Point-of-Care Ultrasound: Applications in Low- and Middle-Income Countries

The Use of Point-of-Care Ultrasound in the Diagnosis and Percutaneous Aspiration of Liver Abscess in a Resource-Limited Country: A Case Report

Diagnosis and management of liver abscesses in low- and middle-income countries (LMICs) is difficult due to limited diagnostic imaging availability. Limited data is available describing the use of point-of-care ultrasound (POCUS) in the diagnosis and percutaneous aspiration of liver abscesses in resource-limited countries. We describe a 21-year-old female who was diagnosed with a liver abscess. The diagnosis of liver abscess was made via POCUS, and the patient was successfully managed with empiric antimicrobials and repeated POCUS-assisted percutaneous needle aspiration. In resource-limited settings, adequate training of personnel and availability of POCUS may help in early diagnosis and treatment of liver abscess - thus helping to reduce its related morbidity and mortality - while also aiding in resource conservation.

Thermal Characterization and Preclinical Feasibility Verification of an Accessible, Carbon Dioxide-Based Cryotherapy System

To investigate the potential of an affordable cryotherapy device for the accessible treatment of breast cancer, the performance of a novel carbon dioxide-based device was evaluated through both benchtop testing and an in vivo canine model. This novel device was quantitatively compared to a commercial device that utilizes argon gas as the cryogen. The thermal behavior of each device was characterized through calorimetry and by measuring the temperature profiles of iceballs generated in tissue phantoms. A 45 min treatment in a tissue phantom from the carbon dioxide device produced a 1.67 ± 0.06 cm diameter lethal isotherm that was equivalent to a 7 min treatment from the commercial argon-based device, which produced a 1.53 ± 0.15 cm diameter lethal isotherm. An in vivo treatment was performed with the carbon dioxide-based device in one spontaneously occurring canine mammary mass with two standard 10 min freezes. Following cryotherapy, this mass was surgically resected and analyzed for necrosis margins via histopathology. The histopathology margin of necrosis from the in vivo treatment with the carbon dioxide device at 14 days post-cryoablation was 1.57 cm. While carbon dioxide gas has historically been considered an impractical cryogen due to its low working pressure and high boiling point, this study shows that carbon dioxide-based cryotherapy may be equivalent to conventional argon-based cryotherapy in size of the ablation zone in a standard treatment time. The feasibility of the carbon dioxide device demonstrated in this study is an important step towards bringing accessible breast cancer treatment to women in low-resource settings.

Non-Invasive Quantitative Approximation of Intracranial Pressure in Pediatric Idiopathic Intracranial Hypertension Based on Point-of-Care Ultrasound of the Optic Nerve Sheath Diameter

BACKGROUND

To investigate whether ultrasound-based optic nerve sheath diameter (US-ONSD) is a reliable measure to follow up children with idiopathic intracranial hypertension (IIH). In addition, to analyze the inter- and intra-individual relationships between US-ONSD and intracranial pressure (ICP), and to investigate whether an individualized mathematical regression equation obtained from two paired US-ONSD/ICP values can be used to approximate ICP from US-ONSD values.

METHODS

159 US examinations and 53 invasive ICP measures via lumbar puncture (LP) were performed in 28 children with IIH. US-ONSD was measured using a 12 Mhz linear transducer and compared to ICP values. In 15 children, a minimum of 2 paired US-ONSD/ICP determinations were performed, and repeated-measures correlation (rmcorr) and intra-individual correlations were analyzed.

RESULTS

The cohort correlation between US-ONSD and ICP was moderate (r = 0.504, p < 0.01). Rmcorr (r = 0.91, p < 0.01) and intra-individual correlations (r = 0.956-1) of US-ONSD and ICP were excellent. A mathematical regression equation can be calculated from two paired US-ONSD/ICP values and applied to the individual patient to approximate ICP from US-ONSD.

CONCLUSIONS

Related to excellent intra-individual correlations between US-ONSD and ICP, an individualized regression formula, created from two pairs of US-ONSD/ICP values, may be used to directly approximate ICP based on US-ONSD values. Hence, US-ONSD may become a non-invasive and reliable measure to control treatment efficacy in pediatric IIH.

Point-of-Care Ultrasound-History, Current and Evolving Clinical Concepts in Emergency Medicine

Point-of-care ultrasound (PoCUS) has become an indispensable standard in emergency medicine. Emergency medicine ultrasound (EMUS) is the application of bedside PoCUS by the attending emergency physician to assist in the diagnosis and management of many time-sensitive health emergencies. In many ways, using PoCUS is not only the mere application of technology, but also a fusion of already existing examiner skills and technology in the context of a patient encounter. EMUS practice can be defined using distinct anatomy-based applications. The type of applications and their complexity usually depend on local needs and resources, and practice patterns can vary significantly among regions, countries, or even continents. A different approach suggests defining EMUS in categories such as resuscitative, diagnostic, procedural guidance, symptom- or sign-based, and therapeutic. Because EMUS is practiced in a constantly evolving emergency medical setting where no two patient encounters are identical, the concept of EMUS should also be practiced in a fluid, constantly adapting manner driven by the physician treating the patient. Many recent advances in ultrasound technology have received little or no attention from the EMUS community, and several important technical advances and research findings have not been translated into routine clinical practice. The authors believe that four main areas have great potential for the future growth and development of EMUS and are worth integrating: 1. In recent years, many articles have been published on novel ultrasound applications. Only a small percentage has found its way into routine use. We will discuss two important examples: trauma ultrasound that goes beyond e-FAST and EMUS lung ultrasound for suspected pulmonary embolism. 2. The more ultrasound equipment becomes financially affordable; the more ultrasound should be incorporated into the physical examination. This merging and possibly even replacement of aspects of the classical physical exam by technology will likely outperform the isolated use of stethoscope, percussion, and auscultation. 3. The knowledge of pathophysiological processes in acute illness and ultrasound findings should be merged in clinical practice. The translation of this knowledge into practical concepts will allow us to better manage many presentations, such as hypotension or the dyspnea of unclear etiology. 4. Technical innovations such as elastography; CEUS; highly sensitive color Doppler such as M-flow, vector flow, or other novel technology; artificial intelligence; cloud-based POCUS functions; and augmented reality devices such as smart glasses should become standard in emergencies over time.

Diagnostic accuracy of chest ultrasound scan in the diagnosis of childhood tuberculosis

Chest Ultrasound Scan (CUS) has been utilized in place of CXR in the diagnosis of adult pneumonia with similar or higher sensitivity and specificity to CXR. However, there is a paucity of data on the use of CUS for the diagnosis of childhood TB. This study aimed to determine the diagnostic accuracy of CUS for childhood TB. This cross-sectional study was conducted at the Mulago National Referral Hospital in Uganda. Eighty children up to 14 years of age with presumptive TB were enrolled. They all had CUS and CXR performed and interpreted independently by radiologists. The radiologist who performed the CXR was blinded to the CUS findings, and vice versa. Radiologists noted whether TB was likely or unlikely. A two-by-two table was developed to compare the absolute number of children as either TB likely or TB unlikely on CXR or CUS. This was used to calculate the sensitivity and specificity of CUS when screening for TB in children, with a correction to accommodate the use of CXR as a reference test. The sensitivity of CUS was 64% (95% CI 48.5%-77.3%), while its specificity was 42.7% (95% CI 25.5%-60.8%). Both the CUS and CXR found 29 children with a likelihood of TB, and 27 children unlikely to have TB. CUS met the sensitivity target set by the WHO TPP for Triage, and it had a sensitivity and specificity comparable to that of CXR.

Role of Point-of-Care Diagnostics in Lower- and Middle-Income Countries and Austere Environments

INTRODUCTION

Austere environments include the wilderness and many lower- and middle-income countries, with many of these countries facing unrest and war. The access to advanced diagnostic equipment is often unaffordable, even if available, and the equipment is often liable to break down.

METHODS

A short review paper examining the options available to medical professionals to undertake clinical and point-of-care diagnostic testing in resource-constrained environments that also illustrates the development of mobile advanced diagnostic equipment. The aim is to provide an overview of the spectrum and functionality of these devices beyond clinical acumen.

RESULTS

Details and examples of products covering all aspects of diagnostic testing are provided. Where relevant, reliability and cost implications are discussed.

CONCLUSIONS

The review highlights the need for more cost-effective accessible and utilitarian products and devices that will bring cost-effective health care to many in lower- and middle-income or austere environments.

The use of lung ultrasound in COVID-19

This review article addresses the role of lung ultrasound in patients with coronavirus disease 2019 (COVID-19) for diagnosis and disease management. As a simple imaging procedure, lung ultrasound contributes to the early identification of patients with clinical conditions suggestive of COVID-19, supports decisions about hospital admission and informs therapeutic strategy. It can be performed in various clinical settings (primary care facilities, emergency departments, hospital wards, intensive care units), but also in outpatient settings using portable devices. The article describes typical lung ultrasound findings for COVID-19 pneumonia (interstitial pattern, pleural abnormalities and consolidations), as one component of COVID-19 diagnostic workup that otherwise includes clinical and laboratory evaluation. Advantages and limitations of lung ultrasound use in COVID-19 are described, along with equipment requirements and training needs. To infer on the use of lung ultrasound in different regions, a literature search was performed using key words "COVID-19", "lung ultrasound" and "imaging". Lung ultrasound is a noninvasive, rapid and reproducible procedure; can be performed at the point of care; requires simple sterilisation; and involves non-ionising radiation, allowing repeated exams on the same patient, with special benefit in children and pregnant women. However, physical proximity between the patient and the ultrasound operator is a limitation in the current pandemic context, emphasising the need to implement specific infection prevention and control measures. Availability of qualified staff adequately trained to perform lung ultrasound remains a major barrier to lung ultrasound utilisation. Training, advocacy and awareness rising can help build up capacities of local providers to facilitate lung ultrasound use for COVID-19 management, in particular in low- and middle-income countries.

Point‑of‑Care Ultrasound - accuracy, education

A review article discussing the reliability of Point-of-Care ultrasound and education in this method in various fields of medicine.

Current use and perceived barriers of emergency point-of-care ultrasound by African health care practitioners

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Point-of-care ultrasound is a key skill for emergency care practitioners in Africa.

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Access barriers to point-of-care ultrasound training and equipment are still relevant in Africa.

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Many users of point-of-care ultrasound in Africa have not been formally credentialed.

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A potential discordance exists between local burden of disease and point-of-care ultrasound training.

Introduction

The African Federation of Emergency Medicine (AFEM) recommends the use of emergency point-of-care ultrasound (ePOCUS) as a core skill for health care practitioners in Africa. The study explored the use of ePOCUS by health care practitioners among AFEM members who work across Africa.

Methods

An anonymous online survey was distributed to individual members of AFEM and affiliated organisations. The questionnaire was tested by the AFEM Scientific Committee for potential content modifications prior to distribution. Summary statistics are presented.

Results

Of the 220 participants that were analysed, 148 (67.3%) were using ePOCUS. The mean age was 36 years; 146 (66%) were male; and 198 (90%) obtained their primary medical qualification in Africa. In total, 168 (76%) were doctors, and most participants (n = 204, 93%) have worked in Africa during the last 5 years. Reasons for not using ePOCUS mainly related to lack of training and problems with ultrasound machines or consumables. Most ePOCUS users (116/148, 78%) attended courses with hands-on training, but only 65 (44%) participants were credentialed (by 18 different organizations). The median score for self-perceived level of ePOCUS skills was 75 in credentialed users versus 50 in those that were not credentialed. Ultrasound in trauma was the most frequently used module (n = 141, 99%), followed by focused cardiac assessment (n = 128, 90%) and thoracic (including lung) assessment (n = 128, 90.1%). The FASH-module (Focused Assessment with Sonography for HIV/TB) was the least used (n = 69, 49%).

Conclusion

Access barriers to ePOCUS training, mentorship, equipment and consumables are still relevant in Africa. The low credentialing rate and the potential discordance between local burden of disease and ePOCUS training requires further investigation.

Point-of-Care Ultrasound Reduces Visit Time and Cost of Care for Infants with Developmental Dysplasia of the Hip

BACKGROUND

Healthcare institutions and policymakers are searching for system-wide approaches to reduce costs while maintaining quality and improving patient outcomes. In most healthcare systems infants referred for the detecting or treating developmental dysplasia of the hip (DDH) are sent to a radiology department for sonographic evaluation. The total duration of visit and cost of visit are essential variables in any healthcare setting and affect both efficiency and "the bottom line". By having the treating clinician perform point-of-care ultrasound (POCUS) for the detection and follow-up of patients with DDH, we hypothesize that there would be a significant reduction in the time spent on the visit and the cost incurred without compromising quality or patient satisfaction. To our knowledge, no prior study has examined the effect of incorporating POCUS on the duration and cost of the visit in patients with DDH.

PURPOSE

To determine if there was a difference in the duration of the visit for patients with DDH when POCUS was performed compared to when traditional "formal" sonography was performed. To determine if there was a difference in the cost of the visit for patients with DDH when POCUS was performed compared to when traditional "formal" sonography was performed.

METHODS

Data for visits to a specialized outpatient office were collected over two years at a single-specialty orthopedic hospital, comparing the duration and cost of the visit between patient encounters for infants who had "formal" sonograms performed in the radiology suite to infants who underwent POCUS of the hip. In all, we included 532 patient encounters, 326 patients had POCUS performed, and 206 had a "formal" ultrasonographic evaluation performed. Of these, 140 were new evaluations and 392 were follow-up evaluations for treatment. Of the 140 new patients, 80 were in the POCUS group, and 60 were in the "formal" US group. Of the 392 follow-ups, 246 were in the POCUS group, and 146 were in the "formal" US group.

RESULTS

The mean duration of the encounter for the POCUS group was 42 min (range 16-75 min), and for the "formal" US group, it was 92 min (range 36-163 min). This difference was statistically significant (p = 0.002). The mean cost of the encounter for the POCUS group was $121.13, and for the "formal" US group, it was $339.38. This difference was statistically significant (p = 0.002).

CONCLUSION

Ultimately, our study demonstrated a statistically significant reduction in the duration and cost of a patient encounter for infants with DDH when they undergo POCUS rather than "formal" sonographic evaluation.

Diagnostic accuracy of point-of-care ultrasound for pulmonary tuberculosis: A systematic review

The advent of affordable, portable ultrasound devices has led to increasing interest in the use of point-of-care ultrasound (POCUS) for the detection of pulmonary TB (PTB). We undertook a systematic review of the diagnostic accuracy of POCUS for PTB. Five databases were searched for articles published between January 2010 and June 2020. Risk of bias was assessed using QUADAS-2. Data on sensitivity and specificity of individual lung ultrasound findings were collected, with variable reference standards including PCR and sputum smear microscopy. Six of 3,919 reviewed articles were included: five in adults and one in children, with a total sample size of 564. Studies had high risk of bias in many domains. In adults, subpleural nodule and lung consolidation were the lung ultrasound findings with the highest sensitivities, ranging from 72.5% to 100.0% and 46.7% to 80.4%, respectively. Only one study reported specificity data. Variability in sensitivity may be due to variable reference standards or may imply operator dependence. There is insufficient evidence to judge the diagnostic accuracy of POCUS for PTB. There is also no consensus on the optimal protocols for acquiring and analysing POCUS images for PTB. New studies which minimise potential sources of bias are required to further assess the diagnostic accuracy of POCUS for PTB.

A marathon, not a sprint - neuroimaging, Open Science and ethics

Open Science is calling for a radical re-thinking of existing scientific practices. Within the neuroimaging community, Open Science practices are taking the form of open data repositories and open lab notebooks. The broad sharing of data that accompanies Open Science, however, raises some difficult ethical and legal issues. With neuroethics as a focusing lens, we explore eight central concerns posed by open data with regard to human brain imaging studies: respect for individuals and communities, concern for marginalized communities, consent, privacy protections, participatory research designs, contextual integrity, fusions of clinical and research goals, and incidental findings. Each consideration assists in bringing nuance to the potential benefits for open data sharing against associated challenges. We combine current understandings with forward-looking solutions to key issues. We conclude by underscoring the need for new policy tools to enhance the potential for responsible open data.