Seeing through the myths: Practical aspects of diagnostic point-of-care ultrasound in nephrology

Point of care ultrasonography (POCUS) is emerging as an invaluable tool for guiding patient care at the bedside, providing real-time diagnostic information to clinicians. Today, POCUS is recognized as the fifth pillar of bedside clinical examination, alongside inspection, palpation, percussion, and auscultation. In spite of growing interest, the adoption of diagnostic POCUS in nephrology remains limited, and comprehensive training beyond kidney ultrasound is offered in only a few fellowship programs. Moreover, several misconceptions and barriers surround the integration of POCUS into day-to-day nephrology practice. These include myths about its scope, utility, impact on patient outcomes and legal implications. In this minireview, we address some of these issues to encourage wider and proper utilization of POCUS.

Development of a novel observed structured clinical exam to assess clinical ultrasound proficiency in undergraduate medical education

OBJECTIVES

A pilot study was performed to develop and test an observed structured clinical exam (OSCE) for clinical ultrasound in second-year medical students. The goal was to assess a longitudinal clinical ultrasound curriculum for medical students and to help determine readiness to perform ultrasound during clinical clerkships.

METHODS

The OSCE contained 40 tasks over 30 min in a one-to-one examiner to examinee environment using standardized patients covering cardiac, pulmonary, and inferior vena cava (IVC) ultrasound exams along with 6 critical diagnoses. Examinees were assessed using a binary checklist approach. A two-way ANOVA analysis was performed to determine if there were differences between the day and session the OSCE was administered. Results are presented as mean ± standard deviation.

RESULTS

One hundred fifty-two students were tested with an overall mean score of 64.9 ± 17.6%. Scores between the cardiac, IVC, and lung sections varied-67.8% ± 18.8%, 62.4% ± 26.2%, and 57.1% ± 20.6%, respectively. One hundred twenty-six (82.9%) answered at least one critical diagnosis incorrectly. Students in the late session performed better than the early session (1: 60% vs 2: 69%, p = .001).

CONCLUSIONS

Students performed better in later sessions. Additionally, the number of questions left blank at the end of the exam suggests that the length of the OSCE should be evaluated. Incorporating critical diagnoses was challenging for examinees. The proposed OSCE is a valuable assessment tool that could be adapted to assess student's readiness to use clinical ultrasound prior to clerkships.

Emergency department point-of-care ultrasound diagnosis of active bleeding into the intraluminal thrombus of an abdominal aortic aneurysm

Rupture of an abdominal aortic aneurysm (AAA) is an immediately life-threatening phenomenon with substantial mortality. Although most AAAs are asymptomatic, an impending AAA rupture can be heralded by nonspecific symptoms and imaging findings on CT and point-of-care ultrasound (POCUS). In this report, we present a case of an 81-year-old male with an atypical presentation of an AAA with novel sonographic findings of imminent rupture on POCUS with Doppler that prompted successful emergent intervention. In the emergency department, imaging findings on aortic POCUS and CT imaging with angiography can facilitate assessment for impending aortic rupture, which can expedite appropriate disposition and potentially life-saving intervention.

Transverse colon volvulus presenting as bowel obstruction, atelectasis, and displacement of the right lobe of the liver into the left upper abdominal quadrant: a case report

BACKGROUND

Transverse colon volvulus is an uncommon cause of intestinal obstruction. It is a surgical emergency that can lead to bowel infarction, peritonitis, and death.

CASE PRESENTATION

We report a case of transverse colon volvulus in a 35-year-old Congolese immigrant man who had a rare presentation with features of intestinal obstruction associated with right lung collapse and left mediastinal shift.

CONCLUSION

This case is unusual because it presented with respiratory features that mimicked a pneumothorax in addition to features of intestinal obstruction. The use of point-of-care lung ultrasound was helpful in ruling out a pneumothorax, and this could help avoid situations such as unintentional chest drain insertions by other professionals who may encounter a similar case. Because transverse colon volvulus is rare, a high level of suspicion and awareness is required to make an accurate diagnosis.

Point of care ultrasonography in onco-nephrology: A stride toward better physical examination

Onco-Nephrology is an emerging subspecialty of Nephrology that focuses on a broad spectrum of renal disorders that can arise in patients with cancer. It encompasses acute kidney injury (AKI), complex fluid, electrolyte, and acid-base disorders, as well as chronic kidney disease caused or exacerbated by cancer and/or its treatment. In many such scenarios including AKI and hyponatremia, objective evaluation of hemodynamics is vital for appropriate management. Point of care ultrasonography (POCUS) is a limited ultrasound exam performed at the bedside and interpreted by the treating physician intended to answer focused clinical questions and guide therapy. Compared to conventional physical examination, POCUS offers substantially higher diagnostic accuracy for various structural and hemodynamic derangements. In this narrative review, we provide an overview of the utility of POCUS enhanced physical examination for the Onconephrologist supported by the current evidence and our experience-based opinion.

Point of Care Ultrasound Training in Nephrology: Twitter Poll as a Modern Tool for Development of an Effective Curriculum

INTRODUCTION

Point of care ultrasonography (POCUS) is being increasingly recognized as an adjunct to physical examination in the field of nephrology. However, paucity of trained faculty and standardized curricula remain key barriers to widespread adoption of this skill as well as development of reliable quality assessment programs at the institutional level. Herein, we sought to explore the utility of Twitter polls to gain insights into knowledge deficits of the learners for making curricular improvements while simultaneously disseminating POCUS pearls and pitfalls.

METHODS

A series of 57 single-question polls were tweeted over a 12-month period, each containing an ultrasound image or a video asking for correct interpretation. These were sent out from the Twitter handle of NephroPOCUS.com (@NephroP), an online POCUS education tool. The answer and a brief explanation were shared in a subsequent tweet at the end of the voting period. Information on the percentage of correct answers, Tweet impressions, and engagements was collected and analyzed by the pre-determined difficulty level (I-III) and the organ/learning objective being tested.

RESULTS

The number of responses per poll was 228 ± 94.6 (mean ± SD), and the percentage of correct responses was 57.9 ± 17.5 (mean ± SD). 16 (of 57) polls received less than 50% correct responses, of which 8 belonged to level III difficulty. The learning objectives that received the least number of correct responses in the kidney, cardiac, lung, vascular, and other categories were identification of end-stage kidney (16.2% correct answers), right pleural effusion on the parasternal short axis view of the heart (29%), right pleural effusion from the subxiphoid window (39%), grading of systemic venous congestion (27.3%), and identification of ascites on the right lateral chest window (15%), respectively. The overall engagement rate was 6.96%, which was above the median for health and higher education-related tweets on Twitter. Targeted didactic material was developed based on these results, published on various open-access nephrology education platforms.

CONCLUSIONS

Twitter polls aid in identifying the knowledge gaps among POCUS learners. Information obtained from the polls can be used to improve POCUS-related curricula and develop targeted educational material to facilitate remote learning.

Diagnostic accuracy of point-of-care knee ultrasound for evaluation of meniscus and collateral ligaments pathology in comparison with MRI

BACKGROUND

Although magnetic resonance imaging (MRI) is often the "gold standard" for diagnosing knee problems, it has many limitations. Therefore, ultrasonography has been suggested as an effective rapid alternative in many knee abnormalities, especially after injuries of the meniscus and collateral ligaments.

PURPOSE

To determine the diagnostic accuracy of point-of-care ultrasound (POCUS) in detecting injuries of the meniscus and collateral ligament compared to MRI.

MATERIAL AND METHODS

An observational cross-sectional blinded study was conducted of 60 patients with clinically suspicious meniscus and collateral ligament injuries who were planned for an arthroscopy and or operative procedure. These patients underwent both blinded POCUS and MRI of the knees before the intervention procedure and results of both imaging modalities were compared according to the operative and arthroscopic findings.

RESULTS

The preoperative reliability of POCUS compared to MRI for the assessment of meniscus injuries was sensitivity (92.9% vs. 90.5%), specificity (88.9% vs. 83.3%), positive predictive value (PPV; 95.1% vs. 92.7%), negative predictive value (NPV; 84.2% vs. 79%), and overall accuracy (91.7% vs. 88.3%). However, for diagnosing collateral ligament injures, POCUS versus MRI assessed sensitivity (92.3% vs. 88.5%), specificity (100% vs. 97.1%), PPV (100% vs. 95.8%), NPV (94.4% vs. 91.7%), and overall accuracy (96.7% vs. 93.3%).

CONCLUSION

Ultrasonography is a useful screening tool for the initial diagnosis of meniscal and collateral ligament pathology compared to or even with potential advantages over MRI, especially when MRI is unavailable or contraindicated. As newly advanced portable ultrasonography becomes available, it could be considered as a point-of-injury diagnostic modality.

Point of care venous Doppler ultrasound: Exploring the missing piece of bedside hemodynamic assessment

Accurate assessment of the hemodynamic status is vital for appropriate management of patients with critical illness. As such, there has been a constant quest for reliable and non-invasive bedside tools to assess and monitor circulatory status in order to ensure end-organ perfusion. In the recent past, point of care ultrasonography (POCUS) has emerged as a valuable adjunct to physical examination in various specialties, which basically is a clinician-performed bedside ultrasound to answer focused questions. POCUS allows visualization of the internal anatomy and flow dynamics in real time, guiding apt interventions. While both arterial (forward flow) and venous (organ outflow or afterload) limbs of hemodynamic circuit are important for tissue perfusion, the venous side remains relatively under-explored. With recent data underscoring the deleterious consequences of iatrogenic volume overload, objective evaluation of venous congestion is gaining attention. Bedside Doppler ultrasound serves this purpose and aids in diagnosing and monitoring the congestion/venous blood flow pattern. In this article, we summarize the rationale for integrating this technology into routine care of patients with volume-related disorders, discuss the normal and abnormal waveforms, limitations, and future directions.

Point of Care Ultrasonography for Objective Assessment of Heart Failure: Integration of Cardiac, Vascular, and Extravascular Determinants of Volume Status

BACKGROUND

Lingering congestion portends poor outcomes in patients with heart failure (HF) and is a key target in their management. Studies have shown that physical exam has low yield in this setting and conventional methods for more precise assessment and monitoring of volume status (e.g., body weight, natriuretic peptides, and chest radiography) have significant inherent shortcomings.

SUMMARY

Point of care ultrasonography (POCUS) is a noninvasive versatile bedside diagnostic tool that enhances the sensitivity of conventional physical examination to gauge congestion in these patients. It also aids in monitoring the efficacy of decongestive therapy and bears prognostic significance. In this narrative review, we discuss the role of focused sonographic assessment of the heart, venous system, and extravascular lung water/ascites (i.e., the pump, pipes, and the leaks) in objective assessment of fluid volume status. Key Messages: Since each of the discussed components of POCUS has its limitations, a combinational ultrasound evaluation guided by the main clinical features would be the key to reliable assessment and effective management of congestion in patients with HF.

The Relationship of Pleural and Pericardial Effusion With Pulmonary Hemodynamics in Patients With Pulmonary Hypertension

BACKGROUND

The relationship between the presence of pleural and pericardial effusion in reference to hemodynamic parameters remains unclear in ambulatory patients with pulmonary hypertension (PH).

METHODS

Consecutive patients who underwent right catheterization (RHC) for the evaluation of pulmonary hypertension were enrolled. Point-of- care ultrasound was performed prior to the RHC to determine the presence of pleural effusion and pericardial effusion. We conducted a cross-sectional study to determine the association between presence of pericardial and pleural effusion with pulmonary hemodynamic variables.

RESULTS

Twenty-five (78.1%) of 32 patients had evidence of PH by RHC. Mean pulmonary artery pressure of the population was 40.6 mmHg, and 68% (17/25) had WHO group I PH. Six (24.0%) of 25 PH patients had pleural effusions identified, of which 4 out of 6 (66.7%) had a pulmonary artery wedge pressure >15 mmHg. Eleven (44.0%) of the 25 PH patients were also found to have pericardial effusions, and most of those patients 10/11(90.9%) had an elevated right atrial pressure >10 mmHg. The presence of a pleural effusion was associated with a pulmonary artery wedge pressure >15 mmHg (p = 0.032) and the presence of a pericardial effusion was associated with a right atrial pressure >10 mmHg (p = 0.004). Detection of pleural effusion had a poor positive predictive value (67%) for the presence of pulmonary venous hypertension, whereas presence of a pericardial effusion was highly predictive (89%) of the presence of systemic venous hypertension.

CONCLUSIONS

Systemic venous hypertension was associated with the presence of pericardial effusions, while pulmonary venous hypertension is associated with pleural effusion development in ambulatory patients with pulmonary hypertension.

Prevalence of asymptomatic deep vein thrombosis in patients hospitalized with SARS-CoV-2 pneumonia: a cross-sectional study

The association between coronavirus disease 2019 (COVID-19) pneumonia and venous thrombotic disorders is still unclear. We assessed the association between COVID-19 infection-related pneumonia and proximal deep-vein thrombosis (DVT) in a cohort of patients admitted to our hospital during the European outbreak in the front line of Cremona, Lombardy. In a single-center cross-sectional study, all patients hospitalized for more than 5 days in Internal Medicine Department with confirmed COVID-19 pneumonia received 2-point compressive ultrasound assessment (CUS) of the leg vein system during a single day. Ninety-four percent of patients received enoxaparin as standard pharmacological prophylaxis for venous thromboembolism. The presence of DVT was defined as incompressibility of popliteal or common femoral vein. Out of 121 patients with COVID-19 pneumonia (mean age 71.8, 66.3% males) hospitalized on March 31st, 70 stayed in hospital for over 5 days and 66 of them underwent CUS of deep venous system of the legs. The presence of asymptomatic DVT was found in 9 patients (13.6%). No symptomatic DVT was found. Patients with DVT showed mean age = 75.7 years, mean D-dimer levels = 4.02 ng/ml and all of them received enoxaparin for thromboprophylaxis, except one. Computed tomography pulmonary angiogram confirmed pulmonary embolism in five patients. One every seven patients with COVID-19-related pneumonia, hospitalized for more than 5 days, had asymptomatic proximal DVT and half of them had confirmed PE despite standard pharmacological thromboprophylaxis. This observational study suggests the need of an active surveillance through CUS in patients hospitalized with acute SARS-COV-2 and underline the need of a more intense thromboprophylaxis.

Atypical presentation of hemorrhagic shock in pregnancy: a case highlighting the developing field of emergency medicine in Israel

BACKGROUND

Occult hemorrhagic shock secondary to uterine rupture represents a true obstetric emergency and can result in significant morbidity and mortality for both the patient and the fetus. Multiparity and prior cesarean sections are known risk factors. Typically, these patients present late in gestation, often secondary to the physiologic stresses on the uterus related to contractions. This pathology is less common earlier in pregnancy and can often be overlooked in the acute setting.

CASE PRESENTATION

We present the case of a 31-year-old female with three prior gestations, two parities and two prior cesarean sections, resulting in three live births, who presented to the Emergency Department (ED) 22-weeks pregnant with acute onset dyspnea and an episode of syncope. Due to her altered mental status there was concern for occult shock, despite normal vital signs. Large amounts of free fluid in the abdomen were noted on bedside ultrasonography with a high suspicion for uterine pathology. She was resuscitated with blood and taken immediately to the operating room for surgical management where she was found to have had a uterine rupture.

CONCLUSION

This case highlights a rare presentation of a well-known obstetric emergency, due to the patient's development of uterine rupture early in gestation. Consequently, emergency physicians should consider atraumatic hypovolemic shock, secondary to this obstetric catastrophe, even at a stage that far precedes its expected presentation. In addition, we make note of how this case validated our department's integrated emergency medicine model, the first in the State of Israel.

Renal intraparenchymal resistive index: the ultrasonographic answer to many clinical questions

The use of renal resistive indices (RRIs) for the study of renal microcirculation has in the past been proposed for the identification of renal organ damage or even to specifically identify injury to some areas of the renal parenchyma. Nevertheless, according to the most recent evidences from literature this organ-based conception of RRIs has been proven to be partial and unable to explain the RRIs variations in clinical settings of sepsis or combined organ failure of primitively extrarenal origin or, more generally, the deep connection between RRIs and hemodynamic factors such as compliance and pulsatility of the large vessels. The aim of this review is to explain the physiopathological basis of RRIs determination and the most common interpretative errors in their analysis. Moreover, through a comprehensive vision of these Doppler indices, the traditional and emerging clinical application fields for RRIs are discussed.

Economic analysis of bedside ultrasonography (US) implementation in an Internal Medicine department

The economic crisis, the growing healthcare demand, and Defensive Medicine wastefulness, strongly recommend the restructuring of the entire medical network. New health technology, such as bedside ultrasonography, might successfully integrate the clinical approach optimizing the use of limited resources, especially in a person-oriented vision of medicine. Bedside ultrasonography is a safe and reliable technique, with worldwide expanding employment in various clinical settings, being considered as "the stethoscope of the 21st century". However, at present, bedside ultrasonography lacks economic analysis. We performed a Cost-Benefit Analysis "ex ante", with a break-even point computing, of bedside ultrasonography implementation in an Internal Medicine department in the mid-term. Number and kind estimation of bedside ultrasonographic studies were obtained by a retrospective study, whose data results were applied to the next 3-year period (foresight study). All 1980 foreseen bedside examinations, with prevailing multiorgan ultrasonographic studies, were considered to calculate direct and indirect costs, while specific and generic revenues were considered only after the first semester. Physician professional training, equipment purchase and working time represented the main fixed and variable cost items. DRG increase/appropriateness, hospitalization stay shortening and reduction of traditional ultrasonography examination requests mainly impacted on calculated revenues. The break-even point, i.e. the volume of activity at which revenues exactly equal total incurred costs, was calculated to be 734 US examinations, corresponding to € 81,998 and the time considered necessary to reach it resulting 406 days. Our economic analysis clearly shows that bedside ultrasonography implementation in clinical daily management of an Internal Medicine department can produce consistent savings, or economic profit according to managerial choices (i.e., considering public or private targets), other than evident medical benefits.