Point-of-care (POC) ultrasound — in which the treating physician scans patients instead of sending them to an imaging specialist — can speed patient management decisions, providing more time-efficient and effective patient care. A POC ultrasound exam is typically performed to answer a specific clinical question.
POC ultrasound (commonly known as POC US or POCUS) is also routinely used to guide interventional procedures such as therapeutic injection of medications, as well as for a range of other applications performed by various health care providers. Outside of health care facilities, it is used at trauma sites and disaster sites, during extra-hospital patient transport, and at sporting events.
What Is Point-of-Care Ultrasound Imaging?
Diagnostic ultrasound scanners are medical imaging devices that use high-frequency sound waves to allow users to obtain information about patients’ anatomy and physiology. Point-of-care ultrasound imaging refers to the use of medical ultrasound by the treating physician — as opposed to referring the patient to an ultrasound specialist — to acquire anatomical and physiologic information at the bedside. Such exams are typically performed to answer a specific clinical question.
The main benefit of POC ultrasound is that it allows physicians to quickly determine whether an abnormality is present so that they can then make patient management decisions. Because patients don’t need to be referred to imaging specialists, they don’t need to make an additional appointment for the imaging exam and wait for the diagnosis to be provided to their treating physician. The result is more time-efficient and effective patient care.
An Alternative to Traditional Practice
Diagnostic ultrasound imaging has historically been, and still is, used in such clinical settings as radiology departments and freestanding imaging clinics, obstetrics and gynecology (OB/GYN) departments, cardiology departments, and noninvasive vascular testing laboratories. Patients are typically referred to providers in these settings to receive comprehensive diagnostic ultrasound examinations, performed by trained ultrasound professionals (sonographers, echocardiographers and vascular technologists). The results of the ultrasound examinations are then interpreted by specially trained physicians, and a formal diagnostic report is provided to the referring physician, who then must decide the most appropriate course of action.
Early adopters of POC ultrasound had no choice but to use the available ultrasound scanners that were originally designed for use by imaging professionals. The physical size of these conventional cart-based scanners, combined with their cost (which ranges from approximately $70,000 to more than $250,000) and the complexity of the user interface, created barriers to the widespread clinical utilization of POC ultrasound.
Who Uses It, and Why?
More recently, however, ultrasound technology has become more economical to purchase and less complex to use. As a result, there has been a trend toward it being used by physicians and other non-imaging-specialist health care professionals in a wide range of medical disciplines. These new users have recognized the clinical benefits of POC ultrasound imaging, and have begun to employ it to enhance patient care. To address the needs of these users, ultrasound equipment manufacturers have developed and are currently marketing systems — primarily portable scanners — that are specifically designed for POC applications and new users.
POC ultrasound is also routinely used to guide interventional procedures such as therapeutic injection of medications, and POC ultrasound scanners commonly have features that facilitate use for these interventions. While hospitals and private physician offices are the most common setting where POC ultrasound is used, it is also utilized at trauma sites and disaster sites, during extra-hospital patient transport, and at sporting events.
The use of POC ultrasound is expected to increase in many areas of medicine as the technology advances and its many clinical benefits are recognized.
Styles of Portable Scanners
The vast majority of POC ultrasounds are performed using portable scanners — small scanners that are not permanently mounted on wheels and that can be battery operated. These models are smaller and usually less expensive than conventional cart-based systems.
Portable scanners come in three different styles: (1) handheld (or pocket-size), (2) laptop-style (in the form of a laptop computer), or (3) tablet-style (in the form of a tablet computer).
Handheld scanners are compact enough to be held in one hand during use while the transducer is held in the other hand. Compared to other portable ultrasound systems, these pocket-size devices have the fewest features and imaging capabilities, and therefore have a more limited range of applications. Typically, these models do not support interchangeable transducers, nor do they possess some ultrasound modes — factors that limit the types of examinations that can be performed and the amount of information that can be obtained. Furthermore, handheld scanners do not have many of the user-adjustable parameter controls available with other types of scanners, which can limit how well the images can be optimized for a given scanning situation or patient. Handheld scanners have very small monitors (usually only three to four inches in size) and typically lack hardware and/or software features used to enhance ultrasound guidance for interventional procedures.
Laptop-style scanners are the most complex type of portable scanners. They frequently have many of the same features and capabilities found on cart-based systems such as advanced analysis packages and three-dimensional ultrasound capabilities. In some cases, the only difference between conventional cart-based scanners and laptop-style scanners is that the latter are more compact, lack certain ergonomic features (e.g., adjustable monitors), and may not be compatible with specialized transducers (e.g., transesophageal probes).
Tablet-style scanners, as their name implies, resemble tablet computers and have similar user-interface features, including touchscreen-activated controls positioned around the screen on which the ultrasound image is displayed. Although tablet-style scanners can be carried from one location to another, they are commonly attached to a wheeled stand or cart to facilitate portability and ease of use. The cart provides storage space for transducers and other accessories, resulting in a relatively self-contained system, and also allows the scanner to be easily positioned near the patient’s bedside during an examination.
Compared to handheld models, tablet scanners provide the user with more options in terms of transducers, parameter adjustments, and imaging capabilities (e.g., pulsed Doppler with spectral analysis). However, compared to laptop-style or cart-based scanners, tablet scanners aren’t as fully featured and do not support as many different types of transducers.
This article is excerpted from a digital story posted 4/8/15 on ECRI Institute’s Health Devices membership website. The full article features additional information on common users of POC ultrasound with examples of how the modality is used in that specialty. To learn more, visit www.ecri.org; call (610) 825-6000; or e-mail communications@ecri.org.
