Point-of-Care Ultrasound in Critical Care Obstetrics: A Scoping Review of the Current Evidence

OBJECTIVES

To synthesize the current evidence of maternal point-of-care ultrasound (POCUS) in obstetrics. A scoping review was conducted using PubMed, Clinicaltrials.gov, and the Cochrane library from inception through October 2023.

METHODS

Studies were eligible for inclusion if they described the use of POCUS among obstetric or postpartum patients. Two authors independently screened all abstracts. Quantitative, qualitative, and mixed-methods studies were eligible for inclusion. Case reports of single cases, review articles, and expert opinion articles were excluded. Studies describing detailed maternal nonobstetric sonograms or maternal first trimester sonograms to confirm viability and rule out ectopic pregnancy were also excluded. Data were tabulated using Microsoft Excel and summarized using a narrative review and descriptive statistics.

RESULTS

A total of 689 publications were identified through the search strategy and 12 studies met the inclusion criteria. Nine studies evaluated the use of lung POCUS in obstetrics in different clinical scenarios. Lung ultrasound (LUS) findings in preeclampsia showed an excellent ability to detect pulmonary edema (area under the receiver operating characteristic 0.961) and findings were correlated with clinical evidence of respiratory distress (21 of 57 [37%] versus 14 of 109 [13%]; P = .001). Three studies evaluated abdominal POCUS, two of the inferior vena cava (IVC) to predict postspinal anesthesia hypotension (PSAH) and fluid receptivity and one to assess the rate of ascites in patients with preeclampsia. Patients with PSAH had higher IVC collapsibility (area under the curve = 0.950, P < .001) and, in patients with severe preeclampsia, there is a high rate of ascites (52%) associated with increased risk of adverse outcomes. There were no studies on the use of subjective cardiac POCUS.

CONCLUSION

POCUS use in the management of high-risk obstetrics has increased. LUS has been the most studied modality and appears to have a potential role in the setting of preeclampsia complicated by pulmonary edema. Cardiac and abdominal POCUS have not been well studied. Trials are needed to evaluate its clinical applicability, reliability, and technique standardization before widespread use.

A survey of paediatric difficult peripheral intravenous access in the emergency department and use of point-of-care ultrasound

Introduction/Purpose

Peripheral intravenous catheter (PIVC) insertion can be challenging in children, with point-of-care ultrasound (POCUS) known to increase success rates. The objective of this study was to survey how emergency department (ED) clinicians identify and escalate paediatric patients with difficult intravenous access (DIVA), specifically the use of POCUS.

Methods

This cross-sectional study was conducted in an Australian academic mixed ED that surveyed resident medical officers (RMOs), registrars, consultants and senior paediatric nurses. A 15 multiple-choice questionnaire evaluated clinicians experience with paediatric PIVC insertion, approach to identifying and managing DIVA and the use of POCUS or other adjuncts.

Results

Eighty clinicians (34.2% response rate) completed the survey. Poor vein palpability was rated the highest predictor of DIVA. Of the respondents, 19 consultants (86.4%), 28 registrars (90.3%) and 16 RMOs (64.0%) used POCUS as an adjunct for paediatric DIVA patients but 16 consultants (72.8%), 21 registrars (67.8%) and 20 RMOs (80.0%) would use this less than 25% of the time in clinical practice.

Discussion

This survey suggests more clinicians to prefer using objective factors when identifying paediatric DIVA patients, rather than subjectively using gestalt, which relies on clinician experience. Whilst clearly recognised as a useful tool in our study, POCUS was used infrequently for paediatric DIVA patients.

Conclusions

There is currently no consistent process for the identification and escalation of paediatric DIVA patients, including the use of adjuncts such as POCUS. Clinician awareness for these issues should be addressed, which should include the development of guidelines and clinician training in POCUS for PIVC insertion in children.

Lung ultrasound: A comparison of image interpretation accuracy between curvilinear and phased array transducers

Introduction

Both curvilinear and phased array transducers are commonly used to perform lung ultrasound (LUS). This study seeks to compare LUS interpretation accuracy of images obtained using a curvilinear transducer with those obtained using a phased array transducer.

Methods

We invited 166 internists and trainees to interpret 16 LUS images/cineloops of eight patients in an online survey: eight curvilinear and eight phased array, performed on the same lung location. Images depicted normal lung, pneumothorax, pleural irregularities, consolidation/hepatisation, pleural effusions and B-lines. Primary outcome for each participant is the difference in image interpretation accuracy scores between the two transducers.

Results

A total of 112 (67%) participants completed the survey. The mean paired accuracy score difference between the curvilinear and phased array images was 3.0% (95% CI: 0.6 to 5.4%, P = 0.015). For novices, scores were higher on curvilinear images (mean difference: 5.4%, 95% CI: 0.9 to 9.9%, P = 0.020). For non-novices, there were no differences between the two transducers (mean difference: 1.4%, 95% CI: -1.1 to 3.9%, P = 0.263). For pleural-based findings, the mean of the paired differences between transducers was higher in the novice group (estimated mean difference-in-differences: 9.5%, 95% CI: 0.6 to 18.4%; P = 0.036). No difference in mean accuracies was noted between novices and non-novices for non-pleural-based pathologies (estimated mean difference-in-differences: 0.6%, 95% CI to 5.4-6.6%; P = 0.837).

Conclusions

Lung ultrasound images obtained using the curvilinear transducer are associated with higher interpretation accuracy than the phased array transducer. This is especially true for novices interpreting pleural-based pathologies.

Neonatal and paediatric point-of-care ultrasound review

Purpose

Point-of-care ultrasound (POCUS) examinations for children and newborns are different from POCUS exams for adults due to dissimilarities in size and body composition, as well as distinct surgical procedures and pathologies in the paediatric patient. This review describes the major paediatric POCUS exams and how to perform them and summarizes the current evidence-based perioperative applications of POCUS in paediatric and neonatal patients.

Method

Literature searches using PubMed and Google Scholar databases for the period from January 2000 to November 2021 that included MeSH headings of [ultrasonography] and [point of care systems] and keywords including "ultrasound" for studies involving children aged 0 to 18 years.

Results

Paediatric and neonatal POCUS exams can evaluate airway, gastric, pulmonary, cardiac, abdominal, vascular, and cerebral systems.

Discussion

POCUS is rapidly expanding in its utility and presence in the perioperative care of paediatric and neonatal patients as their anatomy and pathophysiology are uniquely suited for ultrasound imaging applications that extend beyond the standard adult POCUS exams.

Conclusions

Paediatric POCUS is a powerful adjunct that complements and augments clinical diagnostic evaluation and treatment.

A consensus list of ultrasound competencies for graduating emergency medicine residents

OBJECTIVES

Emergency ultrasound (EUS) is a critical component of emergency medicine (EM) resident education. Currently, there is no consensus list of competencies for EUS training, and graduating residents have varying levels of skill and comfort. The objective of this study was to define a widely accepted comprehensive list of EUS competencies for graduating EM residents through a modified Delphi method.

METHODS

We developed a list of EUS applications through a comprehensive literature search, the American College of Emergency Physicians list of core EUS benchmarks, and the Council of Emergency Medicine Residency-Academy of Emergency Ultrasound consensus document. We assembled a multi-institutional expert panel including 15 faculty members from diverse practice environments and geographical regions. The panel voted on the list of competencies through two rounds of a modified Delphi process using a modified Likert scale (1 = not at all important, 5 = very important) to determine levels of agreement for each application-with revisions occurring between the two rounds. High agreement for consensus was set at >80%.

RESULTS

Fifteen of 15 panelists completed the first-round survey (100%) that included 359 topics related to EUS. After the first round, 195 applications achieved high agreement, four applications achieved medium agreement, and 164 applications achieved low agreement. After the discussion, we removed three questions and added 13 questions. Fifteen of 15 panelists completed the second round of the survey (100%) with 209 of the 369 applications achieving consensus.

CONCLUSION

Our final list represents expert opinion on EUS competencies for graduating EM residents. We hope to use this consensus list to implement a more consistent EUS curriculum for graduating EM residents and to standardize EUS training across EM residency programs.

Emergency medicine trainees' perceived barriers to training and credentialing in point-of-care ultrasound: A cross-sectional study

Introduction

Point-of-care ultrasound (POCUS) is an important tool in emergency medicine (EM), with the Australasian College for Emergency Medicine (ACEM) recommending core modalities as part of fellowship training. In Australia, acquisition of these skills is certified via credentialing but is currently poorly undertaken by EM trainees.

Methods

We performed a cross-sectional survey of EM trainees across two academic teaching hospitals in Gold Coast, Queensland, between December 2018 and January 2019, to determine the current state of training and perceived barriers to credentialing in POCUS.

Results

Fifty-two (59%) eligible EM trainees participated. Although credentialing rates (15%) were low amongst respondents, the majority agreed that it was necessary (69%) and should form part of ACEM training (88%). Amongst these trainees, we identified the desire for increased POCUS training and several barriers including time constraints and the credentialing process itself.

Conclusion

Although there is general agreement amongst EM trainees for POCUS credentialing, barriers such as time limitations and technical difficulties were prohibitive for many. We propose the development of an internal structured POCUS training programme within mandatory training time to address these issues.

Young female with abdominal pain and intra-abdominal free fluid: The risk of confirmation bias associated with point-of-care ultrasound

Confirmation bias is an ever-present risk to the rapid decision-making required in emergency departments (EDs). We present a case of a young woman who was brought to ED by ambulance with hypotension, syncope and vaginal bleeding, with a presumptive pre-hospital diagnosis of ruptured ectopic pregnancy. On arrival in ED, she was found to have intra-abdominal free fluid on bedside ultrasound. This finding could have been used by clinicians to confirm their suspicion of a ruptured ectopic; however, with further investigations, it was found that anaphylaxis was the most likely cause of the patient's symptoms. This case highlights that point-of-care ultrasound findings can play a potentially dangerous role in confirmation bias and that we should maintain an open mind when making a diagnosis by treating the patient, rather than the ultrasound picture.

Describing the learning curve of novices for the diagnosis of paediatric distal forearm fractures using point-of-care ultrasound

Purpose

The learning curve of nurse practitioners (NPs) to accurately diagnose paediatric distal forearm fractures using point-of-care ultrasound (POCUS) was investigated.

Methods

Each NP's learning curve was calculated as cumulative diagnostic accuracy against a number of scans performed. The curve's plateau represented the attainment of competency. Secondary outcomes were the comparisons before and after this cut-off of diagnostic accuracy, classification of diagnostic errors, pain scores, duration and preference.

Results

Five NPs performed 201 POCUS studies with diagnostic accuracy plateauing at 90%, providing a 'cut-off' point at scan 15. Accuracy of POCUS scanning before and after the fifteenth scan was 81% (95% CI 70%-89%) and 90% (95% CI 84%-94%), respectively, demonstrating 9% improvement (P = 0.07). There was a 10% reduction in image interpretation errors. After fifteen scans, POCUS became faster (mean difference (MD) 2.6 min [95% CI 2.0-3.3], P < 0.001), less painful (MD 0.61 points FPSR scale [95% CI 0.04-1.18], P = 0.04) and more preferred by NPs (63% vs 77%, P = 0.03).

Discussion

The learning curve of POCUS-novice NPs independently scanning paediatric distal forearm injuries plateaued with mean diagnostic accuracy of 90% after 15 scans, suggesting competency was attained at this cut-off, supported by higher accuracy, being faster, less painful and more preferred by NPs. Future training packages in forearm POCUS should further address image interpretation and provide ongoing expert feedback.

Conclusions

The findings from this study suggest that competency in paediatric distal forearm POCUS can be attained by novices after a short training course and approximately 15 scans.

A trend skill that makes pediatric intensivists stand out: Critical care echocardiography

Recently, the use of point-of-care ultrasonography (POCUS) by pediatricians especially in emergency and intensive care departments has become increasingly popular. Critical care echocardiography (CCE) quickly and accurately identifies cardiac function, allowing intensivists to manage critically ill pediatric patients by manipulating vasoactive-inotrope-fluid treatment based on the echocardiographic results. Training courses for POCUS are increasingly available and more intensivists are learning how to use CCE. In this review, we focus on the importance and utility of CCE in pediatric intensive units and how it assists in the management of hemodynamically unstable pediatric patients. We highlight the common measurements carried out by intensive care specialists and emphasize the role of the CCE methods in PICUs.

The green man enigma: Unique presentation of toxicology in the emergency department

We describe a case report of hypertensive crisis induced by a combination of amphetamine and Marwitt's Kidney Pills. Diagnosis was delayed because of nonspecific physical findings including chest pain, abdominal pain, coughing, and diarrhea. This was confounded by puzzling physical examination findings, including green-colored urine and fingernails. Diagnosis was aided with point-of-care ultrasound, which presented a picture of acute cardiac insufficiency, pulmonary congestion, and bilateral effusions. Laboratory values on admission indicated acute multiorgan injury. Detailed patient history revealed chronic consumption of "Kidney," an over-the-counter drug available in Thailand with the primary ingredient methylene blue and used for a myriad of renal and genitourinary conditions. The patient also had a history of amphetamine use, which ultimately initiated his acute presentation.

Point-of-care Doppler ultrasound in the management of hyponatremia: Another string to nephrologists' Bow

Objective assessment of fluid status is vital for the appropriate management of patients with hyponatremia. Conventional physical examination suffers from several limitations in this regard, and point-of-care Doppler ultrasonography can be used as an adjunct to clinical and laboratory data in evaluating these patients.

Design of a point-of-care ultrasound curriculum for pediatric emergency medicine fellows: A Delphi study

OBJECTIVES

There has been a steady increase in the growth and utilization of point-of-care ultrasound (POCUS) in pediatric emergency medicine (PEM). POCUS has been established as an Accreditation Council for Graduate Medical Education (ACGME) core requirement for accreditation of PEM fellowship programs. Despite this requirement, training guidelines regarding POCUS knowledge and skills have yet to be developed. The purpose of this project was to develop a curriculum and a competency checklist for PEM fellow POCUS education.

METHODS

We formed a core leadership group based on expertise in one or more key areas: PEM, POCUS, curriculum development, or Delphi methods. We recruited 29 PEM POCUS or ultrasound education experts from North America to participate in a three-round electronic Delphi project. The first Delphi round asked experts to generate a list of the core POCUS knowledge and skills that a PEM fellow would need during training to function as an autonomous practitioner. Subsequent rounds prioritized the list of knowledge and skills, and the core leadership group organized knowledge and skills into global competencies and subcompetencies.

RESULTS

The first Delphi round yielded 61 POCUS areas of knowledge and skills considered important for PEM fellow learning. After two subsequent Delphi rounds, the list of POCUS knowledge and skills was narrowed to 38 items that addressed elements of six global competencies. The core leadership group then revised items into subcompetencies and categorized them under global competencies, developing a curriculum that defined the scope (depth of content) and sequence (order of teaching) of these POCUS knowledge and skill items.

CONCLUSIONS

This expert, consensus-generated POCUS curriculum provides detailed guidance for PEM fellowships to incorporate POCUS education into their programs. Our curriculum also identifies core ultrasound knowledge and skills needed by PEM fellows to perform the specific POCUS applications recommended in prior publications.

A randomized controlled trial of simulation-based mastery learning to teach the extended focused assessment with sonography in trauma

BACKGROUND

Mastery learning has gained popularity for training residents in procedural skills due to its demonstrated superiority over traditional methods. However, no studies have compared the efficacy of traditional versus mastery learning methods in residency point-of-care ultrasound education. We hypothesized that mastery learning would improve residents' skills in performing the extended focused assessment with sonography in trauma (eFAST).

METHODS

All first-year emergency medicine (EM) resident physicians at a single university hospital underwent a crossover randomized controlled trial to receive mastery-learning eFAST training either at the beginning of the academic year or 6 months into intern year. Participants were taught using a checklist validated by a panel of experts using Mastery Angoff methods and were given feedback on missed tasks until each trainee completed the eFAST with a minimum passing standard (MPS). Our primary outcome was technical proficiency between the two groups for eFAST examinations performed in the emergency department during the academic year.

RESULTS

Sixteen interns were enrolled; eight were randomized to each group. The group that received mastery training at the beginning of the year had mean clinical eFAST proficiency scores above the MPS in the first two quarters of the academic year, while the control group did not. Once the control group underwent eFAST mastery training at the midpoint of the year, both groups had mean proficiency scores above the MPS for the remainder of the year.

CONCLUSION

Simulation-based mastery learning is an effective method of teaching the eFAST examination. This training during intern orientation conferred early proficiency in clinical performance of eFAST among EM residents. This difference in proficiency was no longer present after the control group received mastery learning education halfway through the academic year.

Assessing COVID-19 pneumonia-Clinical extension and risk with point-of-care ultrasound: A multicenter, prospective, observational study

BACKGROUND

Assessing the extent of lung involvement is important for the triage and care of COVID-19 pneumonia. We sought to determine the utility of point-of-care ultrasound (POCUS) for characterizing lung involvement and, thereby, clinical risk determination in COVID-19 pneumonia.

METHODS

This multicenter, prospective, observational study included patients with COVID-19 who received 12-zone lung ultrasound and chest computed tomography (CT) scanning in the emergency department (ED). We defined lung disease severity using the lung ultrasound score (LUS) and chest CT severity score (CTSS). We assessed the association between the LUS and poor outcome (ICU admission or 30-day all-cause mortality). We also assessed the association between the LUS and hospital length of stay. We examined the ability of the LUS to differentiate between disease severity groups. Lastly, we estimated the correlation between the LUS and CTSS and the interrater agreement for the LUS. We handled missing data by multiple imputation with chained equations and predictive mean matching.

RESULTS

We included 114 patients treated between March 19, 2020, and May 4, 2020. An LUS ≥12 was associated with a poor outcome within 30 days (hazard ratio [HR], 5.59; 95% confidence interval [CI], 1.26-24.80; P = 0.02). Admission duration was shorter in patients with an LUS <12 (adjusted HR, 2.24; 95% CI, 1.47-3.40; P < 0.001). Mean LUS differed between disease severity groups: no admission, 6.3 (standard deviation [SD], 4.4); hospital/ward, 13.1 (SD, 6.4); and ICU, 18.0 (SD, 5.0). The LUS was able to discriminate between ED discharge and hospital admission excellently, with an area under the curve of 0.83 (95% CI, 0.75-0.91). Interrater agreement for the LUS was strong: κ = 0.88 (95% CI, 0.77-0.95). Correlation between the LUS and CTSS was strong: κ = 0.60 (95% CI, 0.48-0.71).

CONCLUSIONS

We showed that baseline lung ultrasound - is associated with poor outcomes, admission duration, and disease severity. The LUS also correlates well with CTSS. Point-of-care lung ultrasound may aid the risk stratification and triage of patients with COVID-19 at the ED.

Point-of-care ultrasound diagnosis of a pyogenic liver abscess in the emergency department

Pyogenic liver abscess (PLA) is a rarely encountered condition in the emergency department (ED) that necessitates a timely diagnosis by the emergency physician. An early ED diagnosis is challenging as the presenting symptoms of PLA are often variable and nonspecific. The rapid bedside diagnosis of PLA with point-of-care ultrasound (POCUS) performed by emergency physicians has not been investigated thoroughly. This case report describes the expeditious identification and ED management of PLA by implementing emergency physician-performed POCUS as the initial diagnostic modality.

Emergency physician-performed bedside ultrasound of pyomyositis

Point-of-care ultrasound (POCUS) is an indispensable tool for emergency physicians in the rapid bedside diagnosis of skin and soft tissue infections. The utility of POCUS for the differentiation of cellulitis and subcutaneous abscess is well established; however, there is a paucity of studies highlighting POCUS as a first-line imaging approach for pyomyositis, an uncommon skeletal muscle infection and/or intramuscular abscess formation requiring emergent diagnosis. This report describes a case in which emergency physician-performed POCUS led to the early detection and timely management of pyomyositis in the emergency department.

Forced diuresis oriented by point-of-care ultrasound in cardiorenal syndrome type 5 due to light chain myeloma-The role of hepatic venogram: A case report

Monitoring venous congestion by ultrasound assessment of hepatic venogram allowed individualized fluid management in severe cardiorenal syndrome type 5 due to light chain myeloma, preserving residual renal function and avoiding heart failure.

Venous congestion assessment using point-of-care Doppler ultrasound: Welcome to the future of volume status assessment

With evolution of clinician-performed bedside ultrasonography, noninvasive markers of venous congestion such as hepatic, portal, and intrarenal venous Doppler waveforms are gaining importance as an adjunct to volume status assessment. The intent of this clinical image is to illustrate the classic sonographic stigmata of severe venous congestion, associated with worse prognosis.

SARS-CoV-2-related ARDS in a maintenance hemodialysis patient: case report on tailored approach by daily hemodialysis, noninvasive ventilation, tocilizumab, anxiolytics, and point-of-care ultrasound

Without rescue drugs approved, holistic approach by daily hemodialysis, noninvasive ventilation, anti-inflammatory medications, fluid assessment by bedside ultrasound, and anxiolytics improved outcomes of a maintenance hemodialysis patient affected by severe COVID-19.

Point-of-care ultrasound for prompt diagnosis and treatment monitoring of acute epiglottitis

A 72-year-old woman presented with a 1-day history of acute throat pain, hoarseness. On cervical ultrasonography (transverse view), the epiglottis was swollen with anterior-posterior diameter of 3.5 and 3.8 mm at right and left edges, respectively. Laryngeal endoscopy showed marked swelling of the epiglottis, and acute epiglottitis was diagnosed.

Point-of-care ultrasound stewardship

Rapid adoption and widespread use of point-of-care ultrasound (POCUS) has impacted diagnostic testing and clinical care across medical disciplines. The benefits of POCUS must be weighed against certain pitfalls, such as the risk of misdiagnosis and false assurance. Beyond technical error in image acquisition and interpretation, an important pitfall is reliance on POCUS results without considering pre-test patient characteristics or the diagnostic accuracy of POCUS in varying clinical contexts. In this article, we introduce the concept of POCUS stewardship that emphasizes critical evaluation of clinical indications prior to performing POCUS as well as the individual patient and test characteristics of POCUS when integrating results into clinical decisionmaking. Adherence to these principles can lead to optimized POCUS application and improved patient care.

Difficult intravenous access as an independent predictor of delayed care and prolonged length of stay in the emergency department

OBJECTIVES

Difficult intravenous access (DIVA) is common in the emergency department (ED). We investigated the extent to which DIVA is associated with care delay outcomes including time to first laboratory draw, therapies, imaging, and ED disposition.

METHODS

An observational retrospective cohort analysis of patients with DIVA treated between 2018 and 2020 at 2 urban academic EDs was performed. DIVA was defined as patients requiring ultrasound-guided intravenous access placed by physicians or advanced practice providers (APPs) as opposed to landmark-based intravenous placement by nurses. ED throughput variables and disposition time were compared. We correlated DIVA with time to administration of intravenous pain medications, fluids, imaging contrast, laboratory results, and ED disposition.

RESULTS

A total of 108,256 subjects with 161,122 total encounters were included. DIVA occurred in 4961 (3.1%) of ED visits. Patients with DIVA were more likely to be female (3.5% vs 2.6% for males, odds ratio [OR] 1.34, 95% confidence interval [CI]: 1.27-1.42), self-identify as black (OR 1.78, 95% CI: 1.66-1.91), and have higher acuity of illness (P < 0.001). Among pediatric patients, DIVA occurred most often in the first year of life at a rate of 3.25%. In adults, DIVA occurred in 2 age peaks; at 35 years (4.02%), and at 63 years (3.44%). In all workflow metrics, the presence of DIVA was associated with significant delays in median time to completion: 50 minutes for pain medication administration, 36 minutes for intravenous fluid administration, 29 minutes for laboratory results, 57 minutes for intravenous contrast administration, and 87 minutes for discharge orders.

CONCLUSION

DIVA was associated with increased time to therapies, diagnostic studies, imaging completion, and ED disposition. A more expeditious approach to achieving intravenous access in patients with predicted DIVA could improve ED throughput and patient care overall.

A novel measure for characterizing ultrasound device use and wear

Point-of-care ultrasound (POCUS) equipment management is critical in optimizing daily clinical operations in emergency departments (EDs). Traditional consultative ultrasound laboratories are well practiced at operations management, but this is not the case for POCUS programs, because machine upgrade and replacement metrics have not been developed or tested. We present a data-driven method for assessment of POCUS equipment maintenance and replacement named the ULTrA (a data-driven approach to point-of-care ultrasound upgrade) score. This novel model of assessing each ultrasound machine by quantitative scoring in each of four mostly objective categories: use (U), likeability (L), trustworthiness (Tr), and age (A). We propose the ULTrA model as a method to identify underperforming devices which could be upgraded or eliminated, and to compare relative performance amongst a group of departmental ultrasound machines. This composite score may be a useful objective tool that could replace individual proxies for clinical effectiveness, such as age, use, or individual provider preference. Additional research in multiple centers would be needed to refine and validate the ULTrA score. Once fully developed, the ULTrA score could be deployed in EDs and other clinical settings where POCUS is used to help streamline resources to maintain a functional and state-of-the-art fleet of ultrasound machines over time.

Artificial intelligence versus expert: a comparison of rapid visual inferior vena cava collapsibility assessment between POCUS experts and a deep learning algorithm

OBJECTIVES

We sought to create a deep learning algorithm to determine the degree of inferior vena cava (IVC) collapsibility in critically ill patients to enable novice point-of-care ultrasound (POCUS) providers.

METHODS

We used publicly available long short term memory (LSTM) deep learning basic architecture that can track temporal changes and relationships in real-time video, to create an algorithm for ultrasound video analysis. The algorithm was trained on public domain IVC ultrasound videos to improve its ability to recognize changes in varied ultrasound video. A total of 220 IVC videos were used, 10% of the data was randomly used for cross correlation during training. Data were augmented through video rotation and manipulation to multiply effective training data quantity. After training, the algorithm was tested on the 50 new IVC ultrasound video obtained from public domain sources and not part of the data set used in training or cross validation. Fleiss' κ was calculated to compare level of agreement between the 3 POCUS experts and between deep learning algorithm and POCUS experts.

RESULTS

There was very substantial agreement between the 3 POCUS experts with κ = 0.65 (95% CI = 0.49-0.81). Agreement between experts and algorithm was moderate with κ = 0.45 (95% CI = 0.33-0.56).

CONCLUSIONS

Our algorithm showed good agreement with POCUS experts in visually estimating degree of IVC collapsibility that has been shown in previously published studies to differentiate fluid responsive from fluid unresponsive septic shock patients. Such an algorithm could be adopted to run in real-time on any ultrasound machine with a video output, easing the burden on novice POCUS users by limiting their task to obtaining and maintaining a sagittal proximal IVC view and allowing the artificial intelligence make real-time determinations.

Unexpected finding of myocardial depression in 2 healthy young patients with COVID-19 pneumonia: possible support for COVID-19-related myocarditis

COVID-19 is proving to be a devastating pandemic with both tragic economic and health consequences worldwide. Point-of-care ultrasound (POCUS) of the lungs has been thrust into the forefront of resources that could be used in the management of COVID-19 acute care patients. However, relatively little attention has been paid to POCUS utility in assessing the heart in COVID-19 patients. Anecdotal reports suggest encounters of likely COVID-19 induced pericardial effusions and myocardial electrical dysfunction. This article presents 2 cases of generally healthy patients who were noted to have classic COVID-19 bilateral pneumonia findings on lung ultrasound and incidentally discovered to have unsuspected left ventricular dysfunction likely resulting from myocarditis. POCUS videos are presented as illustrations of this potentially overlooked complication.

Utility of Doppler ultrasound derived hepatic and portal venous waveforms in the management of heart failure exacerbation

Doppler ultrasound assessment of hepatic and portal vein waveforms aids in the management of patients with heart failure by noninvasively monitoring the efficacy of decongestive therapy. In the right clinical context, these waveforms can be used as an adjunct to physical examination and inferior vena cava ultrasound.

DIY AI, deep learning network development for automated image classification in a point-of-care ultrasound quality assurance program

BACKGROUND

Artificial intelligence (AI) is increasingly a part of daily life and offers great possibilities to enrich health care. Imaging applications of AI have been mostly developed by large, well-funded companies and currently are inaccessible to the comparatively small market of point-of-care ultrasound (POCUS) programs. Given this absence of commercial solutions, we sought to create and test a do-it-yourself (DIY) deep learning algorithm to classify ultrasound images to enhance the quality assurance work-flow for POCUS programs.

METHODS

We created a convolutional neural network using publicly available software tools and pre-existing convolutional neural network architecture. The convolutional neural network was subsequently trained using ultrasound images from seven ultrasound exam types: pelvis, heart, lung, abdomen, musculoskeletal, ocular, and central vascular access from 189 publicly available POCUS videos. Approximately 121,000 individual images were extracted from the videos, 80% were used for model training and 10% each for cross validation and testing. We then tested the algorithm for accuracy against a set of 160 randomly extracted ultrasound frames from ultrasound videos not previously used for training and that were performed on different ultrasound equipment. Three POCUS experts blindly categorized the 160 random images, and results were compared to the convolutional neural network algorithm. Descriptive statistics and Krippendorff alpha reliability estimates were calculated.

RESULTS

The cross validation of the convolutional neural network approached 99% for accuracy. The algorithm accurately classified 98% of the test ultrasound images. In the new POCUS program simulation phase, the algorithm accurately classified 70% of 160 new images for moderate correlation with the ground truth, α = 0.64. The three blinded POCUS experts correctly classified 93%, 94%, and 98% of the images, respectively. There was excellent agreement among the experts with α = 0.87. Agreement between experts and algorithm was good with α = 0.74. The most common error was misclassifying musculoskeletal images for both the algorithm (40%) and POCUS experts (40.6%). The algorithm took 7 minutes 45 seconds to review and classify the new 160 images. The 3 expert reviewers took 27, 32, and 45 minutes to classify the images, respectively.

CONCLUSIONS

Our algorithm accurately classified 98% of new images, by body scan area, related to its training pool, simulating POCUS program workflow. Performance was diminished with exam images from an unrelated image pool and ultrasound equipment, suggesting additional images and convolutional neural network training are necessary for fine tuning when using across different POCUS programs. The algorithm showed theoretical potential to improve workflow for POCUS program directors, if fully implemented. The implications of our DIY AI for POCUS are scalable and further work to maximize the collaboration between AI and POCUS programs is warranted.

Getting started in paediatric emergency medicine point-of-care ultrasound: Five fundamental applications

Point-of-care ultrasound is a valuable tool in the Paediatric Emergency Medicine department. It can be utilised at the patient bedside to augment the physical examination, improving clinical accuracy. Alternatively, it can safeguard needle guided procedures and improve their success rate. It allows real-time information to be gathered without exposing the child to ionising radiation. This article outlines five fundamental applications and how it can be incorporated into clinical practice.

Point-of-care ultrasound for deep venous thrombosis of the lower limb

The incidence and morbidity of deep venous thrombosis (DVT) and pulmonary embolus are high. Although efforts to increase screening for DVT have been recommended, this is limited by resources. Venous duplex ultrasound has replaced venography as the first-line investigation of choice for DVT, increasing availability and reducing patient exposure to radiation and intravenous contrast. Furthermore, an abbreviated ultrasound where DVT is inferred from incomplete venous compressibility has an equivalent accuracy to venous duplex, requiring less time and training enabling its widespread use by emergency, critical care and anaesthesia clinicians. In this review, the evolution and method of lower limb venous compression ultrasound is described along with evidence for its use in patients at high risk for DVT in these clinical settings.

Alterations in Portal Vein Flow and Intrarenal Venous Flow Are Associated With Acute Kidney Injury After Cardiac Surgery: A Prospective Observational Cohort Study

Background

Acute kidney injury (AKI) after cardiac surgery is associated with adverse outcomes. Venous congestion can impair kidney function, but few tools are available to assess its impact at the bedside. The objective of this study was to determine whether portal flow pulsatility and alterations in intrarenal venous flow assessed by Point‐Of‐Care ultrasound are associated with AKI after cardiac surgery.

Methods and Results

This single‐center prospective cohort study recruited patients undergoing cardiac surgery with cardiopulmonary bypass. Hepatic and renal Doppler ultrasound assessments were performed before surgery, at the intensive care unit admission, and daily for 3 days after surgery. The primary statistical analysis was performed using proportional hazards model for time‐dependent variables. Among the 145 patients included, 49 patients (33.8%) developed AKI after cardiac surgery. The detection of portal flow pulsatility was associated with an increased risk of AKI (hazard ratio: 2.09, confidence interval, 1.11–3.94, P=0.02), as were severe alterations of intrarenal venous flow (hazard ratio: 2.81, confidence interval, 1.42–5.56, P=0.003). These associations remained significant in multivariable models. The addition of these markers to preoperative risk factors and central venous pressure measurement at intensive care unit admission improved the prediction of AKI. (Continuous net reclassification improvement: 0.364, confidence interval, 0.081–0.652 for portal Doppler and net reclassification improvement: 0.343, confidence interval, 0.081–0.628 for intrarenal Doppler)

Conclusions

Portal flow pulsatility and intrarenal flow alterations are markers of venous congestion and are independently associated with AKI after cardiac surgery. These tools might offer valuable information to develop strategies aimed at treating or preventing congestive cardiorenal syndrome after cardiac surgery.

Clinical Trial Registration

URL: https://www.clinicaltrials.gov. Unique identifier: NCT02831907.

Usefulness of point-of-care ultrasound in the clinical suspicion of lung tumours prior to CT: A case report and discussion

Lung ultrasound may serve as a diagnostic and therapeutic guidance in many respiratory conditions, especially before thorax CT is available.

Point-of-care gastrointestinal ultrasound in inflammatory bowel disease: An accurate alternative for disease monitoring

Background and Aim

Point‐of‐care ultrasound (POCUS) is a noninvasive alternative to ileocolonoscopy for monitoring disease activity in inflammatory bowel disease (IBD) but is underutilized in practice. Accuracy data are needed to engender clinician confidence in POCUS and increase uptake. The aim of this study was to evaluate the accuracy of POCUS compared to ileocolonoscopy in detecting active disease and extent in patients with IBD.

Methods

A prospective, blinded study was performed at a single tertiary center in South Australia between May 2017 and May 2018. Consecutive patients with a formal diagnosis of IBD who underwent both POCUS and ileocolonoscopy within 30 days of one another, performed to evaluate IBD disease activity, were eligible for participation. The accuracy of POCUS compared to ileocolonoscopy was assessed using sensitivity, specificity, and Cohen's kappa coefficient analyses.

Results

A total of 74 patients were included in the final analysis, 35 (47%) of whom had Crohn's disease and 39 (53%) ulcerative colitis; 37 subjects (50%) underwent a POCUS and ileocolonoscopy on the same day. POCUS demonstrated 91% sensitivity and 83% specificity for detecting endoscopically active IBD, correlating with a positive predictive value (PPV) of 89%, a negative predictive value (NPV) of 86%, and a kappa coefficient of 0.74 (88%). POCUS defined disease extent with 87% sensitivity and 81% specificity, correlating with a PPV of 85% and NPV of 83% and a kappa coefficient of 0.70 (85%).

Conclusion

POCUS is accurate in defining disease activity and extent in IBD compared to ileocolonoscopy. POCUS represents an appealing, noninvasive alternative to ileocolonoscopy for monitoring disease activity in IBD.

Gastrointestinal ultrasound in inflammatory bowel disease care: Patient perceptions and impact on disease-related knowledge

Background and Aim

Objective monitoring of disease activity is integral to therapeutic decision-making in inflammatory bowel disease (IBD). Data are sparse on patients' perspectives of tools used to monitor disease activity in IBD. To evaluate patients' perspectives of gastrointestinal ultrasound (GIUS) performed during routine IBD clinical care, along with its impact on IBD-specific knowledge.

Methods

Patients with a formal diagnosis of IBD who underwent GIUS at two tertiary IBD services between March 2017 and January 2019 participated in this prospective study. Participants completed a questionnaire measuring the acceptability, tolerability, and usefulness of GIUS using a visual analogue scale (VAS) from 0 (disagree) to 10 (strongly agree). Comparative acceptability of IBD monitoring tools and the impact of GIUS on IBD-specific knowledge was measured.

Results

A total of 121 participants completed the questionnaire, with a mean age of 42 years (range 17-78), 54 (45%) males, and 79 (65%) Crohn's disease patients. In the overall population, GIUS was scored as highly acceptable for monitoring IBD (mean 9.20 ± 1.37) compared to colonoscopy (7.94 ± 2.30), stool sampling (8.17 ± 1.96), blood sampling (8.87 ± 1.62), and imaging (8.67 ± 1.60); P < 0.01 for each comparison. GIUS caused little patient discomfort (1.88 ± 1.83), and 98 (81%) participants ranked GIUS as their preferred IBD monitoring tool. GIUS also improved patients' overall IBD-specific knowledge (VAS IBD-specific knowledge 7.96 ± 1.92), including their understanding of the need for medical therapy and disease extent.

Conclusion

GIUS is a highly acceptable and well-tolerated tool for monitoring disease activity in IBD patients. GIUS is preferred by patients and enhances IBD-specific knowledge.

Impact of one-day course on medical student knowledge, attitudes and comfort with point-of-care ultrasound-guided procedures

Introduction

Given the ubiquity of procedural ultrasound in clinical practice, the importance of exposing medical students to the topic is increasingly relevant. We examined final-year medical student knowledge, attitudes and comfort level with procedural ultrasound before and after a one-day course.

Methods

This was a prospective cross-sectional survey of final-year students at a single university. We collected data regarding ultrasound experience, career goals and knowledge of procedural ultrasound, as well as attitudes and comfort (each assessed with three questions using a Likert scale). All students were sent a pre- and post-test survey, and we compared pre- and post-test results using the chi-square test, with a two-tailed P-value < 0.05 considered statistically significant.

Results

All of the 94 course participants completed both the pre- and post-tests. Of the 23 non-participants, 16 (70%) completed both pre- and post-tests. Almost all (99%) respondents reported some prior ultrasound exposure, but only 34% had previously performed at least one core procedure with ultrasound guidance. Among participants, we found a 13% average increase in knowledge score (P < 0.05) between pre- and post-tests; there was no significant change in knowledge score among non-participants. Among participants, we also found an increase in positive attitudes (P < 0.05 for two of three questions) and an increased comfort level with procedural ultrasound (P < 0.05 for all three questions).

Discussion

A one-day course can impact medical student knowledge, attitudes and comfort with the use of ultrasound for procedural guidance.

Conclusion

Further research is needed to assess long-term outcomes and explore alternative educational modalities.

Expanding our FoCUS: the utility of advanced echocardiography in the emergency department

Point-of-care ultrasound (POCUS) use is widespread amongst emergency physicians (EPs). Many sonographic modalities have proven useful in the emergency department (ED), including basic echocardiography. Progressing to more advanced echocardiography allows for improved accuracy when making time-critical diagnoses and management decisions, particularly among the sickest patients. Acquisition of this skill set by EPs is feasible and enhances patient care.

Time to establish pillars in point-of-care ultrasound

Point of care ultrasound (PoCUS) has evolved rapidly and is used by many medical specialties. We propose five essential pillars of PoCUS that are necessary framework for hospital-based PoCUS training and credentialing programs. The pillars are: governance, infrastructure, administration, education and quality. It is time to establish these pillars to ensure the best practice in PoCUS use.

The path to ultrasound proficiency: A systematic review of ultrasound education and training programmes for junior medical practitioners

Background

Point-of-care ultrasound (POCUS) is a form of diagnostic ultrasonography, which has a defined role as a clinical adjunct in patient assessment and management. If it is to continue to develop as a core clinical skill, junior medical practitioners and trainees may benefit from dedicated ultrasound education and familiarisation early in their training. Controversy endures, however, as inappropriate use of this highly technical and operator-dependent imaging modality has negative clinical implications.

Aims

A systematic review was performed to assess the ability of doctors in training to perform clinically appropriate and beneficial diagnostic ultrasound after undergoing a formal training programme.

Methods

Studies meeting pre-defined inclusion criteria were identified in electronic databases MEDLINE, EMBASE, CINAHL, PUBMED and through Google Scholar. Methodological quality was assessed using an established series of indicators.

Results

Fifteen studies were included in the review. Ten of these were performed in the United States, and eight focused on emergency medicine trainees. After the teaching intervention, ten studies assessed overall ultrasound capacity by calculating the collective sensitivity and specificity of trainee-performed ultrasound. Five studies used a standardised objective assessment tool to evaluate ultrasound skills and technique. Studies varied in terms of the specific ultrasound use investigated, teaching programmes used and methodological quality. Consistently identified areas for further research included the definition of the trainee learning curve and what constitutes competency in ultrasound.

Conclusions

Ultrasound can feasibly be incorporated into junior medical practitioner training, but more research is required to assess its effectiveness and appropriateness.