Point-of-Care Ocular Ultrasound for the Diagnosis of Retinal Detachment: A Systematic Review and Meta-Analysis

Remote Diagnosis of Retinal Detachment in an Emergency Department Using Nonmydriatic Hybrid Ocular Imaging

Background: Ocular emergencies are commonly evaluated in general emergency departments (ED) where ophthalmologists are rarely available. Nonmydriatic ocular imaging combining color fundus photographs and optical coherence tomography (NMFP-OCT) can help with rapid remote triage by ophthalmologists. We evaluated the rate at which retinal detachments (RDs) can be diagnosed with NMFP-OCT in the ED. Methods: Quality improvement project with prospective collection of data on RD patients who had NMFP-OCT obtained by ED staff over 1 year. Photographs were interpreted remotely by ophthalmologists and all patients underwent an in-person ophthalmologic examination in the ED to confirm the presence of a RD. Results: A total of 63 eyes (58 patients) had a RD, among which 53 (84.1%) had strong suggestion of RD on ocular imaging (34 [54%] were seen on both color and OCT nerve/macula; 11 [17.5%] were seen on color but missed on OCT; 8 [12.7%] were missed on color but seen on OCT). Ten RDs (15.9%) were missed on both color and OCT because of peripheral location of the RD (4, 40%), vitreous hemorrhage (4, 40%), or poor image quality (2, 20%). A total of 40 out of 58 patients were not seen by an eye care provider prior to reaching our ED and 10 had an inappropriate stroke workup for acute vision loss of presumed vascular origin. Conclusion: NMFP-OCT of the posterior pole obtained by ED staff revealed the RD in 84.1% of eyes, allowing for rapid remote triage of patients with visual symptoms and avoiding unnecessary testing when the diagnosis of RD is confirmed.

Ocular Ultrasound

Point-of-care ultrasound may be used to assist in the diagnosis of ocular complaints in the emergency department. With the use of a linear probe, the emergency physician can view anterior and posterior chamber structures of the patient's eye and evaluate for signs of pathology.

Ocular Disease Detection with Deep Learning (Fine-Grained Image Categorization) Applied to Ocular B-Scan Ultrasound Images

INTRODUCTION

The aim of this work is to develop a deep learning (DL) system for rapidly and accurately screening for intraocular tumor (IOT), retinal detachment (RD), vitreous hemorrhage (VH), and posterior scleral staphyloma (PSS) using ocular B-scan ultrasound images.

METHODS

Ultrasound images from five clinically confirmed categories, including vitreous hemorrhage, retinal detachment, intraocular tumor, posterior scleral staphyloma, and normal eyes, were used to develop and evaluate a fine-grained classification system (the Dual-Path Lesion Attention Network, DPLA-Net). Images were derived from five centers scanned by different sonographers and divided into training, validation, and test sets in a ratio of 7:1:2. Two senior ophthalmologists and four junior ophthalmologists were recruited to evaluate the system's performance.

RESULTS

This multi-center cross-sectional study was conducted in six hospitals in China. A total of 6054 ultrasound images were collected; 4758 images were used for the training and validation of the system, and 1296 images were used as a testing set. DPLA-Net achieved a mean accuracy of 0.943 in the testing set, and the area under the curve was 0.988 for IOT, 0.997 for RD, 0.994 for PSS, 0.988 for VH, and 0.993 for normal. With the help of DPLA-Net, the accuracy of the four junior ophthalmologists improved from 0.696 (95% confidence interval [CI] 0.684-0.707) to 0.919 (95% CI 0.912-0.926, p < 0.001), and the time used for classifying each image reduced from 16.84 ± 2.34 s to 10.09 ± 1.79 s.

CONCLUSIONS

The proposed DPLA-Net showed high accuracy for screening and classifying multiple ophthalmic diseases using B-scan ultrasound images across mutiple centers. Moreover, the system can promote the efficiency of classification by ophthalmologists.

Comparing New Smartphone-Connected Handheld Ultrasound Device vs. Traditional Ultrasound in Vitreo-Retinal Disease Diagnosis

(1) Background: Ocular emergencies account for 1.5-3% of emergency department (ED) visits and require urgent diagnosis to prevent serious complications. Ultrasonography is a crucial, non-invasive diagnostic tool for these conditions but traditionally lacks portability and integration with modern electronic smart devices. The purpose of this study was to assess the accuracy and performance of a new handheld ultrasound device in comparison to a conventional cart-based sonographic machine in patients attending to the ED for vitreo-retinal diseases. (2) Methods: three specialists in ophthalmology, with at least 4-year experience in vitreo-retinal diseases and eye ultrasound, evaluated images of 50 eyes with both portable and traditional ultrasound probes. Each specialist made the diagnosis based on the images captured with both probes and then rated their overall image quality and confidence of diagnosis with a five-point Likert scale. The concordance of diagnosis between the two probes was evaluated. (3) Results: The sample comprised 42 patients. Twenty (40%) healthy eyes and thirty eyes with the following vitreo-retinal interface conditions were examined: 12 retinal detachment (24%), 8 vitreous hemorrhage (16%), and 10 posterior vitreous detachment (20%). The overall accuracy of the two devices appeared to be comparable (70.7% vs. 69.3%). The Butterfly iQ+ probe showed similar sensitivity in retinal detachment diagnosis (91.7% vs. 94.4% of the Accutome B-scan Pro), while it showed poor performance in diagnosing posterior vitreous detachment (sensitivity = 27.2%); (4) Conclusions: The Butterfly iQ+ device demonstrated high sensitivity in the diagnosis of retinal detachment. Significant adjustments are still needed to improve the resolution of the vitreous body.

A comparison of five point-of-care ultrasound devices for use in ophthalmology and facial aesthetics

Introduction

Point-of-care ultrasound is becoming increasingly popular, and we sought to examine its role in evaluating ocular and periocular structures and facial vasculature. With the large number of point-of-care ultrasound devices available, it is difficult to determine which devices may be best suited for ophthalmic and facial aesthetic applications. This study compares five popular handheld point-of-care ultrasound devices to help guide clinicians in choosing the device best suited for their needs.

Methods

We compared five point-of-care ultrasound devices: Butterfly IQ+ (Butterfly, Burlington, MA), L15 (Clarius Mobile Health, Vancouver, British Columbia, Canada), L20 (Clarius Mobile Health, Vancouver, British Columbia, Canada), Lumify (Philips, Amsterdam, Netherlands) and Vscan Air (GE, Boston, MA). Three ophthalmologists obtained the following views on three volunteers: eight arteries, four ocular and periocular structures and areas of filler injections. The image quality of each view was graded on a four-point Likert-type scale. In addition, graders filled out a survey. The data were analysed using analysis of variance tests with the significance level set to p < 0.05.

Results

In terms of overall image quality, the L20 received the highest mean rating, followed by the L15, Vscan Air, Butterfly IQ+ and the Lumify (p < 0.05). With further stratification for structure type, the L20 was ranked first for filler, artery and orbital imaging (p < 0.05).

Conclusions

The L20 received the highest image quality rankings. While image quality is an important aspect of point-of-care ultrasound device selection, other factors such as cost, wireless capabilities, range of presets and battery life should also be considered.

Utilization of Point-of-Care Ultrasound as an Imaging Modality in the Emergency Department: A Systematic Review and Meta-Analysis

Point-of-care ultrasound (POCUS) is an imaging modality that has become a fundamental part of clinical care provided in the emergency department (ED). The applications of this tool in the ED have ranged from resuscitation, diagnosis, and therapeutic to procedure guidance. This review aims to summarize the evidence on the use of POCUS for diagnosis and procedure guidance. To achieve this, CrossRef, PubMed, Cochrane Library, Web of Science, and Google Scholar databases were extensively searched for studies published between January 2000 and November 2023. Additionally, the risk of bias assessment was performed using the Quality Assessment of Diagnostic Accuracy Studies 2 (for studies on the diagnostic role of POCUS) and Cochrane Risk of Bias tool (for studies on the use of POCUS for procedure guidance). Furthermore, diagnostic accuracy outcomes were pooled using STATA 16 software (StatCorp., College Station, TX, USA), while outcomes related to procedure guidance were pooled using the Review Manager software. The study included 81 articles (74 evaluating the diagnostic application of POCUS and seven evaluating the use of POCUS in guiding clinical procedures). In our findings sensitivities and specificities for various conditions were as follows: appendicitis, 65% and 89%; hydronephrosis, 82% and 74%; small bowel obstruction, 93% and 82%; cholecystitis, 75% and 96%; retinal detachment, 94% and 91%; abscess, 95% and 85%; foreign bodies, 67% and 97%; clavicle fractures, 93% and 94%; distal forearm fractures, 97% and 94%; metacarpal fractures, 94% and 92%; skull fractures, 91% and 97%; and pleural effusion, 91% and 97%. A subgroup analysis of data from 11 studies also showed that the two-point POCUS has a sensitivity and specificity of 89% and 96%, while the three-point POCUS is 87% sensitive and 92% specific in the diagnosis of deep vein thrombosis. In addition, the analyses showed that ultrasound guidance significantly increases the overall success rate of peripheral venous access (p = 0.02) and significantly reduces the number of skin punctures (p = 0.01) compared to conventional methods. In conclusion, POCUS can be used in the ED to diagnose a wide range of clinical conditions accurately. Furthermore, it can be used to guide peripheral venous access and central venous catheter insertion.

Success and complications in lumbar punctures of pediatric patients with leukemia: a study protocol for a randomized clinical crossover trial of a bioimpedance needle system versus conventional procedure

BACKGROUND

Acute lymphoblastic leukemia (ALL) is the most common malignancy diagnosed in children. At present, the long-term survival from pediatric ALL is well over 90%. However, the probability of event-free survival is reduced if the lumbar puncture (LP) procedures at the beginning of the patient's intrathecal therapy cause blood leakage into the spinal canal and blast cells contaminate the cerebrospinal fluid. According to the literature, such traumatic LP procedures concern one out of five pediatric patients with ALL. Recently, a novel medical device measuring the tissue bioimpedance at the tip of a spinal needle was found feasible in pediatric patients with ALL. The LP procedure was successful at the first attempt in 80% of procedures, and the incidence of traumatic LPs was then 11%. The purpose of the present study is to compare the bioimpedance spinal needle system with the standard clinical practice resting on a conventional spinal needle and investigate its efficacy in clinical practice.

METHODS

The study is a multicenter, randomized, two-arm crossover noninferiority trial of pediatric hemato-oncology patients that will be conducted within the usual clinical workflow. Patients' LP procedures will be performed alternately either with the IQ-Tip system (study arm A) or a conventional Quincke-type 22G spinal needle (study arm B). For each enrolled patient, the order of procedures is randomly assigned either as ABAB or BABA. The total number of LP procedures will be at least 300, and the number of procedures per patient between two and four. After each study LP procedure, the performance will be recorded immediately, and 1-week diary-based and 4-week record-based follow-ups on symptoms, complications, and adverse events will be conducted thereafter. The main outcomes are the incidence of traumatic LP, first puncture success rate, and incidence of post-dural puncture headache.

DISCUSSION

The present study will provide sound scientific evidence on the clinical benefit, performance, and safety of the novel bioimpedance spinal needle compared with the standard clinical practice of using conventional spinal needles in the LP procedures of pediatric patients with leukemia.

TRIAL REGISTRATION

ISRCTN ISRCTN16161453. Registered on 8 July 2022.

Diagnostic test accuracy of ultrasound for orbital cellulitis: A systematic review

BACKGROUND

Periorbital and orbital cellulitis are inflammatory conditions of the eye that can be difficult to distinguish using clinical examination alone. Computer tomography (CT) scans are often used to differentiate these two infections and to evaluate for complications. Orbital ultrasound (US) could be used as a diagnostic tool to supplement or replace CT scans as the main diagnostic modality. No prior systematic review has evaluated the diagnostic test accuracy (DTA) of ultrasound compared to cross-sectional imaging.

OBJECTIVE

To conduct a systematic review of studies evaluating the DTA of orbital ultrasound compared with cross-sectional imaging, to diagnose orbital cellulitis.

METHODS

MEDLINE, EMBASE, CENTRAL, and Web of Science were searched from inception to August 10, 2022. All study types were included that enrolled patients of any age with suspected or diagnosed orbital cellulitis who underwent ultrasound and a diagnostic reference standard (i.e., CT or magnetic resonance imaging [MRI]). Two authors screened titles/abstracts for inclusion, extracted data, and assessed the risk of bias.

RESULTS

Of the 3548 studies identified, 20 were included: 3 cohort studies and 17 case reports/series. None of the cohort studies directly compared the diagnostic accuracy of ultrasound with CT or MRI, and all had high risk of bias. Among the 46 participants, diagnostic findings were interpretable in 18 (39%) cases which reported 100% accuracy. We were unable to calculate sensitivity and specificity due to limited data. In the descriptive analysis of the case reports, ultrasound was able to diagnose orbital cellulitis in most (n = 21/23) cases.

CONCLUSION

Few studies have evaluated the diagnostic accuracy of orbital ultrasound for orbital cellulitis. The limited evidence based on low quality studies suggests that ultrasound may provide helpful diagnostic information to differentiate orbital inflammation. Future research should focus studies to determine the accuracy of orbital US and potentially reduce unnecessary exposure to radiation.

Spinal sonography and central neuraxial blocks

Central neuraxial blocks (CNBs), which include spinal, epidural, and combined spinal epidural injections, are indispensable techniques in the anesthesiologist's armamentarium. Indeed, in scenarios such as when dealing with the obstetric population, patients with obesity, or patients having respiratory compromise (e.g., lung disease or scoliosis), CNBs are the mainstay for anesthesia and/or analgesia. Traditionally, CNBs are performed using anatomical landmarks, which are simple, easy to master, and exceptionally successful in most cases. Nevertheless, there are notable limitations with this approach, especially in scenarios where CNBs are considered mandatory and vital. Any limitation of an anatomic landmark-based approach is an opportunity for an ultrasound-guided (USG) technique. This has become particularly true for CNBs, where recent advances in ultrasound technology and research data have addressed many of the shortcomings of the traditional anatomic landmark-based approaches. This article reviews the ultrasound imaging of the lumbosacral spine and its application for CNBs.

Covered or uncovered: A randomized control trial of Tegaderm versus no Tegaderm for ocular ultrasound

BACKGROUND

Studies on ocular point-of-care ultrasound vary on whether gel should be directly applied to the eye or on top of an adhesive membrane (i.e., Tegaderm™). However, there are currently no data regarding which approach has better image quality and the impact of patient preference. In this study, we sought to address this gap by assessing the difference in image quality and patient preference between Tegaderm™ versus no Tegaderm™ for ocular ultrasound in the emergency department.

METHODS

Patients were randomized to have a Tegaderm™ placed on either their right or left eye. The other eye served as a comparator with no Tegaderm™. Ultrasound was performed on the right eye followed by the left eye in all instances. After performing each ultrasound, the sonographer asked the patient to rate their maximal discomfort from the ultrasound of that eye using a Likert scale (0 = no discomfort; 10 = severe discomfort). The sonographer then asked the patient which side (Tegaderm™ vs no Tegaderm™) they preferred. Finally, images were reviewed by an experienced ultrasound fellowship-trained sonographer blinded to allocation and rated from 1 to 5. Continuous data were analyzed using descriptive statistics with mean and standard deviation. A paired samples t-test was performed to assess for differences between groups. Categorical data were presented as frequency and percentage.

RESULTS

The mean image score was significantly worse with Tegaderm™ compared with no Tegaderm™ (mean difference: 0.94/5.00; 95% CI 0.79-1.08; p < 0.001). This was consistent in both the transverse and the sagittal plane subgroups. The percentage of acceptable images was also higher in the no Tegaderm™ group compared with the Tegaderm™ group (97.8% versus 82.8%). There was no statistically significant difference in patient discomfort with the Tegaderm™ versus no Tegaderm™ group. When asked to compare the two approaches, 54.4% of patients preferred Tegaderm™, 30.0% preferred no Tegaderm™, and 15.6% had no preference.

CONCLUSIONS

Tegaderm™ was associated with reduced image quality and no significant difference in patient discomfort when utilized for ocular ultrasound. This study suggests that ocular ultrasound may be better performed without the use of Tegaderm™. Future research should evaluate the impact of Tegaderm™ vs. no Tegaderm™ among more novice users.

Post-intravitreal Injection Endophthalmitis Identified with Point-of-care Ultrasound

Case Presentation

An 88-year-old female presented to the emergency department (ED) with complaints of painful vision loss four days after an intravitreal injection for her neovascular macular degeneration. Her right eye visual acuity was markedly diminished with an absence of red reflex. A point-of-care ocular ultrasound was performed and demonstrated hyperechoic vitreous debris concerning for endophthalmitis.

Discussion

Endophthalmitis is an infection of the vitreous or aqueous humors commonly caused by exogenous sources, such as inoculation of bacteria into the eye from surgery, injections, or trauma. It is an ophthalmologic emergency as it is a vision-threatening infection. Although a rare complication, post-surgery or post-injection are the leading causes of endophthalmitis. Point-of-care ocular ultrasound findings suggestive of endophthalmitis, such as hyperechoic vitreous debris, aid in the timely diagnosis and treatment of patients in the ED.

Ultrasound Measurement of the Intervertebral Space in the Lateral Recumbent Versus Sitting Positions

BACKGROUND

Diagnostic lumbar puncture (LP) is an invasive procedure routinely performed within the emergency department (ED). LP is traditionally performed with the patient in either the lateral recumbent or sitting position. We investigated if the intervertebral space is larger in one of these positions. If one position is larger than the other, this would imply that one position offers a higher chance of a successful lumbar puncture than the other position.

OBJECTIVE

We sought to determine if there is a significant size difference of the L4/L5 intervertebral space in the lateral recumbent compared with the sitting position.

METHODS

Point-of-care ultrasound (POCUS) was performed to measure the size of each volunteer's L4/L5 intervertebral space in both the seated and lateral recumbent positions. All volunteers >18 years of age were eligible for the study. Thirty volunteers had measurements taken. Three measurements were taken by each investigator in both positions for each volunteer.

RESULTS

The median L4/L5 intervertebral space distance was 1.7511 cm in the lateral recumbent position and 1.9511 cm in the seated position with a Wilcoxon signed rank p value <.0001. The interspinous space in the seated position was found to be significantly larger than in the lateral recumbent position.

CONCLUSION

The size of the interspinous space in the seated position on ultrasound was found to be larger than the lateral recumbent position, suggesting that LP may be more successful in the seated position.

Point-of-Care Ultrasound Findings in a Case of Orbital Cellulitis: A Case Report

BACKGROUND

Ophthalmologic complaints are common in the emergency department. The utility of point-of-care ultrasound (POCUS) as an accessible, noninvasive modality to evaluate ocular pathology is of great value-particularly in settings where resources are limited or where ophthalmologic consultation may not be readily available.

CASE REPORT

A 21-year-old woman presented to the emergency department with periorbital edema, erythema, and drainage that was worsening despite topical and oral antimicrobial therapy. Mild proptosis was present on examination. POCUS was performed to investigate her symptoms further. A modified ocular ultrasound revealed prominence and edema of the retro-orbital soft tissue with echogenic fat, consistent with the diagnosis of orbital cellulitis. These findings were corroborated with computed tomography imaging. Why Should an Emergency Physician Be Aware of This?: Few reports describe the utility of POCUS in evaluating patients for orbital cellulitis. This case emphasizes the value of POCUS in assessing patients presenting to the emergency department with ocular complaints and demonstrates ultrasound-specific findings that may lead the clinician toward the diagnosis of orbital cellulitis. © 2021 Elsevier Inc.

Benefits to utilising ultrasound in examining the eye

Ocular ultrasound (US) is not one of ACEMs 'big 5' in terms of US capability that is expected of a trainee or FACEM. Most texts have a small chapter dedicated to ocular US but it is usually at the back or a subsection of a chapter where it is rarely seen or appreciated. However, it is a straightforward scan to perform with many benefits which will be discussed in this article. The eye offers an excellent medium for US beam penetration, making good quality images of the retina easy and quick to acquire. This has the added benefit of being able to share images with an ophthalmologist remotely, improving time to definitive treatment. It can also be used in patients who cannot cooperate with sitting at a slitlamp, for example moribund or trauma patients. The authors propose that ocular US teaching should be incorporated into the ACEM syllabus, being a vital adjunct to a comprehensive eye examination.

Point of care ultrasound and ocular injuries: A case of lens dislocation and a comprehensive review of the literature

Point-of-care ultrasound (POCUS) can help the clinician diagnose different ocular pathologies including retinal detachment, vitreous detachment, lens dislocation, and intraocular foreign bodies. Ocular pathologies such as blurry vision, double vision, loss of vision, and eye trauma are common chief complaints and require a comprehensive evaluation in order to determine the etiology and choose the correct treatment. Specifically ultrasound can help the clinician decide whether an urgent ophthalmology consult is appropriate. We present a case in which a lens dislocation was diagnosed using POCUS and review the available literature.

Investigation of Changes in Retinal Detachment-Related Brain Region Activities and Functions Using the Percent Amplitude of Fluctuation Method: A Resting-State Functional Magnetic Resonance Imaging Study

PURPOSE

The percent amplitude of fluctuation (PerAF) method was used to study the changes in neural activities and functions in specific brain regions of patients with a retinal detachment (RD).

PATIENTS AND METHODS

In this study, we recruited 15 RD patients (nine males and six females) and 15 healthy controls (HCs) matched for gender, age, and weight. All participants were scanned with resting functional magnetic resonance imaging (rs-fMRI). The PerAF method was then used for data analysis to evaluate and detect changes in neural activity in relevant brain regions. Receiver operating characteristic (ROC) curve analysis was used to evaluate the two groups.

RESULTS

The PerAF signal values of the right fusiform gyrus and the left inferior temporal gyrus of RD patients were significantly higher than those of HCs. This may indicate changes in neural activity and function in the related brain regions. The anxiety and depression scores of hospital anxiety and depression scale (HADS) and the durations in RD patients were positively correlated with the PerAF values of the left inferior temporal gyrus.

CONCLUSION

In this study, we demonstrated that there were significant changes in the PerAF values in specific areas of the brain in patients with RD. The change of PerAF values represent the changes of BOLD signal intensity, which reflect the hyperactivity or weakening of specific brain regions in RD patients, which are helpful to predict the development and prognosis of RD patients, and play an important role in the early diagnosis of RD. In addition, according to the results, changes in neural activity in specific brain regions of RD patients increase the risk of brain dysfunction related diseases, which may help to understand the pathological mechanism of vision loss in RD patients.

Emergency Ocular Ultrasound - Common Traumatic and Non-Traumatic Emergencies Diagnosed with Bedside Ultrasound

Point-of-care ocular ultrasound (POCOUS) in the ambulatory and critical care setting has become an invaluable diagnostic tool for patients presenting with traumatic or atraumatic vision and ocular complaints. Sonographic bedside evaluation is intuitive and easy to perform and can accurately diagnose a variety of pathologies. These include detachment or hemorrhage of the retina or vitreous, lens dislocation, retrobulbar hematoma or air, as well as ocular foreign bodies, infections, tumors, and increased optic nerve sheath diameter that can be assessed in the setting of suspected increased intracranial pressure. The ocular anatomy is easy to visualize with sonography, as the eye is a superficial structure filled with fluid. Over the last two decades, a large number of scientific publications have documented that POCOUS in emergent or critical care settings is an accurate diagnostic tool and expands and improves emergency diagnosis and management. This article will review POCOUS exam techniques as well as normal sonographic findings and common pathologies.

Efficacy of ultrasound guidance for lumbar punctures: a systematic review and meta-analysis of randomised controlled trials

Ultrasound guidance has been reported to facilitate the performance of lumbar punctures (LPs). However, the use of ultrasound guidance has not yet received consistent conclusions. We performed a systematic review and meta-analysis to determine the efficacy of ultrasound-guided LPs. PubMed, Embase and the Cochrane Library were searched for randomised controlled trials comparing ultrasound guidance with traditional palpation for LPs in adults. The primary outcome was risk of failed procedures. A random-effects Mantel-Haenzsel model or random-effects inverse variance model was used to calculate relative risks (RRs) or standardised mean differences (SMDs) with 95% CIs. Twenty-eight trials (N=2813) met the inclusion criteria. Ultrasound-guided LPs were associated with a reduced risk of failed procedures (RR=0.58, 95% CI 0.39 to 0.85, p=0.005). No significant heterogeneity was detected (I2=27%) among these trials. It further decreased first attempt to failure (RR=0.43, 95% CI 0.30 to 0.62, p<0.00001), mean attempts to success (SMD=-0.61, 95% CI -0.80 to -0.43, p=0.00001) and incidences of complications of headache and backache (RR=0.63, 95% CI 0.46 to 0.85, p=0.003). Ultrasound guidance is an effective technique for LPs in adults.

Diagnostic Ultrasound Safety Review for Point-of-Care Ultrasound Practitioners

Potential ultrasound exposure safety issues are reviewed, with guidance for prudent use of point-of-care ultrasound (POCUS). Safety assurance begins with the training of POCUS practitioners in the generation and interpretation of diagnostically valid and clinically relevant images. Sonographers themselves should minimize patient exposure in accordance with the as-low-as-reasonably-achievable principle, particularly for the safety of the eye, lung, and fetus. This practice entails the reduction of output indices or the exposure duration, consistent with the acquisition of diagnostically definitive images. Informed adoption of POCUS worldwide promises a reduction of ionizing radiation risks, enhanced cost-effectiveness, and prompt diagnoses for optimal patient care.

Factors Associated with Lumbar Puncture Participation in Alzheimer's Disease Research

BACKGROUND

Cerebrospinal fluid (CSF) provides insight into the spectrum of Alzheimer's disease (AD) pathology. While lumbar punctures (LPs) for CSF collection are generally considered safe procedures, many participants remain hesitant to participate in research involving LPs.

OBJECTIVE

To explore factors associated with participant willingness to undergo a research LP at baseline and follow-up research study visit.

METHODS

We analyzed data from 700 participants with varying cognition (unimpaired, mild cognitive impairment, and dementia) in the Wisconsin Alzheimer's Disease Research Center. We evaluated the relationship of demographic variables (age, sex, race, ethnicity, and years of education) and clinical variables (waist-to-hip ratio, body mass index, AD parental history, cognitive diagnosis) on decision to undergo baseline LP1. We evaluated the relationship of prior LP1 experience (procedure success and adverse events) with the decision to undergo follow-up LP2. The strongest predictors were incorporated into regression models.

RESULTS

Over half of eligible participants opted into both baseline and follow-up LP. Participants who underwent LP1 had higher mean education than those who declined (p = 0.020). White participants were more likely to choose to undergo LP1 (p < 0.001); 33% of African American participants opted in compared to 65% of white participants. Controlling for age, education, and AD parental history, race was the only significant predictor for LP1 participation. Controlling for LP1 mild adverse events, successful LP1 predicted LP2 participation.

CONCLUSION

Race was the most important predictor of baseline LP participation, and successful prior LP was the most important predictor of follow-up LP participation.

Role of routine use of ultrasonographic guidance for performing lumbar punctures

PURPOSE OF STUDY

Ultrasound (US) for lumbar puncture has seen the most success in obese patients and in patients with difficult to palpate landmarks. We aimed to elucidate the advantage of the use of routine US for performing lumbar punctures over the traditional landmark method.

STUDY DESIGN

This was a prospective study with consecutive sampling with a sample size of convenience. Three residents were chosen to perform the lumbar punctures after a training session. Patients were assigned to either the US group or the landmark group. The outcomes studied were number of attempts at needle insertion, patient and physician anxiety, pain experienced, time to procedure, number of traumatic attempts and the difficulties faced during the procedure.

RESULTS

A total of 77 patients were included in this study, of which 36 patients (46.8%) underwent landmark-based lumbar puncture and 41 (53.2%) underwent US-guided lumbar puncture. There was no statistically significant difference between the two groups among the following characteristics: number of attempts to a successful procedure, number of traumatic punctures, procedure time, preprocedure anxiety of the participants and physicians and pain score rating of the procedure.

CONCLUSION

There was no significant difference between the landmark method and US-guided method for performing lumbar puncture in the number of successful attempts, number of traumatic punctures, procedure time and pain during the procedure. Further studies are required to elucidate the advantage of the use of ultrasonography in subsets of the population such as the low body mass index population.

Point-of-care ultrasound in primary care: a systematic review of generalist performed point-of-care ultrasound in unselected populations

BACKGROUND

Both the interest and actual extent of use of point-of-care ultrasound, PoCUS, among general practitioners or family physicians are increasing and training is also increasingly implemented in residency programs. However, the amount of research within the field is still rather limited compared to what is seen within other specialties in which it has become more established, such as in the specialty of emergency medicine. An assumption is made that what is relevant for emergency medicine physicians and their populations is also relevant to the general practitioner, as both groups are generalists working in unselected populations. This systematic review aims to examine the extent of use and to identify clinical studies on the use of PoCUS by either general practitioners or emergency physicians on indications that are relevant for the former, both in their daily practice and in out-of-hours services.

METHODS

Systematic searches were done in PubMed/MEDLINE using terms related to general practice, emergency medicine, and ultrasound.

RESULTS

On the extent of use, we identified 19 articles, as well as 26 meta-analyses and 168 primary studies on the clinical use of PoCUS. We found variable, but generally low, use among general practitioners, while it seems to be thoroughly established in emergency medicine in North America, and increasingly also in the rest of the world. In terms of clinical studies, most were on diagnostic accuracy, and most organ systems were studied; the heart, lungs/thorax, vessels, abdominal and pelvic organs, obstetric ultrasound, the eye, soft tissue, and the musculoskeletal system. The studies found in general either high sensitivity or high specificity for the particular test studied, and in some cases high total accuracy and superiority to other established diagnostic imaging modalities. PoCUS also showed faster time to diagnosis and change in management in some studies.

CONCLUSION

Our review shows that generalists can, given a certain level of pre-test probability, safely use PoCUS in a wide range of clinical settings to aid diagnosis and better the care of their patients.

Success of bedside ultrasound to identify puncture site for spinal anesthesia in neonates and infants

Spinal anesthesia (SA) may be difficult in small infants. Conceptual advantages of ultrasound imaging to view critical neuraxial structures and exploiting the acoustic window unique to infants have been described but not clinically verified. We present 14 preterm-infants aged 35-48 weeks, weighing 1575-5800 g, and describe ultrasound imaging to locate an appropriate puncture site for SA. The success rate for first puncture was 64%, and the overall success on three attempts was 86%. The mean dural depth was 8 mm (1.6). The inferior medullary cone location was just above L3-L4 in 85.7% of patients. Ultrasound imaging for SA in infants may offer advantages.

Point-of-Care Ultrasonography in the Diagnosis of Retinal Detachment, Vitreous Hemorrhage, and Vitreous Detachment in the Emergency Department

IMPORTANCE

Ocular symptoms represent approximately 2% to 3% of all emergency department (ED) visits. These disease processes may progress to permanent vision loss if not diagnosed and treated quickly. Use of ocular point-of-care ultrasonography (POCUS) may be effective for early and accurate detection of ocular disease.

OBJECTIVE

To perform a large-scale, multicenter study to determine the utility of POCUS for diagnosing retinal detachment, vitreous hemorrhage, and vitreous detachment in the ED.

DESIGN, SETTING, AND PARTICIPANTS

A prospective diagnostic study was conducted at 2 academic EDs and 2 county hospital EDs from February 3, 2016, to April 30, 2018. Patients who were eligible for inclusion were older than 18 years; were English- or Spanish-speaking; presented to the ED with ocular symptoms with concern for retinal detachment, vitreous hemorrhage, or vitreous detachment; and underwent an ophthalmologic consultation that included POCUS. Patients with ocular trauma or suspicion for globe rupture were excluded. The accuracy of the ultrasonographic diagnosis was compared with the criterion standard of the final diagnosis of an ophthalmologist who was masked to the POCUS findings. Seventy-five unique emergency medicine attending physicians, resident physicians, and physician assistants performed ocular ultrasonography.

EXPOSURE

Point-of-care ultrasonography performed by an emergency medicine attending physician, resident physician, or physician assistant.

MAIN OUTCOMES AND MEASURES

Sensitivity and specificity of POCUS in identifying retinal detachment, vitreous hemorrhage, and vitreous detachment in patients presenting to the ED with ocular symptoms.

RESULTS

Two hundred twenty-five patients were enrolled. Of these, the mean age was 51 years (range, 18-91 years) and 135 (60.0%) were men; ophthalmologists diagnosed 47 (20.8%) with retinal detachment, 54 (24.0%) with vitreous hemorrhage, and 34 (15.1%) with vitreous detachment. Point-of-care ultrasonography had an overall sensitivity of 96.9% (95% CI, 80.6%-99.6%) and specificity of 88.1% (95% CI, 81.8%-92.4%) for diagnosis of retinal detachment. For diagnosis of vitreous hemorrhage, the sensitivity of POCUS was 81.9% (95% CI, 63.0%-92.4%) and specificity was 82.3% (95% CI, 75.4%-87.5%). For vitreous detachment, the sensitivity was 42.5% (95% CI, 24.7%-62.4%) and specificity was 96.0% (95% CI, 91.2%-98.2%).

CONCLUSIONS AND RELEVANCE

These findings suggest that emergency medicine practitioners can use POCUS to accurately identify retinal detachment, vitreous hemorrhage, and vitreous detachment. Point-of-care ultrasonography is not intended to replace the role of the ophthalmologist for definitive diagnosis of these conditions, but it may serve as an adjunct to help emergency medicine practitioners improve care for patients with ocular symptoms.