Hand-carried Ultrasound Research Articles

The Feasibility of Using an HCU System for Investigating Ergonomic Injury Among Autoworkers

A preexperimental case study was conducted to determine the feasibility of imaging musculoskeletal changes in the anatomy of the elbow, which might be attributed to the use of a tool, commonly blamed for ergonomic injury among autoworkers. The aim of the feasibility study was to determine if a hand-carried ultrasound (HCU) system could be used to document any physiologic changes. An HCU system with a 12-MHz linear probe was taken portably to image a patient's elbow before and after use of the tool. Increased vascular flow within the muscle tissue was noted, but no changes to the musculature were noted with sonography 1, 12, and 24 hours after prolonged use. The preexperimentally designed case study provided evidence that it was possible to document the elbow and forearm anatomy before and after tool use. Higher level evidence is needed on the ability to use an HCU system to detect musculoskeletal injury at the job site. The portability and high-resolution imaging provided by the specific HCU system used have potential for this innovative clinical application.

Hand-carried echocardiography for assessment of left ventricular filling and ejection fraction in the surgical intensive care unit

Purpose To better define the reliability of left ventricular ejection fraction (LVEF) and left ventricular filling, as determined by either hand-carried ultrasound (HCU) or formal transthoracic echocardiography (TTE), in the critically ill surgical patient. Materials and Methods Prospective cross-sectional study of 80 surgical intensive care unit patients with concomitant (<30 minutes apart) formal TTE and clinician-performed cardiac HCU. Visual estimates of LVEF and left ventricular filling (“underfilled” vs “normally filled”) were recorded, both by clinicians performing HCU and fellowship-trained echocardiographers. Results Bland-Altman plot analysis of LVEF estimates revealed good interobserver agreement between HCU and formal TTE (% LVEF mean bias, −2.2; with 95% limits of agreement, ±22.1). This was similar to agreement between independent echocardiography observers (% LVEF mean bias, 1.3; with 95% limits of agreement, ±21.0). However, assessments of left ventricular filling demonstrated only fair to moderate interobserver agreement ( κ = 0.22-0.40). Of note, a greater percentage of the 5 standard acoustic windows were obtainable using formal TTE (72% vs 56%). Conclusions Formal TTE offers no advantage over HCU for determination of LVEF in critically ill surgical patients, even though the former allows for a more complete examination. However, estimations of left ventricular filling only demonstrate fair to moderate interrater agreement and thus should be interpreted with care when used as markers of volume responsiveness.

Brachial artery flow velocity variation: another victory for hand-carried ultrasound?

Dynamic predictors are clearly superior to static pressures in predicting whether a patient will respond to a fluid bolus. Hand-carried ultrasound (HCUS) can measure changes in blood flow velocity in the brachial artery that parallel arterial pulse pressure variation. The potential for HCUS to guide fluid therapy non-invasively must overcome problems of sensitivity and applicability.

Comparison of Hand-Carried Ultrasound Assessment of the Inferior Vena Cava and N-Terminal Pro-Brain Natriuretic Peptide for Predicting Readmission After Hospitalization for Acute Decompensated Heart Failure

We sought to compare the value of serial assessment with hand-carried ultrasound (HCU) of the inferior vena cava (IVC) with brain natriuretic peptide (BNP) to identify patients with acute decompensated heart failure (ADHF) who will be readmitted or seek emergency department treatment after hospital discharge. Congestive heart failure (CHF) is a leading cause for hospitalization and, once hospitalized, patients with CHF frequently are readmitted. To date, no reliable index exists that can be used to predict whether patients with ADHF can be discharged with low readmission likelihood. A total of 75 patients who were admitted with a primary diagnosis of ADHF were followed. All patients were assessed at admission and discharge with the use of routine clinical evaluation, BNP measurement, and HCU evaluation of the IVC by physicians with limited training in ultrasound. During the 30-day follow-up, 31 patients were rehospitalized or presented to the emergency department. Patients who were subsequently readmitted could not be differentiated from those who were not readmitted by their demographics, comorbidities, vital signs, presence of symptoms/signs suggestive of persistent congestion, hospital length of stay, or net volume removal. Routine laboratory tests, including assessment of renal function, also failed to predict readmission with the exception of serum sodium. Although admission BNP was similar in patients readmitted and not readmitted, pre-discharge log-transformed BNP was greater in patients who subsequently were readmitted. Patients who required repeat hospitalization had a larger IVC size on admission as well as at discharge. In addition, patients who were readmitted had persistently plethoric IVCs with lower IVC collapsibility indexes. At discharge, only serum sodium, log-transformed BNP, IVC size, and collapsibility were statistically significant predictors of readmission. This study confirms that, once hospitalized, patients with CHF frequently are readmitted. Bedside evaluation of the IVC with a HCU device at the time of admission and discharge, as well as pre-discharge BNP, identified patients admitted with ADHF who were more likely to be readmitted to the hospital.

A Comparison by Medicine Residents of Physical Examination Versus Hand-carried Ultrasound for Estimation of Right Atrial Pressure: Brennan JM, Blair JE, Goonewardena S, et al. Am J Cardiol 2007;99:1614–6

A Comparison by Medicine Residents of Physical Examination Versus Hand-carried Ultrasound for Estimation of Right Atrial Pressure: Brennan JM, Blair JE, Goonewardena S, et al. Am J Cardiol 2007;99:1614–6

The utility of handheld ultrasound in an austere medical setting in Guatemala after a natural disaster

To identify equipment needs, utility, clinical applications, and acuity of diagnoses made by hand-carried ultrasound (HCU) after a natural disaster. An HCU with four probes (curved array, linear array, phased array, and endocavitary) was taken to the site of a natural disaster in Guatemala as part of the relief effort after mudslides killed approximately 1,000 people. Ultrasound (US) scans were classified by transducer type, anatomic region, presenting complaint, and therapeutic urgency of treatment. Ninety-nine patients received 137 US: 58 pelvic, 34 right upper quadrant, 23 renal, six other abdominal, five orthopedic, four cardiac, three pleura and lung, three soft tissue, and one focused assessment by sonography in trauma. Acuity of presenting illness: 23 percent <24 hours, 15 percent 1-14 days, 44 percent >14 days. Eighteen percent were performed in prenatal clinic. Results of US ruled in 12 percent with an emergent problem and excluded disease in 42 percent. In 14 percent, US diagnosed a problem needing flu in <2 weeks, and 32 percent with a problem needing long-term observation. Transducer utilization was general purpose curved array 88 percent, linear array 10 percent, endocavitary 8 percent, and phased array 4 percent. HCU has a range of applications in an austere medical setting after a natural disaster. Most can be dealt with using a single transducer.

Hand carried echocardiography screening for LV systolic dysfunction in a pulmonary function laboratory☆

Dyspnea is a common indication for pulmonary evaluation but also a common symptom in heart failure. Identification of dyspneic patients with significant LV systolic dysfunction is critical because of high morbidity of untreated heart failure. We sought to determine whether screening patients referred for pulmonary function testing (PFT) using a hand carried ultrasound (HCU) device could identify LV systolic dysfunction. Forty-nine subjects were recruited from a pulmonary function lab to undergo a brief echocardiographic examination by an internist using a HCU device. All subjects also received an examination with a full-featured echocardiogram machine as a gold standard. All subjects with normal PFT had normal LV systolic function. Among subjects with abnormal PFT, 6 (15%) had LV systolic dysfunction and the remainder had normal LV systolic function. No subjects with LV systolic dysfunction by full-featured echocardiograms were missed by the HCU (sensitivity 100%, specificity 95%, negative predictive value 100%, positive predictive value 75%). LV systolic dysfunction is prevalent among patients with pulmonary disease and can be accurately screened for by a physician using a hand carried ultrasound device with subsequent confirmation with complete echocardiography.

Non-Invasive Estimation of Cardiac Filling Pressures by Residents Using Tissue Doppler Imaging and Handcarried Ultrasound

Non-Invasive Estimation of Cardiac Filling Pressures by Residents Using Tissue Doppler Imaging and Handcarried Ultrasound

Radial Artery Pulse Pressure Variation Correlates With Brachial Artery Peak Velocity Variation in Ventilated Subjects When Measured by Internal Medicine Residents Using Hand-Carried Ultrasound Devices

Rapid prediction of the effect of volume expansion is crucial in unstable patients receiving mechanical ventilation. Both radial artery pulse pressure variation (DeltaPP) and change of aortic blood flow peak velocity are accurate predictors but may be impractical point-of-care tools. We sought to determine whether respiratory changes in the brachial artery blood flow velocity (DeltaVpeak-BA) as measured by internal medicine residents using a hand-carried ultrasound (HCU) device could provide an accurate corollary to DeltaPP in patients receiving mechanical ventilation. Thirty patients passively receiving volume-control ventilation with preexisting radial artery catheters were enrolled. The brachial artery Doppler signal was recorded and analyzed by blinded internal medicine residents using a HCU device. Simultaneous radial artery pulse wave and central venous pressure recordings (when available) were analyzed by a blinded critical care physician. A Doppler signal was obtained in all 30 subjects. The DeltaVpeak-BA correlated well with DeltaPP (r = 0.84) with excellent agreement (weighted kappa, 0.82) and limited intraobserver variability (2.8 +/- 2.8%) [mean +/- SD]. A DeltaVpeak-BA cutoff of 16% was highly predictive of DeltaPP > or = 13% (sensitivity, 91%; specificity, 95%). A poor correlation existed between the CVP and both DeltaVpeak-BA (r = - 0.21) and DeltaPP (r = - 0.16). The HCU Doppler assessment of the DeltaVpeak-BA as performed by internal medicine residents is a rapid, noninvasive bedside correlate to DeltaPP, and a DeltaVpeak-BA cutoff of 16% may prove useful as a point-of-care tool for the prediction of volume responsiveness in patients receiving mechanical ventilation.

The Impact of Evolving Hand-carried Echocardiographic Technology on Outpatient Physical Examination Accuracy in Pediatric Cardiology

Cardiac auscultory skills are declining. Hand-carried ultrasound (HCU) has been proposed as a method to enhance diagnostic accuracy of the physical examination (PE). However, features of HCU devices are varied. The aim of this study was to compare the diagnostic accuracies of an experienced pediatric cardiac PE alone vs. the PE combined with the assistance of an HCU device when using 2 HCU devices with different capabilities. The results were compared with conventional echo as the reference standard. All outpatients seen by a single pediatric cardiologist underwent physical examination and HCU. Two HCU devices were compared. The first HCU device (HCU-1) had limited options with only 2-dimensional echo, limited Doppler, and a single transducer frequency (2.5 MHz). The second HCU device (HCU-2) was a unit with greater transducer choices and a wider variety of applications. A single echocardiologist performed the PEs & HCUs. Conventional echoes were performed by a pediatric sonographer and interpreted by a second pediatric echocardiologist. Examination accuracies centered on 3 broad areas including: cardiac shunts, valvular insufficiency, and valvular anatomy. The accuracy of the PE alone was compared with the accuracy of the combined PE & HCU-1 vs. PE & HCU-2. Thirty patients total (3 months-19 years, 4-82 kg) were evaluated. Eighteen were examined with HCU-1 and 12 were examined with HCU-2. The accuracy of the combined PE & HCU-1 did not improve accuracy over the PE alone. However, the accuracy of the combined PE & HCU-2 was greater than the PE alone. Use of a limited HCU device does not improve diagnostic accuracy over an experienced PE alone and may actually worsen diagnostic accuracy in some cases. However, the improvements in newer HCU devices may enhance diagnostic accuracy over the PE alone, even for experienced physicians.

A Comparison by Medicine Residents of Physical Examination Versus Hand-Carried Ultrasound for Estimation of Right Atrial Pressure

Physicians' ability to accurately estimate right atrial (RA) pressure from bedside evaluation of the jugular venous waveform is poor, particularly when performed by physicians in training. Conventional ultrasound measurement of the inferior vena cava (IVC) accurately predicts RA pressure, but the cost, lack of portability, and specialized training required to acquire and interpret the data render this modality impractical for routine clinical use. The objective of this study was to compare physical examination with hand-carried ultrasound (HCU) in the detection of elevated RA pressure (>10 mm Hg). After limited training (4 hours didactic and 20 studies), 4 internal medicine residents using an HCU device estimated RA pressure from images of the IVC in 40 consecutive patients <1 hour after right-sided cardiac catheterization. RA pressure was also estimated from examination of the jugular venous pulse (JVP) in 40 patients before right-sided cardiac catheterization. RA pressure was successfully estimated from HCU images of the IVC in 90% of patients, compared with 63% from JVP examination. The sensitivity for predicting RA pressure >10 mm Hg was 82% with HCU and 14% from JVP inspection. Specificities were similar between the techniques. Overall accuracies were 71% using HCU and 60% with JVP assessment. In conclusion, internal medicine residents with brief training in echocardiography can more frequently and more accurately predict elevated RA pressure using HCU measurements of the IVC than with physical examination of the JVP.

Rapid assessment of left ventricular systolic function in a pacemaker clinic using a hand-carried ultrasound device

Pacemaker recipients with left ventricular (LV) dysfunction are potential candidates for upgrades to implantable defibrillators or cardiac resynchronization devices. This study sought to determine if a hand-carried ultrasound (HCU) device could be used for rapid, inexpensive identification of LV dysfunction in a busy pacemaker clinic. Eighty patients undergoing routine pacemaker check were enrolled. Patients underwent HCU imaging in the sitting position during device interrogation, by an internist who had 20 h of didactic training and 20 practice examinations. LV dysfunction was defined as ejection fraction (EF) <40%. Patients also underwent echocardiography limited to EF assessment by a sonographer using a full-feature platform. The mean age was 75 +/- 13 years; 49% were female. Coronary artery disease was present in 29%; 82% were NYHA class I or II. At the time of HCU imaging, 48% of patients were receiving RV pacing. HCU images were interpretable in 91% (73/80) and required 3.7 +/- 0.9 min to complete. Based on the full-feature echo, LV dysfunction prevalence was 17/80 (21%); 25% of these patients were NYHA class I. The sensitivity of the HCU exam was 75%, specificity was 91%, negative predictive value was 93%, positive predictive value was 71%, and accuracy was 88%. HCU screening in a pacemaker clinic by a non-cardiologist can rapidly and accurately identify pacemaker recipients with at least moderate LV dysfunction who might be candidates for device upgrades. Ventricular dyssynchrony associated with RV pacing does not limit HCU identification of LV dysfunction.

RESPIRATORY CHANGE IN BRACHIAL BLOOD VELOCITY AS A NONINVASIVE, BEDSIDE CORRELATE TO PULSE PRESSURE VARIATION IN THE VENTILATED PATIENT

PURPOSE: Rapid prediction of the effect of volume expansion (VE) is crucial in hemodynamically unstable patients on mechanical ventilation. While accurate, both radial artery pulse pressure variation (ΔPP) and changes of aortic blood flow peak velocity (ΔVPeakAo) have limitations that make them impractical as point-of-care tools. In this study, we sought to determine whether respiratory changes in the brachial artery blood flow velocity (VPeakBA) as measured by Internal Medicine residents using a hand-carried ultrasound (HCU) could provide an accurate corollary to ΔPP in mechanically ventilated patients.

Handcarried Ultrasound Measurement of the Inferior Vena Cava for Assessment of Intravascular Volume Status in the Outpatient Hemodialysis Clinic

Accurate intravascular volume assessment is critical in the treatment of patients who receive chronic hemodialysis (HD) therapy. Clinically assessed dry weight is a poor surrogate of intravascular volume; however, ultrasound assessment of the inferior vena cava (IVC) is an effective tool for volume management. This study sought to determine the feasibility of using operators with limited ultrasound experience to assess IVC dimensions using hand-carried ultrasounds (HCU) in the outpatient clinical setting. The IVC was assessed in 89 consecutive patients at two outpatient clinics before and after HD. Intradialytic IVC was recorded during episodes of hypotension, chest pain, or cramping. High-quality IVC images were obtained in 79 of 89 patients. Despite that 89% of patients presented at or above dry weight, 39% of these patients were hypovolemic by HCU. Of the 75% of patients who left HD at or below goal weight, 10% were still hypervolemic by HCU standards. Hypovolemic patients had more episodes of chest pain and cramping (33 versus 14%, P = 0.06) and more episodes of hypotension (22 versus 3%, P = 0.02). The clinic with a higher prevalence of predialysis hypovolemia had significantly more intradialytic adverse events (58 versus 27%; P = 0.01). HCU measurement of the IVC is a feasible option for rapid assessment of intravascular volume status in an outpatient dialysis setting by operators with limited formal training in echocardiography. There is a poor relationship between dry weight goals and IVC collapsibility. Practice variation in the maintenance of volume status is correlated with significant differences in intradialysis adverse events.

Transesophageal Echocardiography Using Cypress‐Miniaturized Echocardiogram Unit: Initial Clinical Experience

Transesophageal echocardiography (TEE) was introduced clinically in the United States in 1987. Recent technologic advances have resulted in the creation of a small portable hand-carried ultrasound (HCU) device that can be easily carried throughout the hospital with greater flexibility for cardiac imaging. These HCU devices have harmonic, color, and spectral Doppler (continuous/pulsed wave). Siemens Medical Solutions USA, Inc. has incorporated a TEE connector, which connects to its Cypress (highly miniaturized echocardiogram unit) and allows the performance of a TEE with this unit, which is mildly heavier than a typical HCU. We describe our initial clinical experience with this unit. The image quality is comparable to routine TEEs, with the advantages of shorter duration, portability, affordable cost, avoiding the use of high-end machine from the echo lab, availability of non-HCU units for other studies, and preventing the need for an echo technician to be involved in the procedure.

Bedside Diagnosis and Follow-up of Patients With Pleural Effusion by a Hand-Carried Ultrasound Device Early After Cardiac Surgery

The aim of this study was to assess the potential value of hand-carried ultrasound (HCU) devices in the diagnosis and follow-up of patients with pleural effusion (PE) after cardiac surgery. Seventy consecutive patients were evaluated at bedside early after cardiac surgery, in the upright sitting position, using an HCU device on hospital admission and every 3 days until hospital discharge. The posterior chest wall was scanned along the paravertebral, scapular, and posterior axillary lines. For each hemithorax, an effusion index was derived as the sum of the intercostal spaces between the lower and upper limits of the PE along the lines of scanning, divided by 3. A standard chest radiograph was performed in all patients on hospital admission and at hospital discharge, and was qualitatively scored (0, absent; 1, small; 2, large PE). The findings of the HCU device and radiograph were compared using kappa statistics and the Kruskal-Wallis test. A chest ultrasound was feasible in all patients (mean [+/- SD] time, 5 +/- 2 min). Compared with the chest ultrasound, a physical examination showed a sensitivity of 69% and a specificity of 77%. On hospital admission, the HCU device detected a PE in 72 of 140 hemithoraxes. Agreement with the finding of the radiograph was 76% (kappa = 0.52). In 15 hemithoraxes, the HCU device revealed a PE that had not been diagnosed using the radiograph. Conversely, in 18 hemithoraxes a PE that had been diagnosed with a radiograph was not confirmed by the HCU device. The correlation between ultrasound and radiographic scores was statistically significant (p < 0.001). At hospital discharge, a PE was present in 31 of 140 hemithoraxes according to the findings of the HCU device, and in 38 of 140 hemithoraxes according to the findings of the radiograph (agreement, 78%; kappa = 0.44). In patients early after cardiac surgery, HCU devices allow rapid PE detection and improve the clinical diagnosis. Compared to a radiograph, this method offers the unique advantage of the bedside evaluation of patients without the need for radiation exposure.

Comparison of Effectiveness of Hand-Carried Ultrasound to Bedside Cardiovascular Physical Examination

This study compared the accuracy of cardiovascular diagnoses by medical students operating a small hand-carried ultrasound (HCU) device with that of board-certified cardiologists using standard physical examinations. Sixty-one patients (38% women; mean age 70 +/- 19 years) with clinically significant cardiac disease had HCU studies performed by 1 of 2 medical students with 18 hours of training in cardiac ultrasound and physical examinations by 1 of 5 cardiologists. Diagnostic accuracy was determined by standard echocardiography. Two-hundred thirty-nine abnormal findings were detected by standard echocardiography. The students correctly identified 75% (180 of 239) of the pathologies, whereas cardiologists found 49% (116 of 239) (p <0.001). The students' diagnostic specificity of 87% was also greater than cardiologists' specificity of 76% (p <0.001). For nonvalvular pathologies (115 findings), students' sensitivity was 61%, compared with 47% for cardiologists (p = 0.040). There were 124 clinically significant valvular lesions (111 regurgitations, 13 stenoses). Students' and cardiologists' sensitivities for recognizing lesions that cause a systolic murmur were 93% and 62% (p <0.001), respectively. Students' sensitivity for diagnosing lesions that produce a diastolic murmur was 75%; cardiologists recognized 16% of these lesions (p <0.001). The diagnostic accuracy of medical students using an HCU device after brief echocardiographic training to detect valvular disease, left ventricular dysfunction, enlargement, and hypertrophy was superior to that of experienced cardiologists performing cardiac physical examinations.

The Use of Hand-carried Ultrasound in the Hospital Setting-A Cost-effective Analysis

We sought to assess the accuracy of hand-carried ultrasound (HCU) in the prediction of a normal study, and its cost-effectiveness in reducing the number of standard departmental echocardiograms (SDE) performed on hospital inpatients. The setting was a district general hospital. Participants were 157 consecutive inpatients, mean age 68 (range: 18-97) years, 95 men (61%), referred for SDE. HCU was performed at the bedside as part of the clinical assessment. SDE was performed routinely. Main outcome measures were: (1) assessment of the accuracy of HCU in detection of a normal or abnormal study as determined by SDE; and (2) a cost-effectiveness analysis. Indications for echocardiography were: left ventricular (LV) function assessment, n = 101 (64.3%); valvular abnormalities, n = 11 (7%); arrhythmia, n = 4 (2.6%); miscellaneous, n = 10 (6.4%); and no reason stated, 31 (19.7%). The sensitivity, specificity, and positive and negative predictive values of HCU predicting a completely normal scan were 74%, 96%, 94%, and 81%, respectively, and of predicting normal LV function in requests specific for LV function assessment were 81%, 100%, 100%, and 77%, respectively. If either all inpatients or those with requests for LV function assessment underwent HCU initially, and only those with abnormal scans underwent further SDE, there would be a 29% and 22% reduction in departmental workload and a cost saving of pound sterling 23,000 and pound sterling 30,000, respectively. HCU is an accurate method of identifying patients with normal hearts as determined by SDE. Its routine use is cost-effective and can significantly reduce the number of SDE that need be performed.

Effectiveness of Echocardiographic Imaging by Nurses to Identify Left Ventricular Systolic Dysfunction in High-Risk Patients

Recognizing left ventricular (LV) systolic dysfunction is critical. The investigators sought to evaluate whether nurses could be trained to use a hand-carried ultrasound (HCU) device to screen for LV systolic dysfunction in high-risk patients. Sixty-three patients from an outpatient diabetes clinic underwent brief echocardiographic examinations by nurses using HCU devices. Of the 63 patients enrolled in the study, 3 (4.7%) had LV systolic dysfunction. The nurses correctly identified these 3 patients as having LV systolic dysfunction (sensitivity 100%, negative predictive value 100%). The identification of occult LV systolic dysfunction in diabetic patients may allow the initiation of therapies known to improve prognosis.

Use of hand-carried ultrasound devices to augment the accuracy of medical student bedside cardiac diagnoses

Hand-carried ultrasound (HCU) devices used by cardiologists as extensions of the physical examination have been shown to improve the accuracy of bedside diagnoses. We tested the feasibility of teaching medical students to use HCU devices to make bedside cardiac diagnoses and compared the accuracy of their HCU and physical examinations. In all, 10 fourth-year medical students enrolled in a 4-week medical school course on the cardiac examination. Students examined 12 standardized patients at 3 different time intervals: (1) on day 1 of the course; (2) on day 10 after review of cardiac physical examination using traditional teaching methods; and (3) after instruction on the use of HCU devices. Students were scored at each time interval for primary findings (most salient) and all findings, accounting for both errors of commission and omission. Scores could range from +12 to -12 for primary findings and from +22 to -22 for all findings. A perfect score was +12 for primary findings and +22 for all findings. The average score for all students at baseline was -3.2 +/- 3.1 and -5.7 +/- 4.8 for primary and all findings, respectively. A significant improvement in the scores was noted with use of the HCU device (2.6 +/- 3.1 and 5.2 +/- 6.6 for primary and all findings, respectively) compared with the baseline and two subsequent physical examinations. Instruction of fourth-year medical students on the use of HCU device is feasible and results in significantly more accurate bedside diagnoses.