Outcomes of Simplified Lung Ultrasound Exam in COVID-19: Implications for Self-Imaging.

OBJECTIVES: Lung ultrasound B-lines represent interstitial thickening or edema and relate to mortality in COVID-19. As B-lines can be detected with minimal training using point-of-care ultrasound (POCUS), we examined the frequency, clinical associations, and outcomes of B-lines when found using a simplified POCUS method in acutely ill patients with COVID-19. METHODS: In this retrospective cohort study, hospital data from COVID-19 patients who had undergone lung imaging during standard echocardiography or POCUS were reviewed for an ultrasound lung comet (ULC) sign, defined as the presence of ≥3 B-lines from images of only the antero-apex of either lung (ULC+). Clinical risk factors, oximetry and radiographic results, and disease severity were analyzed for associations with ULC+. Clinical risk factors and ULC+ were analyzed for associations with hospital mortality or the need for intensive care in multivariable models. RESULTS: Of N = 160 patients, age (mean ± standard deviation) was 64.8 ± 15.5 years, and 46 (29%) died. ULC+ was present in 100/160 (62%) of patients overall, in 81/103 (79%) of severe-or-greater disease versus 19/57 (33%) of moderate-or-less disease (P < .0001) and was associated with mortality (odds ratio [OR] = 2.4 [95% confidence interval [CI]: 1.1-5.4], P = .02) and the need for intensive care (OR = 5.23 [95% CI: 2.42-12.40], P < .0001). In the multivariable models, symptom duration and severe-or-greater disease were associated with ULC+, and ULC+, diabetes, and symptom duration were associated with the need for intensive care. CONCLUSIONS: B-lines in the upper chest were common and related to disease severity, intensive care, and hospital mortality in COVID-19. Validation of a simplified lung POCUS exam could provide the evidence basis for a self-imaging application during the pandemic.

The RVEIO and RV function: More, please.

Early proof of the value of RVEIO is currently limited by acquisition biases in specific patient populations. More research is needed on this potentially important index.

Prognostic Implications of a Point-of-Care Ultrasound Examination on Hospital Ward Admission.

OBJECTIVES: Few data exist regarding the use of ultrasound (US) to risk stratify ward admissions. Therefore, we evaluated associations between a cardiopulmonary limited ultrasound examination (CLUE) on admission and subsequent hospital outcomes. METHODS: Over a 22-month period in a 300-bed hospital, CLUE data reviewed from a series of nonelective ward admissions were correlated with the composite outcome of a hospital stay of longer than 2 days, disposition to hospice, or death. The CLUE included 5 quick-look signs of left ventricular dysfunction, left atrial enlargement, lung B-lines, pleural effusions, and inferior vena cava plethora and had been performed as warranted by 1 of 31 US-trained admitting residents and then repeated by a cardiologist as the reference standard. The admitting condition, medical history, results of routine admission testing, and CLUE were assessed for an association with the outcome in univariate and multivariable models. RESULTS: Of 547 patients, the mean age ± SD was 62.9 ± 15.5 years; 59% were male; and the mean stay was 5.6 ± 8.1 days, with 355 (65%) lasting longer than 2 days and 21 (4%) having hospice disposition or death. An abnormal CLUE exam was found in 368 (67%) of patients, was related to the outcome (odds ratio [OR], 1.86; 95% confidence interval [CI], 1.23-2.68; P = .001) when obtained by a resident or cardiologist, and was included in a best-fit multivariable model with renal failure (OR, 2.44; 95% CI, 1.44-4.14; P < .001), infection/sepsis (OR, 2.25; 95% CI, 1.17-4.32; P = .02), and chest pain (OR, 0.36; 95% CI, 0.21-0.61; P < .001). CONCLUSIONS: An abnormal admission point of care ultrasound exam was related to complex hospitalization, specifically a longer length of stay.

Lung Ultrasound Findings Detected During Inpatient Echocardiography Are Common and Associated With Short- and Long-term Mortality.

OBJECTIVES: Although pulmonary abnormalities are easily seen with standard echocardiography or pocket-sized ultrasound devices, we sought to observe the prevalence of lung ultrasound apical B-lines and pleural effusions and their associations with inpatient, 1-year, and 5-year mortality when found in hospitalized patients referred for echocardiography. METHODS: We reviewed 486 initial echocardiograms obtained from consecutive inpatients over a 3-month period, in which each examination included 4 supplemental images of the apex and the base of both lungs. Kaplan-Meier survival curves were used to compare mortality rates among patients with versus without lung findings. Cox proportional hazard regression was used to determine the relative contributions of age, sex, effusions, and B-lines to overall mortality. RESULTS: Of the 486 studies, the mean patient age ± SD was 68 ± 17 years; the median age was 70 years (interquartile range, 27 years); and 191 (39%) had abnormal lung findings. The presence versus absence of abnormal lung findings was related to initial-hospital (8.9% versus 2.0%; P = .001), 1-year (33% versus 14%; P < .001), and 5-year (56% versus 31%; P < .001) mortality. Ultrasound apical B-lines and pleural effusions were both independently associated with increased mortality during initial hospitalization (hazard ratio [HR], 4.3; 95% confidence interval [CI], 1.7-11.0; and HR, 2.5; 95% CI, 1.1-6.0, respectively). Pleural effusions were also associated with increased 1-year mortality (HR, 2.3; 95% CI, 1.5-3.4). CONCLUSIONS: In hospitalized patients undergoing echocardiography, the simple addition of 4 quick 2-dimensional pulmonary views to the echocardiogram often detects abnormal findings that have important implications for short- and long-term mortality.

Cardiac Limited Ultrasound Examination Techniques to Augment the Bedside Cardiac Physical Examination.

The current practice of physical diagnosis is dependent on physician skills and biases, inductive reasoning, and time efficiency. Although the clinical utility of echocardiography is well known, few data exist on how to integrate 2-dimensional screening "quick-look" ultrasound applications into a novel, modernized cardiac physical examination. We discuss the evidence basis behind ultrasound "signs" pertinent to the cardiovascular system and elemental in synthesis of bedside diagnoses and propose the application of a brief cardiac limited ultrasound examination based on these signs. An ultrasound-augmented cardiac physical examination can be taught in traditional medical education and has the potential to improve bedside diagnosis and patient care.

Assessment of left atrial volume before and after pulmonary thromboendarterectomy in chronic thromboembolic pulmonary hypertension.

BACKGROUND: Impaired left ventricular diastolic filling is common in chronic thromboembolic pulmonary hypertension (CTEPH), and recent studies support left ventricular underfilling as a cause. To investigate this further, we assessed left atrial volume index (LAVI) in patients with CTEPH before and after pulmonary thromboendarterectomy (PTE). METHODS: Forty-eight consecutive CTEPH patients had pre- & post-PTE echocardiograms and right heart catheterizations. Parameters included mean pulmonary artery pressure (mPAP), pulmonary vascular resistance (PVR), cardiac index, LAVI, & mitral E/A ratio. Echocardiograms were performed 6 ± 3 days pre-PTE and 10 ± 4 days post-PTE. Regression analyses compared pre- and post-PTE LAVI with other parameters. RESULTS: Pre-op LAVI (mean 19.0 ± 7 mL/m2) correlated significantly with pre-op PVR (R = -0.45, p = 0.001), mPAP (R = -0.28, p = 0.05) and cardiac index (R = 0.38, p = 0.006). Post-PTE, LAVI increased by 18% to 22.4 ± 7 mL/m2 (p = 0.003). This change correlated with change in PVR (765 to 311 dyne-s/cm5, p = 0.01), cardiac index (2.6 to 3.2 L/min/m2, p = 0.02), and E/A (.95 to 1.44, p = 0.002). CONCLUSION: In CTEPH, smaller LAVI is associated with lower cardiac output, higher mPAP, and higher PVR. LAVI increases by ~20% after PTE, and this change correlates with changes in PVR and mitral E/A. The rapid increase in LAVI supports the concept that left ventricular diastolic impairment and low E/A pre-PTE are due to left heart underfilling rather than inherent left ventricular diastolic dysfunction.

Novel Scoring Scale for Quality Assessment of Lung Ultrasound in the Emergency Department.

Introduction: The use of a reliable scoring system for quality assessment (QA) is imperative to limit inconsistencies in measuring ultrasound acquisition skills. The current grading scale used for QA endorsed by the American College of Emergency Physicians (ACEP) is non-specific, applies irrespective of the type of study performed, and has not been rigorously validated. Our goal in this study was to determine whether a succinct, organ-specific grading scale designed for lung-specific QA would be more precise with better interobserver agreement. Methods: This was a prospective validation study of an objective QA scale for lung ultrasound (LUS) in the emergency department. We identified the first 100 LUS performed in normal clinical practice in the year 2020. Four reviewers at an urban academic center who were either emergency ultrasound fellowship-trained or current fellows with at least six months of QA experience scored each study, resulting in a total of 400. The primary outcome was the level of agreement between the reviewers. Our secondary outcome was the variability of the scores given to the studies. For the agreement between reviewers, we computed the intraclass correlation coefficient (ICC) based on a two-way random-effect model with a single rater for each grading scale. We generated 10,000 bootstrapped ICCs to construct 95% confidence intervals (CI) for both grading systems. A two-sided one-sample t-test was used to determine whether there were differences in the bootstrapped ICCs between the two grading systems. Results: The ICC between reviewers was 0.552 (95% CI 0.40-0.68) for the ACEP grading scale and 0.703 (95% CI 0.59-0.79) for the novel grading scale (P < 0.001), indicating significantly more interobserver agreement using the novel scale compared to the ACEP scale. The variance of scores was similar (0.93 and 0.92 for the novel and ACEP scales, respectively). Conclusion: We found an increased interobserver agreement between reviewers when using the novel, organ-specific scale when compared with the ACEP grading scale. Increased consistency in feedback based on objective criteria directed to the specific, targeted organ provides an opportunity to enhance learner education and satisfaction with their ultrasound education.

Diminished aortic excursion in chronic thromboembolic pulmonary hypertension.

BACKGROUND: Although studies have found diminished aortic root motion in left ventricular systolic dysfunction, few data exist on aortic root excursion in isolated right ventricular dysfunction due to chronic thromboembolic pulmonary hypertension (CTEPH). OBJECTIVE: We conducted this study to evaluate aortic root excursion in CTEPH. METHODS: We studied 20 consecutive patients with CTEPH, normal left ventricular ejection fraction and pulmonary capillary wedge pressures, and 10 normal control subjects. Anterior excursion of the aortic root was measured using M-mode echocardiography as the difference between the maximal and minimal anterior distance of the posterior wall of the aortic root at the level of the aortic valve. RESULTS: Mean aortic excursion for CTEPH patients was approximately half that of normal controls (0.66 ± 0.25 cm vs. 1.16 ± 0.15 cm, P < 0.0001). There was a significant inverse linear correlation between mean pulmonary artery pressure and aortic excursion in the CTEPH group (r = 0.66, P = 0.001). CONCLUSION: Aortic excursion is diminished in the right ventricular pressure overload of CTEPH. This impaired motion of the aortic root may influence systolic expansion of the left atrium, and may contribute to the impaired left atrial diastolic filling patterns often seen in patients with CTEPH.

Diagnostic performance of a pocket-sized ultrasound device for quick-look cardiac imaging.

BACKGROUND: Although pocket-sized, simplified ultrasound devices have emerged to enable subjective point-of-care assessment, few data on their cardiac application exist. We sought to examine the image quality and the accuracy of subjective diagnosis of video loops obtained from a pocket-sized ultrasound device for 2 significant cardiac abnormalities, left ventricular systolic dysfunction and left atrial enlargement, obtained from a single, quick-look view. METHODS: Parasternal left ventricular long-axis images acquired with a miniaturized commercially available device (Acuson P10) were reviewed using subjective criteria for left ventricular systolic dysfunction and left atrial enlargement and were compared with M-mode measurements of left atrial systolic diameter and E-point septal separation from a fully featured echocardiograph in 78 inpatients referred for standard echocardiography. Interpretive confidence and image quality were evaluated with each interpretation. RESULTS: Of 78 inpatient studies, 19% of pocket ultrasound and 13% of standard studies were technically limited (P = NS). Of 61 technically adequate studies, subjective interpretation of pocket ultrasound images had a sensitivity, specificity, and accuracy of 79%, 52%, and 64% for left atrial diameter more than 4 cm; 47%, 98%, and 82% for E-point septal separation more than 1 cm of; 83%, 62%, and 74% for either abnormality; and 92%, 82%, and 87% for either abnormality when interpretive confidence was present (n = 23). The pocket ultrasound image quality scores were significantly lower than the standard echocardiograph (P < .001). CONCLUSION: The pocket-sized device provided adequate imaging for screening of 2 significant cardiac entities. Subjective interpretation of a single parasternal view may help identify patients with cardiac disease.

Handheld ultrasonography in cardiovascular medicine, updates and controversies.

A variety of hand-held ultrasound (HHU) machines have recently become available and offer different capabilities and features. Despite the differences of the individual HHU devices, all offer the potential for faster diagnoses and are more sensitive than clinical assessment in identifying cardiovascular abnormalities. In addition, they provide enhanced transportability, can potentially reduce waiting time for full echocardiograms, and may save health-care resources. Significant potential for the growth of HHU as a tool to facilitate patient care exists when performed by well-trained and competent providers is anticipated. This paper presents the characteristics, benefits, limitations, and future perspectives of HHU devices.

Simplified Lung Ultrasound Examination and Telehealth Feasibility in Early SARS-CoV-2 Infection.

BACKGROUND: In COVID-19, inpatient studies have demonstrated that lung ultrasound B-lines relate to disease severity and mortality and can occur in apical regions that can be imaged by patients themselves. However, as illness begins in an ambulatory setting, the aim of this study was to determine the prevalence of apical B-lines in early outpatient infection and then test the accuracy of their detection using telehealth and automated methods. METHODS: Consecutive adult patients (N = 201) with positive results for SARS-CoV-2, at least one clinical risk factor, and mild to moderate disease were prospectively enrolled at a monoclonal antibody infusion clinic. Physician imaging of the lung apices for three B-lines (ultrasound lung comet [ULC]) using 3-MHz ultrasound was performed on all patients for prevalence data and served as the standard for a nested subset (n = 50) to test the accuracy of telehealth methods, including patient self-imaging and automated B-line detection. Patient characteristics, vaccination data, and hospitalizations were analyzed for associations with the presence of ULC. RESULTS: Patients' mean age was 54 ± 15 years, and all lacked hypoxemia or fever. ULC was present in 55 of 201 patients (27%) at a median of 7 symptomatic days (interquartile range, 5-8 days) and in four of five patients who were later hospitalized (P = .03). Presence of ULC was associated with unvaccinated status (odds ratio [OR], 4.11; 95% CI, 1.85-9.33; P = .001), diabetes (OR, 2.56; 95% CI, 1.08-6.05; P = .03), male sex (OR, 2.14; 95% CI, 1.07-4.37; P = .03), and hypertension or cardiovascular disease (OR, 2.06; 95% CI, 1.02-4.23; P = .04), while adjusting for body mass index > 25 kg/m2. Telehealth and automated B-line detection had 84% and 82% accuracy, respectively. CONCLUSIONS: In high-risk outpatients, B-lines in the upper lungs were common in early SARS-CoV-2 infection, were related to subsequent hospitalization, and could be detected by telehealth and automated methods.

The effect of breathing manner on inferior vena caval diameter.

AIMS: Although the inspiratory 'collapse' of the inferior vena cava (IVC) has been used to signify normal central venous pressure, the effect of the manner of breathing IVC size is incompletely understood. As intra-abdominal pressure rises during descent of the diaphragm, we hypothesized that inspiration through diaphragmatic excursion may have a compressive effect on the IVC. METHODS AND RESULTS: We measured minimal and maximal intrahepatic IVC diameter on echocardiography and popliteal venous return by spectral Doppler during isovolemic inspiratory efforts in 19 healthy non-obese volunteers who were instructed to inhale using either diaphragmatic or chest wall expansion. During inspiration, the maximal diaphragmatic excursion and popliteal vein flow were compared between breathing methods. The IVC 'collapsibility index,' IVCCI, was calculated as (IVC(max)-IVC(min))/IVC(max). The difference in diaphragmatic excursion between diaphragmatic and chest wall breaths in each subject was correlated with the corresponding change in IVCCI. Diaphragmatic breathing resulted in more diaphragmatic excursion than chest wall breathing (median 3.4 cm, range 1.7-5.8 vs. 2.2 cm, range 1.0-5.2, P= 0.0003), and was universally associated with decreased popliteal venous return (19/19 vs. 9/19 subjects, P< 0.004). The difference in diaphragmatic excursion correlated with the difference in IVCCI (Spearman's rho = 0.53, P= 0.024). CONCLUSION: During inspiration of equivalent tidal volumes, the reduction in IVC diameter and lower extremity venous return was related to diaphragmatic excursion, suggesting that the IVC may be compressed through descent of the diaphragm.

A bedside ultrasound sign of cardiac disease: the left atrium-to-aorta diastolic diameter ratio.

PURPOSE: This study evaluated a simple ultrasound method to detect left atrial (LA) enlargement by comparing the diameters of the LA and aortic root. PROCEDURES: The LA and aortic diameters, the LA volume index (LAVI), and significant echo findings were analyzed in 101 consecutive echocardiograms. Mean LAVI and the prevalence of an abnormal echo were compared between groups in which the ratio of the LA diameter to aortic diameter in diastole was >1 vs < or = 1. FINDINGS: Left atrial-to-aortic diameter ratio increased with LAVI (r = 0.64, P < .001). Left atrial-to-aortic diameter ratio >1 vs < or = 1 was noted in 45% vs 55% of patients and had a mean (+ or - SD) LAVI = 39 + or - 12 vs 27 + or - 7 mL/m(2) (P < .001) and a 78% vs 43% prevalence of an abnormal echo (P < .001). CONCLUSION: The left atrium-to-aorta diastolic diameter ratio can detect LA enlargement and may be useful as a quick bedside technique to screen for cardiac disease.

"Asymptomatic" Flash Pulmonary Edema by Point-of-Care Ultrasound: A Novel Bedside Finding of Transient Global Ischemia.

A 65-year-old man with remitted chest pain and no tachypnea was taken urgently to catheterization because of diffuse lung ultrasound B-lines on bedside examination. He was found to have severe left-main disease. This case emphasizes the value of ultrasound to recognize acute cardiogenic interstitial pulmonary edema despite minimal symptoms. (Level of Difficulty: Advanced.).

Use of point-of-care ultrasound to assess esophageal insufflation during bag mask ventilation: A case report.

Bag-valve-mask ventilation is a basic airway management technique often used in patients with acute respiratory failure. Although highly effective in providing oxygenation and ventilation, this technique has been associated with gastric regurgitation and tracheal aspiration. In this case, the esophagus visualized with bedside ultrasonography during bag-mask ventilation of an unresponsive and critically ill patient. Images were obtained both with and without cricoid pressure. Additionally, images were obtained during ultrasound-guided probe pressure on the lateral neck. Esophageal insufflation was identified consistently during bag mask ventilation. Cricoid pressure did not prevent esophageal insufflation. Ultrasound-guided probe pressure attenuated esophageal insufflation. This case depicts a unique instance of using a novel method to assess breath delivery during bag mask ventilation of a critically ill patient.

Evidence Basis for a Point-of-Care Ultrasound Examination to Refine Referral for Outpatient Echocardiography.

BACKGROUND: Few data exist on the potential utility of a cardiac point-of-care ultrasound (POCUS) examination in the outpatient setting to assist diagnosis of significant cardiac disease. Using a retrospective sequential cohort design, we sought to derive and then validate a POCUS examination for cardiac application and model its potential use for prognostication and cost-effective echo referral. METHODS: For POCUS examination derivation, we reviewed 233 consecutive outpatient echo studies for 4 specific POCUS "signs" contained therein representing left ventricular systolic dysfunction, left atrial enlargement, inferior vena cava plethora, and lung apical B-lines. The corresponding formal echo reports were then queried for any significant abnormality. The optimal POCUS examination for identifying an abnormal echo was determined. We then reviewed 244 consecutive outpatient echo studies from another institution for associations between the optimal POCUS examination, clinical variables, and referral source with major adverse cardiac events and all-cause mortality in univariate and multivariate models. Assuming a referral model where the absence of POCUS signs or variables would negate initial echo referral, theoretical cost savings were expressed as a percentage in reduction of echo studies. RESULTS: In the derivation cohort, the combination of two signs, denoting left atrial enlargement and inferior vena cava plethora resulted in the highest accuracy of 72% [95% CI: 65%, 78%] in detecting an abnormal echocardiogram. In the validation cohort, mortality at 5.5 years was 14.6% overall, 23% in patients with the left atrial enlargement sign (OR 3.5 [1.6, 7.6]), 25% with inferior vena cava plethora sign (OR 2.2 [0.8, 6.0]), and 8.0% (OR 0.3 [0.2, 0.7]) in those lacking both signs. After adjusting for age, both diabetes (OR 4.8 [2.0, 11.6]), and the left atrial enlargement sign (OR 2.4 [1.1, 5.4]) remained independently associated with mortality (p<0.05). In the referral model, patients younger than 65 years of age without diabetes and without the left atrial enlargement sign would not have received echo referral, resulting in a 33% reduction in total echo cost and would have constituted a low-risk group with a 1.2% 5.5-year mortality. CONCLUSIONS: A quick-look sign for left atrial enlargement is associated with 5-year mortality and could function as an easily obtained outpatient POCUS examination to help in identifying patients in need of echo referral.