The Accuracy of Point-of-Care Ultrasound in the Detection of Gallbladder Disease: A Meta-analysis

RATIONALE AND OBJECTIVES

The aim of this meta-analysis was to systematically assess the diagnostic value of point of care ultrasound (POCUS) in the detection of gallbladder diseases.

MATERIALS AND METHODS

Pubmed, Web of Science, Embase, and the Cochrane Library were searched for studies up to May 22, 2023. Pooled sensitivity, specificity, positive likelihood ratio and negative likelihood ratio, diagnostic odds ratio, area under the curve of summary receiver operating characteristic were calculated using the bivariate model. Subgroup analysis based on cholecystitis and cholelithiasis was conducted.

RESULTS

A total of seven studies with 1464 participants were identified in this meta-analysis. The pooled sensitivity of POCUS for the detection of gallbladder disease was 0.86 (95% CI: 0.75, 0.93) and the pooled specificity was 0.92 (95% CI: 0.87, 0.96). The pooled sensitivity and specificity of POCUS for the detection of acute cholecystitis were 0.73 (95% CI: 0.55, 0.86) and 0.93 (95% CI: 0.82, 0.98). The pooled sensitivity and specificity of POCUS for the detection of gallstones were 0.94 (95% CI: 0.91, 0.96) and 0.93 (95% CI: 0.91, 0.95).

CONCLUSION

POCUS was a favorable modality for the detection of patients suspected of gallbladder disease, especially for cholelithiasis. Physicians are advised to use POCUS in clinical practice as a non-invasive test to detect gallbladder disease.

Automatic deep learning-based pleural effusion segmentation in lung ultrasound images

BACKGROUND

Point-of-care lung ultrasound (LUS) allows real-time patient scanning to help diagnose pleural effusion (PE) and plan further investigation and treatment. LUS typically requires training and experience from the clinician to accurately interpret the images. To address this limitation, we previously demonstrated a deep-learning model capable of detecting the presence of PE on LUS at an accuracy greater than 90%, when compared to an experienced LUS operator.

METHODS

This follow-up study aimed to develop a deep-learning model to provide segmentations for PE in LUS. Three thousand and forty-one LUS images from twenty-four patients diagnosed with PE were selected for this study. Two LUS experts provided the ground truth for training by reviewing and segmenting the images. The algorithm was then trained using ten-fold cross-validation. Once training was completed, the algorithm segmented a separate subset of patients.

RESULTS

Comparing the segmentations, we demonstrated an average Dice Similarity Coefficient (DSC) of 0.70 between the algorithm and experts. In contrast, an average DSC of 0.61 was observed between the experts.

CONCLUSION

In summary, we showed that the trained algorithm achieved a comparable average DSC at PE segmentation. This represents a promising step toward developing a computational tool for accurately augmenting PE diagnosis and treatment.

Listen Before You Auscultate: An Active-Learning Approach to Bedside Cardiac Assessment

Introduction

Bedside cardiac assessment (BCA) is deficient across a spectrum of noncardiology trainees. Learners not taught BCA well may become instructors who do not teach well, creating a self-perpetuating problem. To improve BCA teaching and learning, we developed a high-quality, patient-centered curriculum for medicine clerkship students that could be flexibly implemented and accessible to other health professions learners.

Methods

With a constructivist perspective, we aligned learning goals, activities, and assessments. The curriculum used a "listen before you auscultate" framework, capturing patient history as context for a six-step, systematic approach. In the flipped classroom, short videos and practice questions preceded two 1-hour class activities that integrated diagnostic reasoning, pathophysiology, physical diagnosis, and reflection. Activities included case discussions, jugular venous pressure evaluation, heart sound competitions, and simulated conversations with patients. Two hundred sixty-eight students at four US and international medical schools participated. We incorporated feedback, performed thematic analysis, and assessed learners' confidence and knowledge.

Results

Low posttest data capture limited quantitative results. Students reported increased confidence in BCA ability. Knowledge increased in both BCA and control groups. Thematic analysis suggested instructional design strategies were effective and peer encounters, skills practice, and encounters with educators were meaningful.

Discussion

The curriculum supported active learning of day-to-day clinical competencies and promoted professional identity formation alongside BCA ability. Feedback and increased confidence on the late-clerkship posttest suggested durable learning. We recommend approaches to confirm this and other elements of knowledge, skill acquisition, or behaviors and are surveying impacts on professional identity formation-related constructs.

Rural family physician use of point-of-care ultrasonography: experiences of primary care providers in British Columbia, Canada

BACKGROUND

In British Columbia (BC), rural and remote areas lack proximal access to radiographic services. Poor access to radiographic services in rural settings presents a challenge to timely diagnosis and screening across many disease states and healthy pregnancies. As a solution to the lack of access to radiographic services in rural settings, the Rural Coordination Centre of BC (RCCbc) supported rural Family Physicians (FPs) wishing to use PoCUS through the Intelligent Network for PoCUS (IN PoCUS) program. This study evaluates FPs' experience and use of PoCUS in their clinical practice.

METHODS

This qualitative study conducted in-depth virtual interviews with 21 FPs across rural BC. The interview asked participants' motivation to participate in the RCCbc program, the type of training they received, their current use of PoCUS, their experience with the technology, and their experience interacting with specialists in regional centres. Thematic analysis of findings was undertaken.

RESULTS

This study used Rogers' framework on the five elements of diffusion of innovation to understand the factors that impede and enable the adoption of PoCUS in rural practice. Rural FPs in this study differentiated PoCUS from formal imaging done by specialists. The adoption of PoCUS was viewed as an extension of physical exams and was compatible with their values of providing generalist care. This study found that the use of PoCUS provided additional information that led to better clinical decision-making for triage and allowed FPs to determine the urgency for patient referral and transport to tertiary hospitals. FPs also reported an increase in job satisfaction with PoCUS use. Some barriers to using PoCUS included the time needed to be acquainted with the technology and learning how to integrate it into their clinical flow in a seamless manner.

CONCLUSION

This study has demonstrated the importance of PoCUS in improving patient care and facilitating timely diagnosis and treatment. As the use of PoCUS among FPs is relatively new in Canada, larger infrastructure support such as improving billing structures, long-term subsidies, educational opportunities, and a quality improvement framework is needed to support the use of PoCUS among rural FPs.

Three-Dimensional Imaging of Commonly Performed Peripheral Blocks: Using a Handheld Point-of-Care Ultrasound System

Background

Handheld ultrasound devices have become popular among clinicians due to their affordability and compatibility with tablets and smartphones. Several handheld ultrasound devices have the capability to construct three-dimensional (3D) images using a traditional two-dimensional (2D) ultrasound transducer.

Objectives

The current study aimed to construct 3D images of common peripheral nerve and fascial plane blocks using a handheld ultrasound device with a 2D ultrasound probe.

Methods

A total of 10 patients who were scheduled to receive ultrasound-guided peripheral nerve blocks for outpatient surgery and classified as the American Society of Anesthesiologists physical status I or II with a body mass index of ≤ 30 kg/m² were included in the study. Patients who presented with anatomical variations during the initial ultrasound scanning were excluded.

Results

This study successfully constructed 3D images of 10 peripheral nerve blocks. The average time to complete each 3D scan was less than 5 seconds per attempt, with fascial plane blocks requiring twice the amount of time to complete. All the nerve blocks provided effective postoperative analgesia without complications. The 3D images were successfully captured in all patients.

Conclusions

The 3D images provide clinicians with valuable information on the anatomical boundaries of the injectate that can further direct needle direction and placement of local anesthetic to achieve visual confidence of anesthetic spread.

An Introductory Point-of-Care Ultrasound Curriculum for an Anesthesiology Residency Program

INTRODUCTION

The use of point-of-care ultrasound (POCUS) is a growing trend in the field of anesthesiology. However, formal POCUS curriculums are still not widely implemented in residency programs. As the Accreditation Council for Graduate Medical Education and the American Board of Anesthesiology have both incorporated POCUS into their educational aims and expectations for graduates, we recognized the need for a formal POCUS curriculum for our residency program. We developed and implemented a comprehensive 3-week POCUS curriculum for our first-year anesthesiology residents (CA1s) in the latter half of their academic year.

METHODS

Twenty CA1s participated in this educational activity. The POCUS curriculum spanned seven topics and was given in weekly 2-hour sessions over the course of 3 weeks. Each session was designed with the first hour consisting of a traditional lecture-based presentation followed by live hands-on practice. A pretest on POCUS knowledge was given to every resident before the curriculum, and a posttest and survey were administered afterwards.

RESULTS

Every CA1 showed an improvement in their posttest scores. The median scores of the pretest and posttest were 49% and 75%, respectively. Survey results were positive, with all of the CA1s agreeing that the POCUS educational materials were appropriate to their level of training and that their POCUS knowledge and technical skills improved after the curriculum.

DISCUSSION

We have shown that our formal POCUS curriculum improved anesthesiology residents' knowledge as well as resulting in positive views on the implementation of this intervention.

Interprofessional Point-of-Care Ultrasound Training of Resident Physicians by Sonography Student-Coaches

INTRODUCTION

Point-of-care ultrasound (POCUS) education is growing throughout medical education, but many institutions lack POCUS-trained faculty. Interprofessional education offers a strategy for expanding the pool of available teachers while providing an opportunity for collaboration between health professional students.

METHODS

Six students enrolled in the diagnostic medical sonography (DMS) program participated in a case-based, train-the-trainer session to practice a standardized approach for POCUS instruction. They then served as coaches to 25 first-year internal medicine residents learning to perform ultrasound exams of the kidneys, bladder, and aorta. Course assessment included an objective structured exam (OSCE), coaching evaluations, and course evaluations.

RESULTS

Residents scored an average of 81% (71.3 out of 88 points, SD = 7.5) on the OSCE. Residents rated the DMS student-coaches positively on all teacher evaluation questions. Both the residents and DMS student-coaches gave positive course evaluations scores.

DISCUSSION

An interprofessional workshop with DMS students coaching internal medicine residents was an effective strategy for teaching POCUS skills. This approach may offer a solution for programs wanting to implement POCUS training with limited faculty expertise or time.

Point-of-Care Ultrasound Diagnosis of High Flow Priapism

BACKGROUND

Priapism can be categorized as low flow or high flow. Low flow priapism is a compartment syndrome and requires immediate treatment to avoid long-term ischemic damage. Alternatively, high flow priapism is not an emergent condition and can be managed as an outpatient. The diagnosis has traditionally been made via cavernosal blood gas analysis; however, this is painful and can cause iatrogenic harm.

CASE REPORT

We present a case of high flow priapism whereby point-of-care ultrasound (POCUS) identified the presence of pulsatile cavernosal arterial flow to confirm the diagnosis. This is the first case report in the emergency medicine literature to highlight the utility of POCUS in the diagnosis and management of high flow priapism. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Low flow priapism accounts for 95% of cases and is a urologic emergency requiring immediate invasive intervention. High flow priapism is much less common and does not require emergent management. While blood gas analysis can differentiate between high and low flow priapism, POCUS is a rapid, noninvasive, accurate diagnostic means to identify the presence or absence of cavernosal pulsatile arterial flow.

Stay Still's for POCUS: using bedside ultrasound to screen for cardiac complications

Adult Still's disease (ASD) is a rare systemic inflammatory disorder of unknown etiology most commonly characterized by daily spiking fevers, an evanescent, 'salmon-colored' rash, and arthralgia. Cardiac complications such as pericarditis, myocarditis, heart failure, and pericardial effusion progressing to tamponade have been reported. Because of the severe and potentially lethal complications associated with these processes, the clinician's index of suspicion must remain high and the threshold for cardiac imaging low. Here, we present a case of ASD-associated myocarditis identified quickly by point-of-care ultrasound, allowing for prompt workup and treatment.

Point-of-Care Ultrasound (POCUS) for the Cardiothoracic Anesthesiologist

Point-of-Care Ultrasound (POCUS) is a valuable bedside diagnostic tool for a variety of expeditious clinical assessments or as guidance for a multitude of acute care procedures. Varying aspects of nearly all organ systems can be evaluated using POCUS and, with the increasing availability of affordable ultrasound systems over the past decade, many now refer to POCUS as the 21^st-century stethoscope. With the current available and growing evidence for the clinical value of POCUS, its utility across the perioperative arena adds enormous benefit to clinical decision-making. Cardiothoracic anesthesiologists routinely have used portable ultrasound systems for nearly as long as the technology has been available, making POCUS applications a natural extension of existing cardiothoracic anesthesia practice. This narrative review presents a broad discussion of the utility of POCUS for the cardiothoracic anesthesiologist in varying perioperative contexts, including the preoperative clinic, the operating room (OR), intensive care unit (ICU), and others. Furthermore, POCUS-related education, competence, and certification are addressed.

Point-of-Care Ultrasound Training and Credentialing for mid-late Career Emergency Physicians: Is it worth it?

Point-of-care ultrasound (POCUS) is becoming more prevalent in community emergency medicine (EM) practice with the current American College of Emergency Physician guidelines recommending POCUS training for all graduates from United States based residency programs as well as support for POCUS privileging by the American Medical Association. However, in a recent survey of nonacademic EDs, it was found that most providers lack US training, credentialing, and quality assurance (QA) assessments of their POCUS studies. In 2017, our healthcare system embarked on a system-wide credentialing process for POCUS to credential community physicians with little to no POCUS training.

Integrating Basic and Clinical Sciences Using Point-of-Care Renal Ultrasound for Preclerkship Education

INTRODUCTION

Point-of-care ultrasound (POCUS) is a valuable asset in bedside clinical care. Undergraduate medical education is increasingly using POCUS as an adjunct tool for teaching anatomy, pathophysiology, and physical exam in an integrated manner. Many medical schools teach content in an organ systems-based format in the preclerkship years. POCUS teaching can be very effectively tailored to specific organ systems. Though pilot curricula for generalized ultrasound education exist, few teach organ systems-based content using POCUS. To address this gap, we designed and implemented an integrated POCUS module to supplement anatomy, pathophysiology, and physical exam teaching in the renal course.

METHODS

The module consisted of (1) a 30-minute didactic lecture introducing students to renal ultrasound technique and image interpretation and (2) a practical hands-on skills session. Pre- and postmodule surveys assessed the efficacy and impact of the curriculum.

RESULTS

A total of 31 first-year medical students completed the POCUS renal curriculum. A majority reported that the module positively affected their understanding of renal pathophysiology and the physical exam. They also reported increased confidence in using POCUS to detect renal pathology and make clinical decisions.

DISCUSSION

It was feasible to implement a POCUS curriculum to supplement integrated teaching of renal system concepts in the first year of medical school, and students found POCUS teaching valuable. POCUS provides educators with another tool to integrate basic and clinical sciences with hands-on relevant clinical skills practice in early medical school years.

Postpartum reverse-Takotsubo from pheochromocytoma diagnosed by bedside point-of-care ultrasound: A case report

Point-of-care ultrasound is invaluable in the setting of obstetric anesthesia, where the differential diagnosis for dyspnea, hypoxemia and/or hemodynamic abnormalities is broad. This report describes a previously apparently healthy parturient with an uncomplicated pregnancy at 35-weeks gestation who underwent an emergency cesarean section under general anesthesia due to severe acute abdominal pain and fetal bradycardia. Intraoperatively, she presented with severe hypertension and tachycardia that were difficult to control and associated with ischemic ECG changes. In the immediate postoperative period, she developed retrosternal tightness and dyspnea, and a bedside point-of-care ultrasound scan revealed a grossly dilated and hypokinetic left ventricle, as well as diffuse B-lines throughout all lung fields - consistent with cardiogenic pulmonary edema. She was admitted to the intensive care unit, where she recovered over several days. Pheochromocytoma was subsequently diagnosed, and she eventually underwent uneventful elective adrenalectomy after appropriate endocrine and hemodynamic optimization.

Accelerated Remote Consultation Tele-POCUS in Cardiopulmonary Assessment (ARCTICA)

The ability of point-of-care ultrasound (POCUS) to provide rapid and accurate bedside assessment of both the heart and lungs allows it to be a powerful tool in the management of patients presenting with dyspnea. However, while ultrasound equipment is readily available even in remote healthcare settings in Canada, physicians lack effective training opportunities to develop expertise in this potentially life-saving skill. To answer this critical call to action, we have developed the Accelerated Remote Consultation Tele-POCUS in Cardiopulmonary Assessment (ARCTICA) program to innovate POCUS training for today’s physician leaders. This article outlines the background, research methods, and progress-to-date of ARCTICA.

Point-of-Care Ultrasound is Having Its Moment

Hospital culture regarding imaging and the specialties which perform it has been resistant to change. In particular, ultrasound performed at the point of care (POCUS) has taken a while to become established within hospital systems. The COVID-19 pandemic has seemingly caused acceleration of POCUS acceptance. What is driving this rapid culture change?

Developing and Evaluating a Remote Quality Assurance System for Point-of-Care Ultrasound for an Internal Medicine Residency Global Health Track

Background: A quality assurance system is vital when using point-of-care ultrasound (POCUS) to ensure safe and effective ultrasound use. There are many barriers to implementing a quality assurance system including need for costly software, faculty time, and extra work to log images. Methods: With minimal funding or protected faculty time, we successfully developed an effective remote quality assurance system between residents rotating internationally and faculty in the US. Results: 270 total exams were logged using this system (41 per resident over a 7 week period). Over the course of the implementation period, a significant increase was seen in average image quality (p = 0.030) and percent agreement with reviewer (p = 0.021). No significant increase was seen for percent images with quality rating 5/5 (p = 0.068) or for studies per resident per week (p = 0.30). Discussion/Conclusions: A quality assurance system for remote review and feedback of POCUS exams was successfully developed with limited available funding, using consumer-level software and an educational collaboration. Residents used the system regularly and demonstrated improvement in reviewer-rated image acquisition and interpretation skills. A similar system can be applied for physicians in any geographic area looking to learn POCUS, in partnership with local or international POCUS mentors. We detail a step-by-step approach, challenges encountered, and lessons learned, to help guide others seeking to implement similar programs.

SCOLIOSIS SCREENING AND MONITORING USING SELF CONTAINED ULTRASOUND AND NEURAL NETWORKS

We aim to diagnose scoliosis using a self contained ultrasound device that does not require significant training to operate. The device knows its angle relative to vertical using an embedded inertial measurement unit, and it estimates its angle relative to a vertebrae using a neural network analysis of its ultrasound images. The composition of those angles defines the angle of a vertebrae from vertical. The maximum difference between vertebrae angles collected from a scan of a spine yields the Cobb angle measure that is used to quantify scoliosis severity.

Transforming Learning Anatomy: Basics of Ultrasound Lecture and Abdominal Ultrasound Anatomy Hands-on Session

INTRODUCTION

As point-of-care ultrasound units become more compact and portable, clinicians in over 20 different medical and surgical specialties have begun using the technology in diverse clinical applications. However, a knowledge gap still exists between what medical students are learning in their undergraduate medical education curriculum and the clinical skills required for practice. Over the last 10 years, point-of-care ultrasound content has been slowly incorporated into undergraduate medical education, yet only a handful of medical schools have developed ultrasound curricula. This module was developed at our institution in response to survey feedback from medical students overwhelmingly requesting preclerkship ultrasound education. The target audience for this module is first-year medical students with no prior ultrasound exposure.

METHODS

The module consists of a 1-hour introductory lecture and a 1-hour hands-on session during the abdominal anatomy course. Associated materials include the introductory lecture, presenter notes for the introductory lecture, instructor guidelines for the hands-on session, hands-on session setup instructions, a student handout for the hands-on session, and a module evaluation form.

RESULTS

We have successfully implemented this module for the past 3-years and learner feedback has been overwhelmingly positive. Learner comments on a postmodule survey included, "Great job of explaining the science behind ultrasounds as well as how to interpret the images."

DISCUSSION

As a result of our first-year students' evaluation responses, this module has been incorporated into our medical school's anatomy course.