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.

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.

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.

Creating a Novel Cardiac Limited Ultrasound Exam Curriculum for Internal Medical Residency: Four Unanticipated Tasks.

Over the past two decades, our internal medicine residency has created a unique postgraduate education in internal medicine by incorporating a formal curriculum in point-of-care cardiac ultrasound as a mandatory component. The details regarding content and implementation were critical to the initial and subsequent success of this novel program. In this paper, we discuss the evidence-based advances, considerations, and pitfalls that we have encountered in the program's development through the discussion of four unanticipated tasks unique to a point-of-care ultrasound curriculum. The formatted discussion of these tasks will hopefully assist development of ultrasound programs at other institutions.

Observations during development of an internal medicine residency training program in cardiovascular limited ultrasound examination.

BACKGROUND: Despite the future potential of using ultrasound stethoscopes to augment the bedside cardiac physical, few data exist on a general cardiovascular imaging protocol that can be taught to physicians on a perpetual basis as a curriculum in graduate medical education. METHODS: During the past decade, we developed and integrated a cardiovascular limited ultrasound training program within the confines of an internal medicine residency. The evidence-based rationale for the exam, the teaching methods, and curriculum are delineated, and subsequent observations regarding program requirements, proficiency, and academic outcomes are explored. Analysis of variance and linear regression assessed for relationships between academic scores, chief resident selection, and gender to proficiency in ultrasound. RESULTS: A brief, 5-minute cardiovascular limited ultrasound exam (CLUE) was taught using both didactic and bedside methods, and practiced primarily within the cardiology consult, outpatient clinic, and intensive care rotations. Program costs were minimized by employing readily available institutional resources. After a 2-year lead-in training phase, the subsequent 4 years of senior resident performance (n = 41 residents) showed an 81% pass rate in CLUE competency. Resident ultrasound performance did not relate to academic scores (r = 0.05, P = 0.75), chief resident selection, nor gender. Observations regarding resident pitfalls in CLUE practice and increased participation in extracurricular research are described. CONCLUSIONS: We report our initial experience in developing and implementing a training program for bedside cardiovascular ultrasound examination that employed evidence-based techniques, set proficiency goals, and assessed resident performance. It may be feasible to teach future internist-hospitalists the technique of bedside ultrasound during residency.

Cardiopulmonary limited ultrasound examination for "quick-look" bedside application.

Although taking a "quick look" at the heart using a small ultrasound device is now feasible, a formal ultrasound imaging protocol to augment the bedside physical examination has not been developed. Therefore, we sought to evaluate the diagnostic accuracy and prognostic value of a cardiopulmonary limited ultrasound examination (CLUE) using 4 simplified diagnostic criteria that would screen for left ventricular dysfunction (LV), left atrial (LA) enlargement, inferior vena cava plethora (IVC+), and ultrasound lung comet-tail artifacts (ULC+) in patients referred for echocardiography. The CLUE was tested by interpretation of only the parasternal LV long-axis, subcostal IVC, and 2 lung apical views in each of 1,016 consecutive echocardiograms performed with apical lung imaging. For inpatients, univariate and multivariate logistic regression analyses were performed to assess the relations between mortality, CLUE findings, age, and gender. In this echocardiographic referral series, 78% (n = 792) were inpatient and 22% (n = 224) were outpatient. The CLUE criteria demonstrated a sensitivity, specificity, and accuracy for a LV ejection fraction of ≤40% of 69%, 91%, and 89% and for LA enlargement of 75%, 72%, and 73%, respectively. CLUE findings of LV dysfunction, LA enlargement, IVC+, and ULC+ were seen in 16%, 53%, 34%, and 28% of inpatients. The best multivariate logistic model contained 3 predictors of in-hospital mortality: ULC+, IVC+ and male gender, with adjusted odds ratios (95% confidence intervals) of 3.5 (1.4 to 8.8), 5.8 (2.1 to 16.4), and 2.3 (0.9 to 5.8), respectively. In conclusion, a CLUE consisting of 4 quick-look "signs" has reasonable diagnostic accuracy for bedside use and contains prognostic information.