John L. Kendall

History of emergency and critical care ultrasound: The evolution of a new imaging paradigm

The tradition of clinical ultrasound in the hands of physicians who provide critical care to the most acutely ill patients stretches back into the 1980s and is rich with experiences from surgical, emergency medicine, and other practices. Now, as critical care ultrasound explodes around the world, it is important to realize the path its development has taken and learn from trials and tribulations of early practitioners in the field. The development and battles for the right to use ultrasound at the patients bedside for >20 yrs is described in relation to its emergency medicine and surgical origins. Approaches to education, scanning, documentation, and organization at the national and regional levels are described.

Performance and interpretation of focused right upper quadrant ultrasound by emergency physicians.

The objectives of this study were to determine the accuracy of Emergency Physicians (EP) performing focused right upper quadrant (RUQ) ultrasound, to quantify how sonographic experience affects accuracy for gallbladder pathology, and to establish the time needed to complete a focused RUQ ultrasound. A convenience sample of patients with suspected gallbladder disease received a focused RUQ ultrasound by an EP. Sonographic findings, number of previous RUQ ultrasounds performed, and time for examination completion were recorded. Each patient then had a formal RUQ ultrasound by a sonographer blinded to the focused RUQ ultrasound results. Focused RUQ and formal ultrasound findings were compared, with the exception of the sonographic Murphy sign, which was compared to pathology reports. One hundred nine patients were enrolled. Fifty-one had gallstones. Forty-nine were detected by EPs, yielding a sensitivity of 96% [95% confidence interval (CI).87-.99]. Of the 58 patients without gallstones, 51 were correctly diagnosed by EPs (specificity = 88%, 95% CI.77-.95). The sonographic Murphy sign was present during 54 emergency examinations, but in only 24 formal studies. When compared to pathology reports, the emergency sonographic Murphy sign had a sensitivity of 75% compared to the formal ultrasound sensitivity of 45% for acute cholecystitis. EPs were less accurate for other sonographic findings, and level of experience had little effect on sensitivity or specificity for detecting gallstones. Eighty-three percent of emergency studies were completed in less than 10 min. Gallstones are accurately detected by EPs in a timely fashion. Additionally, compared to the radiologists interpretation, the EP-detected sonographic Murphy sign was more sensitive for diagnosing acute cholecystitis.

PENETRATING NECK TRAUMA

Penetrating neck trauma can pose significant diagnostic and therapeutic challenges for emergency physicians. Factors contributing to these problems are complex anatomy, proximity of vital structures, and potential for rapid deterioration of airway, vascular, or neurologic injuries. Other contributing factors are the lack of consensus in the literature regarding appropriate evaluation and management of penetrating neck injuries, and insufficient resources or experienced personnel at some institutions. This review focuses on the key components of the history and physical examinations that allow for an assessment of the severity and type of structures involved. In addition, current methods of airway management, as well as ways to manage penetrating neck trauma efficiently and cost effectively, are discussed.

AIUM practice guideline for the performance of the focused assessment with sonography for trauma (FAST) examination.

The American Institute of Ultrasound in Medicine (AIUM) is a multidisciplinary association dedicated to advancing the safe and effective use of ultrasound in medicine through professional and public education, research, development of guidelines, and accreditation. To promote this mission, the AIUM is pleased to publish, in conjunction with the American College of Emergency Physicians (ACEP), this AIUM Practice Guideline for the Performance of the Focused Assessment With Sonography for Trauma (FAST) Examination. We are indebted to the many volunteers who contributed their time, knowledge, and energy to bringing this document to completion. The AIUM represents the entire range of clinical and basic science interests in medical diagnostic ultrasound, and with hundreds of volunteers, the AIUM has promoted the safe and effective use of ultrasound in clinical medicine for more than 50 years. This document and others like it will continue to advance this mission. Practice guidelines of the AIUM are intended to provide the medical ultra-sound community with guidelines for the performance and recording of high-quality ultrasound examinations. The guidelines reflect what the AIUM considers the minimum criteria for a complete examination in each area but are not intended to establish a legal standard of care. AIUM-accredited practices are expected to generally follow the guidelines with the recognition that deviations from the guidelines will be needed in some cases depending on patient needs and available equipment. Practices are encouraged to go beyond the guidelines to provide additional service and information as needed by their referring physicians and patients.

Intranasal midazolam in patients with status epilepticus.

The patient in status epilepticus presents many challenges to the emergency physician. IV access is frequently difficult to achieve, and prolonged attempts at access can jeopardize the patient and endanger the caregiver. We present two cases in which the administration of intranasal midazolam appeared to successfully terminate status epilepticus. No adverse effects were noted. Studies are needed to clarify the safety, optimal dosing, and clinical utility of this treatment modality.

Ultrasound-guided central venous access: a homemade phantom for simulation.

While the base layer of the mould is congealing, select the latex tubes (Penrose drains) that will be used to simulate the vessels. One-half inch diameter tubes work well to simulate the neck and femoral vessels and one-quarter inch diameter tubes appear like brachial vessels. Tie the latex tubes at one end and fill them with water, being careful to minimize the amount of trapped air. The volume of water in each tube determines whether it will be used to simulate an artery or a vein. For example, tubes that have less water will compress easily and therefore will appear like veins. After the desired volume of water is placed in the latex tube, tie off the open end. After the base layer of the mould is firm, place the latex tubes on top of it. A second aliquot of the gelatin‐Metamucil mixture (enough to fill one-third of the container’s volume, as described above) is poured onto the base layer, with enough volume to surround and cover the latex drains. This will form the middle layer. Chill the mould again until firm. Lastly, prepare another gelatin‐Metamucil mixture and pour it on top of the middle layer until the container is filled to the point that the latex drains are no longer visible. Chill the mould a third time until it is firm and then remove it from the Pyrex container. At this point the phantom is ready for use. Discussion

Emergency department ultrasound for hemothorax after blunt traumatic injury

Diagnosing hemothorax after blunt trauma may be aided by emergency department (ED) ultrasound (US). Various prior studies have evaluated ED US using different gold standards. A prospective study of blunt trauma patients who underwent computed tomography (CT) scan of the chest, abdomen, or both, was performed. Before CT scan, an US examination was performed specifically to identify free fluid in the thorax. The CT scan findings were used as the gold standard for validation of US results. From July 1998 to June 1999, 142 of 155 patients who underwent US and CT scan for evaluation of blunt trauma were included in this study. The CT scan identified 16 cases of hemothorax among these patients. ED US resulted in 2 true-positive, 2 false-positive, 14 false-negative, and 124 true-negative findings. ED US was 12.5% sensitive and 98.4% specific. ED US did not detect small-volume hemothorax identified by CT scan. Future research should focus on further defining the size of hemothorax appreciable with ED US, with increased attention paid to the type of gold standard implemented for its evaluation.

Use of Ultrasound Guidance for Central Venous Catheter Placement: Survey From the American Board of Emergency Medicine Longitudinal Study of Emergency Physicians

OBJECTIVES The objective was to survey practicing emergency physicians (EPs) across the United States regarding the frequency of using ultrasound (US) guidance in central venous catheter (CVC) placement and, secondarily, to determine factors associated with the use or barriers to the use of US guidance. METHODS This was a cross-sectional survey mailed to presumed practicing EPs as part of the American Board of Emergency Medicine (ABEM)s longitudinal study of EPs. The selection process used stratified, random sampling of cohorts thought to represent four different stages within the development of the specialty of emergency medicine (EM). Multivariable logistic regression was used to identify independent factors associated with both high comfort using US guidance and high-percentage usage of US guidance. RESULTS The survey was mailed to 1,165 subjects, and the response rate was 79%. The median number of years of practice was 20 (interquartile range [IQR]=7 to 28 years). As their primary practice setting, 64% work in private or community hospitals, 60% received training in US-guided vascular access, and 44% never use US guidance in placing CVCs. Barriers differed in those who never use US and those who sometimes or always used US guidance. In those who never use US, top barriers were insufficient training (67%) and lack of equipment (25%). In those who use US, top barriers were the perceptions that US was too time-consuming (27%) and that the preferred site was not amenable to US (24%). Independent factors associated with high comfort and high-percentage use of US guidance were training in US-guided vascular access (adjusted odds ratio=5.1 [high comfort]; 95% confidence interval [CI]=2.6 to 10.1; adjusted odds ratio 11.1=(high percentage); 95% CI=5.0 to 24.8) and being a recent residency graduate. CONCLUSIONS Among EPs, the translation of evidence to clinical practice regarding the benefits of US guidance for CVC placement is poor and still faces many barriers. Training and education are potentially the best ways to overcome such barriers.

Blunt Abdominal Trauma Patients Are at Very Low Risk for Intra-Abdominal Injury after Emergency Department Observation

Introduction Patients are commonly admitted to the hospital for observation following blunt abdominal trauma (BAT), despite initially negative emergency department (ED) evaluations. With the current use of screening technology, such as computed tomography (CT) of the abdomen and pelvis, ultrasound, and laboratory evaluations, it is unclear which patients require observation. The objective of this study was to determine the prevalence of intra-abdominal injury (IAI) and death in hemodynamically normal and stable BAT patients with initially negative ED evaluations admitted to an ED observation unit and to define a low-risk subgroup of patients and assess whether they may be discharged without abdominal/pelvic CT or observation. Methods This was a retrospective cohort study performed at an urban level 1 trauma center and included all BAT patients admitted to an ED observation unit as part of a BAT key clinical pathway. All were observed for at least 8 hours as part of the key clinical pathway, and only minors and pregnant women were excluded. Outcomes included the presence of IAI or death during a 40-month follow-up period. Prior to data collection, low-risk criteria were defined as no intoxication, no hypotension or tachycardia, no abdominal pain or tenderness, no hematuria, and no distracting injury. To be considered low risk, patients needed to meet all low-risk criteria. Results Of the 1,169 patients included over the 2-year study period, 29% received a CT of the abdomen and pelvis, 6% were admitted to the hospital from the observation unit for further management, 0.4% (95% confidence interval [CI], 0.1%–1%) were diagnosed with IAI, and 0% (95% CI, 0%–0.3%) died. Patients had a median combined ED and observation length of stay of 9.5 hours. Of the 237 (20%) patients who met low-risk criteria, 7% had a CT of the abdomen and pelvis and 0% (95% CI, 0%–1.5%) were diagnosed with IAI or died. Conclusion Most BAT patients who have initially negative ED evaluations are at low risk for IAI but still require some combination of observation and CT. A subgroup of BAT patients may be safely discharged without CT or observation after the initial evaluation.

The Current State of Ultrasound Training in Canadian Emergency Medicine Programs: Perspectives From Program Directors

OBJECTIVES There is a paucity of data about emergency ultrasound (EUS) training in emergency medicine (EM) residency programs accredited by the Royal College of Physicians and Surgeons of Canada (Royal College) and the College of Family Physicians of Canada (CFPC). Historically the progress of EUS in Canada has been different from that in the United States. We describe the current state of EUS training in both Royal College and CFPC-EM programs. METHODS All Royal College EM program directors and all CFPC-EM program directors were invited to participate in a website-based survey. Main outcome measures were characteristics of currently offered EUS training. RESULTS The response rate of the survey was 100% (30/30). EUS is part of the formal residency curriculum in 100% (13/13) of Royal College EM programs and in 88% (15/17) of CFPC-EM programs. EM resident rotations in ultrasound (US) are provided by 77% (10/13) of Royal College programs but only 47% (8/17) of CFPC-EM programs. There are specific requirements for numbers of EUS exams to be completed by graduation in 77% (10/13) of Royal College programs and 47% (8/17) of CFPC-EM programs. EM faculty and residents make clinical decisions and patient dispositions based on their EUS interpretation without a consultative study by radiology in 100% (13/13) of Royal College programs and 88% (15/17) of CFPC-EM programs. However, 69% (9/13) of Royal College programs and 53% (9/17) of CFPC-EM programs have no formal quality assurance program in place. CONCLUSIONS EUS training in Canadian EM programs is prevalent, but there are considerable discrepancies among residency programs in scope of training, curricula, determination of proficiency, and quality assurance. These findings suggest variability in both the level and the quality of EUS training in Canada.