Clinical applications of point-of-care ultrasound in brain injury: a narrative review.

The use of point-of-care ultrasound has increased considerably over the last two decades. It has become a readily available, non-invasive bed-side modality for the rapid diagnosis and management of patients in various settings. Point-of-care ultrasound for assessing the heart, lung, abdomen, airway and vascular systems is now well established. Transcranial Doppler ultrasound for assessing cerebral blood flow has been in use for many years. In recent years, brain ultrasonography has been shown to be a powerful tool in the rapid bed-side assessment of cerebral haemodynamics and structural pathology. Brain ultrasound has been shown to be useful in both the emergency department and neurocritical care setting for the non-invasive assessment of raised intracranial pressure, cerebral autoregulation and diagnosis of intracranial haematoma and other space-occupying lesions. Point-of-care ultrasound is an important alternative technique to routine imaging and invasive monitoring techniques, and results are comparable. Competence is easily attainable without formal radiology training. With technological advancement, applications for the use of brain ultrasound continue to grow. This review discusses the clinical use of point-of-care ultrasound in the diagnosis and management of brain injury.

Which Septic Shock Patients With Non-Overt DIC Progress to DIC After Admission? Point-of-Care Thromboelastography Testing.

BACKGROUND: Disseminated intravascular coagulation (DIC) is a life-threatening complication of septic shock; however, risk factors for its development after admission are unknown. Thromboelastography (TEG) can reflect coagulation disturbances in early non-overt DIC that are not detected by standard coagulation tests. This study investigated the risk factors including TEG findings as early predictors for DIC development after admission in septic shock patients with non-overt DIC. METHODS: This retrospective observation study included 295 consecutive septic shock patients with non-overt DIC at admission between January 2016 and December 2019. DIC was defined as an International Society on Thrombosis and Hemostasis (ISTH) score ≥ 5. The primary outcome was non-overt DIC at admission that met the ISTH DIC criteria within 3 days after admission. RESULTS: Of the 295 patients with non-overt DIC, 89 (30.2%) developed DIC after admission. The DIC group showed a higher ISTH score and 28-day mortality rate than the non-DIC group (2 vs. 3, P < 0.001; 13.6% vs. 27.0%, P = 0.008, respectively). The DIC rate increased with the ISTH score (7.7%, 13.3%, 15.8%, 36.5%, and 61.4% for scores of 0, 1, 2, 3, and 4, respectively). Among TEG values, the maximum amplitude (MA) was higher in the non-DIC group (P < 0.001). On multivariate analysis, an MA < 64 mm was independently associated with DIC development (odds ratio, 2.311; 95% confidence interval, 1.298-4.115). CONCLUSIONS: DIC more often developed among those with admission ISTH scores ≥ 3 and was associated with higher mortality rates. An MA < 64 mm was independently associated with DIC development in septic shock patients.

The Use of Antigenic SARS-CoV-2 Point-of-Care Test: The Italian Pediatric Real-Life Experience.

In Italy, during the second epidemic wave of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), rapid antigenic (Ag) test at point-of-care (POCT) station were employed to quickly evaluate large numbers of swabs. We collected data of all children who underwent the Ag test in our hospital. All positive patients were recalled to perform reverse transcription polymerase chain reaction. A total of 2133 tests were collected over 1 month. Clinical data of 1941 children (median age = 3.7 years) were analyzed: 1343 (69.2%) patients complained of symptoms, 594 (30.6%) had a history of close contact with SARS-CoV-2-positive individuals. Among symptoms reported, acute rhinitis was the most frequent (67.9%), followed by cough (42.6%) and fever (31.5%). Among all tests, 95.8% resulted negative, 4.2% positive: 37/89 were confirmed. In confirmed cases, fever (56.2% vs 32.2%; P = .041) and gastrointestinal symptoms (18.8% vs 6.25%; P = .041) were significantly more frequent compared with negative children. The use of POCT for Ag test seems appropriate for SARS-CoV-2 screening in the pediatric population. In children, fever and gastrointestinal symptoms may constitute red flags of SARS-CoV-2.

Preoperative Point-of-Care Ultrasound to Identify Frailty and Predict Postoperative Outcomes: A Diagnostic Accuracy Study.

BACKGROUND: Frailty is increasingly being recognized as a public health issue, straining healthcare resources and increasing costs to care for these patients. Frailty is the decline in physical and cognitive reserves leading to increased vulnerability to stressors such as surgery or disease states. The goal of this pilot diagnostic accuracy study was to identify whether point-of-care ultrasound measurements of the quadriceps and rectus femoris muscles can be used to discriminate between frail and not-frail patients and predict postoperative outcomes. This study hypothesized that ultrasound could discriminate between frail and not-frail patients before surgery. METHODS: Preoperative ultrasound measurements of the quadriceps and rectus femoris were obtained in patients with previous computed tomography scans. Using the computed tomography scans, psoas muscle area was measured in all patients for comparative purposes. Frailty was identified using the Fried phenotype assessment. Postoperative outcomes included unplanned intensive care unit admission, delirium, intensive care unit length of stay, hospital length of stay, unplanned skilled nursing facility admission, rehospitalization, falls within 30 days, and all-cause 30-day and 1-yr mortality. RESULTS: A total of 32 patients and 20 healthy volunteers were included. Frailty was identified in 18 of the 32 patients. Receiver operating characteristic curve analysis showed that quadriceps depth and psoas muscle area are able to identify frailty (area under the curve-receiver operating characteristic, 0.80 [95% CI, 0.64 to 0.97] and 0.88 [95% CI, 0.76 to 1.00], respectively), whereas the cross-sectional area of the rectus femoris is less promising (area under the curve-receiver operating characteristic, 0.70 [95% CI, 0.49 to 0.91]). Quadriceps depth was also associated with unplanned postoperative skilled nursing facility discharge disposition (area under the curve 0.81 [95% CI, 0.61 to 1.00]) and delirium (area under the curve 0.89 [95% CI, 0.77 to 1.00]). CONCLUSIONS: Similar to computed tomography measurements of psoas muscle area, preoperative ultrasound measurements of quadriceps depth shows promise in discriminating between frail and not-frail patients before surgery. It was also associated with skilled nursing facility admission and postoperative delirium.

Evaluation of the Point-of-Care Circulating Cathodic Antigen Assay for Monitoring Mass Drug Administration in a Schistosoma mansoni Control Program in Western Kenya.

The WHO guidelines for monitoring and evaluating Schistosoma mansoni control programs are based on the Kato-Katz (KK) fecal examination method; however, there are limitations to its use, particularly in low prevalence areas. The point-of-care urine circulating cathodic antigen (POC-CCA) assay has emerged as a useful tool for mapping schistosomiasis prevalence, but its use in monitoring and evaluating control programs has not been evaluated. Before POC-CCA can be used for these programs, it must be determined how previous guidance based on the KK method can be translated to the POC-CCA assay; furthermore, its performance in different endemicity settings must be evaluated. Urine and stool specimens were collected from students attending public primary schools in western Kenya before mass treatment with praziquantel at baseline (51 schools), year 1 (45 schools), year 2 (34 schools), and year 3 (20 schools). Prevalence and infection intensity were determined by the KK method and POC-CCA assay. Changes in prevalence and intensity were compared within the strata of schools grouped according to the baseline prevalence determined by the KK method (0-10%, > 10-20%, > 20%). The prevalence determined by the POC-CCA assay was higher than that determined by the KK method at all time points for all strata. The prevalence determined by the KK method decreased from baseline to 2 and 3 years, as did infection intensity (with one exception). A corresponding decrease was not always replicated by the POC-CCA assay results. The POC-CCA assay did not perform as expected, and the concordance of results of the two tests was poor. Furthermore, there are emerging concerns regarding the specificity of the POC-CCA assay. Therefore, it is impossible to translate historical data and programmatic guidelines based on the KK method results to the POC-CCA assay.

Microparticle-tagged image-based cell counting (ImmunoSpin) for CD4 + T cells.

Affordable point-of-care (POC) CD4 + T lymphocyte counting techniques have been developed as alternatives to flow cytometry-based instruments caring for patients with human immunodeficiency virus (HIV)-1. However, POC CD4 enumeration technologies can be inaccurate. Here, we developed a microparticle-based visual detector of CD4 + T lymphocytes (ImmunoSpin) using microparticles conjugated with anti-CD4 antibodies, independent of microfluidic or fluorescence detection systems. Visual enumeration of CD4 + T cells under conventional light microscope was accurate compared to flow cytometry. Microparticle-tagged CD4 + T cells were well-recognized under a light microscope. ImmunoSpin showed very good precision (coefficients of variation of ImmunoSpin were ≤ 10%) and high correlation with clinical-grade flow cytometry for the enumeration of CD4 + T cells (y = 0.4232 + 0.9485 × for the %CD4 + T cell count, R2 = 0.99). At thresholds of 200 and 350 cells/µL, there was no misclassification of the ImmunoSpin system compared to the reference flow cytometry. ImmunoSpin showed clear differential classification of CD4 + T lymphocytes from granulocytes and monocytes. Because non-fluorescence microparticle-tags and cytospin slides are used in ImmunoSpin, they can be applied to an automatic digital image analyzer. Slide preparation allows long-term storage, no analysis time limitations, and image transfer in remote areas.

Towards the use of a smartphone imaging-based tool for point-of-care detection of asymptomatic low-density malaria parasitaemia.

BACKGROUND: Globally, there are over 200 million cases of malaria annually and over 400,000 deaths. Early and accurate detection of low-density parasitaemia and asymptomatic individuals is key to achieving the World Health Organization (WHO) 2030 sustainable development goals of reducing malaria-related deaths by 90% and eradication in 35 countries. Current rapid diagnostic tests are neither sensitive nor specific enough to detect the low parasite concentrations in the blood of asymptomatic individuals. METHODS: Here, an imaging-based sensing technique, particle diffusometry (PD), is combined with loop mediated isothermal amplification (LAMP) on a smartphone-enabled device to detect low levels of parasitaemia often associated with asymptomatic malaria. After amplification, PD quantifies the Brownian motion of fluorescent nanoparticles in the solution during a 30 s video taken on the phone. The resulting diffusion coefficient is used to detect the presence of Plasmodium DNA amplicons. The coefficients of known negative samples are compared to positive samples using a one-way ANOVA post-hoc Dunnett's test for confirmation of amplification. RESULTS: As few as 3 parasite/µL of blood was detectable in 45 min without DNA extraction. Plasmodium falciparum parasites were detected from asymptomatic individuals' whole blood samples with 89% sensitivity and 100% specificity when compared to quantitative polymerase chain reaction (qPCR). CONCLUSIONS: PD-LAMP is of value for the detection of low density parasitaemia especially in areas where trained personnel may be scarce. The demonstration of this smartphone biosensor paired with the sensitivity of LAMP provides a proof of concept to achieve widespread asymptomatic malaria testing at the point of care.

Designing of various biosensor devices for determination of apoptosis: A comprehensive review.

Apoptosis is a type of cell death caused by the occurrence of both pathological and physiological conditions triggered by ligation of death receptors outside the cell or triggered by DNA damage and/or cytoskeleton disruption. Timely monitoring of apoptosis can effectively help early diagnosis of related diseases and continuous assessment of the effectiveness of drugs. Detecting caspases, a protease family closely related to cellular apoptosis, and its identification as markers of apoptosis is a popular procedure. Biosensors are used for early diagnosis and play a very important role in preventing disease progression in various body sections. Recently, there has been a widespread increase in the desire to use materials made of paper (e.g. nitrocellulose membrane) for Point-of-Care (POC) testing systems since paper and paper-like materials are cheap, abundant and degradable. Microfluidic paper-based analytical devices (µPADs) are highly promising as they are cost-effective, easy to use, fast, precise and sustainable over time and under different environmental conditions. In this review, we focused our efforts on compiling the different approaches on identifying apoptosis pathway while giving brief information about apoptosis and biosensors. This review includes recent advantages in biosensing techniques to simply determine what happened in the cell life and which direction it would continue. As a conclusion, we believed that the review may help to researchers to compare/update the knowledge about diagnosis of the apoptosis pathway while reminding the basic definitions about the apoptosis and biosensor technologies.

Reference and point-of-care testing for G6PD deficiency: Blood disorder interference, contrived specimens, and fingerstick equivalence and precision.

Certain clinical indications and treatments such as the use of rasburicase in cancer therapy and 8-aminoquinolines for Plasmodium vivax malaria treatment would benefit from a point-of-care test for glucose-6-phosphate dehydrogenase (G6PD) deficiency. Three studies were conducted to evaluate the performance of one such test: the STANDARD™ G6PD Test (SD BIOSENSOR, South Korea). First, biological interference on the test performance was evaluated in specimens with common blood disorders, including high white blood cell (WBC) counts. Second, the test precision on fingerstick specimens was evaluated against five individuals of each, deficient, intermediate, and normal G6PD activity status. Third, clinical performance of the test was evaluated at three point-of-care settings in the United States. The test performed equivalently to the reference assay in specimens with common blood disorders. High WBC count blood samples resulted in overestimation of G6PD activity in both the reference assay and the STANDARD G6PD Test. The STANDARD G6PD Test showed good precision on multiple fingerstick specimens from the same individual. The same G6PD threshold values (U/g Hb) were applied for a semiquantitative interpretation for fingerstick- and venous-derived results. The sensitivity/specificity values (95% confidence intervals) for the test for G6PD deficiency were 100 (92.3-100.0)/97 (95.2-98.2) and 100 (95.7-100.0)/97.4 (95.7-98.5) for venous and capillary specimens, respectively. The same values for females with intermediate (> 30% to ≤ 70%) G6PD activity were 94.1 (71.3-99.9)/88.2 (83.9-91.7) and 82.4 (56.6-96.2)/87.6(83.3-91.2) for venous and capillary specimens, respectively. The STANDARD G6PD Test enables point-of-care testing for G6PD deficiency.

Technical Note: Glycolic Acid Exacerbates the Analytical Performance of Lactate Assay.

In this study, we evaluated the analytical interference of glycolic acid on several lactate assays that use lactate oxidase and dehydrogenase. Herein, we tested the effect of different concentrations of glycolic acid (0.01-46mM) on the lactate assay by using central lab and point of care (POCT) analyzers: Radiometer ABL 800, Beckman AU480, Roche Cobas c502, and Abbott i-STAT. Glycolic acid concentrations as low as 0.12mM resulted in a ≥20% positive bias in lactate assay on the ABL 800 and a concentration of approximately 0.23mM resulted in >20% on the Roche Cobas c502 and Abbott i-STAT. A significant lactate gap is found at concentrations >0.06mM between the Radiometer ABL 800 and Roche Cobas c502/Abbott i-STAT. However, at concentrations ≥0.92mM, the lactate gap is very significant among all three platforms. Falsely elevated lactate levels could result in misdiagnosis.

Can family physicians accurately screen for AAA with point-of-care ultrasound?

Likely yes. Point-of-care ultrasound (POCUS) screening for abdominal aortic aneurysm (AAA) by nonradiologist physicians is 98% sensitive and 99% specific, compared with imaging performed by radiologists (strength of recommendation [SOR]: B, meta-analysis of diagnostic accuracy studies mostly involving emergency medicine physicians). European family physicians demonstrated 100% concordance with radiologist readings (SOR: C, very small subsequent diagnostic accuracy studies).

A scoping review of person and family engagement in the context of multiple chronic conditions.

OBJECTIVE: To review definitions, concepts, and evidence regarding person and family engagement for persons with multiple chronic conditions (MCCs) in order to identify opportunities to advance the field. DATA SOURCE: Ovid MEDLINE. STUDY DESIGN: We performed a two-step process as follows: (1) a critical review of conceptual models of engagement to identify key concepts most pertinent to engagement among persons with MCC as a "launch pad" to our scoping review and (2) a scoping review of reviews of engagement for persons living with MCC. DATA COLLECTION/EXTRACTION METHODS: First, we critically reviewed six models of engagement. Second, our scoping review identified 1297 citations, with 67 articles meeting criteria for inclusion. Of these, we focused on reviews, of which there were nine titles/abstracts retained for full-text consideration. Six full-text reviews were included in the final analysis. The purpose, review type, population, number/type of included studies, theoretical framework, and findings of each study were extracted and analyzed thematically. PRINCIPAL FINDINGS: Conceptual models of engagement differ with respect to areas of emphasis (e.g., systems or clinical encounters) as well as attention to vulnerable populations, involvement of family, consideration of cost-benefit trade-offs, and attention to outcomes that matter most. Our scoping review of reviews identified just one article explicitly focused on engagement interventions for those with MCC. Other reviews examined elements of self-management and involvement in decision making, conceptually related to engagement without explicit use of the word. We find that existing evidence has predominantly described individual-level strategies rather than targeting organizations, systems, or policies. Barriers to engagement are not well described nor are potential downsides to engagement. Family engagement is rarely considered. CONCLUSIONS: Promising areas of future work include attention to barriers to engagement including trust, goal-based care, the design of structural changes to care delivery, trade-offs between benefits and costs, and family engagement.

Detection of SARS-CoV-2 at the point of care.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the etiologic agent of COVID-19. Testing for SARS-CoV-2 infection is a critical element of the public health response to COVID-19. Point-of-care (POC) tests can drive patient management decisions for infectious diseases, including COVID-19. POC tests are available for the diagnosis of SARS-CoV-2 infections and include those that detect SARS-CoV-2 antigens as well as amplified RNA sequences. We provide a review of SARS-CoV-2 POC tests including their performance, settings for which they might be used, their impact and future directions. Further optimization and validation, new technologies as well as studies to determine clinical and epidemiological impact of SARS-CoV-2 POC tests are needed.

Impact of an epic-integrated point-of-care ultrasound workflow on ultrasound performance, compliance, and potential revenue.

OBJECTIVES: The purpose of this study was to describe the design and impact of a point-of-care ultrasound (PoCUS) workflow integrated into the electronic medical record (EMR) on PoCUS utilization, documentation compliance, and resultant revenue potential. METHODS: This was a single-center retrospective study at an academic center. The study period spanned from December 1, 2018 to June 30, 2019 (pre-implementation) to August 1, 2019 to February 29, 2020 (post-implementation). The implementation date was July 11, 2019 at which time a PoCUS workflow was integrated into the EMR in the emergency department without the purchase of middleware. Prior to this new workflow, a non-automated workflow was in place. PoCUS scan data were extracted from the EMR and archived examinations. The mean number of PoCUS examinations performed per month per 100 ED visits before and after implementation of the new workflow were compared using an unpaired t-test, stratified by all health care professionals, and attending physicians alone. The rate of documentation compliance before and after implementation of the new workflow were compared using a chi square contingency test. Potential revenue was calculated for each period by multiplying the number of eligible examinations by the respective 2020 Medicare conversion factor Relative Value Units. RESULTS: Utilization of PoCUS from pre-implementation to post-implementation increased 28.7% from 5.01 to 6.45 mean examinations per month per 100 ED visits by all health care professionals (p = 0.063), and 75.1% from 2.01 to 3.52 by attending physicians (p = 0.0001). Examinations in compliance with workflow requirements increased from 153 (14.7%) to 1307 (94.0%). The rate of workflow compliance improved from 14.7% to 94.0% of examinations (p < 0.0001). Potential revenue increased from $546.01 to $22,014.47. CONCLUSIONS: The implementation of a middleware-free PoCUS workflow at our institution was associated with increased PoCUS utilization, documentation compliance, and potential revenue.

Emergency Medicine Society of South Africa guidelines for the training and credentialing in emergency point-of-care ultrasound.

This is the second guideline from the Emergency Medicine Society of South Africa (EMSSA) on the use of emergency point-of-care ultrasound in South Africa. It supersedes and replaces the guidelines produced in 2009. This document contains information on the changes from the 2009 guidelines and details of the training and credentialing processes recommended by EMSSA. It also contains detailed information on the curricula of the Core Emergency Point-of-Care Ultrasound and Advanced Emergency Point-of-Care Ultrasound courses.

The Impact of Increasing Disease Prevalence, False Omissions, and Diagnostic Uncertainty on Coronavirus Disease 2019 (COVID-19) Test Performance.

CONTEXT.­: Coronavirus disease 2019 (COVID-19) test performance depends on predictive values in settings of increasing disease prevalence. Geospatially distributed diagnostics with minimal uncertainty facilitate efficient point-of-need strategies. OBJECTIVES.­: To use original mathematics to interpret COVID-19 test metrics; assess US Food and Drug Administration Emergency Use Authorizations and Health Canada targets; compare predictive values for multiplex, antigen, polymerase chain reaction kit, point-of-care antibody, and home tests; enhance test performance; and improve decision-making. DESIGN.­: PubMed/newsprint-generated articles documenting prevalence. Mathematica and open access software helped perform recursive calculations, graph multivariate relationships, and visualize performance by comparing predictive value geometric mean-squared patterns. RESULTS.­: Tiered sensitivity/specificity comprised: T1, 90%, 95%; T2, 95%, 97.5%; and T3, 100%, ≥99%. Tier 1 false negatives exceeded true negatives at >90.5% prevalence; false positives exceeded true positives at <5.3% prevalence. High-sensitivity/specificity tests reduced false negatives and false positives, yielding superior predictive values. Recursive testing improved predictive values. Visual logistics facilitated test comparisons. Antigen test quality fell off as prevalence increased. Multiplex severe acute respiratory syndrome (SARS)-CoV-2)*influenza A/B*respiratory syncytial virus testing performed reasonably well compared with tier 3. Tier 3 performance with a tier 2 confidence band lower limit will generate excellent performance and reliability. CONCLUSIONS.­: The overriding principle is to select the best combined performance and reliability pattern for the prevalence bracket. Some public health professionals recommend repetitive testing to compensate for low sensitivity. More logically, improved COVID-19 assays with less uncertainty conserve resources. Multiplex differentiation of COVID-19 from influenza A/B-respiratory syncytial virus represents an effective strategy if seasonal flu surges next year.

Methodologic Quality of Guidelines for Training or Competence Processes for Basic Point-of-Care Echocardiography in Critical Care: A Systematic Review of the Literature.

BACKGROUND: The formulation of expert opinion guidelines has several sources of bias that may adversely affect their quality. To minimize bias, guideline creators must use rigorous methodology. There has been no appraisal of the methodologic quality of basic critical care echocardiography (BCCE) training/education guidelines. RESEARCH QUESTION: What is the methodologic quality of expert guidelines/recommendations on BCCE training? STUDY DESIGN AND METHODS: The review was performed by a multidisciplinary team including intensive care specialists, a hospital scientist, a trainee, a nurse sonographer, and a public health expert. Four databases (PubMed, OVID-Embase, Clarivate Analytics Web of Science, and Google Scholar) were searched on July 31, 2020, to identify guidelines on BCCE training/education. Every guideline was assessed subjectively for the degree of detail of the recommendations and assessed objectively by using the AGREE-II critical appraisal tool for clinical practice guidelines to generate a scaled domain score. A score ≥ 75% in every domain was the cut off for guidelines to be used without modifications. RESULTS: From 4,288 abstracts screened, 24 guidelines met the inclusion criteria. Very few guidelines made clear recommendations regarding introductory courses: physics (n = 6 [25%]), instrumentation (n = 5 [20.8%]), image acquisition theory (n = 6 [25%]), course curriculum (n = 5 [[20.8%]), pre-course/post-course tests (n = 1 [4.2%]), minimum course duration (n = 6 [25%]), or trainer qualifications (n = 5 [20.8%]). Very few provided clear recommendations for longitudinal competence programs: clinically indicated scans (n = 8 [33.3%]), logbook (n = 14 [58.3%]), image storage (n = 9 [37.5%]), formative assessment (n = 6 [25%]), minimum scan numbers (n = 14 [58.3%]), image acquisition competence (n = 3 [12.5%]), image interpretation competence (n = 2 [8.3%]), and credentialing/certification (n = 3 [12.5%]). Five guidelines (20.8%) attained a scaled overall AGREE-II score ≥ 75%. One guideline (4.2%) attained scores ≥ 75% in every domain. INTERPRETATION: The methodologic appraisal of BCCE-training guidelines showed widespread deficiencies in guideline formulation processes. The impact of these deficiencies on the validity of the recommendations requires further evaluation in longitudinal studies.