From the Chair: Workflow Toolkit and White Paper Updates - Emergency Ultrasound Section Newsletter, October 2013
Rajesh Geria, MD, RDMS, FACEP
The Industry Relations and Community subcommittees have been hard at work developing a toolkit designed to help our members optimize workflow in their ultrasound programs. In order to gain some insight into what the major obstacles people have been running into we conducted a section survey several months ago. I will be sharing the results of the survey at the section meeting but a recurring theme was clearly problems with hospital IT.
The toolkit will target this problem from a ground and aerial attack. The ground attack will consist of documents, spreadsheets and powerpoint presentations that ultrasound directors can download and show their chairs and hospital IT in order to help choose the right workflow solution, open dialogue, and ease fears of implementation. The aerial attack will focus on hospital administration as IT often prioritizes tasks based on what comes from above.
A task force was created within the above subcommittees to write a paper on the importance of point of care ultrasound workflow. This document will lead to the development of an ACEP policy statement on EUS workflow systems. Thank you and look forward to seeing all of you in Seattle.
White Paper - Point of Care Ultrasound Workflow Systems
Point of Care Ultrasound (POCUS) has been shown to dramatically improve patient flow and satisfaction, reduce costs, and above all improve patient safety. It is vital that hospitals have workflow systems that facilitate not only learning but credentialing and privileging for the practitioner using POCUS. Tracking, documenting and image retention of POCUS is a critical component of this modality for purposes of training, quality improvement, privileging, compliance with standards and reimbursement.
An ultrasound workflow system generally involves software that allows bedside ultrasound studies to be retained, reviewed, feedback can be provided to the practitioner. The newer software programs perform these tasks in an electronic format that are consistent with the trend and direction of electronic medical records and “meaningful use” goals.
A workflow system differs from a Picture Archiving and Communication System (PACS). In most hospitals PACS is currently being used to store studies done by credentialed providers for radiologist review. However, a new paradigm with POCUS studies shows that many new users must perform studies to obtain ultrasound privileges (credentialing).
It is commonplace to have a non-credentialed provider performing POCUS studies for training purposes only, thereby putting those studies into a separate category. POCUS studies also require a real-time interpretation, followed by a peer review by a credentialed provider. The peer review component of POCUS is essential given the new Joint Commission (TJC) guidelines for Focused Provider Performance Evaluations and Ongoing Provider Performance Evaluations (FPPE and OPPE) respective to medical staff privileging and credentialing. This same process of review can benefit all levels of users from those credentialed, seeking credentials, residents and other practitioners.
Regulatory bodies such as the Office of the National Coordinator of Health Information Technology (ONC-HIT) have begun recognizing the need for workflow systems through its focus on transferability and storage of radiologic imaging. This will only expand as health care information technology comes under additional scrutiny. The Center for Medicare and Medicaid Services (CMS) mandates that all ultrasound images must be stored for a minimum of 5 years – strengthening the need for a computer ultrasound study archiving system. Thermal paper prints are not storable for long periods of time, and do not provide information to adequately review and critique the study.
US workflow systems are gradually being adopted in hospitals throughout the United States. The solution to the documentation, compliance and regulatory aspects for the transparent integration of POCUS is the adoption of ultrasound workflow systems.
Tips & Tricks: FAST Exam Suprapubic View Part 3 - Emergency Ultrasound Section Newsletter, October 2013
By Viveta Lobo, MD and Laleh Gharahbaghian, MD, FACEP
As discussed in our last entry, the FAST exam is undoubtedly the most widely used bedside ultrasound application used in emergency medicine. Its incorporation in the ATLS revised protocol, the RUSH exam, and several other published protocols, makes it an invaluable screening tool for intra abdominal injury causing hemoperitoneum, cardiac injury with pericardial effusion, and unexplained hypotension.(1,2)
We will continue our discussion of the FAST scan by reviewing the pelvis views, and relay some tips and tricks. Refer to the March 2013 Newsletter for our article reviewing tips for scanning the right upper quadrant (RUQ) and left upper quadrants (LUQ), and the June 2013 newsletter for our article reviewing the tips for the cardiac views.
The Suprapubic View
The suprapubic view on the FAST exam is generally the last of the four views performed.
Theoretically, given its dependent anatomical position, one might logically conclude that it should in fact be the most sensitive view to visualize free fluid; unfortunately, the literature has negated this theory – and in fact this can often be the least sensitive view, largely in part of human error, and especially in pelvic fractures.(1,2,4) Anatomically, when we scan the suprapubic area in both transverse and longitudinal planes, there’s a lot that we see –the bladder, bowel, pelvic bones, pelvic organs, and rectum to name a few. This might make it harder for us to visualize free fluid, and separate it out from these other structures. But here’s a few tips to help overcome these limitations. Begin by placing your phased array or curvilinear probe just above the pubic symphysis, aiming inferiorly/caudad into the pelvis.
Tips for the Suprapubic View:
1. Look through a full bladder. A full bladder - The suprapubic view is visualized using a filled bladder as the acoustic window. Not all trauma patients come in with a full bladder and we will not likely go back to the days when a foley catheter used to be placed in order to fill the bladder for visualization. While we are sure our patients appreciate us not doing this anymore – its important to note, that if your patient has an empty bladder, it is best to hydrate them up with the fluids, and repeat the scan when the bladder is more full.(5) With an empty bladder your ability to adequately discern free fluid is very limited. Mostly due to gas scatter from bowel, inadequate depth adjustments, and inability to discern bowel fluid from free fluid. Click Here for a Video of A Normal Female.
2. Adjust your depth - More often than not, when it is time to scan the suprapubic area, your depth is set too deep from scanning the upper quadrants or cardiac views. We often find that a depth of about 13cm to 16cm optimizes your view. The goal is to have your bladder centered on the screen, to easily visualize the areas surrounding the bladder
3. Adjust your gain - The bladder is a fluid filled structure, and as mentioned before, fluid is the “lover” of ultrasound, allowing structures deep to it to be well visualized, however this often creates an artifact called “posterior acoustic enhancement” that produces a hyperechoic and bright area deep to the bladder. This makes it hard to visualize anechoic or black free fluid. One of the biggest pitfalls is not decreasing your gain to accommodate for this, and limiting your ability to pick up anechoic free fluid. A good rule of thumb, is to ensure that you can easily visualize pelvic organs. If you are able to identify a uterus or a prostate easily, that usually means you have adjusted your gain appropriately. Click Here for a Video of Posterior Acoustic Enhancement.
4. Look everywhere - Unlike in your upper quadrants, free fluid in the pelvic cavity can in fact collect anywhere – anterior, lateral, and posterior to the bladder as well as anterior, lateral, and posterior to the uterus in female patients. This often is dictated by your patient’s position, the lay of the uterus, how full the bladder is, and the size of the prostate to name a few. We suggest looking in four areas –
a. Look anterior and cephalad to the bladder. Click Here for Video of Free Fluid Anterior to the Bladder. This is especially true if the bladder is empty. At times, free fluid will be mistaken for the bladder and thought to be a septated bladder, when in fact it is free fluid cephalad to the bladder. Click Here for Video of Free Fluid Easily Mistaken for Bladder.
b. Look adjacent/lateral to your bladder; free fluid will collect into a “wedge” shape or triangular shape in between bowel folds which will be most evident with appropriate fanning through the region. Click Here for Video of Wedge of Free Fluid.
c. Look deep/posterior to the bladder between it and your pelvic organs. Click Here for Free Fluid Posterior to the Bladder. Especially in females, you can see a collection of free fluid between the bladder and the uterus. This often looks like boxed shaped anechoic structures that as you fan through will appreciate it not being a “contained” structure.
d. Look posterior to your pelvic organs. Free fluid can collect deep to your uterus or prostate. Click Here for Video of Free Fluid Posterior to the Uterus.
5. Seminal vesicles are also anechoic/black - In males, don’t be fooled by the seminal vesicles. These lie immediately posterior to the bladder, and often appear like a anechoic “bow-tie” shape, with contained fluid and equal on each side. They will always appear in the same location, and you should fan slowly and carefully through the region to ensure that this is a contained structure and not mistake it for free fluid.
6. Physiological free fluid in females - In menstruating females you can appreciate some physiological free fluid that may be normal. This is hard to differentiate truly from traumatic free fluid, and you will need to consider the clinical picture – Is there any abdominal pain? Is there abdominal or pelvic trauma? Are her vital signs abnormal? Also, the amount and location of free fluid can help – physiological free fluid is found deep to the uterus, and along its border – it should not be greater than 1/3 the length of the border, anything greater than 1/3 should be considered pathological.
7. Fan slowly - While fanning is always important in evaluating any region by ultrasound – we cannot stress it enough when evaluating the suprapubic area. It is impressive and often surprising just how much free fluid can “hide” behind and around the many structures present in this region, and not be visualized unless you dedicatedly fan through the area. It is strongly encouraged to view the suprapubic area in 2 planes – horizontally and longitudinally and fan through each section slowly to make sure you don’t miss any free fluid!(3)
8. Quick Pregnancy Test- In female patients of reproductive age, while performing the pelvic view, take a quick look inside the uterus. You just may quickly get your answer to whether she is pregnant or not but visualizing a gestational sac with fetal pole or yolks sac. However, if you only see a gestational sac and you are performing a FAST scan for unexplained hypotension or shock, this could be an identifier for a pseudosac of an ectopic pregnancy.
Look out for the next and last entry on the FAST scan – the Lung Views in the next newsletter.
- Abrams BJ, Sukumvanich P, Seibel R, et al. Ultrasound for the detection of intraperitoneal fluid: the role of Trendelenburg positioning. Am J Emerg Med. 1999;17(2):117-20.
- Friese RS, Malekzadeh S, Shafi S, et al. Abdominal ultrasound is an unreliable modality for the detection of hemoperitoneum in patients with pelvic fracture. J Trauma. 2007;63(1):97-102.
- Ma OJ, Kefer MP, Mateer JR, et al. Evaluation of hemoperitoneum using a single- vs multiple-view ultrasonographic examination. Acad Emerg Med. 1995;2(7):581-6.
- Von Kuenssberg Jehle D, Stiller G, Wagner D. Sensitivity in detecting free intraperitoneal fluid with the pelvic view of the FAST exam. Am J Emerg Med. 2003;21:476-8.
- Blackbourne LH, Soffer D, McKenney M, et al. Secondary ultrasound examination increases the sensitivity of the FAST exam in blunt trauma. J Trauma. 2004;57:934-8.
Journal Watch - Emergency Ultrasound Section Newsletter, October 2013
Brian D. Euerle, MD, RDMS, FACEP and Greg R. Bell, MD
Article: Platz E, Solomon SD. Point-of-care echocardiography in the accountable care organization era. Circ Cardiovasc Imaging. 2012;5(5):676–682.
Reviewer: Gregory Bell, MD
Background: With the advancement of ultrasound technology and portability, more studies are performed and interpreted at the bedside. Point-of-care (POC) echocardiography is becoming an indispensable tool for patient assessment and management. POC echocardiography has caused a distinct differentiation between it and traditional comprehensive ultrasonography, which has given rise to concerns about POC training, documentation, and reimbursement of physician “non-experts.”
Discussion: The authors, from emergency medicine and cardiology, begin by discussing the current expanding role of POC echocardiography, including assessment of pericardial effusion, cardiac activity in pulseless electrical activity, global left ventricular function, right ventricular dilatation, as well as volume status and pulmonary problems linked to cardiac function. They make an interesting comparison that ultrasonography in European countries is generally performed by physicians, specific to their own disciplines, while scanning in the United States is commonly performed by sonographers and interpreted by physicians. The difference in scanning speed and cost is significant.
In the United States, hospital medical staffs continue to be concerned about granting privileges for POC ultrasound, questioning user competency, quality assurance programing, and appropriate documentation. Platz and Solomon reference several studies endorsing accurate POC results, with cost-saving consequences, of echocardiography by novice users who completed training programs. The authors highlight the AMA resolution declaring ultrasound as an imaging modality that lies within the scope of practice of the appropriately trained physician. An example of training and performance standards is found in ACEP’s comprehensive emergency ultrasound guidelines. With proficiency expectations such as these, the authors ask if the resistance to POC echocardiography is related to which imaging studies offer the best reimbursement and who bills for them.
The article turns to changes in health care delivery and their effects on POC echocardiography. Hospitals or accountable care organizations in the future will offer reimbursement incentives to providers who reduce health care costs and improve quality of care. Reimbursement will favor reduced specialty care and limited use of imaging and other testing. This is likely to foster more demand for POC ultrasonography, especially in light of increased patient satisfaction garnered by rapid and efficient diagnosis and treatment. The authors conclude by endorsing formal specialty-specific certification processes for POC echocardiography and standardized documentation in order to improve communication.
Comments: The issues of accuracy of POC studies, quality training guidelines, the rise in demand for POC echocardiography, as forecasted by upcoming changes in reimbursement, and the need for formalized credentialing and reporting are probably all applicable to the use of POC emergency ultrasonography. This article details the reasons that POC ultrasonography requires rigorous performance expectations and affirms why it is so important in early care decision-making.
Article: Shostak E, Brylka D, Krepp J, et al. Bedside sonography for detection of postprocedure pneumothorax. J Ultrasound Med. 2013;32(6):1003–1009.
Reviewer: Sam Hsu, MD, RDMS
Objective: To describe the performance of bedside ultrasound to detect pneumothorax after selected thoracic procedures.
Methods: This was a prospective study of patients who underwent thoracentesis, transbronchial biopsy, or CT-guided needle lung biopsy. The patients underwent lung sonography before and after the procedures. The ultrasound exam consisted of scanning the chest from the apex of the lung to the diaphragm in the mid-clavicular, anterior-axillary, mid-axillary, and posterior-axillary lines. Scans were judged to be “limited” quality if lung sliding or B-lines were not present on the pre-procedure scan or if the pleural surface was not seen in three consecutive intercostal spaces along each scan line on the post-procedure scan. Pneumothorax was excluded if lung sliding or B-lines were visualized. Pneumothorax was diagnosed if both lung sliding and B-lines were absent and a lung point was identified. A second-year pulmonary fellow who had received 2 hours of training in lung sonography performed all the scans. Video clips were saved and reviewed by a general board-certified radiologist with no specialty training in lung sonography. Neither was present when the procedures were performed. Chest radiography was the gold standard.
Results: A total of 185 patients were scanned. Twenty-three percent of the scans were judged to be limited in quality, largely due to reduced lung sliding related to underlying lung disease. Pneumothorax occurred in eight patients; seven were identified by the fellow, and six were identified by the radiologist. The patient with a false-negative result had a chest CT scan that ultimately excluded pneumothorax. There were five false-positive sonograms, three occurring in patients with limited-quality scans and one from a patient who was found to have a pneumothorax on CT. The sensitivity and specificity of the fellow for detecting pneumothorax were 88% and 97%, respectively. For adequate scans, the positive likelihood ratio was 55, and the negative likelihood ratio was 0.17. Limited scans had a likelihood ratio of 1.0.
Commentary: This study is a reminder that ultrasound can be used to detect pneumothorax not just in trauma patients, but also in patients undergoing procedures. An important lesson from this study is to scan the patient before the procedure to identify potentially difficult scans and to provide a baseline for comparison. The somewhat low sensitivity causes some concern, but if the false-negative result that proved to be a true negative on CT is excluded, the sensitivity rises to 100%. There were several false-positive readings among the limited scans, in which pleural sliding was difficult to detect. The addition of M-mode ultrasound―curiously not used in this study―might have improved the specificity in these cases, since M-mode interpretation does not depend on visualizing pleural sliding. Lung ultrasound is an advanced skill that is not intuitive because it includes interpreting artifacts, but with thorough training and experience, sonologists can incorporate lung sonography into procedures around the chest and recognize when another imaging modality is required.
Article: Mittal MK, Dayan PS, Macias CG, et al. Performance of ultrasound in the diagnosis of appendicitis in children in a multicenter cohort. Acad Emerg Med. 2013;20(7):697–702.
Reviewer: Jennifer Chang, MD
Objective: To assess the usefulness of ultrasound (US) in pediatric emergency departments, based on frequency of utilization at each site and whether the appendix was visualized.
Methods: This was a secondary analysis of a prospective, observational study of children with suspected appendicitis. The Pediatric Emergency Medicine Collaborative Research Committee (PEM-CRC) enrolled patients 3 to 18 years of age with acute abdominal pain, who were being evaluated for suspected appendicitis at 10 pediatric emergency departments. Final diagnosis of appendicitis was determined by pathology, operative reports, or telephone follow-up. The study analyzed US test characteristics of sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and likelihood ratios, as well as the change in sensitivity based on frequency and availability of utilization of ultrasound for evaluation. In addition, a subset analysis of the test characteristics was done on studies that definitively visualized the appendix, whether positive or negative.
Results: Overall, with all sites combined, US had a sensitivity of 72.5% (95% CI, 58.8%–86.3%), specificity of 97.0% (95% CI, 96.2%–97.9%), PPV of 92.5% (95% CI, 87.4%–97.7%), NPV of 87.5% (95% CI, 84.3%–90.7%), positive likelihood ratio (+LR) of 24.5 (95% CI, 15.6–38.3), negative likelihood ratio (–LR) of 0.28 (95% CI, 0.24–0.34), and overall accuracy of 88.8% (95% CI, 85.9%–91.7%). At sites where US was available 24 hours a day and used as the primary modality in evaluating pediatrics patients for appendicitis, the combined sensitivity increased to 77.7% (95% CI, 54.7%–99.9%). At sites where ultrasound was used infrequently, the combined sensitivity decreased to 35% (95% CI, 20.0%–50.0%). For the middle ground site, where ultrasound was available only during the day but was utilized primarily when available, the sensitivity was 51.6% (95% CI, 33.0%–70.2%). In the subgroup analysis of ultrasounds where the appendix was specifically identified and classified as normal or abnormal (48.6% of the total cases), the authors found an overall sensitivity of 97.9% (95% CI, 95.2%–99.9%), specificity of 91.7% (95% CI, 86.7%–96.7%), PPV of 92.5% (95% CI, 87.4%–97.7%), NPV of 97.7% (95% CI, 94.7%–99.9%), +LR of 11.8 (95% CI, 7.7–18.2), and –LR of 0.02 (95% CI, 0.009–0.05).
Discussion: This study analyzed the reliability of ultrasound in diagnosing or ruling out appendicitis in the emergency department. Overall, the sensitivity for US was low but was generally higher in institutions that utilized US more frequently for evaluation. This appears to be related to variable operator experience and overall performance, which has remained a limiting factor in the reliability of this imaging modality. However, the authors did find that if the operator can specifically identify the appendix, whether normal or abnormal, the sensitivity, specificity, PPV, NPV, +LR, and –LR all improved. As with previous studies, the authors concluded that US, when available, is a useful initial imaging modality to evaluate patients for acute appendicitis, but if the appendix is not specifically identified, the provider must proceed to subsequent diagnostic strategies.
Article: Abbasi S, Molaie H, Hafezimoghadam P, et al. Diagnostic accuracy of ultrasonographic examination in the management of shoulder dislocation in the emergency department. Ann Emerg Med. 2013;62(2):170–175.
Reviewer: T. Andrew Windsor, MD
Objective: To assess the diagnostic accuracy of bedside ultrasound for detecting shoulder dislocation and confirming proper reduction of the dislocation.
Methods: This was a prospective observational study involving a convenience sample of adult patients presenting to the ED with suspected shoulder dislocation. One of two emergency physician investigators performed ultrasonography before and after reduction with a 7.5- to 10-MHz linear transducer. Shoulder dislocation was confirmed by standard plain radiographs, after which a reduction procedure was performed. Appropriate reduction was assessed with ultrasound and confirmed with plain radiograph, with the sonographer blinded to the radiographic results. All radiographs were interpreted by an attending radiologist who was blinded to the sonographic results. All ultrasounds were also later reviewed by an attending radiologist who was blinded to the radiographic results. The primary endpoints of the study were the ability to detect dislocation in patients with possible shoulder dislocation and to confirm reduction in patients with definitive dislocation.
Results: Of the 73 patients enrolled, 69 were found to have dislocations, as confirmed by three-view plain radiographs. Ultrasonography did not miss any dislocation, and there were no false-positives. Therefore, the sensitivity and specificity of ultrasonography for detection of shoulder dislocation were 100% (95% CI, 93.4%–100%) and 100% (95% CI, 39.5%–100%), respectively. First-attempt reduction was successful in 97.1% of patients, with two failed attempts that were identified with ultrasound and confirmed by radiograph. The sensitivity and specificity of ultrasonography for assessment of complete reduction of the shoulder were 100% (95% CI, 93.2%–100%) and 100% (95% CI, 19.7%–100%). The mean time elapsed between triage and diagnosis of shoulder dislocation was 4.4 minutes by ultrasonography (95% CI, 4.18–4.65 min) and 16.49 minutes by radiography (95% CI, 15.63–17.39 min) (p<0.001).
Discussion: This study proposes that ultrasound can accurately confirm shoulder dislocation and appropriate reduction in patients for whom the diagnosis is suspected based on history and physical examination. While the reported accuracy of ultrasound was excellent, the study suffers mostly from the limitation of a small number of patients and only two ultrasound operators. Nonetheless, the findings show promising potential for bedside ultrasonography as an accurate, fast, repeatable, and convenient modality without ionizing radiation for evaluating shoulder dislocation. The authors point out that many practitioners may be uncomfortable reducing a traumatic shoulder dislocation without pre-reduction radiographs because of the possibility of fractures. Ultrasonography may therefore have a more acceptable role in verifying proper reduction of the shoulder at the bedside in an expedited manner without repeated radiation exposure. Future larger studies may confirm their results and better estimate the ability of ultrasonography to safely detect fractures associated with dislocation.
Article: Ünlüer EE, Yavasi Ö, Akoglu H, et al. Bedside assessment of central venous pressure by sonographic measurement of right ventricular outflow-tract fractional shortening. Eur J Emerg Med. 2013;20(2):18–22.
Reviewer: Eleanor Oakley, MA, MD
Objective: To determine if right ventricular outflow tract fractional shortening can be used to detect a low central venous pressure (CVP).
Methods: This cross-sectional study was conducted at a high-volume emergency department (ED) at an academic adult tertiary care center in Turkey. All adult patients undergoing invasive CVP monitoring in the critical care area of the ED were recruited for the study over a 4-month period. Patients were excluded if they were intubated; were pregnant; had elevated cardiac biomarkers; had any tricuspid pathology, COPD, or pulmonary hypertension; had a CVP ≥12; or if the cardiac echo was technically limited. Emergency physicians who had undergone a 2-hour training course spent about 10 minutes measuring right ventricular outflow tract fractional shortening (RVOT-FS).
Results: The study group consisted of 44 patients with a mean age of 63±15 years. Pathologies included sepsis (9), diarrhea and vomiting (8), decreased oral intake (6), DKA (6), GI hemorrhage (5), pneumonia (4), meningitis or encephalitis (2), and burn (1). RVOT-FS was lower in patients who had a low CVP. The measurements had a point biserial correlation coefficient of 0.76 (p<0.001). A receiver-operating curve (ROC) was used to calculate a cutoff point of 26.44% to distinguish between a low (<8) and normal (8–12) CVP. The area under the ROC curve was 0.933 (95% CI, 0.810–0.987). Sensitivity was 95% and specificity was 80.95%.
Discussion: This study shows a correlation between reduced RVOT-FS and low CVP in a group of older patients who are likely to require volume resuscitation. This test may guide decision making while physicians obtain more objective clinical markers of volume status. The authors suggest that RVOT-FS could act as an adjunct to IVC measurements or could be utilized when IVC measurements are unobtainable. Notably, these measurements were made by ED physicians at the bedside who had undergone a brief period of training in measurement of RVOT-FS. The authors report that precision, accuracy, and inter-rater reliability were not measured and would likely be an area of future study. Unfortunately, the authors do not report how many physicians participated, nor do we know their level of experience in cardiac ultrasound. Another methodologic question that arises is in patient enrollment. The authors performed power analysis, which indicated that they would require 35 patients to show a correlation, but they enrolled an additional 11 patients for unclear reasons. Also, nearly 10% of eligible patients were excluded because of low-quality images, bringing feasibility into question. Finally, while the ED physicians were blinded to CVP, they were not blinded to the clinical condition of the patient, which could have biased their results. Unfortunately, the measurements were not repeated and there are no indications that the studies were over-read by a truly blinded observer. In conclusion, this study has many variables that need to be addressed before its findings could be used to change clinical practice.
Article: Egan G, Healy D, O'Neill H, et al. Ultrasound guidance for difficult peripheral venous access: systematic review and meta-analysis. Emerg Med J. 2013;30(7):521–526.
Reviewer: Zahir Basrai, MD
Objective: This meta-analysis aimed to assess the clinical effectiveness of ultrasound-guided peripheral intravenous (PIV) cannulation compared with standard technique in patients with known difficult access. The primary outcome was successful PIV cannulation. The secondary outcomes were number of skin punctures and procedure time until successful cannulation.
Methods: The MEDLINE database, EMBASE databases, clinical trials registry, and the web were searched from1956 to February 2012 using the search terms peripheral venous cannulation and peripheral venous access. Studies were included in the meta-analysis if they met the following criteria: (1) randomized controlled trial, (2) patients of any age requiring PIV cannulation, (3) patients randomized to ultrasound versus standard technique for the placement of PIV cannulas, (4) patients identified as having difficult venous access, and (5) inclusion of at least one clinical outcome (procedural success, time to catheter placement, number of attempts). Trial quality was evaluated using the JADAD score. The weighted mean difference was determined for continuous variables. Pooled odds ratios (ORs) were used for all outcome measures. Heterogeneity was assessed qualitatively by visual inspection of funnel plots and quantitatively by calculation of the Egger test.
Results: The initial search produced 15,405 potentially relevant citations. After title screening, excluding non-comparative clinical studies and reviews, and adding supplementary searches for unpublished studies, a total of seven studies met inclusion criteria for the meta-analysis. The trials included a total of 289 patients scheduled for PIV cannulation. Six of the seven studies were used to evaluate the primary outcome of successful cannulation. The meta-analysis revealed that ultrasound-guidance increased the likelihood of a successful cannulation attempt (pooled OR, 2.42; 95% CI, 1.26–4.68; p=0.008). There was no evidence of heterogeneity (Cochran’s Q, 1.79; 5 df; p=0.144) or bias (Egger test=[–]0.25; p=0.69). The funnel plot was symmetric overall. Five of the seven trials were used to evaluate the secondary outcome of procedure time. There was no statistically significant difference in procedure time between ultrasound and the standard therapy group (weighted mean difference [WMD], 1.1.8 min; 95% CI, [–]3.55–5.90 min; p=0.63). Cochran’s Q test was 26.24 (4 df; p<0.0001), indicating evidence of heterogeneity. Egger test=(–)2.92 (p=0.72), indicating no evidence of bias. Four of the seven trials were used to evaluate the secondary outcome of number of attempts. Ultrasound guidance had no significant influence on the number of skin puncture attempts. Cochran’s Q of 152.53 (4 df; p<0.0001) indicates evidence of heterogeneity. Egger test=[–]2.92 (p=0.72) indicates no evidence of bias.
Discussion: Although the authors of the study recommend the use of ultrasound guidance in patients who have difficult venous access and in whom venous cannulation by standard methods failed, the many shortcomings of this meta-analysis make it difficult to draw generalized conclusions. For instance, two of the studies included in the meta-analysis had a JADAD score <2, indicating lower quality studies. Furthermore, the study with the most power had a JADAD score of 1. Five of the six studies used to evaluate the primary outcomes had odds ratios that crossed 1 and hence showed no statistical significance between ultrasound and the standard approach. It is also difficult to draw generalized conclusions from this study given the heterogeneity of the providers and enrolled patient populations. The studies included in the meta-analysis evaluated both physicians and non-physicians, leaving room for significant provider variability. Also, the patients enrolled in the study were of varying ages, from pediatric to geriatric.
Article: McArthur TA, Planz V, Fineburg NS, et al. The common duct dilates after cholecystectomy and with advancing age: reality or myth?J Ultrasound Med. 2013;32(8):1385–1391.
Reviewer: Brian D. Euerle, MD, RDMS, FACEP
Objective: To evaluate common duct diameter, as measured by sonography, before and after cholecystectomy as well as over time, in patients with and without cholecystectomy.
Methods: This research was performed in the radiology department of a tertiary care academic hospital. A total of 893 patients who had two abdominal ultrasound exams at least 2 years apart were entered into the study. The patients were divided into three groups: group one, patients who had cholecystectomy before the first ultrasound exam; group two, patients who had cholecystectomy between the ultrasound exams; group three, patients who did not have cholecystectomy. A single board-certified radiologist, blinded to patient information, performed the common duct measurements.
Results: The primary results were a comparison of the common duct diameters in the initial and follow-up ultrasound exams in each of the three groups: group one, 4.5 and 5.2 mm (increase of 0.7 mm); group two, 3.6 and 4.9 mm (increase of 1.3 mm); group three, 3.5 and 3.9 mm (increase of 0.4 mm). The increase in common duct size between ultrasound exams was largest in group two (cholecystectomy performed between the two exams) and was statistically larger than in the other two groups. In group one (patients who had cholecystectomy an average of 9.7 years prior to the first ultrasound exam), both the initial and follow-up common duct diameters were statistically larger than in the other two groups. In group three (patients who did not have cholecystectomy), there was a statistically significant small increase in the duct size over decades.
Discussion: It has been a commonly held belief that common duct size increases after cholecystectomy, perhaps because the duct assumes the reservoir function of the absent gallbladder. Some of the previous studies that investigated this change had methodological flaws and conflicting results. The authors of this study feel that it has several advances over prior work because of its strict entry criteria and use of a control group of patients without cholecystectomy. They also point out that the study question is an important issue because patients with a dilated common duct may be subject to further invasive and noninvasive evaluation, which could potentially be avoided if the enlarged common duct was felt to be an expected finding. Although small differences between groups were found, the authors note that the common duct diameter was normal (6 mm or less) in all but a very small percentage of patients, so in asymptomatic patients with or without prior cholecystectomy, a common duct diameter greater than 6 mm may need further evaluation.
Great Case: RLQ Abdominal Pain and RUQ Reverb? - Emergency Ultrasound Section Newsletter, October 2013
Felix Pacheco, MD, Alise Frallicciardi, MD, Meghan Kelly Herbst, MD
Right lower quadrant pain and vomiting
1. What pathology is shown in the Case Video?
2. How sensitive and specific is ultrasound for this finding?
3. What are some potential pitfalls for this exam?
A 36 year old male with history of regular alcohol use presented from home with RLQ pain that began after vomiting eight hours prior to arrival. The onset of his pain was sudden, followed by an interval of improvement, and then worsening again by the time of his ED evaluation. His pain was constant, radiated to the right upper quadrant, worsened with movement, and was accompanied by diaphoresis. On review of systems, he had a single episode of vomiting, but denied fever, chest pain, shortness of breath, or diarrhea. Vital signs were: T 96.7, HR 82, RR 20, BP 136/72, and O2 sat 98% on room air.
Bedside ultrasound demonstrated a reverberation artifact over the anterior subcostal region of the liver, which was highly suspicious for pneumoperitoneum. IV fluids and antibiotics were administered. The surgical service was emergently consulted. CT of the abdomen revealed a perforated duodenal ulcer with free air in the peritoneal cavity. The patient went to the operating room for laparoscopic omental Graham patch repair. H. pylori testing returned positive and he was treated for this as well. He was discharged home 5 days later.
Role of Emergency Ultrasound in Evaluating for Pneumoperitoneum:
The use of ultrasound to visualize free intra-abdominal air was first documented over 30 years ago by Seitz and Reising, when it was found to detect as little as 1 mL of free air. Air outside the bowel is best appreciated over the right hypochondrium, superficial to the liver parenchyma. Position the head of the bed 30-45 degrees upright, or put the stretcher in a reverse trendelenberg position at about the same angle. Use either a high frequency linear probe or a low frequency convex probe, place it over the superior liver border at the costal margin in a sagittal orientation. If air is present outside the bowel, it will interpose itself between the liver and the peritoneum, and can be seen as a hyperechoic reverberation artifact.
Answers to Questions:
- This clip shows two foci of pneumoperitoneum in the form of hyperechoic reverberation artifacts superficial to the liver parenchyma and inferior to the peritoneum line, and extending posteriorly. In a still image taken from the clip, the blue arrow points out one of these reverberation artifacts.
- In a study evaluating 4000 consecutive patients with atraumatic acute abdominal pain, Seitz and Reising found ultrasound to have a sensitivity of 90% and a specificity of 100% for pneumoperitoneum. In a study of 487 consecutive blunt trauma patients with abdominal pain, Moriwaki et al found ultrasound to have a sensitivity of 85% and a specificity of 100% for pneumoperitoneu. In a radiology study involving comprehensive abdominal ultrasound examinations, ultrasound was 100% sensitive and 99% specific for pneumoperitoneum.
- If the colon interposes itself between the liver and diaphragm (Chilaiditi syndrome) the air in the colon may produce a similar reverberation artifact. While this is rare, watching for peristalsis or changing the position of the patient may further help distinguish this from true pneumoperitoneum. Air in the lungs may also mimic pneumoperitoneum. To overcome this pitfall, identify alveolar air artifacts superior to the diaphragm, watch the respiratory pattern, and then look for pneumoperitoneum artifacts inferior and slightly less superficial in origin.
Take Home Points:
1. Ultrasound is sensitive and specific for pneumoperitoneum.
2. Positioning and technique are important: raise the head of the patient 30-45 degrees and look for reverberation artifacts over the anterior surface of the liver.
- Seitz K, Reising KD. Ultrasound detection of free air in the abdominal cavity. Ultraschall Med. 1982;3:4-6.
- Moriwaki Y, Sugiyama M, Toyoda H, et al. Ultrasonography for the diagnosis of intraperitoneal free air in chest-abdominal-pelvic blunt trauma and critical acute abdominal pain. Arch Surg. 2009;144:137-141.
- Asrani A. Sonographic diagnosis of pneumoperitoneum using the enhancement of the peritoneal stripe sign. A prospective study. Emerg Radiol. 2007;14:29-39.
- Hoffmann B, Nürnberg D, Westergaard MC. Focus on abnormal air: diagnostic ultrasonography for the acute abdomen. Eur J Emerg Med. 2012;19:284-291.
Ask the Expert – Ultrasound Beyond the Ivory Tower! - Emergency Ultrasound Section Newsletter, October 2013
Robert Bramante, MD, RDMS, and Michael Zwank, MD, RDMS, FACEP, talk to Srikar Adhikari, MD, Section Chief and Emergency Ultrasound Fellowship Director, University of Arizona
Non-EM boarded or non-EM trained physicians staff many rural ED’s. What emergency ultrasound applications would you encourage these clinicians to learn?
I recommend learning EFAST, aorta, soft tissue infections, and procedural guidance for central venous access. In my opinion, these ultrasound applications have the highest impact on patient care, emergency department throughput and patient safety. This skill set would assist physicians in the rapid assessment of patients, early recognition & treatment of life-threatening conditions and guide invasive procedures. I believe any physician can learn these applications with focused training and practice.
What one application would you strongly promote for any community physician who is reluctant to take the time to learn and then perform ultrasound in a busy ED? And why?
Definitely EFAST. Learning the EFAST exam will not only help with rapid assessment of trauma patients but also helps with evaluation of ED patients (non-trauma) presenting with variety of other symptoms such as:
- SOB or Chest Pain: Assessment for pneumothorax, pleural effusion, pericardial effusion and tamponade.
- Abdominal pain: Look for free fluid in abdomen
- Cardiac arrest: Determine the presence of cardiac activity and help guide resuscitation
- Hypotension or Tachycardia: Look for free fluid in the abdomen, pericardial effusion, pneumothorax and urinary bladder volume.
- Evaluation for Ectopic or Ruptured Ovarian cyst: Check for free fluid in abdomen and determine the need for emergency consultation or transfer.
- Evaluation for Spontaneous Bacterial Peritonitis: Look for ascites and procedural guidance during paracentesis.
- Flank pain: Look for hydronephrosis or renal cyst.
- Suspicion for Urinary Retention: Qualitative assessment of urinary bladder volume with ultrasound and to guide the need for Foley catheter placement.
- Determination of presence of urine in the bladder prior to catheterizing children to obtain a urine sample.
Do you have any suggestions for good ways to learn new techniques if you don't have an “Ultrasound Guy” at your shop?
- Emergency Ultrasound courses: Several courses are offered throughout the country. In an open course, the location is set and participants travel to the course. In an imported, the course travels to the participants. In either case, the key is always to master basic point-of-care ultrasound applications initially before exploring any advanced applications.
- Asynchronous learning: Several ultrasound online learning resources (podcasts, online tutorials, and webinars) are currently available. These discuss in detail scanning technique, pitfalls and pearls.
- Computer-based emergency ultrasound training simulators: Laptop based virtual reality ultrasound training simulators provide didactic teaching, hands-on training, and knowledge assessment on a variety of emergency ultrasound topics (Sonosim, Medaphor, CAE Vimedix etc.). These simulators allow novices to learn in their own time without expert supervision in the early stages of training.
- Continuous scanning and feedback from an expert sonographer: Scanning skills improve only with repetition and feedback from over-reading of images by experienced sonologists. Attending an ultrasound course is simply not enough; proficiency is only achieved with quite a bit of practice after the course. Many emergency ultrasound experts across the country provide online consultative and over-read services.
- Preceptorship or visiting fellowship with experts at other emergency ultrasound training sites: Training should include bedside scanning and proctoring. May vary in duration, but typically last 2-4 weeks.
Highlights from the 2013 Tri-State Inaugural Course for Emergency Ultrasound Fellows - Emergency Ultrasound Section Newsletter, October 2013
Nicole L. Kaban, MD and Nicholas C. Avitabile, DO
Emergency Ultrasound Fellows, St. Luke’s Roosevelt Hospital Center
When the emergency ultrasound fellows were selected for their fellowship slots back in November 2012, those of us who landed in the tri-state area (New York, New Jersey, and Connecticut) had no idea that we would be kicking off our year with a very novel and comprehensive introductory course. Despite the concentration of emergency ultrasound programs and leaders in the area, there had never before been any formalized interaction and grouped education between the fellowships. In December 2012, the St. Luke’s Roosevelt organized City-Wide Grand Rounds, a quarterly conference, hosted Dr. Paul Mayo as the round-table discussant. Dr. Mayo, an intensivist from the North Shore LIJ Health System, described an annual 3-day course he organizes for New York area Critical Care fellows each July. At that time, the emergency ultrasound leaders in the room immediately thought that an emergency ultrasound conference for new fellows would be a great opportunity to congregate the local emergency ultrasound community and help standardize knowledge and training going forward into the fellowship year.
With that inspiration, some regional masterminds decided to spearhead the Tri-State Area Inaugural Course for Emergency Ultrasound Fellows at Lenox Hill Hospital on July 25 and 26, 2013. With a turn out of 15 programs, 30 ultrasound fellows, and 30 ultrasound faculty in attendance, this course was made even more outstanding by a close to 1:1 instructor to fellow ratio.
Day One was an ultrasound management course focused on the organizational, political, and social aspects of running an emergency ultrasound division. Eight speakers educated on various management topics and then led two separate panel discussions where they fielded questions from the audience.
Key Pearls Included:
- Before one elects to lead a division or become a fellowship director, he/she should work one year post-fellowship in an emergency ultrasound division.
- Saying “I want to teach” is analogous to saying “I’m a people person” when it comes to academic careers; one needs to develop a true unique niche, expand his/her educational portfolio, and master networking.
- When teaching a course, lots of hands-on experience and making sure you know your audience is key. And don't forget the ultrasound gel when traveling overseas!
- Become best friends with your bioengineering and IT departments!
- A good QA process, along with good policies, can save you.
- When accepting a new job as an emergency ultrasound director, one should obtain a letter of intent from his/her future employer in order to highlight the educational needs of the department, such as the acquisition of new ultrasound machines.
- The online resources for emergency ultrasound are BOOMING, and this is a great time to get involved with blogs, twitter, and online websites about ultrasound, as long as HIPAA and professionalism are maintained.
Day Two's mantra was strictly, "Practice practice practice!" Local ultrasound industry sponsors provided over fifteen machines and simulation tools for the fellows to use. The ultrasound faculty led discussions and practice-sessions in the following areas: eFAST, Biliary/Renal, Soft Tissue/Central Venous Access, DVT/Aorta, Ob-Gyn, and Cardiac. Many thanks to Resa Lewiss, MD, RDMS, Bret Nelson, MD, RDMS, FACEP, Chris Raio, MD, RDMS, FACEP, Ninfa Mehta, MD, Eitan Dickman, MD, RDMS, FACEP, Anita Datta, MD, FACEP, Lawrence Haines , MD, MPH, FACEP, and everyone else who took part in organizing this exceptional experience.
Interested in Contributing? - Emergency Ultrasound Section Newsletter, October 2013
Many thanks to all section editors! If you have a great case, an article review, commentary, or tech update to contribute to the next newsletter, then just email John Bailitz, MD, FACEP.