Andrew S. Liteplo

International Evidence-Based Recommendations for Focused Cardiac Ultrasound

BACKGROUND Focused cardiac ultrasound (FoCUS) is a simplified, clinician-performed application of echocardiography that is rapidly expanding in use, especially in emergency and critical care medicine. Performed by appropriately trained clinicians, typically not cardiologists, FoCUS ascertains the essential information needed in critical scenarios for time-sensitive clinical decision making. A need exists for quality evidence-based review and clinical recommendations on its use. METHODS The World Interactive Network Focused on Critical UltraSound conducted an international, multispecialty, evidence-based, methodologically rigorous consensus process on FoCUS. Thirty-three experts from 16 countries were involved. A systematic multiple-database, double-track literature search (January 1980 to September 2013) was performed. The Grading of Recommendation, Assessment, Development and Evaluation method was used to determine the quality of available evidence and subsequent development of the recommendations. Evidence-based panel judgment and consensus was collected and analyzed by means of the RAND appropriateness method. RESULTS During four conferences (in New Delhi, Milan, Boston, and Barcelona), 108 statements were elaborated and discussed. Face-to-face debates were held in two rounds using the modified Delphi technique. Disagreement occurred for 10 statements. Weak or conditional recommendations were made for two statements and strong or very strong recommendations for 96. These recommendations delineate the nature, applications, technique, potential benefits, clinical integration, education, and certification principles for FoCUS, both for adults and pediatric patients. CONCLUSIONS This document presents the results of the first International Conference on FoCUS. For the first time, evidence-based clinical recommendations comprehensively address this branch of point-of-care ultrasound, providing a framework for FoCUS to standardize its application in different clinical settings around the world.

Emergency thoracic ultrasound in the differentiation of the etiology of shortness of breath (ETUDES): sonographic B-lines and N-terminal pro-brain-type natriuretic peptide in diagnosing congestive heart failure.

OBJECTIVES Sonographic thoracic B-lines and N-terminal pro-brain-type natriuretic peptide (NT-ProBNP) have been shown to help differentiate between congestive heart failure (CHF) and chronic obstructive pulmonary disease (COPD). The authors hypothesized that ultrasound (US) could be used to predict CHF and that it would provide additional predictive information when combined with NT-ProBNP. They also sought to determine optimal two- and eight-zone scanning protocols when different thresholds for a positive scan were used. METHODS This was a prospective, observational study of a convenience sample of adult patients presenting to the emergency department (ED) with shortness of breath. Each patient had an eight-zone thoracic US performed by one of five sonographers, and serum NT-ProBNP levels were measured. Chart review by two physicians blinded to the US results served as the criterion standard. The operating characteristics of two- and eight-zone thoracic US alone, compared to, and combined with NT-ProBNP test results for predicting CHF were calculated using both dichotomous and interval likelihood ratios (LRs). RESULTS One-hundred patients were enrolled. Six were excluded because of incomplete data. Results of 94 patients were analyzed. A positive eight-zone US, defined as at least two positive zones on each side, had a positive likelihood ratio (LR+) of 3.88 (99% confidence interval [CI] = 1.55 to 9.73) and a negative likelihood ratio (LR-) of 0.5 (95% CI = 0.30 to 0.82), while the NT-ProBNP demonstrated a LR+ of 2.3 (95% CI = 1.41 to 3.76) and LR- of 0.24 (95% CI = 0.09 to 0.66). Using interval LRs for the eight-zone US test alone, the LR for a totally positive test (all eight zones positive) was infinite and for a totally negative test (no zones positive) was 0.22 (95% CI = 0.06 to 0.80). For two-zone US, interval LRs were 4.73 (95% CI = 2.10 to 10.63) when inferior lateral zones were positive bilaterally and 0.3 (95% CI = 0.13 to 0.71) when these were negative. These changed to 8.04 (95% CI = 1.76 to 37.33) and 0.11 (95% CI = 0.02 to 0.69), respectively, when congruent with NT-ProBNP. CONCLUSIONS Bedside thoracic US for B-lines can be a useful test for diagnosing CHF. Predictive accuracy is greatly improved when studies are totally positive or totally negative. A two-zone protocol performs similarly to an eight-zone protocol. Thoracic US can be used alone or can provide additional predictive power to NT-ProBNP in the immediate evaluation of dyspneic patients presenting to the ED.

Ultrasound Assessment for Extravascular Lung Water in Patients Undergoing Hemodialysis: Time Course for Resolution

BACKGROUND 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. METHODS 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. RESULTS 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 value < 0.001. There was no association between subjective dyspnea scores and number of B-lines removed. CONCLUSIONS 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 patients physiologic response to the removal of fluid. TRIAL REGISTRATION Massachusetts General Hospital trial registration protocol No. 2007P 002226.

Original ResearchChest UltrasonographyUltrasound Assessment for Extravascular Lung Water in Patients Undergoing Hemodialysis: Time Course for Resolution

BACKGROUND 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. METHODS 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. RESULTS 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 value < 0.001. There was no association between subjective dyspnea scores and number of B-lines removed. CONCLUSIONS 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 patients physiologic response to the removal of fluid. TRIAL REGISTRATION Massachusetts General Hospital trial registration protocol No. 2007P 002226.

Bedside ultrasound in pediatric emergency medicine fellowship programs in the United States: little formal training.

Background: Bedside ultrasound (BUS) can provide critical information in a rapid and noninvasive manner to the emergency physician. It is widely used in emergency departments (ED) throughout the nation. Literature shows that BUS shortens patient stay and increases patient satisfaction. General emergency medicine (EM) residencies incorporate BUS training in their curricula. However, there are limited data about the training that pediatric emergency medicine (PEM) fellows receive. Objective: To determine the extent of training and use of BUS in PEM fellowship programs. Methods: A 29-question survey was mailed to all (57) PEM fellowship program directors in the spring of 2006. Results: The response rate was 81% (46/57). Fifty-seven percent (26/46) of the responding PEM fellowship program directors reported that their faculty used BUS in their departments. At 50% (23/46) of programs, fellows perform BUS studies. Sixty-five percent (30/46) of PEM fellowships reported that their fellows receive some BUS training, but only 15 of these programs included BUS training in the curriculum as a 2- to 4-week ultrasound rotation. Sixty-five percent (30/46) of PEM fellowship programs had access to an ultrasound machine, but only 28% (13/46) of programs had their own machine. The main reason not to own an ultrasound machine was a lack of ultrasound expertise in their department (67%, 22/33). Bedside ultrasound training was provided by general EM physicians in 57% (17/30) of programs. Eighty-seven percent of the directors agree that BUS training would benefit their practice. The 2 factors significantly associated with the likelihood of having formal BUS training were access to an ultrasound machine (87% vs 55% P = 0.04) and presence of an adult ED with an EM residency at the program (80% vs 42% P = 0.03). Pediatric emergency medicine fellowship programs at childrens hospitals were significantly less likely to have formal training (33.3% vs 74.2%; P = 0.01). Conclusions: Despite literature supporting the benefits of BUS in the ED, many PEM fellowship programs do not incorporate BUS training for their PEM fellows. Most PEM fellows who receive training in BUS are instructed by physicians trained in EM, not PEM.

Focused Maternal Ultrasound by Midwives in Rural Zambia

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.

Ultrasound soft-tissue applications in the pediatric emergency department: to drain or not to drain?

Soft tissue infections frequently prompt visits to the pediatric emergency department. The incidence of these infections has increased markedly in recent years. The emergence of community-acquired methicillin-resistant Staphylococcus aureus is associated with an increasing morbidity, mortality, and frequency of abscess formation. Bedside ultrasound may have a significant impact in the management of patients that present to the pediatric emergency department with soft tissue infections, including cellulitis, cutaneous abscess, peritonsillar abscess, and necrotizing fasciitis. Ultrasound is an efficient, noninvasive diagnostic tool which can augment the physicians clinical examination. Ultrasound has been shown to be superior to clinical judgment alone in determining the presence or the absence of occult abscess formation, ensuring appropriate management and limiting unnecessary invasive procedures.

Ultrasound performs better than radiographs

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 …

Bedside ultrasound maximizes patient satisfaction.

BACKGROUND Bedside ultrasound (US) is associated with improved patient satisfaction, perhaps as a consequence of improved time to diagnosis and decreased length of stay (LOS). OBJECTIVES Our study aimed to quantify the association between beside US and patient satisfaction and to assess patient attitudes toward US and perception of their interaction with the clinician performing the examination. METHODS We enrolled a convenience sample of adult patients who received a bedside US. The control group had similar LOS and presenting complaints but did not have a bedside US. Both groups answered survey questions during their emergency department (ED) visit and again by telephone 1 week later. The questionnaire assessed patient perceptions and satisfaction on a 5-point Likert scale. RESULTS Seventy patients were enrolled over 10 months. The intervention group had significantly higher scores on overall ED satisfaction (4.69 vs. 4.23; mean difference 0.46; 95% confidence interval [CI] 0.17-0.75), diagnostic testing (4.54 vs. 4.09; mean difference 0.46; 95% CI 0.16-0.76), and skills/abilities of the emergency physician (4.77 vs. 4.14; mean difference 0.63; 95% CI 0.29-0.96). A trend to higher scores for the intervention group persisted on follow-up survey. CONCLUSIONS Patients who had a bedside US had statistically significant higher satisfaction scores with overall ED care, diagnostic testing, and with their perception of the emergency physician. Bedside US has the potential not only to expedite care and diagnosis, but also to maximize satisfaction scores and improve the patient-physician relationship, which has increasing relevance to health care organizations and hospitals that rely on satisfaction surveys.

Diagnosing pulmonary edema: lung ultrasound versus chest radiography.

Background Diagnosing the underlying cause of acute dyspnea can be challenging. Lung ultrasound may help to identify pulmonary edema as a possible cause. Objective To evaluate the ability of residents to recognize pulmonary edema on lung ultrasound using chest radiographs as a comparison standard. Methods This is a prospective, blinded, observational study of a convenience sample of resident physicians in the Departments of Emergency Medicine (EM), Internal Medicine (IM), and Radiology. Residents were given a tutorial on interpreting pulmonary edema on both chest radiograph and lung ultrasound. They were then shown both ultrasounds and chest radiographs from 20 patients who had presented to the emergency department with dyspnea, 10 with a primary diagnosis of pulmonary edema, and 10 with alternative diagnoses. Cohen’s &kgr; values were calculated to describe the strength of the correlation between resident and gold standard interpretations. Results Participants included 20 EM, 20 IM, and 20 Radiology residents. The overall agreement with gold standard interpretation of pulmonary edema on lung ultrasound (74%, &kgr;=0.51, 95% confidence interval 0.46–0.55) was superior to chest radiographs (58%, &kgr;=0.25, 95% confidence interval 0.20–0.30) (P<0.0001). EM residents interpreted lung ultrasounds more accurately than IM residents. Radiology residents interpreted chest radiographs more accurately than did EM and IM residents. Conclusion Residents were able to more accurately identify pulmonary edema with lung ultrasound than with chest radiograph. Physicians with minimal exposure to lung ultrasound may be able to correctly recognize pulmonary edema on lung ultrasound.