructors were established in 2009. Additionally, the academic forum “EUS” was initiated in 2009, in the annual meeting of the TSEM.

The certification program for the EUS instructors by the TSEM was established in 2012. Therefore, there are two kinds of certifications for the EUS instructors in Taiwan, through the TSEM or the TSUM. Till now, there are more than 40 EUS instructors to contribute to the EUS education in Taiwan.

In the field of academic development, previous studies focused on the application of EUS in critical care and resuscitation, mainly echocardiography [5,7e9]. Authors in Taiwan also contributed to the advances: Lien et al [10] proposed that hepatic portal venous gas was associated with poor prognosis in patients with cardiac arrest; Chang et al [11] suggested that a longer isovolumic relaxation time predicted poor survival outcomes at the postresuscitation period;Wang et al [12] concluded that in patients with plasma B-type natriuretic peptide levels within 100e500 pg/mL, cardiac ultrasound can help differentiate heart failure or not; Chou et al [13,14] proposed that the application of the

tracheal rapid ultrasound examination (TRUE) to examine endotracheal tube placement during emergency intubation and resuscitation was feasible and could be performed rapidly; and Simet al [15] showed that the positive predictive value of bilateral lung sliding in confirming proper endotracheal intubation was high, especially among patients with a cardiac arrest.

In this issue of Journal of Medical Ultrasound, Sun et al present a prospective observational study confirming the accuracy of tracheal tube placement using the TRUE protocol in the emergency departments of two medical centers [16]. The protocol used is following the previous serial studies: in case of tracheal tube intubation, only one air-emucosa interference is detected; in case of esophageal tube placement, a second airemucosa interference will appear, and the pattern then suggests a false second airway “double tract sign” [13].

Sun et al showed a good accuracy of the TRUE protocol in cardiac arrest patients by trainedining curricula including emergency physicians in twomedical centers in Taiwan [16].

This study is considered an extension of the previous single institutional study, and one part of the future multicenter study.

Sun et al also reviewed prehospital applications of EUS in many situations in this issue, including in patients with cardiac arrest, trauma, and acute dyspnea, as well as in high altitude environment or helicopters. Additionally, previous studies suggested that education of paramedics regarding ultrasound use might be feasible [17,18].

Although the accuracy of images can be improved by communication technologies [19], whether paramedics can perform EUS still depends on different national conditions.

EUS is an emerging ultrasound subspecialty that still has many issues to be explored. Presentation of the emergency department patients is diverse, and EUS can be applied in a prehospital setting, in hospitals, and during the post-resuscitation period. In this issue, some interesting articles on EUS are provided. More efforts will be needed to carry out EUS research in depth and breadth.