Emergency physicians often rely on technology such as portable ultrasound (US) to assist in decision making when treating patients in critical condition. Portable US devices, also referred to as point-of-care US (POCUS), mobile US, bedside US, and encompassing specific procedures such as focused-assessment with sonography for trauma (FAST), comprise a range of technologies including handheld devices, conventional mobile bedside devices and other devices with mobility. Examples include PRIMEDIC HandyScan, V-scan (GE Healthcare), and SonoSite devices. Portable US devices are lauded for being lightweight, small, and durable, and for providing high quality, high-resolution imaging at a lower cost than conventional US. Their application in emergency medicine is widespread as the operation of US is non-invasive, inexpensive and not associated with radiation exposure. Portable US is primarily used for diagnostic purposes, but therapeutic uses (e.g., US guided pericardiocentesis) have been documented. They have shown value in the context of limited resources and expertise such as rural or remote settings where treatment may be improved by transmitting images to central sites.
Another out-of-hospital context that portable US has shown potential for is the pre-hospital setting. Proposed benefits of using portable US in the pre-hospital setting include support in determining the appropriate method of transportation and patient destination (i.e., level of facility), prevention of unnecessary field interventions (e.g., needle thoracostomy for patients with suspected pneumothorax), provision of necessary time-sensitive pharmaceutical treatments (e.g., as may be required by patients with congestive heart failure), and increased efficiency of care of the critically ill. In North America, portable US use has been reported for FAST, pulseless electrical activity arrest, cardiac tamponade, to detect aortic aneurysm, examine for pneumothorax, use for vascular access, assess volume status, or to identify fractures. Diagnostic accuracy, reliability, and feasibility of portable US has been well demonstrated in the out-of-hospital setting.
Despite the proposed utility of these devices, only 4.1% of emergency medical services directors surveyed in Canada and the United States (30% response rate) reported using portable US in the pre-hospital setting. Of the respondents, 21.7% stated that they would consider implementing the technology. Major barriers to adoption include cost, training requirements, and lack of evidence for improvement in patient-related outcomes (e.g., morbidity and mortality). In light of the perceived potential clinical benefit of pre-hospital US but the lack of direct evidence and presence of other factors, such as cost, impeding their use, the purpose of this review is to review the relationship between the use of portable US in the pre-hospital setting and definitive patient outcomes and resource implications, as well as guidance regarding their use.
Disclaimer: The Rapid Response Service is an information service for those involved in planning and providing health care in Canada. Rapid responses are based on a limited literature search and are not comprehensive, systematic reviews. The intent is to provide a list of sources of the best evidence on the topic that CADTH could identify using all reasonable efforts within the time allowed. Rapid responses should be considered along with other types of information and health care considerations. The information included in this response is not intended to replace professional medical advice, nor should it be construed as a recommendation for or against the use of a particular health technology. Readers are also cautioned that a lack of good quality evidence does not necessarily mean a lack of effectiveness particularly in the case of new and emerging health technologies, for which little information can be found, but which may in future prove to be effective. While CADTH has taken care in the preparation of the report to ensure that its contents are accurate, complete and up to date, CADTH does not make any guarantee to that effect. CADTH is not liable for any loss or damages resulting from use of the information in the report.
