Echocardiographic Assessment Using Subxiphoid-Only Examination for Hypotensive Patients

Summary

The protocol here provides a rapid, phenotype-based approach for focused ultrasound evaluation of the hypotensive patient, using subcostal images of the inferior vena cava and heart, with additional views of the upper lungs and pleural spaces.

Abstract

Point-of-care ultrasound, or POCUS, has gathered significant interest as a tool to augment clinical decision-making in the care of acutely ill patients. Patients with hemodynamic instability, in particular, require immediate intervention and are at high risk for further cardiovascular and/or respiratory decompensation. POCUS examination of these patients, therefore, requires a protocol that is sufficient to answer clinicians' questions while still retaining adequate brevity to be feasible in a short period of time at the bedside. Here, we demonstrate a protocol for obtaining such information by the Echocardiographic Assessment using Subxiphoid-Only - Mean Arterial Pressure, or EASy MAP exam, a focused ultrasonographic assessment of the cardiovascular and respiratory systems. The cardiovascular portion of the examination utilizes the subcostal window to obtain views of the heart and inferior vena cava (IVC); this is then supplemented by anterior upper lung and posterolateral diaphragmatic pleural views for the respiratory portion. All six views (cardiac, IVC, left and right anterior upper lung, and left and right posterolateral pleural) are obtained using a low-frequency phased array transducer. We discuss some of the common pitfalls encountered in obtaining these images and the basics of interpreting the most common findings; also described is a 12-point scale for rating the quality of the images obtained from the cardiac view and a small number of supplementary views that may be considered when clinically relevant.

Introduction

In recent years, the increased availability, quality, and portability of ultrasonographic equipment has driven a rapid expansion in the field of point-of-care ultrasound (POCUS). POCUS is defined as an ultrasound exam that is performed for well-defined clinical indications and is interpreted by the patient's primary treating clinician, with the findings immediately incorporated into the treatment plan^1,2. This is in contrast to consultative ultrasound, which refers to an ultrasound exam that is requested by a patient's primary treating clinician but performed by a separate specialist team³

Protocol

All procedures performed in studies involving human participants were in accordance with the ethical standards of the Albany Medical Center institutional research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards. All videos demonstrating the process of performing the EASy MAP examinations and all examples of normal (i.e., non-pathologic) ultrasound images depict the authors themselves or, in some cases, healthy volunteers who gave written consent for involvement in the filming process. The protocol described in this publication has been developed for the evaluation of adult patients with arterial hypotension in ....

Results

When the EASy protocol is used to assess the patient with hypotension, a successful exam is broadly defined as an exam that clarifies the diagnostic picture (in this case, the underlying etiology of hypotension) to a degree that is sufficient to immediately guide patient management. Conversely, an unsuccessful exam is one that is unhelpful in guiding management and does not provide sufficient information to result in actionable recommendations. High-quality imaging is essential for a successful EASy MAP examination, with.......

Discussion

The EASy MAP protocol is just one of several ultrasound protocols that can be clinically useful in the evaluation of a patient with acute hemodynamic instability^37,38. Unlike many more complex exams, however, the core of the EASy exam is its brevity and simplicity, which allows the user to rapidly identify many common pathologies at the bedside through pattern recognition¹⁸. The pattern recognition emphasis allows for simplified knowledge .......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Phased Array Ultraosund Probe	Mindray	P4-2S	Probe used for all components of exam
Portable Ultrasound System	Mindray	TE7	Portable/bedside POCUS unit
Ultrasound Gel	Aquasonic	PLI 01-08	Aqueous sonographic conduction gel