Assessing Competence in Critical Care Echocardiography: Development and Initial Results of an Examination and Certification Processes.

OBJECTIVES: To describe the development and initial results of an examination and certification process assessing competence in critical care echocardiography. DESIGN: A test writing committee of content experts from eight professional societies invested in critical care echocardiography was convened, with the Executive Director representing the National Board of Echocardiography. Using an examination content outline, the writing committee was assigned topics relevant to their areas of expertise. The examination items underwent extensive review, editing, and discussion in several face-to-face meetings supervised by National Board of Medical Examiners editors and psychometricians. A separate certification committee was tasked with establishing criteria required to achieve National Board of Echocardiography certification in critical care echocardiography through detailed review of required supporting material submitted by candidates seeking to fulfill these criteria. SETTING: The writing committee met twice a year in person at the National Board of Medical Examiner office in Philadelphia, PA. SUBJECTS: Physicians enrolled in the examination of Special Competence in Critical Care Electrocardiography (CCEeXAM). MEASUREMENTS AND MAIN RESULTS: A total of 524 physicians sat for the examination, and 426 (81.3%) achieved a passing score. Of the examinees, 41% were anesthesiology trained, 33.2% had pulmonary/critical care background, and the majority had graduated training within the 10 years (91.6%). Most candidates work full-time at an academic hospital (46.9%). CONCLUSIONS: The CCEeXAM is designed to assess a knowledge base that is shared with echocardiologists in addition to that which is unique to critical care. The National Board of Echocardiography certification establishes that the physician has achieved the ability to independently perform and interpret critical care echocardiography at a standard recognized by critical care professional societies encompassing a wide spectrum of backgrounds. The interest shown and the success achieved on the CCEeXAM by practitioners of critical care echocardiography support the standards set by the National Board of Echocardiography for testamur status and certification in this imaging specialty area.

Effect of Machine Settings on Ultrasound Assessment of B-lines.

OBJECTIVES: B-lines are a lung ultrasound (LUS) artifact that often indicate pathology. Little is known about the optimal ultrasound machine settings to assess B-lines. We compared settings typically used to evaluate B-lines at our institution with adjusted settings based on recent studies. METHODS: In order to determine typical settings for B-line assessment, we retrospectively reviewed LUS images obtained at our institution. We then prospectively performed LUS with both typical and adjusted settings, using curvilinear and phased array probes, in 20 patients presenting to the emergency department with shortness of breath. The prospectively obtained clips were rated for quality and quantity of B-lines by 14 clinicians with experience in LUS, with 1 assigned for typical settings "much greater," 2 for typical settings "slightly greater," 3 for both settings "similar," 4 for adjusted settings "slightly greater," and 5 for adjusted settings "much greater." RESULTS: Mean ratings and 95% confidence intervals significantly exceeded the null value of 3 for both B line quality (curvilinear probe: 4.68, 4.50-4.85; phased array probe: 4.02, 3.70-4.35) and B line quantity (curvilinear probe: 4.16, 3.84-4.49; phased array probe: 3.68, 3.41-3.96). CONCLUSIONS: B-line quality and quantity were rated higher using adjusted settings based on recently published evidence than when using settings that are typically employed in our institution. Our findings suggest that B-line assessment should be performed with focal zone at the level of the pleura, harmonics off, and gain increased in the far field.

Evaluation of Noncommercial Ultrasound Gels for Use in Resource-Limited Settings.

OBJECTIVES: Ultrasound (US) is increasingly used in settings where commercial US gel is unavailable. This study evaluated noncommercial gel recipes compared to commercial gel. METHODS: A search for US gel formulations revealed 6 recipes. Half-strength commercial gel and a modified glucomannan recipe were also tested. Nine gels, including commercial gel, were tested in Liberia and the United States. In each session, 2 physician sonologists evaluated 9 gels on 2 models, obtaining videos from the hepatorenal space with a curvilinear transducer, the cardiac parasternal long view with a phased array transducer, and the left basilic vein with a linear transducer. The sonologists and models, who were blinded to gel identity, made independent quantitative and qualitative gel evaluations comparing the test gel to commercial gel. Two physician sonologists who were blinded to the gel identities and a US operator reviewed the images and rated their quality. An analysis of variance in repeated measures was performed to test for differences in the overall score, real-time quality, and other characteristics. Post hoc pairwise comparisons to commercial gel were performed with a Tukey-Kramer adjustment. Inter- and intra-rater reliability was calculated for the image review. RESULTS: Commercial gel earned a perfect score. Compared to commercial gel, xanthine gum gel scored highest, followed by half-strength commercial gel. Hot concentrated glucomannan and cold glucomannan gel were found to be significantly worse than commercial gel. No significant difference was found between images based on the gel used on the image review. CONCLUSIONS: No significant difference in image quality was found between commercial and noncommercial gels on US image review.

The ability of renal ultrasound and ureteral jet evaluation to predict 30-day outcomes in patients with suspected nephrolithiasis.

STUDY OBJECTIVE: We sought to identify findings on bedside renal ultrasound that predicted need for hospitalization in patients with suspected nephrolithiasis. METHODS: A convenience sample of patients with suspected nephrolithiasis was prospectively enrolled and underwent bedside ultrasound of the kidneys and bladder to determine the presence and degree of hydronephrosis and ureteral jets. Sonologists were blinded to any other laboratory and imaging data. Patients were followed up at 30 days by phone call and review of medical records. RESULTS: Seventy-seven patients with suspected renal colic were included in the analysis. Thirteen patients were admitted. Reasons for admission included intractable pain, infection, or emergent urologic intervention. All 13 patients requiring admission had hydronephrosis present on initial bedside ultrasound. Patients with moderate hydronephrosis had a higher admission rate (36%) than those with mild hydronephrosis (24%), P<.01. Of patients without hydronephrosis, none required admission within 30 days. The sensitivity and specificity of hydronephrosis for predicting subsequent hospitalization were 100% and 44%, respectively. Loss of the ipsilateral ureteral jet was not significantly associated with subsequent hospital admission and did not improve the predictive value when used in combination with the degree of hydronephrosis. CONCLUSIONS: No patients with suspected renal colic and absence of hydronephrosis on bedside ultrasound required admission within 30 days. Ureteral jet evaluation did not help in prediction of 30-day outcomes and may not be useful in the emergency department management of renal colic.

The utility of transvaginal ultrasound in the ED evaluation of complications of first trimester pregnancy.

BACKGROUND: For patients with early intrauterine pregnancy (IUP), the sonographic signs of the gestation may be below the resolution of transabdominal ultrasound (TAU); however, it may be identified by transvaginal ultrasound (TVU). We sought to determine how often TVU performed in the emergency department (ED) reveals a viable IUP after a nondiagnostic ED TAU and the impact of ED TVU on patient length of stay (LOS). METHODS: This was a retrospective cohort study of women presenting to our ED with complications of early pregnancy from January 1, 2007 to February 28, 2009 in a single urban adult ED. Abstractors recorded clinical and imaging data in a database. Patient imaging modality and results were recorded and compared with respect to ultrasound (US) findings and LOS. RESULTS: Of 2429 subjects identified, 795 required TVU as part of their care. Emergency department TVU was performed in 528 patients, and 267 went to radiology (RAD). Emergency department TVU identified a viable IUP in 261 patients (49.6%). Patients having initial ED US had shorter LOS than patients with initial RAD US (median 4.0 vs 6.0 hours; P < .001). Emergency department LOS was shorter for women who had ED TVU performed compared with those sent for RAD TVU regardless of the findings of the US (median 4.9 vs 6.7 hours; P < .001). There was no increased LOS for patients who needed further RAD US after an indeterminate ED TVU (7.0 vs 7.1 hours; P = .43). There was no difference in LOS for those who had a viable IUP confirmed on ED TAU vs ED (median 3.1 vs 3.2 hours, respectively; P < .32). CONCLUSION: When an ED TVU was performed, a viable IUP was detected 49.6% of the time. Emergency department LOS was significantly shorter for women who received ED TVU after indeterminate ED TAU compared with those sent to RAD for TVU, with more marked time savings among those with live IUP diagnosed on ED TVU. For patients who do not receive a definitive diagnosis of IUP on ED TVU, this approach does not result in increased LOS.

An Uncommon Complication of Sinusitis in a Young Adolescent.

A young adolescent patient presented to the emergency department with forehead and eyelid swelling after a week of nasal discharge that was suspicious for Pott's puffy tumor. Point-of-care ultrasound facilitated rapid diagnosis and initiation of treatment for a concerning and rare complication of sinusitis, confirmed by computed tomography scan.

Pitfalls in cervical ectopic pregnancy diagnosis by emergency physicians using bedside ultrasonography.

Pelvic pain and vaginal bleeding are common complaints in pregnant women presenting to emergency department. Cervical ectopic pregnancy (EP) is a rare type of EP, with a higher likelihood of complications if missed. Its sonographic findings can be difficult to distinguish from normal pregnancy or an abortion in progress. In this report, we present a rare case of a cervical EP, diagnosed using bedside ultrasonography, and characterize the pitfalls associated with its diagnosis.

The effect of supine versus upright patient positioning on inferior vena cava metrics.

BACKGROUND: Ultrasound of the inferior vena cava (IVC) is a noninvasive and rapidly obtainable method of intravascular volume assessment; however not all patients can lie supine for this procedure. In this study we assess whether patient positioning affects IVC diameter metrics. METHODS: This was a prospective convenience sample of patients in an in-patient dialysis unit at an urban tertiary care center. IVC metrics taken in the supine patient, and then at 45o semi-upright position, pre and post dialysis. Measurements were taken in M-mode in longitudinal plane roughly 2 cm below the level of the diaphragm. IVC-maximum and IVC-minimum diameter measurements were used to determine the IVC collapse index (IVC Max - IVC Min)/IVC Max). Statistics such as means, frequencies and percentages, intraclass correlation coefficient and Bland Altman summary statistics were calculated. RESULTS: Forty-five patients were enrolled. Average age was 57 years, 69% were male, 73% were African American, 82% had hypertension, 42% had diabetes. There was good to excellent agreement between supine and upright IVC measurements. Both the IVC minimum and maximum measurements had similar coefficient correlation (ri) measurements (0.917 and 0.890 respectively), whereas agreement in the collapse index was lower (ri = 0.813). Bland Altman analysis demonstrated excellent agreement and small 95% limits of agreement (±6 mm) with minimal mean bias for both the minimum and maximum measurements. CONCLUSION: IVC metrics do not change significantly based on patient position. For those patients who are unable to lay completely supine, a semi-upright measurement of the IVC for volume status may be an accurate alternative.

Diagnosing heart failure among acutely dyspneic patients with cardiac, inferior vena cava, and lung ultrasonography.

BACKGROUND: Rapid diagnosis (dx) of acutely decompensated heart failure (ADHF) may be challenging in the emergency department (ED). Point-of-care ultrasonography (US) allows rapid determination of cardiac function, intravascular volume status, and presence of pulmonary edema. We test the diagnostic test characteristics of these 3 parameters in making the dx of ADHF among acutely dyspneic patients in the ED. METHODS: This was a prospective observational cohort study at an urban academic ED. Inclusion criteria were as follows: dyspneic patients, at least 18 years old and able to consent, whose differential dx included ADHF. Ultrasonography performed by emergency sonologists evaluated the heart for left ventricular ejection fraction (LVEF), the inferior vena cava for collapsibility index (IVC-CI), and the pleura sampled in each of 8 thoracic regions for presence of B-lines. Cutoff values for ADHF were LVEF less than 45%, IVC-CI less than 20%, and at least 10 B-lines. The US findings were compared with the final dx determined by 2 emergency physicians blinded to the US results. RESULTS: One hundred one participants were enrolled: 52% male, median age 62 (25%-75% interquartile, 53-91). Forty-four (44%) had a final dx of ADHF. Sensitivity and specificity (including 95% confidence interval) for the presence of ADHF were as follows: 74 (65-90) and 74 (62-85) using LVEF less than 45%, 52 (38-67) and 86 (77-95) using IVC-CI less than 20%, and 70 (52-80) and 75 (64-87) using B-lines at least 10. Using all 3 modalities together, the sensitivity and specificity were 36 (22-51) and 100 (95-100). As a comparison, the sensitivity and specificity of brain natriuretic peptide greater than 500 were 75 (55-89) and 83 (67-92). CONCLUSION: In this study, US was 100% specific for the dx of ADHF.

Inter-rater reliability of quantifying pleural B-lines using multiple counting methods.

OBJECTIVES: Sonographic B-lines are a sign of increased extravascular lung water. Several techniques for quantifying B-lines within individual rib spaces have been described, as well as different methods for "scoring" the cumulative B-line counts over the entire thorax. The interobserver reliability of these methods is unknown. This study examined 3 methods of quantifying B-lines for inter-rater reliability. METHODS: Videotaped pleural assessments of adult patients presenting to the emergency department with dyspnea and suspected acute heart failure were reviewed by 3 blinded pairs of emergency physicians. Each pair performed B-line counts within single rib spaces using 1 of the following 3 predetermined methods: 1, individual B-lines are counted over an entire respiratory cycle; 2, as per method 1, but confluent B-lines are counted as multiple based on the percentage of the rib space they occupy; and 3, as per method 2, but the count is made at the moment when the most B-lines are seen, not over an entire respiratory cycle. A single-measures interclass correlation coefficient was used to assess inter-rater reliability for the 3 definitions of B-line counts. RESULTS: A total of 456 video clips were reviewed. The interclass correlation coefficients (95% confidence intervals) for methods 1, 2, and 3 were 0.84 (0.81-0.87), 0.87 (0.85-0.90), and 0.89 (0.87-0.91), respectively. The difference between methods 1 and 3 was significant (P = .003). CONCLUSIONS: All methods of B-line quantification showed substantial inter-rater agreement. Method 3 is more reliable than method 1. There were no other significant differences between the methods. We recommend the use of method 3 because it is technically simpler to perform and more reliable than method 1.

Diagnosis of near-fatal pulmonary embolus-in-transit with focused echocardiography.

BACKGROUND: Among patients who die from pulmonary embolus (PE), approximately two-thirds succumb within an hour of presentation. Computed tomography can provide a definitive diagnosis but is associated with practical limitations. Echocardiography can increase diagnostic certainty of PE by visualizing signs of acute right ventricular (RV) strain. This case highlights a potentially lethal finding associated with PE and the role of clinician-performed bedside echocardiography in the timely management of this disease. OBJECTIVE: To describe a case of PE-in-transit diagnosed by clinician-performed focused echocardiography. CASE REPORT: A 78-year-old man with lymphoma presented to the Emergency Department with shortness of breath. His blood pressure was 95/53 mm Hg; his oxygen saturation was 84% on room air. A focused echocardiogram showed a highly mobile elongated mass traversing the right atrium and right ventricle, consistent with a PE-in-transit. Anticoagulation was initiated and Cardiovascular Surgery was consulted for emergent thrombectomy. Minutes after reviewing the ultrasound with the surgeons, the patient was transported to the operating room. Just before surgery, the patient had a cardiac arrest. Exploration of his heart failed to reveal thrombus; however, extensive clot burden was removed from the pulmonary arteries, with subsequent return of spontaneous circulation. CONCLUSION: The clinician performed a focused echocardiogram to evaluate the cause of the patient's critical state. PE-in-transit, a rare entity associated with large PEs, was identified, which obviated the need for further diagnostic evaluation and led to immediate aggressive therapy. Increased familiarity with the uses of bedside sonography in the evaluation of shock and respiratory distress may allow clinicians to become more proficient in managing these patients.

The effect of vessel depth, diameter, and location on ultrasound-guided peripheral intravenous catheter longevity.

INTRODUCTION: Ultrasound-guided peripheral intravenous catheters (USGPIVs) have been observed to have poor durability. The current study sets out to determine whether vessel characteristics (depth, diameter, and location) predict USGPIV longevity. METHODS: A secondary analysis was performed on a prospectively gathered database of patients who underwent USGPIV placement in an urban, tertiary care emergency department. All patients in the database had a 20-gauge, 48-mm-long catheter placed under ultrasound guidance. The time and reason for USGPIV removal were extracted by retrospective chart review. A Kaplan-Meier survival analysis was performed. RESULTS: After 48 hours from USGPIV placement, 32% (48/151) had failed prematurely, 24% (36/151) had been removed for routine reasons, and 44% (67/151) remained in working condition yielding a survival probability of 0.63 (95% confidence interval [CI], 0.53-0.70). Survival probability was perfect (1.00) when placed in shallow vessels (<0.4 cm), moderate (0.62; 95% CI, 0.51-0.71) for intermediate vessels (0.40-1.19 cm), and poor (0.29; 95% CI, 0.11-0.51) for deep vessels (≥1.2 cm); P < .0001. Intravenous survival probability was higher when placed in the antecubital fossa or forearm locations (0.83; 95% CI, 0.69-0.91) and lower in the brachial region (0.50; 95% CI, 0.38-0.61); P = .0002. The impact of vessel depth and location was significant after 3 hours and 18 hours, respectively. Vessel diameter did not affect USGPIV longevity. CONCLUSION: Cannulation of deep and proximal vessels is associated with poor USGPIV survival. Careful selection of target vessels may help improve success of USGPIV placement and durability.

Lung Ultrasound Imaging: A Primer for Echocardiographers.

Lung ultrasound (LUS) has gained considerable acceptance in emergency and critical care medicine but is yet to be fully implemented in cardiology. Standard imaging protocols for LUS in acute care settings have allowed the rapid and accurate diagnosis of dyspnea, respiratory failure, and shock. LUS is greatly additive to echocardiography and is superior to auscultation and chest radiography, particularly when the diagnosis of acute decompensated heart failure is in question. In this review, the authors describe LUS techniques, interpretation, and clinical applications, with the goal of informing cardiologists on the imaging modality. Additionally, the authors review LUS findings associated with various disease states most relevant to cardiac care. Although there is extensive literature on LUS in the acute care setting, there is a dearth of reviews directly focused for practicing cardiologists. Current evidence demonstrates that this modality is an important adjunct to echocardiography, providing valuable clinical information at the bedside.

Quantitative characterization of left ventricular function during pulseless electrical activity using echocardiography during out-of-hospital cardiac arrest.

BACKGROUND: Several prospective studies have demonstrated that the echocardiographic detection of any myocardial activity during PEA is strongly associated with higher rates of return of spontaneous circulation (ROSC). We hypothesized that PEA represents a spectrum of disease in which not only the presence of myocardial activity, but more specifically that the degree of left ventricular (LV) function would be a predictor of outcomes. The purpose of this study was to retrospectively assess the association between LV function and outcomes in patients with OHCA. MATERIALS AND METHODS: Using prospectively obtained data from an observational cohort of patients receiving focused echocardiography during cardiopulmonary resuscitation (CPR) in the Emergency Department (ED) setting, we analyzed 312 consecutive subjects with available echocardiography images with initial rhythm of PEA. We used left ventricular systolic fractional shortening (LVFS), a unidimensional echocardiographic parameter to perform the quantification of LV function during PEA. Regression analyses were performed independently to evaluate for relationships between LVFS and a primary outcome of ROSC and secondary outcome of survival to hospital admission. We analyzed LVFS both as a continuous variable and as a categorial variable using the quartiles and the median to perform multiple different comparisons and to illustrate the relationship of LVFS and outcomes of interest. We performed survival analysis using Cox proportional hazards model to evaluate the hazard corresponding to length of resuscitation. RESULTS: We found a positive association between LVFS and the primary outcome of ROSC (OR 1.04, 95%CI 1.01-1.08), but not with the secondary outcome of survival to hospital admission (OR 1.02, 95%CI 0.96-1.08). Given that the relationship was not linear and that we observed a threshold effect in the relationship between LVFS and outcomes, we performed an analysis using quartiles of LVFS. The predicted probability of ROSC was 75% for LVFS between 23.4-96% (fourth quartile) compared to 47% for LVFS between 0-4.7% (first quartile). The hazard of not achieving ROSC was significantly greater for subjects with LVFS below the median (13.1%) compared to the subgroup with LVFS greater than 13.1% (p < 0.05), with the separation of the survival curves occurring at approximately 40 min of resuscitation duration. CONCLUSIONS: Left ventricular function measured by LVFS is positively correlated with higher probability of ROSC and may be associated with higher chances of survival in patients with PEA arrest.

Diagnosis of a facial artery pseudoaneurysm using emergency bedside ultrasound.

BACKGROUND: Pseudoaneurysms of the extracranial arterial system are rare. We report a case of a facial artery pseudoaneurysm initially mistaken for an abscess. With bedside ultrasound performed in the Emergency Department (ED) by the treating physician, the mass was identified as a pseudoaneurysm. OBJECTIVES: In this report we review the anatomy of the extracranial arterial system of the head and neck, discuss the pathogenesis and clinical presentation of pseudoaneuryms, and present diagnostic imaging and treatment options for pseudoaneurysms of the face. CASE REPORT: A 51-year-old man presented with facial swelling and pain at the site of a laceration that he had sustained 1 month previously. Before incision and drainage, bedside ultrasound was performed in the ED by the treating physician to confirm the presumptive diagnosis of abscess with possible foreign body. The ultrasound revealed the mass to be a pseudoaneurysm. CONCLUSIONS: Although pseudoaneurysms of the head and neck are rare, a history of trauma should prompt the consideration of a vascular injury with the need for imaging before drainage procedures of a presumed abscess. To our knowledge, the use of clinician-performed bedside ultrasound to detect facial artery pseudoaneurysms has never been reported.

Evaluation of out-of-hospital cardiac arrest using transesophageal echocardiography in the emergency department.

BACKGROUND: Transesophageal echocardiography (TEE) has been proposed as a modality to assess patients in the setting of cardiac arrest, both during resuscitation care and following return of spontaneous circulation (ROSC). In this study we aimed to assess the feasibility and clinical impact of TEE during the emergency department (ED) evaluation during out-of-hospital cardiac arrest (OHCA). MATERIALS AND METHODS: We conducted a prospective observational study consisting of a convenience sample of adult patients presenting to the ED of an urban university medical center with non-traumatic OHCA. TEE was performed by emergency physicians following intubation. Images and clinical data were analyzed. TEE was used intra-arrest in order to assist in diagnosis, assess cardiac activity and determine CPR quality by assessing area of maximal compression (AMC), using a 4 view protocol. RESULTS: A total of 33 OHCA patients were enrolled over a one-year period, 21 patients (64%) presented with ongoing CPR and 12 (36%) presented with ROSC. The 4-view protocol was completed in 100% of the cases, with an average time from ED arrival to TEE of 12 min (min 3 max 30 SD 8.16). Fine ventricular fibrillation (VF) was recognized in 4 (12%) cases thought to be in asystole, leading to defibrillation, and 2 cases of pseudo-PEA were identified. Right ventricular (RV) dilation, was seen in 12 (57%) intraarrest cases. Intra-cardiac thrombus was found in one case, leading to thrombolysis. The AMC was identified over the aortic root or LVOT in 53% of cases. TEE was found to have diagnostic, therapeutic or prognostic clinical impact in 32 of the 33 cases (97%). CONCLUSIONS: TEE is feasible and clinically impactful during OHCA management. Resuscitative TEE may allow for characterization of cardiac activity, including identification of pseudo-PEA and fine VF, determination of reversible pathology, and optimization of CPR quality.