Ten Influential Point-of-Care Ultrasound Papers: 2023 in Review.

In an effort to help keep busy clinicians up to date with the latest ultrasound research, our group of experts has selected 10 influential papers from the past 12 months and provided a short summary of each. We hope to provide emergency physicians, intensivists, and other acute care providers with a succinct update concerning some key areas of ultrasound interest.

High and intermediate risk pulmonary embolism in the ICU.

Pulmonary embolism (PE) is a common and important medical emergency, encountered by clinicians across all acute care specialties. PE is a relatively uncommon cause of direct admission to the intensive care unit (ICU), but these patients are at high risk of death. More commonly, patients admitted to ICU develop PE as a complication of an unrelated acute illness. This paper reviews the epidemiology, diagnosis, risk stratification, and particularly the management of PE from a critical care perspective. Issues around prevention, anticoagulation, fibrinolysis, catheter-based techniques, surgical embolectomy, and extracorporeal support are discussed.

Association of age with death and withdrawal of life-sustaining therapy after severe traumatic brain injury.

BACKGROUND: Compared to younger age, older age (≥ 65 yr) is associated with worse outcomes after severe traumatic brain injury (TBI). We sought to describe the association of older age with in-hospital death and aggressiveness of intervention. METHODS: We conducted a retrospective cohort study of adult (age ≥ 16 yr) patients with severe TBI admitted to a single academic tertiary care neurotrauma centre between January 2014 and December 2015. We collected data through chart review as well as from our institutional administrative database. We provided descriptive statistics and used multivariable logistic regression to evaluate the independent association of age with the primary outcome, in-hospital death. The secondary outcome was early withdrawal of life-sustaining therapy. RESULTS: There were 126 adult patients (median age 67 yr [Q1-Q3, 33-80 yr]) with severe TBI during the study period who met our eligibility criteria. The most common mechanism was high-velocity blunt injury (55 patients [43.6%]). The median Marshall score was 4 (Q1-Q3, 2-6), and the median Injury Severity Score was 26 (Q1-Q3, 25-35). After controlling for confounders including clinical frailty, pre-existing comorbidity, injury severity, Marshall score and neurologic examination at admission, we observed that older patients were more likely than younger patients to die in hospital (odds ratio 5.10, 95% confidence interval 1.65-15.78). Older patients were also more likely to experience early withdrawal of life-sustaining therapy and less likely to receive invasive interventions. CONCLUSION: After controlling for confounding factors relevant to older patients, we observed that age was an important and independent predictor of in-hospital death and early withdrawal of life-sustaining therapy. The mechanism by which age influences clinical decision-making independent of global and neurologic injury severity, clinical frailty and comorbidities remains unclear.

Ten Influential Point-of-Care Ultrasound Papers: 2022 in Review.

Keeping up with the latest developments in the point-of-care ultrasound (POCUS) literature is challenging, as with any area of medicine. Our group of POCUS experts has selected 10 influential papers from the past 12 months and provided a short summary of each. We hope to provide emergency physicians, intensivists, and other acute care providers with a succinct update concerning some key areas of ultrasound interest.

Agitated Saline Contrast Injection in Patients with Severe Hypoxemia.

The use of agitated saline contrast (ASC) during echocardiographic examinations is a well-established practice, most commonly performed to identify atrial septal abnormalities in the context of stroke. In the intensive care unit, this technique may be employed to identify anatomic right-to-left shunts (either intracardiac or transpulmonary) that may be contributing to hypoxemic respiratory failure. This narrative review will describe the technique of ASC injection, summarize clinical scenarios where it may be useful, and review the strengths and limitations of the tool.

Ten Influential Point-of-Care Ultrasound Papers: 2021 in Review.

The ongoing rapid expansion of point-of-care ultrasound (POCUS) and its corresponding supporting literature leaves the frontline clinician in a difficult position when trying to keep abreast of the latest developments. Our group of POCUS experts has selected ten influential POCUS-related papers from the past twelve months and provided a short summary of each. Our aim is to give to emergency physicians, intensivists, and other acute care providers key information, helping them to keep up to date on rapidly evolving POCUS literature.

Setting and Titrating Positive End-Expiratory Pressure.

Although maintaining some amount of positive end-expiratory pressure (PEEP) seems essential, selecting and titrating a specific level for patients with ARDS remains challenging despite extensive research on the subject. Although an "open lung" approach to ventilation is popular and has some degree of biological plausibility, it is not without risk. Furthermore, there is no clear evidence-based guidance regarding initial PEEP settings or how to titrate them early in the course of the illness. Many busy clinicians use a "one-size-fits-all" approach based on local medical culture, but an individualized approach has the potential to offer significant benefit. Here we present a pragmatic approach based on simple measurements available on all ventilators, focused on achieving balance between the potential risks and benefits of PEEP. Acknowledging "best PEEP" as an impossible goal, we aim for a straightforward method to achieve "better PEEP."

Stroke Volume Determination by Echocardiography.

Basic critical care echocardiography emphasizes two-dimensional (2D) findings, such as ventricular function, inferior vena cava size, and pericardial assessment, while generally excluding quantitative findings and Doppler-based techniques. Although this approach offers advantages, including efficiency and expedited training, it complicates attempts to understand the hemodynamic importance of any 2D abnormalities detected. Stroke volume (SV), as the summative event of the cardiac cycle, is the most pragmatic available indicator through which a clinician can rapidly determine, no matter the 2D findings, whether aberrant cardiac physiology is contributing to the state of shock. An estimate of SV allows 2D findings to be placed into better context in terms of both hemodynamic significance and acuity. This article describes the technique of SV determination, reviews common confounding factors and pitfalls, and suggests a systematic approach for using SV measurements to help integrate important 2D findings into the clinical context.

Risks and Benefits of Fluid Administration as Assessed by Ultrasound.

For patients in shock, decisions regarding administering or withholding IV fluids are both difficult and important. Although a strategy of relatively liberal fluid administration has traditionally been popular, recent trial results suggest that moving to a more fluid-restrictive approach may be prudent. The goal of this article was to outline how whole-body point-of-care ultrasound can help clarify both the possible benefits and the potential risks of fluid administration, aiding in the risk/benefit calculations that should always accompany fluid-related decisions.

Ultrasound Assessment of the Inferior Vena Cava for Fluid Responsiveness: Making the Case for Skepticism.

Determining whether a patient in shock is in a state of fluid responsiveness (FR) has long been the Holy Grail for clinicians who care for acutely ill patients. While various tools have been put forth as solutions to this important problem, ultrasound assessment of the inferior vena cava has received particular attention of late. Dozens of studies have examined its ability to determine whether a patient should receive volume expansion, and general enthusiasm has been strengthened by the fact that it is easy to perform and non-invasive, unlike many competing FR tests. A deeper examination of the technique, however, reveals important concerns regarding inaccuracies in measurement and a high prevalence of confounding factors. Furthermore, a detailed review of the evidence (small individual studies, multiple meta-analyses, and a single large trial) reveals that the tool performs poorly in general and is unlikely to be helpful at the bedside in circumstances where genuine clinical uncertainty exists.

Lung Ultrasound for Patients With Coronavirus Disease 2019 Pulmonary Disease.

Given the general utility of lung ultrasound for the evaluation of respiratory failure in acutely ill patients, it is logical to consider its specific advantages in coronavirus disease 2019-related pulmonary disease. The authors, representing the extensive experience of the North American and European coronavirus disease 2019 epicenters, present an ultrasound scanning protocol and report on the common associated ultrasound findings.

Lung Ultrasound Scanning for Respiratory Failure in Acutely Ill Patients: A Review.

Lung ultrasonography (LUS), an imaging modality quickly performed, interpreted, and integrated by the treating physician at the bedside, is a particularly useful tool for acutely ill patients. In the evaluation of a patient with respiratory failure in the ICU or ED, LUS is superior to chest radiograph and generally comparable with CT imaging and reduces the need for patient transport and radiation exposure. This article will provide a concise review of LUS as it pertains to respiratory failure in general and will include examples of relevant ultrasound images and video clips from critically ill patients.

A Shifting Paradigm: The Role of Focused Cardiac Ultrasound in Bedside Patient Assessment.

Transthoracic echocardiography is the standard of care in anatomic and functional cardiovascular assessment; however, focused cardiac ultrasound (FoCUS) performed with portable ultrasound equipment is increasingly being used as an adjunct to comprehensive history and physical examination. FoCUS assessments, unlike formal echocardiography, are intended to assist physicians in answering explicit clinical questions with a narrow differential diagnosis in real time. Over the past decade, a growing body of literature has repeatedly shown the value that FoCUS adds to clinical evaluation. Specifically, FoCUS improves point-of-care diagnostic accuracy, which in turn modifies treatment plans, decreases time to diagnosis, and reduces resource utilization. Although less robust, there is also evidence showing improvement in clinical outcomes. Based on this evidence, clinicians, training programs, and clinical societies have embraced FoCUS as a tool to complement bedside patient evaluation. Herein, we review the evidence for FoCUS in clinical practice, specifically evaluating the diagnostic accuracy, the impact on clinical decision-making, and the effect on clinical outcomes.

How I Do It: Ultrasound-Guided Internal Jugular and Femoral Central Venous Catheter Insertion.

Central venous catheterization is routinely performed in the ICU to obtain venous access for hemodynamic monitoring, parenteral nutritional support, hemodialysis, and delivery of fluids and vasoactive medications. Although central venous catheters can be lifesaving, their insertion is not without risk. Historically, central veins were accessed using landmark-based techniques, but the medical literature strongly supports the use of ultrasound guidance. The purpose of this article is to review the basic principles of real-time ultrasound-guided internal jugular and femoral catheter placement. An approach for incorporating these tools into clinical practice is presented, along with illustrative figures and video.

Better With Ultrasound: Thoracic Ultrasound.

Ultrasound examination of the thorax is superior to chest radiograph or physical examination for diagnosing common conditions such as pneumonia, pulmonary edema, pleural effusion, and pneumothorax. The basic skill set is straightforward to learn, quick to perform, repeatable, and does not involve patient transport, harmful ionizing radiation, or waiting time. This paper outlines the basic building blocks that makeup a thoracic ultrasound examination, regardless of which specific scanning protocol is performed. Narrative videos and illustrative figures demonstrating these techniques are included.

Better With Ultrasound: Detection of DVT.

Ultrasound studies to detect DVT are traditionally performed and interpreted by sonographers and radiologists, respectively, but the growth of point-of-care ultrasound is putting this powerful tool in the hands of front-line physicians. Literature from ambulatory patients in the ED suggests this tool performs well in the hands of nonconventional users, and it is now being commonly deployed to aid in the management of critically ill patients. This article presents an approach for incorporating these tools into bedside practice, including illustrative figures and narrated video presentations to demonstrate the techniques described.