Showing papers by "Vicki E. Noble published in 2010"

Focused Cardiac Ultrasound in the Emergent Setting: A Consensus Statement of the American Society of Echocardiography and American College of Emergency Physicians

Abstract: The use of ultrasound has developed over the last 50 years into an indispensable first-line test for the cardiac evaluation of symptomatic patients. The technologic miniaturization and improvement in transducer technology, as well as the implementation of educational curriculum changes in residency training programs and specialty practice, have facilitated the integration of focused cardiac ultrasound into practice by specialties such as emergency medicine. In the emergency department, focused cardiac ultrasound has become a fundamental tool to expedite the diagnostic evaluation of the patient at the bedside and to initiate emergent treatment and triage decisions by the emergency physician.

Ultrasound Assessment of Severe Dehydration in Children With Diarrhea and Vomiting

Abstract: Objectives: 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). Methods: 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. Results: 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. Conclusions: 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. ACADEMIC EMERGENCY MEDICINE 2010; 17:1035–1041 © 2010 by the Society for Academic Emergency Medicine

Focused maternal ultrasound by midwives in rural Zambia.

Abstract: 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.

Real-time resolution of sonographic B-lines in a patient with pulmonary edema on continuous positive airway pressure.

Abstract: Sonographic B-lines of the lungs have been shown to be able to differentiate between congestive heart failure and chronic obstructive pulmonary disease. Studies have shown that B-lines are often present on presentation and resolve during the course of a hospitalization. What is not known is how quickly B-lines resolve in response to treatment. We describe a case of a patient who presented with pulmonary edema and had diffuse B-lines seen on bedside thoracic ultrasound. She was treated with continuous positive airway pressure only and, a few hours later, had no sonographic Blines. B-lines seen on bedside thoracic ultrasound resolve in real time when pulmonary edema is treated with continuous positive airway pressure. Research to further quantify the use of B-lines in monitoring response to treatment is needed. Thoracic ultrasound has been shown to be a useful way of evaluating patients with dyspnea. Specifically, the presence of diffuse sonographic B-lines is associated with fluid overload states such as pulmonary edema. Although studies have shown that B-lines can aid in the diagnosis of this condition, none have looked at their rate of resolution with treatment. We describe an interesting case of a patient in pulmonary edema whose B-lines resolve in real time when treated with continuous positive airway pressure (CPAP) only. An 82-year-old woman presented to the emergency department (ED) with dyspnea for 4 hours. She had a history of atrial fibrillation, congestive heart failure (CHF), end-stage renal disease, hypertension, and coronary artery disease. She was sitting on her couch in her usual state of health watching TV when she suddenly became short of breath. She had a mild nonproductive cough but denied fever, chest pain, or leg pain. She had been compliant with her medications and with hemodialysis sessions. She had been using 2 to 3 pillows to sleep at night for a while. She reported some intermittent leg swelling, which improves after dialysis. 0735-6757/$ – see front matter © 2010 Elsevier Inc. All rights reserved. On examination, the patient appeared pale and diaphoretic. Her heart rate was 140 beats/min and irregular; blood pressure, 192/108 mmHg; respiratory rate, 32 breaths/min; and oxygen saturation, 91%on room air, which improved to 98%on 100% nonrebreather mask. She was in moderate respiratory distress, using accessory muscles to breathe. Chest examination revealed rales, rhonchi, and wheezing bilaterally. She had no jugular venous distention nor any peripheral edema. A bedside thoracic ultrasound of bilateral anterior and lateral chest walls was performed (Fig. 1). A diagnosis of pulmonary edema was made, and the patient was started on CPAP. Subsequently, a chest x-ray showed cardiomegaly and pulmonary edema consistent with CHF. An NT-ProBNP level was elevated to 4838 (for the patient's age, normal b1800). An electrocardiogram showed atrial fibrillation with rapid ventricular response and no ischemic changes. Three and a half hours after initiation of CPAP, the patient's respiratory status had improved. A repeat thoracic ultrasound was performed (Fig. 2). The patient was admitted to the hospital with a diagnosis of pulmonary edema. Bedside ultrasound of the lungs is a fairly novel tool in the armamentarium of emergency physicians in assessing etiologies of dyspnea. It has been shown to be particularly helpful in differentiating between CHF and chronic obstructive pulmonary disease [1-9]. The thoracic ultrasound relies not on visualization of pulmonary structures but rather on identification of sonographic artifacts called A-lines and Blines. A-lines (Fig. 3) are hyperechoic, horizontal lines that occur at regular intervals below the pleural line and represent a reverberation artifact between the probe and the pleura. These are found in normal lungs or in pulmonary diseases characterized by hyperaeration such as chronic obstructive pulmonary disease. B-lines (Fig. 3), on the other hand, are hyperechoic vertical lines that originate at and slide with the pleura and extend radially to the edge of the screen without fading. Isolated B-lines may be seen in normal lungs, but diffuse B-lines in multiple zones indicate interstitial thickening, most commonly seen in CHF [8]. Although it has been shown that CHF can be diagnosed on bedside ultrasound when a patient initially presents to the ED, little is known about the dynamics of B-lines. One study Fig. 1 Eight zones of the thorax are scanned—upper and lower areas of the anterior and lateral chest walls bilaterally. A 2to 5-MHz curvilinear probe (Sonosite Micromaxx; Sonosite Inc, Bothell, Wash) on abdominal settings was placed on the chest wall perpendicular to the ribs, and the thoracic space was visualized to a depth of 18 cm. These images, performed shortly after arrival to the ED, show diffuse B-lines in all 8 zones. In some zones, the B-lines are so numerous and confluent that they appear as continuous hyperechoic curtains. This diffuse pattern suggests a diagnosis of pulmonary edema. 541.e6 Case Report of patients with CHF showed that B-lines resolved over the course of a hospital admission along with symptoms, chest xray findings, and BNP [10]. Another study of patients with ESRD shows the resolution of B-lines throughout the course of hemodialysis [11]. This case is unique because it is the first description of real-time resolution of B-lines during ED management of CHF, within hours of initiation of treatment. It demonstrates that in CHF, B-lines reflect acute rather than chronic changes within lung parenchyma. Because chest xrays can often lag behind clinical findings in CHF, it is possible that ultrasound may be a better imaging modality to follow pulmonary fluid status in patients with CHF and even help determine optimal treatment. What is also unique about this case is that the patient's only treatment was CPAP. Continuous positive airway pressure is a commonly used noninvasive method of treating pulmonary edema. Increased airway pressure causes a pressure gradient that forces alveolar and interstitial fluid back into the capillaries, improving gas exchange across the membrane. Ultrasonographically, B-lines disappear as interstitia return to normal thickness, and A-lines appear as the lungs become better aerated and less fluid filled. These findings support the understanding that B-lines are caused by extravascular pulmonary fluid. Furthermore, they suggest that thoracic ultrasound could be used not only to diagnose pulmonary edema but also to monitor response to Fig. 2 The identical zones as in Fig. 1 scanned after approximately 31⁄2 hours of CPAP. No B-lines are present. A-lines can be seen in some zones. These findings represent resolution alveolar and interstitial fluid. Fig. 3 A-lines and B-lines. On the left, horizontal hyperechoic reverberation artifacts are seen below and parallel to the pleural line. These are known as A-lines and represent normal or hyperaerated lungs. On the right, again, the pleural line is visualized between adjacent ribs. Here, hyperechoic lines known as B-lines originate at the pleural line and extend vertically to the bottom of the screen. Diffuse B-lines suggest pulmonary interstitial thickening, usually secondary to fluid extravasation. 541.e7 Case Report

Ultrasound Diagnosis of Type A Aortic Dissection

Abstract: Background: An aortic dissection is a life-threatening process that must be diagnosed and treated expeditiously. Imaging modalities used for diagnosis in the emergency department include computed tomography, magnetic resonance imaging, and trans-esophageal echocardiography. There are significant limitations to these studies, including patient contraindications (intravenous contrast dye allergies, renal insufficiency, metal-containing implants, hemodynamic instability) and the length of time required for study completion and interpretation by a radiologist or cardiologist. Objectives: A case is presented that demonstrates how emergency physicians can use trans-thoracic and abdominal bedside ultrasound to diagnose a type A aortic dissection. Case Report: A 72-year-old woman presented with chest pain radiating to her neck and back that was concerning for aortic dissection. This was subsequently confirmed and further classified as a type A dissection by bedside emergency physician-performed ultrasound. The images showed a clear intimal flap in the abdominal aorta, a dilatated aortic root, and extension of the intimal flap into the left common carotid artery. With prompt diagnosis, the patient was able to have emergent surgical consultation, confirmatory imaging, and intervention before further complication occurred. Conclusion: This case provides an example of how emergency trans-thoracic and abdominal ultrasound can be used to promptly diagnose a type A aortic dissection and expedite further consultation and prompt management.

An Evidence-Based Approach for Integrating Bedside Ultrasound Into Routine Practice in the Assessment of Undifferentiated Shock:

Abstract: Undifferentiated hypotension remains a central diagnostic and therapeutic challenge in emergency and critical care medicine. Increasingly, bedside ultrasound conducted by intensivists and emergency medicine providers is assuming a central role in diagnosis and resuscitation of hypotension. This review discusses sample algorithms for the bedside ultrasonographic assessment of undifferentiated shock and outlines an evidence-based framework for the intensivist seeking to incorporate bedside ultrasound into daily clinical practice. The literature regarding specific applications including cardiac, thoracic, pulmonary, and vascular assessment is briefly reviewed, as is the evidence pertaining to effective implementation, training, credentialing, and ongoing quality assurance.

Decreased sensitivity of lung ultrasound limited to the anterior chest in emergency department diagnosis of cardiogenic pulmonary edema: a retrospective analysis

Abstract: B-lines are vertical echogenic artifacts seen on lung ultrasound that allow bedside diagnosis of pulmonary edema. The BLUE protocol, published by Lichtenstein and Meziere, suggests that cardiogenic pulmonary edema is sufficiently ruled out in the ICU setting when B-lines are not predominant in the anterior chest (the B-profile). Our analysis sought to evaluate the sensitivity of the B-profile for ruling out pulmonary edema in the ED patient population. The ultrasound lung scans of patients with confirmed official diagnoses of acute decompensated heart failure (ADHF) from two ED databases were retrospectively analyzed. 170 acutely dyspneic patients had complete studies (130 from one database and 40 from the other). The scans were reviewed using the B-profile definition for ruling out pulmonary edema and comparing that to an alternate scanning protocol that includes ultrasound evaluation of the lateral and anterior chest. Of the 170 ED patients with ADHF diagnoses, the B-profile missed 16.5% (n = 28) for a sensitivity of 83.5% (95% CI 77–89%). These 28 patients did not show anterior bilateral B-lines that fit the criteria for positive under the BLUE protocol. Moreover, 25% (7/28) of these missed patients had only lateral B-lines on their lung scans and B-lines would have been detected only by including scans of the lateral zones. Limiting the sonographic lung examination to the anterior chest areas only will miss cases of ADHF in the dyspneic ED patients. The BLUE protocol (B-profile) may need to be modified to include examination of the lateral chest as necessary for ED patients with ADHF.

Prognostic value of the Duke treadmill score for emergency department patients with chest pain.

Abstract: 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.

The impact of analgesia on the diagnostic accuracy of the sonographic Murphy's sign.

Abstract: ObjectivesAdministering analgesia to patients with abdominal pain before diagnostic imaging is now accepted as standard practice. However, analgesia before diagnostic right upper quadrant ultrasound continues to be controversial for fear of masking the sonographic Murphy's sign (SMS). This study sou

Real-time video transmission of ultrasound images to an iPhone

Abstract: As point-of-care ultrasound spreads across the globe, there is an increased need for training and supervision of ultrasound studies. Real-time oversight is important, especially in critically ill patients, but often an expert ultrasound over-read is not available on location. Technological advances have improved data transmission so that images and videos can be sent great distances very rapidly. In this study, we examine the feasibility of real-time wireless transmission of ultrasound video to an iPhone. An ultrasound machine was connected via a video converter to a laptop. iCam (SKJM, LLC) software was used to transmit the video across the Atlantic Ocean to an iPhone. Images typical for those performed in an emergency department were sent, in random order by a ‘scanning physician.’ An ‘interpreting physician’ overseas was asked to identify the anatomy, presence or absence of pathology, and comment on the quality, speed, and delay of transmission. Rapid image transmission was feasible and the ‘interpreting physician’ was always able to correctly identify the anatomy and orientation. The average delay was minimal (2.7 s), allowing for real-time feedback. The frame rate was markedly slower in the received images as compared to the transmitted images, and was faster when the iPhone was connected via WiFi (1.1 fps) versus a 3G connection (0.4 fps). Transmission of real-time ultrasound video to a remote iPhone using inexpensive technology is feasible, with the preservation of image quality and minimal delay. Transmission speed was superior with a WiFi connection than with a 3G connection.

Blunt cardiac rupture.

Abstract: *Department of Emergency Medicine, North Shore Medical Center, Salem, Massachusetts, †Department of Emergency Medicine, Rhode Island Hospital, Providence, Rhode Island, ‡Department of Emergency Medicine, Massachusetts General Hospital, Boston, Massachusetts, and §Department of Emergency Medicine, Brigham and Women’s Hospital, Boston, Massachusetts Reprint Address: Eric S. Nadel, MD, Department of Emergency Medicine, Brigham and Women’s Hospital, 75 Francis Street, Boston, MA 02115