An argument for using additional bedside tools, such as bedside ultrasound, for volume status assessment in hospitalized medical patients: a needs assessment survey

The Conundrum of Volume Status Assessment: Revisiting Current and Future Tools Available for Physicians at the Bedside

Assessment of patients’ volume status at the bedside is a very important clinical skill that physicians need in many clinical scenarios. Hypovolemia with hypotension and tissue under-perfusion are usually more alarming to physicians, but hypervolemia is also associated with poor outcomes, making euvolemia a crucial goal in clinical practice. Nevertheless, the assessment of volume status can be challenging, especially in the absence of a gold standard test that is reliable and easily accessible to assist with clinical decision-making. Physicians need to have a broad knowledge of the individual non-invasive clinical tools available for them at the bedside to evaluate volume status. In this review, we will discuss the strengths and limitations of the traditional tools, which include careful history taking, physical examination, and basic laboratory tests, and also include the relatively new tool of point-of-care ultrasound.

Point-of-care ultrasound to evaluate volume status in severe hyponatremia

A 51-year-old man was hospitalised for severe hyponatremia. Initial history and physical examination suggested hypovolemia, and he was treated with normal saline at 100 mL/hour. After several days, his hyponatremia failed to improve, and then worsened without resolution of presenting ataxia and fatigue. He had no new complaints including no cough or orthopnea. He had no jugular venous distention or oedema, and his lungs were clear to auscultation. Point-of-care ultrasound was used, revealing a distended inferior vena cava, pulmonary oedema and pleural effusion, suggesting hypervolemia. Based on ultrasound findings, we treated with 60 mg oral torsemide two times per day. Hyponatremia resolved without complication within 48 hours. In this case, physical examination failed to recognise volume status change from hypovolemic to hypervolemic, increasing hospitalisation and morbidity. The point-of-care ultrasound proved to be an accurate tool for proper volume evaluation, and may be used as an adjunct to physical examination for hyponatremic patients.

Internal medicine residents' point-of-care ultrasound skills and need assessment and the role of medical school training

Introduction: Point-of-care-ultrasound (POCUS) as a useful bedside tool is growing. Few studies have examined residents' attitude towards POCUS or compared POCUS image interpretation skills between residents with and without POCUS training in medical school. Material and Methods: We distributed an anonymous survey and image interpretation test to assess residents' attitude towards POCUS, confidence, and skills in interpreting POCUS images and videos. Using independent samples t-tests, we compared mean confidence levels and test scores between residents with and without prior POCUS training. Results: Fifty-two residents responded to survey (response rate 68%) and 59 took the image interpretation test (77%). Most residents (90%) reported being interested in POCUS. Residents with prior POCUS training (n=13) were either PGY-1 (9) or PGY-2 (4). No PGY-3 resident had prior training. Most residents (83%) thought POCUS could be extremely useful in the inpatient setting compared to 29% for outpatient setting. PGY-1 residents with prior training had a higher mean confidence level than PGY-1 residents without prior training, but the difference was not statistically significant (3.26 vs 2.64; p=0.08). PGY-1 with prior training had a mean confidence level that was close to that of PGY-3 residents. PGY-1 residents with prior training scored significantly higher than PGY-1 residents without prior training in image interpretation test (10.25 vs 7; p=0.01). Residents felt most confident in interpreting inferior vena cava images (mean 3.7; max. 5), which also had the highest score in image interpretation test (correct response rate of 88%). Conclusion: Our residents seem very interested in POCUS. PGY-1 residents with prior POCUS training in medical school seem to have higher confidence in their POCUS skills than PGY-1 residents without prior training and outperformed them in image interpretation test. The study is very instructive in building our future POCUS curriculum for residents.

Point of care ultrasound training for internal medicine: a Canadian multi-centre learner needs assessment study

BACKGROUND

Significant gaps currently exist in the Canadian internal medicine point-of-care ultrasound (POCUS) curriculum. From a learner's perspective, it remains unknown what key POCUS skills should be prioritized. This needs assessment study seeks to establish educational priorities for POCUS for internal medicine residents at five Canadian residency training programs.

METHODS

All internal medicine trainees [postgraduate year (PGY) 1-5] from five internal medicine residency training programs in Canada (n = 598) were invited to complete an online survey on 15 diagnostic POCUS applications, 9 bedside procedures, and 18 POCUS knowledge items. For POCUS applications and procedures, participants were asked how applicable they are to patient care in internal medicine and the participants' reported skills in those domains. Self-reported knowledge and skills were rated on a 5-point Likert scale, where 1 = very poor and 5 = very good. Applicability was rated, where 1 = not at all applicable and 5 = very applicable.

RESULTS

A total of 253 of 598 residents (42%) participated in our study. Data from one centre (n = 15) was removed because of low response rate (15%) and significant baseline differences between those trainees and the remaining participants. Of the remaining analyzable data from four training programs (n = 238), participants reported highest applicability to internal medicine for the following applications and procedures: identifying ascites/free fluid [mean applicability score of 4.9 ± standard deviation (SD) 0.4]; gross left ventricular function (mean 4.8 ± SD 0.5) and pericardial effusion (mean 4.7 ± SD 0.5); thoracentesis (mean score 4.9 ± SD 0.3), central line insertion (mean 4.9 ± SD 0.3), and paracentesis (mean 4.9 ± SD 0.3), respectively. Overall reported knowledge/skills was low, with skill gaps being the highest for identifying deep vein thrombosis (mean gap 2.7 ± SD 1.1), right ventricular strain (mean 2.7 ± SD 1.1), and gross left ventricular function (mean 2.7 ± SD 1.0).

CONCLUSIONS

Many POCUS applications and procedures were felt to be applicable to the practice of internal medicine. Significant skill gaps exist in the four Canadian training programs included in the study. POCUS curriculum development efforts should target training based on these perceived skill gaps.

Point-of-Care Ultrasonography in Emergency and Critical Care Medicine

To stabilize critically ill patients, emergency and critical care medicine providers often require rapid diagnosis and intervention. The demand for a safe, timely diagnostic device, alongside technological innovation, led to the advent of point-of-care ultrasonography (POCUS). POCUS allows the provider to gain invaluable clinical information with a high level of accuracy, leading to better clinical decision-making and improvements in patient safety. We have outlined the history of POCUS adaptation in emergency and critical care medicine and various clinical applications of POCUS described in literature.

Learning to prescribe intravenous fluids: A scoping review

INTRODUCTION

Prescribing intravenous (IV) fluid therapy is a core skill expected of qualified doctors at the point of graduation, but medical graduates often feel ill-equipped to perform this task. This lack of preparedness contributes to treatment-related patient harm. This scoping review maps the current state of published evidence about how junior doctors prescribe IV fluid therapy and learn how to do it.

METHODS

We searched five electronic databases and grey literature from 1994 until June 2016 for articles describing any aspect of IV fluid prescribing practice or its education. A total of 63 articles were selected for analysis. Using the WHO Guide to Good Prescribing to categorize the extracted findings, our review focuses on prescribing IV fluids in adult generalist settings.

RESULTS

Most articles studied IV fluid prescribing from the perspective of the doctor. Junior clinicians struggled to conceptualize IV fluid prescribing as a 'whole task' in authentic work settings and lacked support. Educational interventions to improve IV fluid prescribing often focused on enhancing prescriber knowledge about fluid and electrolyte balance rather than execution of the prescribing task.

CONCLUSIONS

Our understanding of IV fluid prescribing as a holistic integrated skill is patchy, as is its performance. Current IV fluid prescribing education appears insufficient to foster safe and effective practice. For education to achieve the ultimate goal of safer prescribing in workplaces, we need a clearer understanding of how healthcare professionals prescribe IV fluids in real world practice.

Reproducibility of point-of-care ultrasonography for central vein diameter measurement: Separating image acquisition from interpretation

PURPOSE

Central vein point-of-care ultrasonography must be reproducible to detect intravascular volume changes. We sought to determine which measurement step, image acquisition or interpretation, could be more compromising for reproducibility.

METHODS

Three investigators each acquired inferior vena cava (IVC) and internal jugular (IJV) vein ultrasonographic sequences (US) from a convenience sample of 21 hospitalized general medicine participants and then interpreted each US three separate times. We partitioned the random errors of acquisition and interpretation, attributing wider dispersions of each to larger reductions in reproducibility.

RESULTS

We analyzed 351 interpretations of 39 IVC and 432 interpretations of 48 IJV US. Reproducibility of the maximum (standard error of measurement 3.3 mm [95% confidence interval, CI 2.7-4.2 mm]) and minimum (4.8 mm [3.9-6.3 mm]) IVC diameter measurements were worse than that of the mediolateral (2.5 mm [2.0-3.2 mm]) and anteroposterior (2.5 mm [2.0-3.1 mm]) IJV diameters. The dispersions of random measurement errors were wider among acquisitions than interpretations.

CONCLUSIONS

Among our investigators, central vein diameter measurements obtained by point-of-care ultrasonography are not sufficiently reproducible to distinguish clinically meaningful intravascular volume changes from measurement errors. Reproducibility could be most effectively improved by reducing the random measurement errors of acquisition. © 2017 Wiley Periodicals, Inc. J Clin Ultrasound 45:488-496, 2017.

Internal Medicine Point-of-Care Ultrasound Curriculum: Consensus Recommendations from the Canadian Internal Medicine Ultrasound (CIMUS) Group

Bedside point-of-care ultrasound (POCUS) is increasingly used to assess medical patients. At present, no consensus exists for what POCUS curriculum is appropriate for internal medicine residency training programs. This document details the consensus-based recommendations by the Canadian Internal Medicine Ultrasound (CIMUS) group, comprising 39 members, representing 14 institutions across Canada. Guiding principles for selecting curricular content were determined a priori. Consensus was defined as agreement by at least 80% of the members on POCUS applications deemed appropriate for teaching and assessment of trainees in the core (internal medicine postgraduate years [PGY] 1-3) and expanded (general internal medicine PGY 4-5) training programs. We recommend four POCUS applications for the core PGY 1-3 curriculum (inferior vena cava, lung B lines, pleural effusion, and abdominal free fluid) and three ultrasound-guided procedures (central venous catheterization, thoracentesis, and paracentesis). For the expanded PGY 4-5 curriculum, we recommend an additional seven applications (internal jugular vein, lung consolidation, pneumothorax, knee effusion, gross left ventricular systolic function, pericardial effusion, and right ventricular strain) and four ultrasound-guided procedures (knee arthrocentesis, arterial line insertion, arterial blood gas sampling, and peripheral venous catheterization). These recommendations will provide a framework for training programs at a national level.

Diagnostic point-of-care ultrasound for hospitalists

We review the literature on diagnostic point-of-care ultrasound applications most relevant to hospital medicine and highlight gaps in the evidence base. Diagnostic point-of-care applications most relevant to hospitalists include cardiac ultrasound for left ventricular systolic function, pericardial effusion, and severe mitral regurgitation; lung ultrasound for pneumonia, pleural effusion, pneumothorax, and pulmonary edema; abdominal ultrasound for ascites, aortic aneurysm, and hydronephrosis; and venous ultrasound for central venous volume assessment and lower extremity deep venous thrombosis. Hospitalists and other frontline providers, as well as physician trainees at various levels of training, have moderate to excellent diagnostic accuracy after brief training programs for most of these applications. Despite the evidence supporting the diagnostic accuracy of point-of-care ultrasound, experimental evidence supporting its clinical use by hospitalists is limited to cardiac ultrasound.