Abstract
Point-of-care ultrasound, or POCUS, has become an increasingly important tool in emergency medicine over the past few decades. POCUS is a type of ultrasound that can be performed at the bedside, allowing emergency physicians to rapidly assess and diagnose a variety of conditions. It has revolutionized the way emergency medicine is practised, and has the potential to save countless lives.
The development of POCUS in emergency medicine began in the 1990s, when early studies showed that emergency physicians could accurately diagnose cardiac pathology using ultrasound. 1 This led to further research, which showed that ultrasound could be used to diagnose and manage other conditions, including trauma, abdominal pain, and early pregnancy complications.
As the technology improved, POCUS became more versatile and easier to use. Today, there are a variety of handheld ultrasound devices available that are designed specifically for use in emergency medicine. These devices are lightweight, portable, user-friendly and can be used to quickly assess a variety of conditions, including undifferentiated shock, pulseless electrical activity (PEA) cardiac arrest, pulmonary oedema and pneumothorax.
Shock evaluation is one of the major areas of POCUS application in critical or emergency settings. Many studies have been conducted to assess the utility of POCUS estimation of the inferior vena cava (IVC) to predict fluid responsiveness. In this issue of the Hong Kong Journal of Emergency Medicine (HKJEM), Unal Akoglu and Akoglu 2 analysed 21 studies including 1321 patients in a meta-analysis. The authors found the overall accuracy, sensitivity and specificity of respiratory variation of the IVC diameter to be 0.85, 0.72 and 0.81, respectively. The respiratory variation of IVC diameter had a moderate diagnostic utility to predict fluid responsiveness, whereas the accuracy of IVC distensibility and IVC collapsibility was similar.
Procedure guidance by ultrasound is another important utility of POCUS. Ultrasound can enhance the success, and safety of various clinical procedures, such as venous cannulation, pericardiocentesis and nerve block. Ultrasound-guided central line cannulation is recommended as a standard of care. Leung et al. 3 explored which shoulder position results in the greatest cross-sectional area of right subclavian vein for cannulation. In 44 healthy adult volunteers, the authors found that the mean cross-sectional area of the vein for the shoulder in either neutral or abduction positions was significantly increased when compared with shoulder retraction.
Over the past decade, the development of POCUS in emergency medicine has significantly advanced in Hong Kong. The ultrasound subcommittee of Hong Kong College of Emergency Medicine was established in 2006 by a group of enthusiastic emergency physicians dedicated to promoting POCUS use in emergency medicine. The Subcommittee is one of the pioneers in Hong Kong to provide training on POCUS for her trainees and physicians through different courses, conferences and certification programme. In 2022, they renamed the ‘Basic Emergency Ultrasound Competency Programme’ as the ‘POCUS EM Certification’ programme in line with the international standard. 4
The core members also collaborated to develop POCUS guidelines and protocols in their hospitals to ensure standardized and safe practices of this technology in emergency medicine. 5 They are involved in research and clinical studies aimed at further improving the use of POCUS in emergency medicine. They collaborate with other organizations and institutions like WINFOCUS to share knowledge and expertise and advance the POCUS field in Hong Kong and beyond.
The POCUS application is not exclusive to emergency physicians. Beyond the emergency department, paramedics have been trained to incorporate POCUS in prehospital trauma care in Hong Kong. Interested emergency nurses also received training on ultrasound-guided peripheral venous cannulation, bladder volume estimation, confirmation of nasogastric tube placement and wound assessment by POCUS in training courses. POCUS education has also been incorporated into some curricula in local medical schools.
The future is promising for POCUS. There are several new applications of POCUS being developed. Resuscitative Trans-Esophageal Echocardiography (TEE) has emerged as a valuable modality of imaging in cardiac arrest to search for the underlying causes, monitor the chest compression and guide the related interventions including extracorporeal cardiopulmonary resuscitation. 6 Currently, only a few emergency physicians in Hong Kong have attended training courses with simulators. Standardization of training, credentialing and quality reassurance of this new technique is warranted before TEE takes root in emergency departments locally.
Success has been made with artificial intelligence (AI) to interpret ultrasound findings and automate measurements. 7 AI can also help guide users to acquire the appropriate ultrasound image. These applications are particularly useful for novice users to master the skill of image acquisition and subsequent interpretation, which in turn enhance diagnostic power and patient safety. Yet, more research on AI-assisted POCUS applications is needed to validate the improvement in patient care with AI guidance.
In conclusion, we witnessed how POCUS has changed our practices in the past two decades. The ultrasound Subcommittee of the Hong Kong College of Emergency Medicine and other enthusiastic emergency physicians will continue to play a vital role in promoting the use of POCUS in emergency medicine in Hong Kong. Their efforts ensure our fellows and trainees acquire the up-to-date knowledge and state-of-the-art skills of POCUS, which benefits our patients.
Footnotes
Declaration of conflicting interests
The author(s) declared no potential conflicts of interest with respect to the research, authorship and/or publication of this article.
Funding
The author(s) received no financial support for the research, authorship and/or publication of this article.
