Bret P. Nelson

Prehospital Ultrasound by Paramedics: Results of Field Trial

OBJECTIVES The objective was to determine if 9-1-1 paramedics trained in ultrasound (US) could adequately perform and interpret the Focused Assessment Sonography in Trauma (FAST) and the abdominal aortic (AA) exams in the prehospital care environment. METHODS Paramedics at two emergency medical services (EMS) agencies received a 6-hour training program in US with ongoing refresher education. Paramedics collected US in the field using a prospective convenience methodology. All US were performed in the ambulance without scene delay. US exams were reviewed in a blinded fashion by an emergency sonographer physician overreader (PO). RESULTS A total of 104 patients had an US performed between January 1, 2008, and January 1, 2009. Twenty AA exams were performed and all were interpreted as negative by the paramedics and the PO. Paramedics were unable to obtain adequate images in 7.7% (8/104) of the patients. Eighty-four patients had the FAST exam performed. Six exams (6/84, 7.1%) were read as positive for free intraperitoneal/pericardial fluid by both the paramedics and the PO. FAST and AA US exam interpretation by the paramedics had a 100% proportion of agreement with the PO. CONCLUSIONS This pilot study shows that with close supervision, paramedics can adequately obtain and interpret prehospital FAST and AA US images under protocol. These results support a growing body of literature that indicates US may be feasible and useful in the prehospital setting.

Use of ultrasound by emergency medical services: a review

Prehospital ultrasound has been deployed in certain areas of the USA and Europe. Physicians, emergency medical technicians, and flight nurses have utilized a variety of medical and trauma ultrasound assessments to impact patient care in the field. The goal of this review is to summarize the literature on emergency medical services (EMS) use of ultrasound to more clearly define the potential utility of this technology for prehospital providers.

Portable ultrasound for remote environments, Part I: Feasibility of field deployment.

BACKGROUND In field medical operations, rapid diagnosis and triage of seriously injured patients is critical. With significant bulk and cost constraints placed on all equipment, it is important that any medical devices deployed in the field demonstrate high utility, durability, and ease of use. When medical ultrasound was first used in patient care, machine cost, bulk, and steep learning curves prevented use outside of the radiology department. Now, lightweight portable ultrasound is widely employed at the bedside by emergency physicians. The techniques and equipment have recently been extrapolated out of the hospital setting in a wide variety of environments in an effort to increase diagnostic accuracy in the field. OBJECTIVES In this review, deployment of lightweight portable ultrasound in the field (by emergency medical services, military operations, disaster relief, medical missions, and expeditions to austere environments) is examined. The feasibility of field deployment and experiences of clinicians using ultrasound in a host of environments are detailed. In addition, special technological considerations such as telemedicine and machine characteristics are reviewed. CONCLUSIONS The use of lightweight portable ultrasound shows great promise in augmenting clinical assessment for field medical operations. Although the feasibility of the technology has been demonstrated in certain medical and trauma applications, further research is needed to determine the utility of ultrasound use for medical illness in the field.

Assessment of knowledge retention and the value of proctored ultrasound exams after the introduction of an emergency ultrasound curriculum

BackgroundOptimal training required for proficiency in bedside ultrasound is unknown. In addition, the value of proctored training is often assumed but has never been quantified.MethodsTo compare different training regimens for both attending physicians and first year residents (interns), a prospective study was undertaken to assess knowledge retention six months after an introductory ultrasound course. Eighteen emergency physicians and twelve emergency medicine interns were assessed before and 6 months after an introductory ultrasound course using a standardized, image-based ultrasound test. In addition, the twelve emergency medicine interns were randomized to a group which received additional proctored ultrasound hands-on instruction from qualified faculty or to a control group with no hands-on instruction to determine if proctored exam training impacts ultrasound knowledge. Paired and unpaired estimates of the median shift in test scores between groups were made with the Hodges-Lehmann extension of the Wilcoxon-Mann-Whitney test.ResultsSix months after the introductory course, test scores (out of a 24 point test) were a median of 2.0 (95% CI 1.0 to 3.0) points higher for residents in the control group, 5.0 (95% CI 3.0 to 6.0) points higher for residents in the proctored group, and 2.5 (95% CI 1.0 to 4.0) points higher for the faculty group. Residents randomized to undergo proctored ultrasound examinations exhibited a higher score improvement than their cohorts who were not with a median difference of 3.0 (95% CI 1.0 to 5.0) points.ConclusionWe conclude that significant improvement in knowledge persists six months after a standard introductory ultrasound course, and incorporating proctored ultrasound training into an emergency ultrasound curriculum may yield even higher knowledge retention.

Portable Ultrasound for Remote Environments, Part II: Current Indications

BACKGROUND With recent advances in ultrasound technology, it is now possible to deploy lightweight portable imaging devices in the field. Techniques and studies initially developed for hospital use have been extrapolated out of the hospital setting in a wide variety of environments in an effort to increase diagnostic accuracy in austere or prehospital environments. OBJECTIVES This review summarizes current ultrasound applications used in out-of-hospital arenas and highlights existing evidence for such use. The diversity of applications and environments is organized by indication to better inform equipment selection as well as future directions for research and development. DISCUSSION Trauma evaluation, casualty triage, and assessment for pneumothorax, acute mountain sickness, and other applications have been studied by field medical teams. A wide range of outcomes have been reported, from alterations in patient care to determinations of accuracy compared to clinical judgment or other diagnostic modalities. CONCLUSIONS The use of lightweight portable ultrasound shows great promise in augmenting clinical assessment for field medical operations. Although some studies of diagnostic accuracy exist in this setting, further research focused on clinically relevant outcomes data is needed.

Handheld ultrasound devices and the training conundrum: how to get to "seeing is believing".

Although the ‘‘stethoscope’’ was developed almost 200 years ago by Rene-Theophile-Hyacinthe Laennec and is unquestionably the foundation for classical teaching of the diagnostic physical examination, it is also true that generations of medical students have been exposed to this misnomer. The stethoscope, hung proudly around every medical student’s neck, is indeed a ‘‘stethophone,’’ as it allows listening (steth = chest, phone = sound) to the human body rather than truly seeing (scope = to look in) into it. 1 Recent developments in ultrasound technology have resulted in miniaturization of ultrasound devices, which can be readily carried in a lab coat pocket and used at the bedside to generate high-quality ultrasound images of cardiac structure and function. 2 These devices can provide immediate feedback and extend the information base of the traditionally acquired history and physical examination, contributing to improved cardiac differential diagnosis formulation. 3,4 By visualizing cardiac anatomy and dynamics immediately, using a true stethoscope, the user can refine clinical decision making and optimize the choice of further testing and treatment. 5 Indeed, the use of these devices in routine clinical practice, akin to the manner in which the traditional stethoscope has been used, may potentially enhance, expedite, and improve costefficient care. 6 However, as this technology has only very recently evolved, there is as of yet no standardized approach for teaching the skills necessary to use these devices optimally, nor is there a systematic approach to assessment of the learner’s capabilities and the impact on patient care. Historically, the knowledge base necessary to use the more sophisticated conventional ultrasound scanners has been acquired only at the postgraduate and specialty training levels, at which programmatic instruction and assessments are well established, with numerous accreditation bodies providing benchmarks for expertise and ‘‘quality control.’’ Traditionally, ultrasound assessments have been performed on large scanners located in imaging areas within radiology, cardiology, and obstetrics departments. With the advent of portable scanners in the 1990s, it became possible to scan patients in real time at the ‘‘point of care,’’ and many other specialties such as emergency medicine, surgery, critical care, and others began to embrace ultrasound technology and change their practices. 7 Thus, a technology innovation enabled diverse new groups of users to perform focused ultrasound assessments, which has been further accelerated by the most recent technologic development of ‘‘handheld’’ or ‘‘pocket-sized’’ ultrasound units. Indeed, point-of-care ultrasound can be viewed as a ‘‘disruptive’’ innovation, changing the paradigm of consultative imaging by specialists to one whereby imaging may be performed at the bedside by the clinicians directly responsible for a patient’s care. This activity has the potential advantage not only to enhance the rapidity of imaging access but also to improve the imaging examination through focused acquisition and interpretation guided by the diagnostic context formulated by the consultant directly evaluating the patient. These miniaturized ultrasound devices truly provide widespread opportunity to extend the physical examination of both novice and expert caregivers by seeing directly into the body at the bedside. The equipment is now readily available, at a price point that is not prohibitive to potential mainstream users. The key issue, then, is the development of appropriate training and education of caregivers in their use, so that they will benefit patients, through enhanced cost-effective delivery of care, and not harm them through underdiagnosis or overdiagnosis. Approaches to point-of-care assessments of patients with portable, handheld ultrasound (HHU) units and their integration into both medical teaching and clinical practice are in the ‘‘emergent’’ and ‘‘early adoption’’ stages of new technology. Several medical organizations have recently developed expert consensus and guideline documents aimed at introducing and guiding the use of HHU, particularly as it pertains to cardiac imaging. The American Society of Echocardiography has recognized that these devices are capable of performing focused cardiac ultrasound (FCU) assessments as an adjunct to the physical examination. Whereas HHU describes a portable miniaturized ultrasound device that can be used to examine any organ or system in the body, FCU is specifically defined as a focused examination of the cardiovascular system performed by a physician using ultrasound (at the bedside with an HHU device) as an adjunct to the physical examination to recognize specific ultrasonic signs that represent a

Manual of Emergency and Critical Care Ultrasound: Acknowledgments

Preface 1. Fundamentals Part I. Diagnostic Ultrasound: 2. Focused assessment with sonography in trauma (FAST) 3. Echocardiography 4. First-trimester ultrasound 5. Abdominal aortic aneurysm 6. Renal and bladder 7. Gallbladder 8. Deep-vein thrombosis 9. Chest ultrasound 10. Ocular ultrasound 11. Musculoskeletal and soft tissue ultrasound 12. Gastrointestinal ultrasound 13. Pediatric ultrasound applications 14. Ultrasound for the hypotensive patient 15. Vascular access 16. Ultrasound for procedure guidance Index.

Manual of Emergency and Critical Care Ultrasound: Contents

Preface 1. Fundamentals Part I. Diagnostic Ultrasound: 2. Focused assessment with sonography in trauma (FAST) 3. Echocardiography 4. First-trimester ultrasound 5. Abdominal aortic aneurysm 6. Renal and bladder 7. Gallbladder 8. Deep-vein thrombosis 9. Chest ultrasound 10. Ocular ultrasound 11. Musculoskeletal and soft tissue ultrasound 12. Gastrointestinal ultrasound 13. Pediatric ultrasound applications 14. Ultrasound for the hypotensive patient 15. Vascular access 16. Ultrasound for procedure guidance Index.

A Brief Educational Intervention Is Effective in Teaching the Femoral Nerve Block Procedure to First-Year Emergency Medicine Residents

BACKGROUND Hip fractures are a painful condition commonly encountered in the emergency department (ED). Older adults in pain often receive suboptimal doses of analgesics, particularly in crowded EDs. Nerve blocks have been utilized by anesthesiologists to help control pain from hip fractures postoperatively. The use of nerve stimulator with ultrasonographic guidance has increased the safety of this procedure. OBJECTIVES We instituted a pilot study to assess the ability of Emergency Medicine (EM) resident physicians to effectively perform this procedure after a didactic and demonstration session. METHODS First-year EM residents from three urban training programs underwent a 1-h didactic and hands-on training session on the femoral nerve block (FNB) procedure. A written pretest was used to assess baseline knowledge; it was administered again (with test items randomized) at 1 and 3 months post training session. A critical actions checklist (direct observation of procedure steps via simulated patient encounter) was used to assess the residents after the training session and again at 3 months. RESULTS A total of 38 EM residents were initially evaluated. Thirty-three successfully completed 1-month and 3-month written test evaluations; 30 completed all written and direct observation evaluations. The mean written pretest scores were 66% (SD 9); post-test 92% (SD 5), 1-month 74% (SD 8), and 3-month 75% (SD 9). After initial training, 37 of 38 (97%) residents demonstrated competency (completing ≥ 15 of 19 critical actions) in the FNB procedure determined via direct observation. At 3 months, 25 of 30 residents (83%) continued to retain 85% of their initial critical action skills, and 3 of 30 (10%) saw an improvement in their proficiency. CONCLUSION A 1-h training and demonstration module yielded high competency rates in residents performing critical actions related to the FNB; these skills were well maintained at 3 months. An ongoing study will attempt to correlate this competency with procedures performed on patients.

How Relevant Is Point-of-Care Ultrasound in LMIC?

The trajectory of medical ultrasound has beenmarked by quantum decreases in size. In the 1950s, the first ultrasounds were performed using refrigerator-sized machines, with patients subjected to water immersion. Adoption of this technology across many medical specialties was hindered by machine bulk and cost, low-resolution still images, and a steep learning curve for image interpretation. Incremental changes in ultrasound technology through the 1970s and 1980s allowed machines to be moved on wheels, and eventually to sit atop a cart. It was not until the 1990s that an ultrasound machine capable of being transported in a backpack was invented, as a result of a Defense Advanced Research Projects Agency (DARPA) grant. As with other computer technology, ultrasound machines then rapidly grew smaller and more powerful, and a wider user base began adopting them for multiple types of medical applications. By the 1990s, portable ultrasound machines were deployed in combat support hospitals, ambulances, helicopters, and a host of austere environments. Researchers described experiences using ultrasound on medical missions in remote Amazon jungle settlements, high-altitude environments in Nepal’s Himalayan Rescue Association Clinic, and the International Space Station. A report from Guatemala in the aftermath of Hurricane Stan demonstrated that point-ofcare ultrasound confirmed or ruled out emergent pathology in almost half of subjects evaluated. During the disaster relief effort following the 2010 Haitian earthquake, point-of-care ultrasound helped clinicians change management in 70% of cases, with nearly half of those decisions based on acute pathology identified examination. On the basis of experiences such as these, the World Health Organization recommends increased use of ultrasound as a main diagnostic modality, especially in underresourced environments. Ultrasound machine costs are generally lower than x-ray or computed tomography scan capital expenses, and ultrasound requires very little ongoing cost for consumables (such as gel), compared to the ongoing upkeep costs of these other modalities. Increasingly, ultrasound is being used in areaswithout easy access to imaging of any kind. Clinicians in the Lugufo refugee camp in Tanzania identifiedmany tropical infectious disease manifestations on ultrasound. Midwives in rural Rwanda, Zambia, and Liberia have been trained in the use of focused obstetric ultrasound with the goal of identifying common and life-threatening complications of late pregnancy. In areas where maternal and fetal mortality are significant health concerns, accurate pregnancy dating, early identification of breech presentation, and proper placental position could significantly impact the care provided and save lives. Advances in telemedicine have enabled expansion in ultrasound use as well. Recently, health care workers in rural India underwent training in basic cardiac and thoracic ultrasound with the goal of transmitting images to physicians at major hospital centers for real-time interpretation. Ultrasound has been described as a disruptive innovation byHarvard professor ClaytonM.Christensen. The term, originally coined by Christensen in reference to disk drives, refers to an innovation that transforms a market “by introducing simplicity, convenience, accessibility, and affordability where complication and high cost are the status quo.” Often, such innovations take the form of a narrow, niche market, overlooked by industry leaders, but as new users take hold, the new product can claim significant market share. In the case of ultrasound, traditional imagers such as radiologists, obstetricians, and cardiologists controlled a market marked by expensive, immobile machines whose images could only be interpreted by highly trained subspecialists within their respective fields. Hand-held ultrasound devices introduced an alternative concept of relatively inexpensive, easy-to-use machines that could generate images interpretable by a wider spectrum of clinicians at the point of care. Soon, concerns about smaller machines having inferior image quality compared to devicesmany times larger andmore expensive were outweighed by evidence that rapid diagnostic decisions could be made with portable machines. In the 1990s, emergencymedicine physicians joined the ranks of clinician-sonographers and described ultrasound training as part of the core competencies for residency training in 1994. Surgeons used ultrasound for trauma at this time as well. A wave of intensivists, ophthalmologists, internists, and other specialists found utility in point-of-care ultrasound by the 2000s, and a 2011 article in the New England Journal of Medicine by Moore and Copel listed 24 specialties who had adopted the technology into common clinical practice. In 2013, the Agency for Healthcare Research and Quality published “Making Health Care Safer II,” an update of its previous 2001 guidelines for best practices in patient safety. Among the top 10 practices in both publications was using ultrasound to guide central venous access. With mounting evidence that iatrogenic complications of many invasive procedures such as venous access, thoracentesis, paracentesis, and others can be mitigated with point-of-care ultrasound, hospitals are increasingly mandating training in ultrasound by clinicians. As of this writing, a number of medical schools have adopted ultrasound curricula as well, incorporating sonographic assessments of multiple organ systems along with traditional courses on physical examination and clinical reasoning. Many authors have argued that ultrasound has become the stethoscope of the 21st century. Why then, do we not see The authors report no relationships that could be construed as a conflict of interest. From the *Department of Emergency Medicine and yDepartment of Cardiology, Icahn School of Medicine at Mount Sinai, New York, NY, USA. Correspondence: J. Narula (Narula@ mountsinai.org).