Gastric Point of Care Ultrasound in Adults: Image Acquisition and Interpretation.

Over the past two decades, diagnostic point-of-care ultrasound (POCUS) has emerged as a rapid and non-invasive bedside tool for addressing clinical inquiries related to gastric content. One emerging concern pertains to patients about to undergo sedation and/or endotracheal intubation: the elevated risk of aspiration from the patient's stomach contents. Aspiration of gastric contents into the lungs poses a serious and potentially life-threatening complication. This occurs more frequently when the stomach is considered "full" and can be affected by the techniques employed for airway management, making it potentially preventable. To mitigate the risk of peri-procedural aspiration, two distinct medical specialties (anesthesiology and critical care medicine) have independently developed techniques to utilize ultrasonography for identifying patients requiring "full stomach" precautions. Due to these separate specialties, the work of each group remains relatively unfamiliar outside its respective field. This article presents descriptions of both techniques for gastric ultrasound. Furthermore, it explains how these approaches can complement each other when one of them falls short. Regarding image acquisition, the article covers the following topics: indications and contraindications, selection of the appropriate probe, patient positioning, and troubleshooting. The article also delves into image interpretation, complete with example images. Additionally, it demonstrates how one of the two techniques can be employed to estimate gastric fluid volume. Lastly, the article briefly discusses medical decision-making based on the findings of this examination.

Focused Assessment with Sonography for Trauma (FAST) Exam: Image Acquisition.

Over the past twenty years, the Focused Assessment with Sonography for Trauma (FAST) exam has transformed the care of patients presenting with a combination of trauma (blunt or penetrating) and hypotension. In these hemodynamically unstable trauma patients, the FAST exam permits rapid and noninvasive screening for free pericardial or peritoneal fluid, the latter of which implicates intra-abdominal injury as a likely contributor to the hypotension and justifies emergent abdominal surgical exploration. Further, the abdominal portion of the FAST exam can also be used outside of the trauma setting to screen for free peritoneal fluid in patients who become hemodynamically unstable in any context, including after procedures that may inadvertently injure abdominal organs. These "non-trauma" situations of hemodynamic instability are often triaged by providers from specialties other than emergency medicine or trauma surgery who are not familiar with the FAST exam. Therefore, there is a need to promulgate knowledge about the FAST exam to all clinicians caring for critically ill patients. Toward this end, this article describes FAST exam image acquisition: patient positioning, transducer selection, image optimization, and exam limitations. Since the free fluid is likely to be found in specific anatomic locations that are unique for each canonical FAST exam view, this work centers on the unique image acquisition considerations for each window: subcostal, right upper quadrant, left upper quadrant, and pelvis.

Point-of-Care Lung Ultrasound in Adults: Image Acquisition.

Consultative ultrasound performed by radiologists has traditionally not been used for imaging the lungs, as the lungs' air-filled nature normally prevents direct visualization of the lung parenchyma. When showing the lung parenchyma, ultrasound typically generates a number of non-anatomic artifacts. However, over the past several decades, these artifacts have been studied by diagnostic point-of-care ultrasound (POCUS) practitioners, who have identified findings that have value in narrowing the differential diagnoses of cardiopulmonary dysfunction. For instance, in patients presenting with dyspnea, lung POCUS is superior to chest radiography (CXR) for the diagnosis of pneumothorax, pulmonary edema, lung consolidations, and pleural effusions. Despite its known diagnostic value, the utilization of lung POCUS in clinical medicine remains variable, in part because training in this modality across hospitals remains inconsistent. To address this educational gap, this narrative review describes lung POCUS image acquisition in adults, including patient positioning, transducer selection, probe placement, acquisition sequence, and image optimization.

Point-Of-Care Ultrasound Screening for Proximal Lower Extremity Deep Venous Thrombosis.

Acute lower extremity deep venous thrombosis (DVT) is a serious vascular disorder that requires accurate and early diagnosis to prevent life-threatening sequelae. While whole leg compression ultrasound with color and spectral Doppler is commonly performed in radiology and vascular labs, point-of-care ultrasound (POCUS) is becoming more common in the acute care setting. Providers appropriately trained in focused POCUS can perform a rapid bedside examination with high sensitivity and specificity in critically ill patients. This paper describes a simplified yet validated approach to POCUS by describing a three-zone protocol for lower extremity DVT POCUS image acquisition. The protocol explains the steps in obtaining vascular images at six compression points in the lower extremity. Beginning at the level of the proximal thigh and moving distally to the popliteal space, the protocol guides the user through each of the compression points in a stepwise manner: from the common femoral vein to the femoral and deep femoral vein bifurcation, and, finally, to the popliteal vein. Further, a visual aid is provided that may assist providers during real-time image acquisition. The goal in presenting this protocol is to help make proximal lower extremity DVT exams more accessible and efficient for POCUS users at the patient's bedside.

Refractory Hypotension During Implantation of a 70 mL Total Artificial Heart in a Patient With Pectus Excavatum: A Case Report.

The Syncardia total artificial heart system is the only commercially approved durable device for treating biventricular heart failure patients awaiting heart transplantation. Conventionally, the Syncardia total artificial heart system is implanted based on the distance from the anterior aspect of the 10th thoracic vertebra to the sternum and the patient's body surface area. However, this criterion does not account for chest wall musculoskeletal deformities. This case report describes a patient with a pectus excavatum who developed compression of the inferior vena cava after Syncardia total artificial heart implantation and how transesophageal echocardiography guided chest wall surgery to accommodate the total artificial heart system.

Image Acquisition Method for the Sonographic Assessment of the Inferior Vena Cava.

Over the past several decades, clinicians have incorporated several applications of diagnostic point-of-care ultrasound (POCUS) into medical decision-making. Among the applications of POCUS, imaging the inferior vena cava (IVC) is practiced by a wide variety of specialties, such as nephrology, emergency medicine, internal medicine, critical care, anesthesiology, pulmonology, and cardiology. Although each specialty uses IVC data in slightly different ways, most medical specialties, at minimum, attempt to use IVC data to make predictions about intravascular volume status. While the relationship between IVC sonographic data and intravascular volume status is complex and highly context-dependent, all clinicians should collect the sonographic data in standardized ways to ensure repeatability. This paper describes standardized IVC image acquisition including patient positioning, transducer selection, probe placement, image optimization, and the pitfalls and limitations of IVC sonographic imaging. This paper also describes the commonly performed anterior IVC long-axis view and three other views of the IVC that can each provide helpful diagnostic information when the anterior long-axis view is difficult to obtain or interpret.

The role of extracorporeal membrane oxygenation in COVID-19.

An extracorporeal membrane oxygenation (ECMO) program is an important component in the management of patients with COVID-19, but it is imperative to implement a system that is well-supported by the institution and staffed with well-trained clinicians to both optimize patient outcomes and to keep providers safe. There are many unknowns related to COVID-19, and one of the most challenging aspects for clinicians is the lack of predictive knowledge as to why some patients fail medical therapy and require advanced support such as ECMO. These factors can create challenges during a time of resource scarcity and interruptions in the supply chain. In the current environment, in which resources are limited and an ongoing pandemic, healthcare practitioners need to focus on evidence-based best practice for supportive care of patients with COVID-19 in refractory respiratory or cardiac failure. with As experience is gained, a greater understanding will develop in this cohort of patients regarding need and timing of ECMO. As this pandemic continues, it will be important to compile and analyze multicentered data pertaining to patient-specific outcomes to help guide clinicians caring for patients with COVID-19 undergoing ECMO support. In this paper, the authors demonstrate the strategies utilized by a major quaternary care center in the utilization and management of ECMO for patients with COVID-19.

Reduced Effective Oxygen Delivery and Ventilation with a Surgical Facemask Placed under Compared to over an Oxygen Mask: A Comparative Study.

OBJECTIVES: Consensus guidelines for perioperative anesthesia management during the COVID-19 pandemic recommend that patients wear a facemask in addition to their oxygen mask or nasal cannulae following tracheal extubation, where this is practical. The effects on effective oxygen delivery and ventilation of a surgical facemask under compared to over an oxygen (O2) mask are unclear. DESIGN: Single-center, comparative pilot study. Setting. Endoscopy procedure room at a major academic hospital. SUBJECTS: Five healthy anesthesiologists. Interventions. Using a carbon dioxide (CO2) sampling line positioned at the lips, the fraction of inspired O2 (FiO2), fraction of expiratory O2 (FeO2), expiratory end-tidal CO2 (EtCO2), and respiratory rate (RR) were measured under the following conditions: (1) a surgical facemask only, (2) a surgical facemask under an O2 mask, (3) an O2 mask only, and (4) a surgical facemask over an O2 mask. Measurements and Main Results. The sampled fractional expired oxygen (FeO2) at the lips was significantly lower when the surgical facemask was under compared to when over the O2 mask (27.9± 1.68 vs. 49.9 ± 6.27, p = 0.001), while there was no significant difference in inspired oxygen (FiO2). The sampled expiratory EtCO2 was significantly higher when the surgical facemask was under the O2 mask compared to when over the O2 mask (28.3 ± 8.5 vs. 23.5 ± 7.6, p = 0.026). The RR was not significantly different when the surgical facemask was under compared to over the O2 mask. CONCLUSIONS: Effective oxygen delivery and ventilation was reduced (lower FeO2 and increased EtCO2) when a surgical facemask was placed under compared to over an O2 mask.

Biplane Imaging Versus Standard Transverse Single-Plane Imaging for Ultrasound-Guided Peripheral Intravenous Access: A Prospective Controlled Crossover Trial.

Obtaining peripheral IV access in critically ill patients is often challenging especially for novice providers. The availability of biplane imaging for ultrasound guided peripheral access has the potential to improve successful venous cannulation compared with standard plane imaging. DESIGN: Single-center quasi-randomized (alternate allocation) crossover trial. SETTING: Surgical ICU at the Massachusetts General Hospital. SUBJECTS: Twenty surgical ICU nurses with no prior experience using ultrasound for peripheral IV were enrolled. INTERVENTIONS: All participants viewed instructional videos on single-plane and biplane imaging for peripheral IV insertion. The participants were then quasi-randomly assigned to use either single-plane or biplane imaging for peripheral IV insertion using a phantom model. The time to catheter completion, successful lumen cannulation, and attempts in which the needle was observed to go through the back wall of the vessel were recorded for each of the three attempts. The following day the participants repeated the peripheral IV insertion with the alternate imaging modality. MEASUREMENTS AND MAIN RESULTS: Biplane imaging compared with single-plane imaging was associated with a significantly greater overall success rate (78.3% ± 22.4% vs 41.7% ± 26%; p < 0.001), higher first-pass success rate (80% ± 41% vs 45% ± 51%; p = 0.015), faster cannulation times (27.8 ± 14.8 vs 36.6 ± 15.8 s; p = 0.003), and reduced frequency of backwall perforations (0.4 ± 0.7 vs 1.5 ± 0.8; p < 0.001). CONCLUSIONS: This proof-of-principle study demonstrates that the biplane ultrasound imaging approach for vessel cannulation resulted in an overall faster, more successful, and safer peripheral IV access than the standard single-plane transverse approach when performed by novice ultrasound users.

Biplane Imaging Using Portable Ultrasound Devices for Vascular Access.

The use of ultrasound guidance for the placement of difficult IVs, arterial lines, and central venous access has become the standard of care. While imaging quality has improved over the last two decades, the lack of affordability, availability, and training have been major limitations in its routine clinical use. We detail the first reported use of biplane imaging using a portable ultrasound probe for difficult vascular access to increase first past success, efficiency, safety, and sterility during the coronavirus disease 2019 (COVID-19) pandemic.

Environments, processes, and outcomes - using the LEPO framework to examine medical student learning preferences with traditional and electronic resources.

Changes in medical student learning preferences help drive innovation in teaching and require schools and commercial resources to quickly adapt. However, few studies have detailed the relationship of learner preferences to the environment and teaching modalities used in the pre-clerkship years, nor do they incorporate third-party resources. Our study attempts to analyze learner preferences by comparing the use of traditional and third-party resources. In 2017-18, a survey was distributed to medical students and residents at two accredited medical schools. Participants noted preferred styles of learning regarding lecture duration, timing, location, format, third-party resources, learner types and USMLE Step 1 scores. The 'Learning Environment, Learning Processes, and Learning Outcomes' (LEPO) framework [5] was used to examine learner preferences, with responses compared using the Mann-Whitney U and two proportion z-tests. A total of 329 respondents completed the survey: 62.7% medical students and 37.3% residents. The majority of participants identified their learning style by Kolb [6] as converging (33.0%) or accommodating (39.2%). Students preferred lectures 30-40 minutes long (43.3%), during morning hours (54.2%), in their own homes (52.0%), via online lectures with simultaneous drawings (56.0%), and classroom/podcast lectures with PowerPoint® presentations (54.3%). Overall, students rated third-party resource characteristics higher than traditional curricula, including effectiveness of teachers, length, quality, time of day, and venue (p < 0.001), but also preferred small group formats. Students reported animated videos (46.6%) and simultaneous drawings (46.5%) as the most effective means of retaining information. Understanding changing learner preferences is important in creating optimal curricula for today's students. Using the LEPO framework, this study identifies critical preferences in successfully teaching medical students, inclusive of commercial and traditional resources. These results can also help guide changes in pedagogy necessary due to the more recent COVID-19 pandemic.

The Vacuum Assisted Negative Pressure Isolation Hood (VANISH) System: Novel Application of the Stryker Neptune™ Suction Machine to Create COVID-19 Negative Pressure Isolation Environments.

Coronavirus disease 2019 (COVID-19) may remain viable in the air for up to three hours, placing health care workers in close proximity to aerosolizing procedures particularly at high risk for infection. This combined with the drastic shortage of negative pressure rooms hospitals worldwide has led to the rapid innovation of novel biohazard isolation hoods, which can be adapted to create negative pressure isolation environments around the patient's airway using the hospital wall suction, which carries many limitations, including weaker suction capabilities, single patient use, and immobility. Here, we report our Vacuum Assisted Negative Pressure Isolation Hood (VANISH) system that uses a mobile and readily available in most hospital operating rooms Stryker Neptune™ (Stryker Corporation, Kalamazoo, Michigan) high-powered suction system to more effectively create a negative pressure biohazard isolation environment. VANISH has been utilized regularly in an anesthesia practice of 30+ providers and, to date, there have been no documented COVID-19 infections.

Personal Protective Equipment N95 Facemask Shortage Quick Fix: The Modified Airway From VEntilatoR Circuit (MAVerIC).

We are in a crisis where healthcare providers on the frontlines are running out of the appropriate personal protective equipment including N95 masks and power air-purifying respirators. Here, we propose a makeshift filter mask that we call the Modified Airway from VEntilatoR Circuit (MAVerIC) that can be assembled within seconds using widely available supplies routinely utilized by anesthesia providers in the operating room to provide practitioners on the frontlines with the high standard of protection of a N95 mask during the coronavirus disease 2019 (COVID-19) pandemic, and can be easily quantitatively "fit tested" to ensure no significant leak to optimize safety and efficacy.

Application of Lung Ultrasound During the COVID-19 Pandemic: A Narrative Review.

This review highlights the ultrasound findings reported from a number of studies and case reports and discusses the unifying findings from coronavirus disease (COVID-19) patients and from the avian (H7N9) and H1N1 influenza epidemics. We discuss the potential role for portable point-of-care ultrasound (PPOCUS) as a safe and effective bedside option in the initial evaluation, management, and monitoring of disease progression in patients with confirmed or suspected COVID-19 infection.