Standardizing evaluation of patient-specific 3D printed models in surgical planning: development of a cross-disciplinary survey tool for physician and trainee feedback.

BACKGROUND: 3D printed models are becoming increasingly popular in healthcare as visual and tactile tools to enhance understanding of anatomy and pathology in medical trainee education, provide procedural simulation training, and guide surgical procedures. Patient-specific 3D models are currently being used preoperatively for trainee medical education in planning surgical approaches and intraoperatively to guide decision-making in several specialties. Our study group utilized a modified Delphi process to create a standardized assessment for trainees using patient-specific 3D models as a tool in medical education during pre-surgical planning. METHODS: A literature review was conducted to identify survey questions administered to clinicians in published surgical planning studies regarding the use of patient-specific 3D models. A core study team reviewed these questions, removed duplicates, categorized them, mapped them to overarching themes, and, where applicable, modified individual questions into a form generalizable across surgical specialties. The core study panel included a physician, physician-scientist, social scientist, engineer/medical student, and 3D printing lab manager. A modified Delphi process was then used to solicit feedback on the clarity and relevance of the individual questions from an expert panel consisting of 12 physicians from specialties including anesthesiology, emergency medicine, radiology, urology, otolaryngology, and obstetrics/gynecology. When the Radiological Society of North America (RSNA)/American College of Radiology (ACR) 3D Printing Registry Data Dictionary was released, additional survey questions were reviewed. A final cross-disciplinary survey of the utility of 3D printed models in surgical planning medical education was developed. RESULTS: The literature review identified 100 questions previously published in surveys assessing patient-specific 3D models for surgical planning. Following the review, generalization, and mapping of survey questions from these studies, a list of 24 questions was generated for review by the expert study team. Five additional questions were identified in the RSNA/ACR 3D Printing Registry Data Dictionary and included for review. A final questionnaire consisting of 20 questions was developed. CONCLUSIONS: As 3D printed models become more common in medical education, the need for standardized assessment is increasingly essential. The standardized questionnaire developed in this study reflects the interests of a variety of stakeholders in patient-specific 3D models across disciplines.

Carotid Ultrasound to Predict Fluid Responsiveness: A Systematic Review.

OBJECTIVES: To perform a systematic review of the accuracy of carotid ultrasound measures in determining volume responsiveness in adults. METHODS: We conducted a systematic review of Ovid MEDLINE and Scopus from conception until January 1, 2019. Two independent reviewers used an iterative process to identify relevant articles and abstract information from them. The quality and risk of bias were assessed with the Quality Assessment of Diagnostic Accuracy Studies version 2 tool. RESULTS: We identified 17 relevant articles with 956 patients. The 2 most frequently cited carotid measures of fluid responsiveness were corrected flow time and peak velocity or change in peak velocity with respiration (ΔCDPV). Accordingly, the diagnostic characteristics of corrected flow time in these studies varied widely, with sensitivities from 60% to 73%, specificities from 82% to 92%, and areas under the receiver operating characteristic curves from 0.75 to 0.88. Optimal cutoff values for ΔCDPV ranged from 9.1% to 14%, with areas under the receiver operating characteristic curves from 0.81 to 0.91, sensitivities from 73% to 86%, and specificities from 78% to 86%. Other measures, such as carotid blood flow and carotid diameter, had limited data to support their use. Heterogeneity of the studies prohibited a meta-analysis. Most studies had a moderate risk of bias and high applicability. CONCLUSIONS: Preliminary research suggests that carotid ultrasound measures may be useful adjunct measures of fluid status; however, they should not be interpreted as absolute and should be placed in a clinical context. The most well-defined and supported measure currently is ΔCDPV, with cutoffs from 9% to 14%. Corrected flow time shows promise, because of heterogeneity of how this value is measured, an optimal cutoff has not been established.

Point-of-Care Ultrasound in the Evaluation of COVID-19.

BACKGROUND: The novel coronavirus SARS-CoV-2 has caused a pandemic, overwhelming health care systems around the world. Hospitals around the world, including the United States, have been struggling to adapt to the influx of patients with COVID-19, the illness caused by SARS-CoV2, given limited resources and high demand for medical care. OBJECTIVES: This article seeks to provide emergency physicians with a guide to sonographic findings in COVID-19 and an algorithm by which point-of-care lung ultrasound may assist emergency physicians caring for these patients during the SARS-CoV-2 pandemic. DISCUSSION: The studies currently being published have established a typical set of ultrasound findings in COVID-19. Point-of-care lung ultrasound is rapid and accessible in most emergency departments in the United States, and even in many resource-poor settings. CONCLUSION: Point-of-care ultrasound provides numerous benefits to emergency providers caring for patients with COVID-19, including decreasing resource utilization, assisting in diagnosis, guiding management of the critically ill patient, and aiding in rapid triage of patients under investigations for COVID-19.

Relationship of the Built Environment on Nursing Communication Patterns in the Emergency Department: A Task Performance and Analysis Time Study.

INTRODUCTION: The physical layout of the emergency department affects the way in which patients and providers move within the space and can cause substantial changes in workflow and, therefore, affect communication patterns between providers. There is no 1 ED design that enables the best patient care, and quantitative studies looking at ED design are limited. The goal of this study was to examine how different ED designs, centralized and decentralized, are associated with communication patterns among health care professionals. METHODS: A task performance, direct observation time study was used. By developing a novel tablet-based digital mapping tool using a cloud-based mapping platform (ArcGIS), data on provider actions and interactions were collected and mapped to a precise location within the emergency department throughout an entire nursing shift. RESULTS: The difference in the duration of nurse-physician interactions between the 2 ED designs was statistically significant. Within the centralized design, nurse-physician interactions totaled 14 minutes and 38 seconds compared with 30 minutes and 11 seconds in the decentralized design (t = 2.31, P = 0.02). More conversations between nurses and physicians occurred inside the patient's room in the decentralized design. DISCUSSION: Our findings suggest that the ED design affects communication patterns among health care providers and that the design has the potential to affect the quality of patient care.

Ultrasonography in Undergraduate Medical Education: A Systematic Review.

OBJECTIVES: The purpose of this study was to conduct a systematic review of the evidence of educational outcomes associated with teaching ultrasonography (US) to medical students. METHODS: A review of databases through 2016 was conducted for research studies that reported data on teaching US to medical students. Each title and abstract were reviewed by teams of 2 independent abstractors to determine whether the article would be ordered for full-text review and subsequently by 2 independent authors for inclusion. Data were abstracted with a form developed a priori by the authors. RESULTS: Ninety-five relevant unique articles were included (of 6936 identified in the databases). Survey data showed that students enjoyed the US courses and desired more US training. Of the studies that assessed US-related knowledge and skill, most of the results were either positive (16 of 25 for knowledge and 24 of 58 for skill) or lacked a control (8 of 25 for knowledge and 27 of 58 for skill). The limited evidence (14 of 95 studies) of the effect of US training on non-US knowledge and skill (eg, anatomy knowledge or physical examination skill) was mixed. CONCLUSIONS: There is ample evidence that students can learn US knowledge and skills and that they enjoy and want US training in medical school. The evidence for the effect of US on external outcomes is limited, and there is insufficient evidence to recommend it for this purpose at this time.

Ultrasound measurement of inferior vena cava collapse predicts propofol-induced hypotension.

STUDY OBJECTIVES: Hypotension is a common side effect of propofol, but there are no reliable methods to determine which patients are at risk for significant propofol-induced hypotension (PIH). Ultrasound has been used to estimate volume status by visualization of inferior vena cava (IVC) collapse. This study explores whether IVC assessment by ultrasound can assist in predicting which patients may experience significant hypotension. METHODS: This was a prospective observational study conducted in the operating suite of an urban community hospital. A convenience sample of consenting adults planned to receive propofol for induction of anesthesia during scheduled surgical procedures were enrolled. Bedside ultrasound was used to measure maximum (IVCmax) and minimum (IVCmin) IVC diameters. IVC-CI was calculated as [(IVCmax-IVCmin)/IVCmax × 100%]. The primary outcome was significant hypotension defined as systolic blood pressure (BP) below 90mmHg and/or administration of a vasopressor to increase BP during surgery. RESULTS: The study sample comprised 40 patients who met inclusion criteria. Mean age was 55years, (95%CI, 49-60) with 53% female. 55% of patients had significant hypotension after propofol administration. 76% of patients with IVC-CI≥50% had significant hypotension compared to 39% with IVC-CI<50%, P=.02. IVC-CI≥50% had a specificity of 77.27% (95%CI, 64.29%-90.26%) and sensitivity of 66.67% (95%CI, 52.06%-81.28%) in predicting PIH. The odds ratio for PIH in patients with IVC-CI≥50% was 6.9 (95%CI, 1.7-27.5). CONCLUSION: Patients with IVC-CI≥50% were more likely to develop significant hypotension from propofol. IVC ultrasound may be a useful tool to predict which patients are at increased risk for PIH.

Isolated Deep Venous Thrombosis: Implications for 2-Point Compression Ultrasonography of the Lower Extremity.

STUDY OBJECTIVE: Two-point compression ultrasonography focuses on the evaluation of common femoral and popliteal veins for complete compressibility. The presence of isolated thrombi in proximal veins other than the common femoral and popliteal veins should prompt modification of 2-point compression technique. The objective of this study is to determine the prevalence and distribution of deep venous thrombi isolated to lower-extremity veins other than the common femoral and popliteal veins in emergency department (ED) patients with clinically suspected deep venous thrombosis. METHODS: This was a retrospective study of all adult ED patients who received a lower-extremity venous duplex ultrasonographic examination for evaluation of deep venous thrombosis during a 6-year period. The ultrasonographic protocol included B-mode, color-flow, and spectral Doppler scanning of the common femoral, femoral, deep femoral, popliteal, and calf veins. RESULTS: Deep venous thrombosis was detected in 362 of 2,451 patients (14.7%; 95% confidence interval [CI] 13.3% to 16.1%). Thrombus confined to the common femoral vein alone was found in 5 of 362 cases (1.4%; 95% CI 0.2% to 2.6%). Isolated femoral vein thrombus was identified in 20 of 362 patients (5.5%; 95% CI 3.2% to 7.9%). Isolated deep femoral vein thrombus was found in 3 of 362 cases (0.8%; 95% CI -0.1% to 1.8%). Thrombus in the popliteal vein alone was identified in 53 of 362 cases (14.6%; 95% CI 11% to 18.2%). CONCLUSION: In our study, 6.3% of ED patients with suspected deep venous thrombosis had isolated thrombi in proximal veins other than common femoral and popliteal veins. Our study results support the addition of femoral and deep femoral vein evaluation to standard compression ultrasonography of the common femoral and popliteal vein, assuming that this does not have a deleterious effect on specificity.

The ability of renal ultrasound and ureteral jet evaluation to predict 30-day outcomes in patients with suspected nephrolithiasis.

STUDY OBJECTIVE: We sought to identify findings on bedside renal ultrasound that predicted need for hospitalization in patients with suspected nephrolithiasis. METHODS: A convenience sample of patients with suspected nephrolithiasis was prospectively enrolled and underwent bedside ultrasound of the kidneys and bladder to determine the presence and degree of hydronephrosis and ureteral jets. Sonologists were blinded to any other laboratory and imaging data. Patients were followed up at 30 days by phone call and review of medical records. RESULTS: Seventy-seven patients with suspected renal colic were included in the analysis. Thirteen patients were admitted. Reasons for admission included intractable pain, infection, or emergent urologic intervention. All 13 patients requiring admission had hydronephrosis present on initial bedside ultrasound. Patients with moderate hydronephrosis had a higher admission rate (36%) than those with mild hydronephrosis (24%), P<.01. Of patients without hydronephrosis, none required admission within 30 days. The sensitivity and specificity of hydronephrosis for predicting subsequent hospitalization were 100% and 44%, respectively. Loss of the ipsilateral ureteral jet was not significantly associated with subsequent hospital admission and did not improve the predictive value when used in combination with the degree of hydronephrosis. CONCLUSIONS: No patients with suspected renal colic and absence of hydronephrosis on bedside ultrasound required admission within 30 days. Ureteral jet evaluation did not help in prediction of 30-day outcomes and may not be useful in the emergency department management of renal colic.

The utility of transvaginal ultrasound in the ED evaluation of complications of first trimester pregnancy.

BACKGROUND: For patients with early intrauterine pregnancy (IUP), the sonographic signs of the gestation may be below the resolution of transabdominal ultrasound (TAU); however, it may be identified by transvaginal ultrasound (TVU). We sought to determine how often TVU performed in the emergency department (ED) reveals a viable IUP after a nondiagnostic ED TAU and the impact of ED TVU on patient length of stay (LOS). METHODS: This was a retrospective cohort study of women presenting to our ED with complications of early pregnancy from January 1, 2007 to February 28, 2009 in a single urban adult ED. Abstractors recorded clinical and imaging data in a database. Patient imaging modality and results were recorded and compared with respect to ultrasound (US) findings and LOS. RESULTS: Of 2429 subjects identified, 795 required TVU as part of their care. Emergency department TVU was performed in 528 patients, and 267 went to radiology (RAD). Emergency department TVU identified a viable IUP in 261 patients (49.6%). Patients having initial ED US had shorter LOS than patients with initial RAD US (median 4.0 vs 6.0 hours; P < .001). Emergency department LOS was shorter for women who had ED TVU performed compared with those sent for RAD TVU regardless of the findings of the US (median 4.9 vs 6.7 hours; P < .001). There was no increased LOS for patients who needed further RAD US after an indeterminate ED TVU (7.0 vs 7.1 hours; P = .43). There was no difference in LOS for those who had a viable IUP confirmed on ED TAU vs ED (median 3.1 vs 3.2 hours, respectively; P < .32). CONCLUSION: When an ED TVU was performed, a viable IUP was detected 49.6% of the time. Emergency department LOS was significantly shorter for women who received ED TVU after indeterminate ED TAU compared with those sent to RAD for TVU, with more marked time savings among those with live IUP diagnosed on ED TVU. For patients who do not receive a definitive diagnosis of IUP on ED TVU, this approach does not result in increased LOS.

Risk factors associated with difficult venous access in adult ED patients.

OBJECTIVE: The objective was to determine risk factors associated with difficult venous access (DVA) in the emergency department (ED). METHODS: This was a prospective, observational study conducted in the ED of an urban tertiary care hospital. Adult patients undergoing intravenous (IV) placement were consecutively enrolled during periods of block enrollment. The primary outcome was DVA, defined as 3 or more IV attempts or use of a method of rescue vascular access to establish IV access. Univariate and multivariate analyses for factors predicting DVA were performed using logistic regression. RESULTS: A total of 743 patients were enrolled, of which 88 (11.8%) met the criteria for DVA. In the adjusted analysis, only 3 medical conditions were significantly associated with DVA: diabetes (odds ratio [OR] 1.72, 95% confidence interval [CI] 1.1-2.8), sickle cell disease (OR 3.8, 95% CI 1.5-9.5), and history of IV drug abuse (OR 2.5, 95% CI 1.1-5.7). Notably, age, body mass index, and dialysis were not. Of patients who reported a history of requiring multiple IV attempts in the past for IV access, 14% met criteria for DVA on this visit (OR 7.7 95% CI 3-18). Of the patients who reported a history of IV insertion into the external jugular, ultrasound-guided IV placement, or a central venous catheter for IV access, 26% had DVA on this visit (OR 16.7, 95% CI 6.8-41). CONCLUSIONS: Nearly 1 of every 9 to 10 adults in an urban ED had DVA. Diabetes, IV drug abuse, and sickle cell disease were found to be significantly associated with DVA.

Emergency physicians' knowledge of the total charges of medical care.

STUDY OBJECTIVES: This study aimed to evaluate emergency medical physician's knowledge of the charges for the entirety of medical care provided to patients they treated and discharged from the emergency department (ED). METHODS: The study was administered in an academic ED. Patients were eligible for the study if they were discharged from the ED by the attending who first evaluated them. Following patient discharge from the ED, the attending physician and resident were asked to estimate the total billed to the patient (all charges billed to patient before adjustments for insurance provider or coverage status were applied). The median error of the physician's estimate was compared to their years of experience. RESULTS: Physicians underestimated actual total charges 93% (127/136) of the time. The median estimate was 36% (IQR 23%-54%) of the actual final ED charge, representing a median underestimation of $1268 (IQR $766-$2347). There was no correlation between degree of error and postgraduate years of the physician. CONCLUSION: This study demonstrated a significant underestimation of a patient's total charges by emergency medical physicians. There was no correlation in years of experience and ability to accurately estimate charges. While all physicians tended to underestimate charges, physicians tended to have good inter-rater agreement.

Diagnosing heart failure among acutely dyspneic patients with cardiac, inferior vena cava, and lung ultrasonography.

BACKGROUND: Rapid diagnosis (dx) of acutely decompensated heart failure (ADHF) may be challenging in the emergency department (ED). Point-of-care ultrasonography (US) allows rapid determination of cardiac function, intravascular volume status, and presence of pulmonary edema. We test the diagnostic test characteristics of these 3 parameters in making the dx of ADHF among acutely dyspneic patients in the ED. METHODS: This was a prospective observational cohort study at an urban academic ED. Inclusion criteria were as follows: dyspneic patients, at least 18 years old and able to consent, whose differential dx included ADHF. Ultrasonography performed by emergency sonologists evaluated the heart for left ventricular ejection fraction (LVEF), the inferior vena cava for collapsibility index (IVC-CI), and the pleura sampled in each of 8 thoracic regions for presence of B-lines. Cutoff values for ADHF were LVEF less than 45%, IVC-CI less than 20%, and at least 10 B-lines. The US findings were compared with the final dx determined by 2 emergency physicians blinded to the US results. RESULTS: One hundred one participants were enrolled: 52% male, median age 62 (25%-75% interquartile, 53-91). Forty-four (44%) had a final dx of ADHF. Sensitivity and specificity (including 95% confidence interval) for the presence of ADHF were as follows: 74 (65-90) and 74 (62-85) using LVEF less than 45%, 52 (38-67) and 86 (77-95) using IVC-CI less than 20%, and 70 (52-80) and 75 (64-87) using B-lines at least 10. Using all 3 modalities together, the sensitivity and specificity were 36 (22-51) and 100 (95-100). As a comparison, the sensitivity and specificity of brain natriuretic peptide greater than 500 were 75 (55-89) and 83 (67-92). CONCLUSION: In this study, US was 100% specific for the dx of ADHF.

Inter-rater reliability of quantifying pleural B-lines using multiple counting methods.

OBJECTIVES: Sonographic B-lines are a sign of increased extravascular lung water. Several techniques for quantifying B-lines within individual rib spaces have been described, as well as different methods for "scoring" the cumulative B-line counts over the entire thorax. The interobserver reliability of these methods is unknown. This study examined 3 methods of quantifying B-lines for inter-rater reliability. METHODS: Videotaped pleural assessments of adult patients presenting to the emergency department with dyspnea and suspected acute heart failure were reviewed by 3 blinded pairs of emergency physicians. Each pair performed B-line counts within single rib spaces using 1 of the following 3 predetermined methods: 1, individual B-lines are counted over an entire respiratory cycle; 2, as per method 1, but confluent B-lines are counted as multiple based on the percentage of the rib space they occupy; and 3, as per method 2, but the count is made at the moment when the most B-lines are seen, not over an entire respiratory cycle. A single-measures interclass correlation coefficient was used to assess inter-rater reliability for the 3 definitions of B-line counts. RESULTS: A total of 456 video clips were reviewed. The interclass correlation coefficients (95% confidence intervals) for methods 1, 2, and 3 were 0.84 (0.81-0.87), 0.87 (0.85-0.90), and 0.89 (0.87-0.91), respectively. The difference between methods 1 and 3 was significant (P = .003). CONCLUSIONS: All methods of B-line quantification showed substantial inter-rater agreement. Method 3 is more reliable than method 1. There were no other significant differences between the methods. We recommend the use of method 3 because it is technically simpler to perform and more reliable than method 1.

The Frequency of POCUS in the Treatment of Sepsis in the Emergency Department: A Retrospective Cohort Study.

Background: Point of care ultrasound (POCUS) is ubiquitous in the modern emergency department (ED). POCUS can be helpful in the management of patients with sepsis in many ways including determining the cause of sepsis, assessing fluid status, guiding resuscitation, and performing procedures. However, the frequency and manner in which POCUS is incorporated into the care of septic patients in community emergency medicine remains unclear. Objective: To evaluate POCUS frequency and exam types used in the care of patients with sepsis in two community EDs in Southern California. Methods: We performed a retrospective analysis of 5,264 ED visits with a diagnosis of sepsis at two community emergency departments between January 2014 and December 2018. Patients 18 years or older who were diagnosed with sepsis and had either lactate ≥ 4 mmol, a documented mean arterial pressure (MAP) < 65 mmHg, or a systolic blood pressure (SBP) < 90 mmHg were included. Charts were reviewed to determine if POCUS was used during the ED evaluation. Primary outcomes were frequency of POCUS use in the cohort, change in POCUS use over the study period, and the types of exams performed. Results: POCUS was used in 21% of encounters meeting inclusion criteria and was positively correlated with ED arrival year (OR = 1.09; CI 1.04, 1.15; p=0.001). The most common POCUS exam was ultrasound-guided central line placement, with the next most common exams being cardiac, followed by inferior vena cava (IVC). Only the frequency of cardiac, IVC, lung and Focused Assessment with Sonography in Trauma (FAST) exams were found to increase significantly over the study period. Conclusions: Total POCUS use increased significantly in this cohort of septic patients over the study period due to more cardiac, IVC, lung and FAST exams being performed.

Decrease in central venous catheter placement due to use of ultrasound guidance for peripheral intravenous catheters.

STUDY OBJECTIVES: Obtaining intravenous (IV) access in the emergency department (ED) can be especially challenging, and physicians often resort to placement of central venous catheters (CVCs). Use of ultrasound-guided peripheral IV catheters (USGPIVs) can prevent many "unnecessary" CVCs, but the true impact of USGPIVs has never been quantified. This study set out to determine the reduction in CVCs by USGPIV placement. METHODS: This was a prospective, observational study conducted in 2 urban EDs. Patients who were to undergo placement of a CVC due to inability to establish IV access by other methods were enrolled. Ultrasound-trained physicians then attempted USGPIV placement. Patients were followed up for up to 7 days to assess for CVC placement and related complications. RESULTS: One hundred patients were enrolled and underwent USGPIV placement. Ultrasound-guided peripheral IV catheters were initially successfully placed in all patients but failed in 12 patients (12.0%; 95 confidence interval [CI], 7.0%-19.8%) before ED disposition, resulting in 4 central lines, 7 repeated USGPIVs, and 1 patient requiring no further intervention. Through the inpatient follow-up period, another 11 patients underwent CVC placement, resulting in a total of 15 CVCs (15.0%; 95 CI, 9.3%-23.3%) placed. Of the 15 patients who did receive a CVC, 1 patient developed a catheter-related infection, resulting in a 6.7% (95 CI, 1.2%-29.8%) complication rate. CONCLUSION: Ultrasound prevented the need for CVC placement in 85% of patients with difficult IV access. This suggests that USGPIVs have the potential to reduce morbidity in this patient population.

The effect of vessel depth, diameter, and location on ultrasound-guided peripheral intravenous catheter longevity.

INTRODUCTION: Ultrasound-guided peripheral intravenous catheters (USGPIVs) have been observed to have poor durability. The current study sets out to determine whether vessel characteristics (depth, diameter, and location) predict USGPIV longevity. METHODS: A secondary analysis was performed on a prospectively gathered database of patients who underwent USGPIV placement in an urban, tertiary care emergency department. All patients in the database had a 20-gauge, 48-mm-long catheter placed under ultrasound guidance. The time and reason for USGPIV removal were extracted by retrospective chart review. A Kaplan-Meier survival analysis was performed. RESULTS: After 48 hours from USGPIV placement, 32% (48/151) had failed prematurely, 24% (36/151) had been removed for routine reasons, and 44% (67/151) remained in working condition yielding a survival probability of 0.63 (95% confidence interval [CI], 0.53-0.70). Survival probability was perfect (1.00) when placed in shallow vessels (<0.4 cm), moderate (0.62; 95% CI, 0.51-0.71) for intermediate vessels (0.40-1.19 cm), and poor (0.29; 95% CI, 0.11-0.51) for deep vessels (≥1.2 cm); P < .0001. Intravenous survival probability was higher when placed in the antecubital fossa or forearm locations (0.83; 95% CI, 0.69-0.91) and lower in the brachial region (0.50; 95% CI, 0.38-0.61); P = .0002. The impact of vessel depth and location was significant after 3 hours and 18 hours, respectively. Vessel diameter did not affect USGPIV longevity. CONCLUSION: Cannulation of deep and proximal vessels is associated with poor USGPIV survival. Careful selection of target vessels may help improve success of USGPIV placement and durability.