Multi-organ point-of-care ultrasound for COVID-19 (PoCUS4COVID): international expert consensus.

COVID-19 has caused great devastation in the past year. Multi-organ point-of-care ultrasound (PoCUS) including lung ultrasound (LUS) and focused cardiac ultrasound (FoCUS) as a clinical adjunct has played a significant role in triaging, diagnosis and medical management of COVID-19 patients. The expert panel from 27 countries and 6 continents with considerable experience of direct application of PoCUS on COVID-19 patients presents evidence-based consensus using GRADE methodology for the quality of evidence and an expedited, modified-Delphi process for the strength of expert consensus. The use of ultrasound is suggested in many clinical situations related to respiratory, cardiovascular and thromboembolic aspects of COVID-19, comparing well with other imaging modalities. The limitations due to insufficient data are highlighted as opportunities for future research.

[Cardiac Strangulation Induced by Epicardial Pacemaker Leads Causing Heart Failure;Report of a Case].

A 5-year-old girl has a history of epicardial VVI-pacemaker implantation due to congenital heart block at the age of 2 months. Five years later, she developed heart failure at the same time of battery depletion. The chest X-ray indicated the loop formation of the epicardial leads and the echocardiogram demonstrated paradoxical movement of ventricles. The 3-dimensional computed tomography finally revealed strangulation of biventricular apex caused by loop of the leads. She underwent reoperation. Cardiac strangulation was relieved by total removal of the loop and repositioning of right atrial and ventricular electrodes in a gentle curve of the leads. She was discharged and doing well. Cardiac strangulation is a rare, but it can be lethal. Therefore epicardial pacemaker leads should not be positioned around the ventricle with excessive redundancy.

[Point-of-Care Ultrasonography Developed in Emergency and Critical Care Medicine and Its Application to the Lungs].

The performance of ultrasound (US) devices is improving every year, and more advanced US is being conducted in laboratory settings with high-end machines. Meanwhile, portable US devices, which have become less expensive and of a higher quality, have come into widespread use at bedsides in emergency rooms, intensive care units, and general wards. In recent years, the concept of point-of-care ultrasonography (POCUS) has been widely accepted. POCUS performed at the bedside in acute care settings has value if it gives clinicians useful clinical information in a short time. The findings are interpreted based on the vital signs, history, and physical examination during the scan, and the interpretations are rapidly applied for decision-making. In this article, we review the findings of lung US, which is one of the main fields in POCUS, as well as diagnoses and evaluations of pneumothorax and pulmonary edema in acute care settings.

Transabdominal ultrasound-guided urethral catheterization with transrectal pressure.

BACKGROUND: Occasionally, difficulty with standard urethral catheterization is encountered. OBJECTIVE: We conducted a pilot study to evaluate whether transabdominal ultrasound (TAUS) showed the tip of a urethral catheter and whether TAUS-guided catheterization with transrectal pressure is successful in male patients in whom performing standard catheterization is difficult. METHODS: The eligible study participants included adult male patients in whom standard catheterization failed in our emergency department or who were transferred from other facilities after failure of catheterization and subsequent urethral bleeding. The enrolled patients included those in whom the tip of a catheter could not be advanced through the posterior and bulbar urethra judging from the inserted length. First, an emergency nurse advanced a catheter until the progress was obstructed. Next, an emergency physician performed TAUS to detect the tip of the catheter. If the tip was detected, the physician inserted the index finger into the rectum and kept pushing the site of the obstruction. After following these procedures, the nurse again advanced the catheter. RESULTS: Six patients were enrolled. The tip of a catheter was detected in the urethra or the false passage using TAUS in 4 of the 6 patients. In these 4 patients, the curve of the urethra became gentle or the false passage was compressed by transrectal pressure and the tip was advanced smoothly to the bladder. CONCLUSIONS: In some male patients in whom performing standard urethral catheterization is difficult, TAUS reveals the tip of the catheter and TAUS-guided catheterization with transrectal pressure can be safe and useful.

Guidance for clinical practice using emergency and point-of-care ultrasonography.

Owing to the miniaturization of diagnostic ultrasound scanners and their spread of their bedside use, ultrasonography has been actively utilized in emergency situations. Ultrasonography performed by medical personnel with focused approaches at the bedside for clinical decision-making and improving the quality of invasive procedures is now called point-of-care ultrasonography (POCUS). The concept of POCUS has spread worldwide; however, in Japan, formal clinical guidance concerning POCUS is lacking, except for the application of focused assessment with sonography for trauma (FAST) and ultrasound-guided central venous cannulation. The Committee for the Promotion of POCUS in the Japanese Association for Acute Medicine (JAAM) has often discussed improving the quality of acute care using POCUS, and the "Clinical Guidance for Emergency and Point-of-Care Ultrasonography" was finally established with the endorsement of JAAM. The background, targets for acute care physicians, rationale based on published articles, and integrated application were mentioned in this guidance. The core points include the fundamental principles of ultrasound, airway, chest, cardiac, abdominal, and deep venous ultrasound, ultrasound-guided procedures, and the usage of ultrasound based on symptoms. Additional points, which are currently being considered as potential core points in the future, have also been widely mentioned. This guidance describes the overview and future direction of ultrasonography for acute care physicians and can be utilized for emergency ultrasound education. We hope this guidance will contribute to the effective use of ultrasonography in acute care settings in Japan.

Self-learning followed by telepresence instruction of focused cardiac ultrasound with a handheld device for medical students: a preliminary study.

PURPOSE: This study aimed to assess the feasibility and efficiency of self-learning with or without self-training (subjects performed scans on themselves) and telepresence instruction in focused cardiac ultrasound (FOCUS) education for medical students. METHODS: This study included 24 medical students. The participants initially completed a written pre-test and were randomized into a video lecture (participants watched a video lecture) or self-training (participants watched a video lecture and self-performed FOCUS) group. After finishing self-learning, they completed a written post-test. Then they undertook a skill pre-test and a first perception survey. Telepresence instruction was then provided. Finally, they undertook a skill post-test and a second perception survey. RESULTS: The written post-test total scores were significantly higher than the pre-test total scores (P < 0.001). In the skill pre-test, the scores for the video lecture and self-training groups were not significantly different (P = 0.542). The skill post-test total scores were significantly higher than the skill pre-test total scores (P = 0.008). Forty-two percent of the video lecture group participants agreed that the video lecture was effective preparation for the skill pre-test, while all participants in the same group agreed that the combination of the video lecture and telepresence instruction was effective preparation for the skill post-test. CONCLUSION: This study demonstrated the feasibility and efficiency of self-learning followed by telepresence instruction on FOCUS for medical students.

The Mechanisms Underlying Vertical Artifacts in Lung Ultrasound and Their Proper Utilization for the Evaluation of Cardiogenic Pulmonary Edema.

The recent advances in lung ultrasound for the diagnosis of cardiogenic pulmonary edema are outstanding; however, the mechanism of vertical artifacts known as B-lines used for the diagnosis has not yet been fully elucidated. The theory of "acoustic trap" is useful when considering the generation of vertical artifacts. Basic research in several studies supports the theory. Published studies with pilot experiments indicate that clarification of the relationship between the length and intensity of vertical artifacts and physical or acoustic composition of sources may be useful for differentiating cardiogenic pulmonary edema from lung diseases. There is no international consensus with regard to the optimal settings of ultrasound machines even though their contribution to the configuration of vertical artifacts is evident. In the clinical setting, the configuration is detrimentally affected by the use of spatial compound imaging, the placement of the focal point at a deep level, and the use of multiple focus. Simple educational materials using a glass microscope slide also show the non-negligible impact of the ultrasound machine settings on the morphology of vertical artifacts.

The effect of attenuation inside the acoustic traps on the configuration of vertical artifacts in lung ultrasound: an experimental study with simple models.

PURPOSE: Using simple experimental models for lung ultrasound, we evaluated the relationship of the attenuation inside the sources of vertical artifacts to the echo intensity and attenuation of artifacts. METHODS: As sources of artifacts, we made 10 different hemispherical gel objects with two different mediums (pure agar or agar containing graphite with an attenuation coefficient of 0.5 dB/cm · MHz) and five different diameters (3.6, 5.6, 7.5, 9.5, or 11.4 mm). Ten of each hemispherical gel object were prepared for the statistical analyses. Each object was placed onto a chest wall phantom as the plane of the hemisphere was placed in an upward position. The echo intensity and attenuation of the artifact generated from each object was measured and compared. RESULTS: For all sizes, the intensity and attenuation of the artifacts in the objects made of agar containing graphite were significantly lower and larger, respectively, than those in the objects made of pure agar. In the objects containing graphite, the intensity decreased when the frequency was changed from 5 to 9 MHz. CONCLUSION: Based on this experiment, assessing the intensity and attenuation of vertical artifacts may help estimate the physical composition of sources of vertical artifacts in lung ultrasound.

Assessment of the risk of disease transmission during fine-needle aspiration cytology under ultrasound guidance by visualization of droplet and aerosol formation.

PURPOSE: Fine-needle aspiration cytology (FNAC) under ultrasound guidance is clinically useful, but there is a risk of spreading infection by generating droplets of contaminated fluids during the procedure. Risk assessment to better control infection remains to be established. The aim of this study was to estimate infection risks during FNAC by visualization of droplet production and deposition using a simulation model. METHODS: The simulation comprised a puncture needle, a device for holding the needle, and a fluid specimen containing fluorescent particles as a model. Simulating each step of FNAC (removal of the inner and outer cylinder and transferring the specimen onto a glass slide), the generation and deposition of droplets were visualized using a laser. RESULTS: After removal of the inner cylinder, an aerosol of droplets in the air surrounding the needle was observed. After removal of the outer cylinder, several large droplets precipitating onto the circumjacent surface were observed. From the beginning of transferring the specimen, a large amount of sizeable droplets first moving away and then precipitating was observed, followed by the production of a cluster of fine droplets drifting and spreading through the air. CONCLUSIONS: Here, the generation of droplets at each step of FNAC, precipitation of large droplets onto the circumjacent surface, and drifting and spreading through the air of fine droplets was visualized. These results emphasize the need for precautions to prevent the transmission of infectious agents during FNAC.

Ultrasonography in undergraduate medical education: a comprehensive review and the education program implemented at Jichi Medical University.

The concept of point-of-care ultrasound has been widely accepted owing to the development of portable ultrasound systems and growing body of evidence concerning its extensive utility. Thus, it is reasonable to suggest that training to use this modality be included in undergraduate medical education. Training in ultrasonography helps medical students learn basic subjects such as anatomy and physiology, improve their physical examination skills, and acquire diagnostic and procedural skills. Technological advances such as simulators, affordable handheld devices, and tele-ultrasound systems can facilitate undergraduate ultrasound education. Several reports have indicated that some medical schools have integrated ultrasound training into their undergraduate medical curricula. Jichi Medical University in Japan has been providing medical students with ultrasound education to fulfill part of its mission to provide medical care to rural areas. Vertical integration of ultrasound education into a curriculum seems reasonable to ensure skill retention and improvement. However, several issues have hampered the integration of ultrasound into medical education, including a lack of trained faculty, the need to recruit human models, requisition of ultrasound machines for training, and limited curricular space; proposed solutions include peer teaching, students as trained simulated patients, the development of more affordable handheld devices, and a flipped classroom approach with access to an e-learning platform, respectively. A curriculum should be developed through multidisciplinary and bottom-up student-initiated approaches. Formulating national and international consensuses concerning the milestones and curricula can promote the incorporation of ultrasound training into undergraduate medical education at the national level.

Simple Experimental Models for Elucidating the Mechanism Underlying Vertical Artifacts in Lung Ultrasound: Tools for Revisiting B-Lines.

Using simple experimental models, we evaluated the generation, configuration and echo intensity of vertical artifacts by varying the point or plane of contact and height of objects that correspond to sources of vertical artifacts in the subpleural space. We used an ultrasound gel spot to imitate the source and a block of bacon as a chest wall phantom. As the size of the point of contact between the gel spot on the polypropylene sheet and the phantom decreased by peeling the sheet, a vertical artifact measuring ≤1 cm was generated and/or extended deeper, finally reaching 10 cm in depth. Next, objects of different shapes made using gel balls were used to observe the generation of artifacts and measure and compare the echo intensity. For a given shape, the intensity was markedly higher in one model with the point of contact than in the other model with the plane of contact. With the same point or plane of contact, the echo intensity was higher in the taller model. The size of the point or plane of contact and height of the source were observed to be key factors in the generation, length and echo intensity of the artifacts.

Point-of-care lung ultrasound for the assessment of pneumonia: a narrative review in the COVID-19 era.

In the coronavirus disease-2019 (COVID-19) era, point-of-care lung ultrasound (LUS) has attracted increased attention. Prospective studies on LUS for the assessment of pneumonia in adult patients were extensively carried out for more than 10 years before this era. None of these prospective studies attempted to differentiate bacterial and viral pneumonia in adult patients using LUS. The majority of studies considered the LUS examination to be positive if sonographic consolidations or multiple B-lines were observed. Significant differences existed in the accuracy of these studies. Some studies revealed that LUS showed superior sensitivity to chest X-ray. These results indicate that point-of-care LUS has the potential to be an initial imaging modality for the diagnosis of pneumonia. The LUS diagnosis of ventilator-associated pneumonia in intensive care units is more challenging in comparison with the diagnosis of community-acquired pneumonia in emergency departments due to the limited access to the mechanically ventilated patients and the high prevalence of atelectasis. However, several studies have demonstrated that the combination of LUS findings with other clinical markers improved the diagnostic accuracy. In the COVID-19 era, many case reports and small observational studies on COVID-19 pneumonia have been published in a short period. Multiple B-lines were the most common and consistent finding in COVID-19 pneumonia. Serial LUS showed the deterioration of the disease. The knowledge and ideas on the application of LUS in the management of pneumonia that are expected to accumulate in the COVID-19 era may provide us with clues regarding more appropriate management.

A case of cardiopulmonary arrest due to left ventricular free wall rupture successfully treated with sutureless repair supported by venoarterial extracorporeal membrane oxygenation.

Extracorporeal membrane oxygenation for cardiopulmonary arrest due to left ventricular free wall rupture is considered effective, because it enables rapid cardiopulmonary support and introduction of targeted temperature management.

Ultrasonography for ureteral stone detection in patients with or without caliceal dilatation.

PURPOSE: To evaluate the relationship between the degree of hydronephrosis and the detection rates of ureteral stones with ultrasonography (US). METHODS: Of 250 consecutive patients with suspected ureterolithiasis, 214 who were diagnosed with ureterolithiasis were enrolled in this study. First, both kidneys were observed by US to evaluate the intrarenal collecting systems. Thereafter, the possible course of the ureters and the bladder were searched to find any stones. RESULTS: Stones were clearly observed in 80 (73%) of 109 patients with caliceal dilatation, whereas stones were clearly observed in 46 (44%) of 105 patients without dilatation (P < 0.05). Of the former 80 patients, 31 (39%) had stones in the ureterovesical junction (UVJ), whereas 51 (64%) had stones in the more proximal ureter. Of the latter 46 patients, 37 (80%) had stones in the UVJ or the bladder, whereas 9 (20%) had stones in the more proximal ureter. CONCLUSION: The US detection rate of ureteral stones was high in patients with caliceal dilatation. The whole ureter should be scanned in patients with caliceal dilatation for detection of ureteral stones. Even when patients have no caliceal dilatation, it is still considered to be useful to scan the UVJ and the bladder.

Basic point-of-care ultrasound framework based on the airway, breathing, and circulation approach for the initial management of shock and dyspnea.

Ultrasound (US) carried out and interpreted by clinicians at the bedside is now called point-of-care US (POCUS). Clinical studies on POCUS have been carried out based on the ideas of "creation", "extraction", and "combination". "Creation" refers to findings for the upper airway and lung being obtained at the bedside. "Extraction" refers to findings suitable for POCUS being extracted from comprehensive US, including echocardiography, abdominal US, and whole-leg US. "Combination" refers to these POCUS applications being combined for the comprehensive assessment of patients with trauma, shock, or dyspnea. Emergency and critical care physicians have many opportunities to encounter trauma or non-trauma patients with shock, dyspnea, or both. Furthermore, the scope of POCUS includes many diseases and injuries that present with both shock and dyspnea. Therefore, we propose a basic POCUS framework based on the systematic airway, breathing, and circulation approach for the initial management of shock and dyspnea in adult patients. In this article, we update and review each application of POCUS and their combination in this framework. Furthermore, we propose the practical usage of the framework based on clinical presentations to improve the management of shock and dyspnea.

Ultrasonic B-Line-Like Artifacts Generated with Simple Experimental Models Provide Clues to Solve Key Issues in B-Lines.

We evaluated the influence of settings on an ultrasound machine on the configuration of a single B-line in a healthy model and analyzed the frequency spectrum. We also devised simple experimental models that generated B-line-like artifacts and evaluated the influence of the machine settings on the configuration. Visualization of B-lines was affected by the spatial compound imaging, the focal zone and the frequency. The spectra of both the B-line and non-B-line region at the same depth had the same center frequency and bandwidth. B-line-like artifact was generated by a spindle-shaped juice sac of a mandarin orange, an edible string-shaped glucomannan gel, glass beads and glass plates. Visualization of B-line-like artifacts was also affected by these machine settings. Our study indicated that the physical basis of some B-lines is multiple reverberations. B-line-like artifacts provide clues for solving key issues, such as the physical basis of B-lines, the sonographic-pathologic correlation in B-lines and the effects of machine settings.