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Objectives As the use of point-of-care sonography spreads, so too does the need for remote expert over-reading via telesonogrpahy. We sought to assess the feasibility of using familiar, widespread, and cost-effective existent technology to allow remote over-reading of sonograms in real time and to compare 4 different methods of transmission and communication for both the feasibility of transmission and image quality. Methods Sonographic video clips were transmitted using 2 different connections (WiFi and 3G) and via 2 different videoconferencing modalities (iChat [Apple Inc, Cupertino, CA] and Skype [Skype Software Sarl, Luxembourg]), for a total of 4 different permutations. The clips were received at a remote location and recorded and then scored by expert reviewers for image quality, resolution, and detail. Results Wireless transmission of sonographic clips was feasible in all cases when WiFi was used and when Skype was used over a 3G connection. Images transmitted via a WiFi connection were statistically superior to those transmitted via 3G in all parameters of quality (average P = .031), and those sent by iChat were superior to those sent by Skype but not statistically so (average P = .057). Conclusions Wireless transmission of sonographic video clips using inexpensive hardware, free videoconferencing software, and domestic Internet networks is feasible with retention of image quality sufficient for interpretation. WiFi transmission results in greater image quality than transmission by a 3G network.

Ultrasound has revolutionized a physician's ability to make urgent and emergent diagnoses at the bedside, and has changed the management of many acute injuries and conditions. This is a practical, concise introduction to what is rapidly becoming an essential tool for all critical care physicians: bedside emergency ultrasound. The Manual covers the full spectrum of conditions diagnosed using ultrasound and gives practical guidance in how to use ultrasound for common invasive procedures. Major applications are introduced using focused diagnostic questions and reviewing the image-acquisition skills needed to answer them. Images of positive and negative findings are presented, and scanning tips for improving image quality. The second edition has been substantially revised and expanded, with new images, updated literature reviews, new applications and clinical algorithms. New chapters cover additional procedures, musculoskeletal and pediatric applications, and the use of ultrasound in resuscitation. This text is invaluable for emergency physicians at all levels.

Introduction We studied the diagnostic accuracy of bedside lung ultrasound (the presence of a comet-tail sign), N-terminal pro-brain natriuretic peptide (NT-proBNP) and clinical assessment (according to the modified Boston criteria) in differentiating heart failure (HF)-related acute dyspnea from pulmonary (chronic obstructive pulmonary disease (COPD)/asthma)-related acute dyspnea in the prehospital setting. Methods Our prospective study was performed at the Center for Emergency Medicine, Maribor, Slovenia, between July 2007 and April 2010. Two groups of patients were compared: a HF-related acute dyspnea group (n = 129) and a pulmonary (asthma/COPD)-related acute dyspnea group (n = 89). All patients underwent lung ultrasound examinations, along with basic laboratory testing, rapid NT-proBNP testing and chest X-rays. Results The ultrasound comet-tail sign has 100% sensitivity, 95% specificity, 100% negative predictive value (NPV) and 96% positive predictive value (PPV) for the diagnosis of HF. NT-proBNP (cutoff point 1,000 pg/mL) has 92% sensitivity, 89% specificity, 86% NPV and 90% PPV. The Boston modified criteria have 85% sensitivity, 86% specificity, 80% NPV and 90% PPV. In comparing the three methods, we found significant differences between ultrasound sign and (1) NT-proBNP (P < 0.05) and (2) Boston modified criteria (P < 0.05). The combination of ultrasound sign and NT-proBNP has 100% sensitivity, 100% specificity, 100% NPV and 100% PPV. With the use of ultrasound, we can exclude HF in patients with pulmonary-related dyspnea who have positive NT-proBNP (> 1,000 pg/mL) and a history of HF. Conclusions An ultrasound comet-tail sign alone or in combination with NT-proBNP has high diagnostic accuracy in differentiating acute HF-related from COPD/asthma-related causes of acute dyspnea in the prehospital emergency setting. Trial registration ClinicalTrials.gov NCT01235182.

This review describes ultrasound techniques of potential use to high altitude researchers and discusses technical issues related to using ultrasound for high altitude research. Ultrasound allows portable, noninvasive evaluation of many physiologic parameters of interest to high altitude researchers. We discuss techniques that have been extensively used and emerging techniques that can be used to assess parameters of particular interest to high altitude researchers. We do not provide a definitive description of all ultrasound scanning methods but references to instructive sources are included. Potential drawbacks of ultrasound use, such as the need for sometimes extensive training and the potential for interobserver variation, are discussed and strategies for mitigating these are suggested. This review is meant to encourage other high altitude researchers to consider using ultrasound, either as a primary investigative modality or as an adjunct for monitoring parameters of interest in studies of physiology, altitude illness, or therapeutics.

We applaud the British Thoracic Society (BTS) for its efforts to improve patient care through scientific evidence. We thus recognise the recent guidelines on pleural procedures and thoracic ultrasound (TUS) as an important attempt to develop a rational approach to chest sonography.1 However, we are concerned that the BTS has reached conclusions based on a less complete review of TUS. The guidelines state that ‘the utility of thoracic ultrasound for diagnosing a pneumothorax is limited in hospital practice due to the ready availability of chest x-rays (CXR) and conflicting data from published reports’.1 This conclusion appears to be based on a small (but landmark) study of 11 patients from 1986 to 1989, two small studies with only four pneumothoraces in …

The objective of this study was to determine the test characteristics for two different ultrasound (US) measures of severe dehydration in children (aorta to inferior vena cava [IVC] ratio and IVC inspiratory collapse) and one clinical measure of severe dehydration (the World Health Organization [WHO] dehydration scale).The authors enrolled a prospective cohort of children presenting with diarrhea and/or vomiting to three rural Rwandan hospitals. Children were assessed clinically using the WHO scale and then underwent US of the IVC by a second clinician. All children were weighed on admission and then fluid-resuscitated according to standard hospital protocols. A percent weight change between admission and discharge of greater than 10% was considered the criterion standard for severe dehydration. Receiver operating characteristic (ROC) curves were created for each of the three tests of severe dehydration compared to the criterion standard.Children ranged in age from 1 month to 10 years; 29% of the children had severe dehydration according to the criterion standard. Of the three different measures of dehydration tested, only US assessment of the aorta/IVC ratio had an area under the ROC curve statistically different from the reference line. At its best cut-point, the aorta/IVC ratio had a sensitivity of 93% and specificity of 59%, compared with 93% and 35% for IVC inspiratory collapse and 73% and 43% for the WHO scale.Ultrasound of the aorta/IVC ratio can be used to identify severe dehydration in children presenting with acute diarrhea and may be helpful in guiding clinical management.

Point-of-care ultrasound is being increasingly implemented in resource-poor settings in an ad hoc fashion. We developed a focused maternal ultrasound-training program for midwives in a rural health district in Zambia. Four hundred forty-one scans were recorded by 21 midwives during the 6-month study period. In 74 scans (17%), the ultrasound findings prompted a change in clinical decision-making. Eight of the midwives were evaluated with a 14-question observed structured clinical examination (OSCE) and demonstrated a slight overall improvement with mean scores at 2 and 6 months of 10.0/14 (71%) and 11.6/14 (83%), respectively. Our pilot project demonstrates that midwives in rural Zambia can be trained to perform basic obstetric ultrasound and that it impacts clinical decision-making. Ultrasound skills were retained over the study period. More data is necessary to determine whether the introduction of ultrasound ultimately improves outcomes of pregnant women in rural Zambia.

A novel method of image analysis for quantifying diaphragmatic motion is described using ultrasound. Nineteen patients scheduled for thoracic surgery were evaluated with ultrasound preoperatively and through their postoperative hospital stay. Diaphragmatic motion was measured using a horizontal on-screen ruler, allowing for quantification and tracking of dynamic diaphragm function. A percentage (73.5%) of all attempted measurements was quantifiable. Preoperative measurements of left and right diaphragm movement were correlated and there was no significant difference between the two. Postoperative diaphragm movement ipsilateral to the incision was statistically significantly less when compared to the contralateral side (p = 0.02 vs. p = 0.19). While not universally feasible in all patients, this method for quantifying diaphragmatic function is the only known imaging technique that can be performed at the bedside. Further evaluation of the impact of diaphragmatic dysfunction on patients undergoing thoracic surgery and its correlation with dyspnea is planned.

Ultrasound measurement of the optic nerve sheath diameter (ONSD) has been shown to correlate with intracranial pressure (ICP). This study looked at intra-observer and inter-observer reliability among three emergency physicians (EPs) using three different imaging protocols.Ocular ultrasound was performed in 20 healthy volunteers. Each physician obtained 3 measurements of the right eye ONSD with both the 10-5 MHz and 13-6 MHz probes using the axial imaging technique (experiment 1). The ONSD was then measured with the 10-5 MHz probe using the axial technique and the intracavitary 8-5 MHz probe using the coronal technique (experiment 2).In experiment 1, larger measurements were obtained with the standard 10-5 MHz probe with an adjusted difference of 0.21 mm (p0.001). The standard deviation between intra-observer measurements for the 10-5 MHz probe was slightly but not significantly larger with an adjusted difference of 0.039 (p=0.10). In experiment 2, larger measurements were obtained with the standard 10-5 MHz probe with an adjusted difference of 0.91 mm (p0.001). The standard deviation between intra-observer measurements was greater for the 10-5 MHz probe with an adjusted difference of 0.06 (p=0.03). The inter-observer measurements in experiment 2 had significantly larger variance with the 10-5 MHz probe (p=0.001).These data suggest comparable precision and inter-observer reliability can be achieved. However, larger values when using the 10-5 MHz probe suggest different cut-off thresholds for normal upper limits. The coronal imaging technique demonstrated less inter-rater variance and may be a better technique when such small measurement differences are important.

Sonographic B-lines, also known as lung comets, have been shown to correlate with the presence of extravascular lung water (EVLW). Absent in normal lungs, these sonographic findings become prominent as interstitia and alveoli fill with fluid. Characterization of the dynamics of B-lines, specifically their rate of disappearance as volume is removed, has not been previously described. In this study, we describe the dynamics of B-line resolution in patients undergoing hemodialysis.Patients undergoing hemodialysis underwent three chest ultrasound examinations: before, at the midpoint, and after dialysis. We followed a previously described chest ultrasound protocol that counts the number of B-lines visualized in 28 lung zones. Baseline demographics, assessment of ejection fraction, time elapsed, net volume of fluid removed, and subjective degree of shortness of breath were recorded for each patient.Forty of 45 patients completed full dialysis runs and had all three lung scans performed; 6 of 40 patients had zero or one B-line predialysis, and none of these 6 patients gained B-lines during dialysis. Thirty-four of 40 patients had statistically significant reductions in the number of B-lines from predialysis to the midpoint scan and from predialysis to postdialysis with a p value0.001. There was no association between subjective dyspnea scores and number of B-lines removed.B-line resolution appears to occur real-time as fluid is removed from the body, and this change was statistically significant. These data support thoracic ultrasound as a useful method for evaluating real-time changes in EVLW and in assessing a patient's physiologic response to the removal of fluid.Massachusetts General Hospital trial registration protocol No. 2007P 002226.

Previous studies suggest that serum myeloperoxidase (MPO) is a potentially useful biomarker to risk stratify troponin-negative patients with suspected myocardial ischemia. We hypothesized that the relationship between initial serum MPO levels would correlate with 30-day adverse cardiac outcomes for low risk emergency department (ED) patients with suspected myocardial ischemia. This prospective cohort study enrolled ED patients with chest pain or suspected myocardial ischemia, non-diagnostic ECG, and initially negative cardiac troponin I. We defined 30-day adverse cardiac events as death, myocardial infarction, or coronary revascularization. We calculated summary statistics, standard deviation (SD), odds ratios (OR), 95% confidence intervals (CI), and receiver operating characteristics (ROC). We enrolled 159 patients who had a mean age of 55 ± 13, were 56% female, of whom 5.2% suffered at least one adverse cardiac event. MPO test characteristics were poor, with an ROC area of only 0.47 (CI 0.23-0.71). MPO levels were not associated with adverse events (OR 0.99, CI 0.98-1.01, p=0.62). The optimal ROC cutpoint to predict adverse cardiac events had poor sensitivity and specificity (57% and 52%, respectively). Mean MPO concentrations in the event group did not differ from the non-event group. In this limited cohort of low risk ED patients with chest pain, we were unable to demonstrate utility of MPO for risk stratification. If confirmed in larger studies, these findings may call into question the routine use of MPO for low-risk chest pain.

Increased intracranial pressure is suspected in the pathogenesis of acute mountain sickness (AMS), but no studies have correlated it with the presence or severity of AMS. We sought to determine whether increased optic nerve sheath diameter, a surrogate measure of intracranial pressure, is associated with the presence and severity of AMS. We performed a cross-sectional study of travelers ascending through Pheriche, Nepal (4,240 m), from March 3 to May 14, 2006. AMS was assessed using the Lake Louise score. Optic nerve sheath diameter was measured by ultrasound. Ultrasound exams were performed and read by separate blinded observers. Two-hundred eighty seven subjects were enrolled. Ten of these underwent repeat examination. Mean optic nerve sheath diameter was 5.34 mm [95% confidence interval (CI) 5.18–5.51 mm] in the 69 subjects with AMS vs. 4.46 mm (95% CI 4.39–4.54 mm) in the 218 other subjects ( P < 0.0001). There was also a positive association between optic nerve sheath diameter and total Lake Louise score ( P for trend < 0.0001). In a multivariate logistic regression model of factors associated with AMS, optic nerve sheath diameter was strongly associated with AMS (odds ratio 6.3; 95% CI, 3.7–10.8; P < 0.001). In 10 subjects with repeat examinations, change in Lake Louise score had a strong positive correlation with change in optic nerve sheath diameter ( R2 = 0.84, P < 0.001). Optic nerve sheath diameter, a proxy for intracranial pressure, is associated with the presence and severity of AMS.

Background While ultrasound (US) has continued to expedite diagnosis and therapy for critical care physicians inside the hospital system, the technology has been slow to diffuse into the pre-hospital system. Given the diagnostic benefits of thoracic ultrasound (TUS), we sought to evaluate image recognition skills for two important TUS applications; the identification of B-lines (used in the US diagnosis of pulmonary edema) and the identification of lung sliding and comet tails (used in the US diagnosis of pneumothorax). In particular we evaluated the impact of a focused training module in a pre-hospital system that utilizes physicians as pre-hospital providers. Methods 27 Paris Service D'Aide Médicale Urgente (SAMU) physicians at the Hôpital Necker with varying levels of US experience were given two twenty-five image recognition pre-tests; the first test had examples of both normal and pneumothorax lung US and the second had examples of both normal and pulmonary edema lung US. All 27 physicians then underwent the same didactic training modules. A post-test was administered upon completing the training module and results were recorded. Results Pre and post-test scores were compared for both the pneumothorax and the pulmonary edema modules. For the pneumothorax module, mean test scores increased from 10.3 +/- 4.1 before the training to 20.1 +/- 3.5 after (p < 0.0001), out of 25 possible points. The standard deviation decreased as well, indicating a collective improvement. For the pulmonary edema module, mean test scores increased from 14.1 +/- 5.2 before the training to 20.9 +/- 2.4 after (p < 0.0001), out of 25 possible points. The standard deviation decreased again by more than half, indicating a collective improvement. Conclusion This brief training module resulted in significant improvement of image recognition skills for physicians both with and without previous ultrasound experience. Given that rapid diagnosis of these conditions in the pre-hospital system can change therapy, especially in systems where physicians can integrate this information into treatment decisions, the further diffusion of this technology would seem to be beneficial and deserves further study.

Background Over the last decade, utilization of ultrasound technology by non-radiologist physicians has grown. Recent advances in affordability, durability, and portability have brought ultrasound to the forefront as a sustainable and high impact technology for use in developing world clinical settings as well. However, ultrasound's impact on patient management plans, program sustainability, and which ultrasound applications are useful in this setting has not been well studied. Methods Ultrasound services were introduced at two rural Rwandan district hospitals affiliated with Partners in Health, a US nongovernmental organization. Data sheets for each ultrasound scan performed during routine clinical care were collected and analyzed to determine patient demographics, which ultrasound applications were most frequently used, and whether the use of the ultrasound changed patient management plans. Ultrasound scans performed by the local physicians during the post-training period were reviewed for accuracy of interpretation and image quality by an ultrasound fellowship trained emergency medicine physician from the United States who was blinded to the original interpretation. Results Adult women appeared to benefit most from the presence of ultrasound services. Of the 345 scans performed during the study period, obstetrical scanning was the most frequently used application. Evaluation of gestational age, fetal head position, and placental positioning were the most common findings. However, other applications used included abdominal, cardiac, renal, pleural, procedural guidance, and vascular ultrasounds. Ultrasound changed patient management plans in 43% of total patients scanned. The most common change was to plan a surgical procedure. The ultrasound program appears sustainable; local staff performed 245 ultrasound scans in the 11 weeks after the departure of the ultrasound instructor. Post-training scan review showed the concordance rate of interpretation between the Rwandese physicians and the ultrasound-trained quality review physicians was 96%. Conclusion We suggest ultrasound is a useful modality that particularly benefits women's health and obstetrical care in the developing world. Ultrasound services significantly impact patient management plans especially with regards to potential surgical interventions. After an initial training period, it appears that an ultrasound program led by local health care providers is sustainable and lead to accurate diagnoses in a rural international setting.

Bedside emergency ultrasound has been used by emergency physicians for >20 years for a variety of conditions. In adult centers, emergency ultrasound is routinely used in the management of victims of blunt abdominal trauma, in patients with abdominal aortic aneurysm and biliary disease, and in women with first-trimester pregnancy complications. Although its use has grown dramatically in the last decade in adult emergency departments, only recently has this tool been embraced by pediatric emergency physicians. As the modality advances and becomes more available, it will be important for primary care pediatricians to understand its uses and limitations and to ensure that pediatric emergency physicians have access to the proper training, equipment, and experience. This article is meant to review the current literature relating to emergency ultrasound in pediatric emergency medicine, as well as to describe potential pediatric applications.

Measurements of the optic nerve sheath diameter (ONSD) using bedside ultrasound (US) have been shown to correlate with clinical and radiologic signs and symptoms of increased intracranial pressure (ICP).Previous literature has identified 5 mm as the ONSD measurement above which patients exhibit either clinical or radiologic signs of elevated ICP. The goals of this study were to evaluate the association between ONSD and ICP and to validate the commonly used ONSD threshold of 5 mm using direct measurements of ICP as measured by ventriculostomy.A prospective blinded observational study was performed using a convenience sample of adult patients in both the emergency department (ED) and the neurologic intensive care unit (ICU) who had invasive intracranial monitors placed as part of their clinical care. Ocular USs were performed with a 10(-5) MHz linear probe. Emergency physicians (EPs) with previous ocular US experience performed ONSD measurements while blinded to the contemporaneous ICP reading obtained directly from invasive monitoring. The association between ONSD and ICP was assessed with the Spearman rank correlation coefficient, and a receiver operator characteristic (ROC) curve was created to determine the optimal ONSD cutoff to detect ICP20 cm H2O.Thirty-eight ocular USs were performed on 15 individual patients. Spearman rank correlation coefficient of ONSD and ICP was 0.59 (p0.0005) demonstrating a significant positive correlation. An ROC curve was created to assess the ability of ONSD to distinguish an abnormal ICP greater than 20 cm H2O. The area under the ROC curve was 0.93 (95% confidence interval [CI] = 0.84 to 0.99). Based on inspection of the ROC curve, ONSD5 mm performed well to detect ICP20 cm H(2)O with a sensitivity of 88% (95% CI = 47% to 99%) and specificity of 93% (95% CI = 78% to 99%).Using an ROC curve the authors systematically confirmed the commonly used threshold of ONSD5 mm to detect ICP20 cm H2O. This study directly correlates ventriculostomy measurements of ICP with US ONSD measurements and provides further support for the use of ONSD measurements as a noninvasive test for elevated ICP.

Vascular thrombosis is an uncommon but recognized peril of high altitude travel. Traditionally, this has been associated with prolonged exposure to extreme altitudes where dehydration, hemoconcentration, cold, use of constrictive clothing, and enforced stasis due to severe weather have been named as contributing factors. It is widely hypothesized that hypoxia itself alters the coagulation cascade to create a prothrombotic milieu, though evidence thus far is limited and frequently conflicting. Case reports have described venous thrombosis, pulmonary embolism, cerebrovascular accidents, transient ischemic attacks, and thromboses of the portal circulation at altitude. We report a unique case of aortic thrombosis presenting with critical lower extremity ischemia in a previously healthy individual after a brief exposure to altitudes up to 4620 m. None of the frequently invoked risk factors of dehydration, cold, enforced use of constrictive clothing, weather-imposed inactivity, or extreme altitude were present, and no medical predisposition to thrombosis was identified, suggesting hypoxia as the most likely prothrombotic stimulus. We discuss the treatment of this problem and the application of Doppler ultrasonography in a wilderness setting.

The use of ultrasound has revolutionized the way in which many acute injuries and conditions are managed in emergency department and critical care areas in hospitals. Emergency departments nationwide are outfitted with ultrasound equipment, allowing acute conditions to be diagnosed within critical seconds. This book is a practical and concise introduction to bedside emergency ultrasound for all critical care physicians. It covers the full spectrum of conditions diagnosed via this modality, both for guiding invasive procedures as well as diagnosis in critical-care settings. It introduces the major applications for emergency ultrasound by using focused diagnostic questions and teaching the image-acquisition skills needed to answer these questions. Images of positive and negative findings for each application (FAST, ECHO, etc.) are presented, as well as scanning tips for improved image quality. Each section also contains a review of the literature supporting each application.

Introduction The kidney and bladder are two of the most sonographically accessible organs. The evidence for using ultrasound to make lifesaving diagnoses in this application is not as apparent as it is for cardiac or aortic ultrasound (except, of course, if flank pain and hydronephrosis are the result of a rapidly expanding AAA – see Chapter 5). Indeed, it is accurate to say that CT is dramatically more sensitive and specific in detecting ureteral stones and that ultrasound has a very low specificity for identifying ureteral stones (1–4). However, despite the advantages of CT for nephrolithiasis, there is still a role for ultrasound in evaluating the urinary tract in the emergency setting. In the most straightforward case, US identification of mild or moderate unilateral hydronephrosis in a patient with known renal colic and normal renal function testing (and a normal aortic screening evaluation) can obviate further radiologic testing. Patients who have relative contraindications to radiation exposure (pregnancy, pediatric patients) can also have ureteral obstruction evaluated by ultrasound. Renal ultrasonography easily and rapidly obtains evidence for or against high-grade obstruction, thereby expediting decisions regarding management and disposition (5, 6). In addition, determination of bladder volume is another important indication for urinary tract ultrasound. Before catheterizing a patient to evaluate for postrenal obstruction or urinary retention secondary to neurologic events, an ultrasound can give an estimation of bladder volume and indicate whether catheterization is even necessary. Pediatric patients can also have bladder volume evaluated with ultrasound.

Introduction Ectopic pregnancy (EP) is the leading cause of maternal mortality in the United States and is estimated to have a prevalence of 8% in pregnant patients presenting to the ED for any complaint (1, 2). Indeed, the incidence of ectopic pregnancy has been rising since the mid-1980s (3). Therefore, any female of child-bearing age who comes to the emergency room with abdominal pain, vaginal bleeding, near-syncope, or syncope has ectopic pregnancy on the differential. This is a “can't miss” diagnosis. Given the volume of female patients presenting with these complaints, an algorithm incorporating first trimester ultrasound can be timesaving for the physician and patient but must increase efficiency without compromising safety. The evaluation for ectopic pregnancy differs from other indications for bedside ultrasound. Evaluation of the uterus seeks to confirm an intrauterine pregnancy (IUP), ruling out ectopic gestation by exclusion. Visualization of the actual ectopic pregnancy is not the goal. In contrast, evaluation of the aorta, heart, and other organs typically confirms pathology (aneurysm, asystole, hydronephrosis) via direct visualization. There are instances where an extrauterine gestation will be seen on bedside ultrasound or free fluid will be seen in a hypotensive pregnant female and ectopic pregnancy will be diagnosed or inferred. This will be the exception, however, to how bedside ultrasound is used for this application. Bedside ultrasonography instead will be used to increase the number of IUP cases that can be definitively diagnosed and discharged in the ED without further imaging.

Background: The potential clinical utility of the Duke Treadmill Score (DTS) in the Emergency Department (ED) to risk-stratify patients with chest pain but negative cardiac biomarkers and non-diagnostic electrocardiograms is unclear. Objective: We evaluated whether DTS was associated with 30-day adverse cardiac outcomes for low-risk ED patients with chest pain. Methods: For this prospective, observational cohort study, the primary outcome was any of the following at 30 days: cardiac death, myocardial infarction, or coronary revascularization. DTS risk categories (low, intermediate, high) were compared with 30-day cardiac outcomes. Results: We enrolled 191 patients, of whom 20 (10%) were lost to follow-up, leaving 171 patients (mean age 53.3 ± 12.4 years, 54% female, 3.5% adverse event rate) for evaluation. Sensitivity and specificity of DTS for 30-day events were 83.3% and 71.5%, respectively, with a 99.2% negative predictive value (confidence interval 95.4–99.9) for 30-day event-free survival. Conclusions: In this cohort of low-risk ED patients with chest pain, DTS demonstrated excellent negative predictive value for 30-day event-free survival and facilitated safe disposition of a large subset of patients.

In December 1999, a group of emergency physicians from the United States, Israel, and Ethiopia met for the Second Annual Symposium on Emergency Medicine and to perform an initial evaluation of the prehospital care system in Addis Ababa. The symposium was structured into a workshop on prehospital care and a clinical seminar for emergency medicine providers. This article describes the current prehospital infrastructure in Addis Ababa, Ethiopia. This serves as the basis for more specific needs assessments and training interventions, which are ongoing. The authors present a list of priorities for the development of an emergency medical services (EMS) system for Addis Ababa that was generated in partnership with local government and the World Health Organization. The article contrasts these initial recommendations with those found in the literature on the development of EMS systems in developing nations.