Quantitative and Qualitative Analysis of Emergency Physician Performed Biparietal Diameter Estimate for Gestational Age.

BACKGROUND: An accurate estimation of fetal gestational age is essential for the management of pregnant patients who present to the emergency department (ED). Point-of-care-ultrasound (POCUS) is an integral part of emergency medicine training and includes measurement of fetal gestational age by the biparietal diameter (BPD) method. OBJECTIVES: In this study we performed a quantitative assessment of emergency physician (EP)-performed BPD estimate of gestational age to identify the percentage of studies performed in our department that had an estimated gestational age within 14 days of an adjusted radiological or obstetrical estimation. METHODS: We performed a chart review of our ED ultrasound database and electronic medical records for cases where a BPD measurement was performed by an EP. We recorded the ED gestational age estimate in days and the radiological or obstetrical estimate of gestational age in days. We then calculated the difference in days between the two examinations. We used a normal binomial approximation to calculate 95% confidence intervals. A secondary analysis looked at the quality of the images based on measurement placement and the view obtained. RESULTS: Seventy-four cases met eligibility criteria; of those, 67 (91%) had a gestational age estimation within 14 days of the adjusted radiological or obstetrical estimate (95% confidence interval 81-96%). CONCLUSION: This study shows that EP-performed BPD measurements for gestational age are quantitatively accurate, with 91% of estimates within 14 days of a standard radiological or obstetrical estimation.

Transesophageal Echocardiography Training of Emergency Physicians Through an E-Learning System.

BACKGROUND: Transesophageal echocardiography (TEE) has been shown to be a powerful tool that emergency physicians can use to guide resuscitation efforts during cardiac arrest. Currently, there is no standardized curriculum to teach TEE to emergency physicians. OBJECTIVE: We hypothesized that the use of a pilot training course combining interactive e-learning and hands-on simulation would increase the percentage of students achieving a score of ≥80% on a multiple-choice test of knowledge and increase self-reported comfort using TEE. METHODS: We designed a 2.5-h TEE course for emergency physicians and medical intensive care unit fellows. Participants took a test of knowledge and a survey of comfort-both online-before, just after, and 4 weeks after taking the course. Survey responses measured participants self-reported comfort with using TEE in clinical practice. A normal binomial approximation was used to calculate the 95% confidence interval. RESULTS: Of the 3 tests of knowledge, 15 participants completed all tests. Of the surveys of comfort, 31 participants completed the precourse survey, 32 completed the postcourse survey, and 19 completed the 4-week follow-up survey. The proportion of students scoring ≥80% improved from 40% on the precourse test to 80% on the postcourse test (95% confidence interval 1-79). The proportion of students indicating comfort with using TEE improved from 3% precourse to 53% postcourse (95% confidence interval 28-71). CONCLUSIONS: A TEE training course resulted in a 50% increase in surveyed participants feeling comfortable using TEE in cardiac arrest and a 40% increase in participants scoring ≥80% on a test of knowledge.

The Use of Transesophageal Echocardiography During Cardiac Arrest Resuscitation: A Literature Review.

We propose that transesophageal echocardiography (TEE) can be used to guide cardiac arrest resuscitation. We undertook a literature search (Medline and EMBase) to assess articles on that topic. Our search yielded 55 articles falling into 3 categories: TEE used in operating rooms, TEE used in emergency departments, and TEE used in other settings. In many cases, TEE changed the direction of the resuscitation; however, it is unclear whether TEE changed patient-oriented outcomes, such as neurologically intact survival. Few adverse events related to TEE have been documented. There is growing evidence that physicians can learn to use TEE during resuscitations and apply the findings to clinical decisions.

How we started an elective in emergency bedside ultrasound.

The expanding use of bedside ultrasonography in the practice of emergency medicine and other specialties is accompanied by the need to train medical students in its applications and interpretation of its results. In this article, the authors describe their successful design, launch, and management of the ultrasound elective at the University of Maryland School of Medicine. Because the course has been so well received, the authors are now exploring ways of presenting its content and skills-building opportunities in more venues, including the Introduction to Clinical Medicine course.

A comparison of longitudinal and transverse approaches to ultrasound-guided axillary vein cannulation.

OBJECTIVE: The axillary vein is an easily accessible vessel that can be used for ultrasound-guided central vascular access and offers an alternative to the internal jugular and subclavian veins. The objective of this study was to identify which transducer orientation, longitudinal or transverse, is better for imaging the axillary vein with ultrasound. METHODS: Emergency medicine physicians at an inner-city academic medical center were asked to cannulate the axillary vein in a torso phantom model. They were randomized to start with either the longitudinal or transverse approach and completed both sequentially. Participants answered questionnaires before and after the cannulation attempts. Measurements were taken regarding time to completion, success, skin punctures, needle redirections, and complications. RESULTS: Fifty-seven operators with a median experience of 85 ultrasound procedures (interquartile range, 26-120) participated. The frequency of first-attempt success was 39 (0.69) of 57 for the longitudinal method and 21 (0.37) of 57 for the transverse method (difference, 0.32; 95% confidence interval [CI], 0.12-0.51 [P = .001]); this difference was similar regardless of operator experience. The longitudinal method was associated with fewer redirections (difference, 1.8; 95% CI, 0.8-2.7 [P = .0002]) and skin punctures (difference, 0.3; 95% CI, -2 to +0.7 [P = .07]). Arterial puncture occurred in 2 of 57 longitudinal and 7 of 57 transverse attempts; no pleural punctures occurred. For successful attempts, the time spent was 24 seconds less for the longitudinal method (95% CI, 3-45 [P = .02]). CONCLUSIONS: The longitudinal method of visualizing the axillary vein during ultrasound-guided venous access is associated with greater first-attempt success, fewer needle redirections, and a trend of fewer arterial punctures compared with the transverse orientation.

No effect of Valsalva maneuver or Trendelenburg angle on axillary vein size.

BACKGROUND: A new technique for establishing ultrasound-guided central access involves the use of the axillary vein, the distal projection of the subclavian vein, via the lateral chest. OBJECTIVE: To examine the effects of Valsalva maneuver and Trendelenburg positioning on axillary vein cross-sectional area (CSA). METHODS: Using a group-sequential design, we enrolled stable emergency patients and measured their axillary veins sonographically. Patients were measured while supine, then after a Valsalva maneuver, and then at 5°, 10°, 15°, and 17° of Trendelenburg positioning, pausing 2 min after each change. We asked patients to score their discomfort from 0 to 10 in each position. RESULTS: We enrolled 30 adult patients with a median age of 39 years (range, 20-66 years). Treating physicians considered 11 of these patients to have hypovolemia. The Valsalva maneuver decreased CSA (Mean difference = -0.03 cm(2)), (95% confidence interval [CI] -0.10-0.04). Trendelenburg positioning did not statistically increase CSA. The 5° position caused the largest increase, that is, 0.04 cm(2) (95% CI -0.04-0.12) in the entire group and 0.1 cm(2) (95% CI -0.07-0.28) in the hypovolemic subgroup. At greater degrees of Trendelenburg positioning, patients reported higher discomfort scores or simply dropped out. CONCLUSION: The Valsalva maneuver and Trendelenburg angles above 10° do not increase axillary vein area but do increase patient discomfort. Our data suggest optimal positioning in the supine resting position or at a 5° Trendelenburg position.

Emergency diagnosis of subarachnoid hemorrhage: an evidence-based debate.

BACKGROUND: The diagnosis of subarachnoid hemorrhage is of paramount concern in patients presenting to the Emergency Department (ED) with acute headache. Computed tomography followed by lumbar puncture is a time-honored practice, but recent technologic advances in magnetic resonance imaging with magnetic resonance angiography and computed tomography with computed tomography angiography can present alternatives for clinicians and patients. OBJECTIVE: The aim of this article was to compare diagnostic strategies for ED patients in whom subarachnoid hemorrhage is suspected. METHODS: We analyze and discuss current protocols, in addition to summarizing the advantages and disadvantages of each method. RESULTS: Through our residency's journal club, we organized an evidence-based debate that pitted proponents of the three subarachnoid hemorrhage diagnostic strategies against one another. Proponents of each strategy described its advantages and disadvantages. Briefly, computed tomography/lumbar puncture is time honored and effective, but is limited by complications and indeterminate lumbar puncture results. Magnetic resonance imaging with magnetic resonance angiography might be more effective in late presentations and can visualize aneurysms, yet has limited availability. Computed tomography with computed tomography angiography offers rapid diagnosis and is considered the most sensitive for diagnosing aneurysms, but has the highest radiation exposure. CONCLUSIONS: Each of the three strategies used to diagnose subarachnoid hemorrhage has advantages and disadvantages with which clinicians should be familiar. Patient factors (e.g., age, body habitus, and risk factors), presentation factors (e.g., time from headache onset and severity of presentation), and institutional factors (availability of magnetic resonance imaging with magnetic resonance angiography) can influence the choice of protocol.

Mixed-Model Curriculum for Nerve Block Education in Emergency Medicine Residency.

Introduction With the rising opioid epidemic, there has been a push for multimodal pain management within the emergency department. Nerve blocks have been shown to be an effective pain management strategy for many conditions, with improved success when used with ultrasound. However, there is no generally accepted method for teaching residents how to perform nerve blocks. Materials and methods Seventeen residents from a single academic center were enrolled. The residents were surveyed pre-intervention regarding demographics, confidence, and use of nerve blocks. The residents then completed a mixed-model curriculum that included an electronic module (e-module) on three plane nerve blocks and a practice session. Three months later, residents were tested on their ability to independently perform the nerve blocks and resurveyed regarding confidence and use. Results Of the 56 residents in the program, 17 enrolled in the study; 16 participated in the first session, and nine participated in the second session. Each resident had < four ultrasound-guided nerve blocks prior to participation with a slight increase in the total number of nerve blocks after the sessions. Residents were able to perform, on average, 4.8 of seven tasks independently. Residents who completed the study reported feeling more confident in their ability to perform ultrasound-guided nerve blocks (p = 0.01) and to complete associated tasks (p < 0.01). Conclusion This educational model resulted in residents completing the majority of tasks independently with improved confidence in ultrasound-guided nerve blocks. There was only a slight increase in clinically performed blocks.

Effects of vein width and depth on ultrasound-guided peripheral intravenous success rates.

BACKGROUND: Increasing numbers of operators are learning to use ultrasound to guide peripheral intravenous (i.v.) catheter insertion in patients with difficult access. Unfortunately, failed cutaneous punctures are common. Some veins seen on ultrasound may be better choices than others. OBJECTIVES: To estimate the effects of vein width and depth on the probability of success in ultrasound-guided i.v. catheter insertion. METHODS: We prospectively collected data from attempts at ultrasound-guided venous catheter insertion between the antecubital fossa and mid-humerus. Each ultrasound machine's ruler function was used to determine depth from the skin to the closest vein edge and that vein's largest diameter. Success was defined as being able to freely withdraw blood or inject saline after the first skin puncture, considering each encounter independently. We calculated relative success rates, confidence intervals, and p values using reference groups selected by histogram analysis. RESULTS: Thirty-five operators recorded 180 encounters; 100 (56%) were successful on the first skin puncture, and 152 (84%) were eventually successful. Success rates were not linearly related to vein width or depth. Success rates were higher for veins with diameter > or = 0.4 cm vs. those < 0.4 cm (63% [78/124] vs. 39% [22/56], relative success 1.6 [95% confidence interval (CI) 1.1-2.3], p = 0.005) and for veins of depth 0.3-1.5 cm vs. veins of depth < 0.3 or > 1.5 cm (58% [96/165] vs. 27% [4/15], relative success 2.2 [95% CI 0.9-5.1], p = 0.04). CONCLUSION: Success rates are higher in larger veins (> or = 0.4 cm) and veins at moderate depth (0.3-1.5 cm).

Ultrasound in pregnancy.

For the emergency physician tasked with evaluating the patient with an obstetric emergency, ultrasound can provide important and potentially life-saving information. Ultrasound of the pregnant patient is unique in that two possible approaches can be used: transabdominal and transvaginal. Another unique feature is that an understanding of developmental anatomy, which changes during pregnancy, is important. Two of the most basic yet important uses of ultrasound in the pregnant patient are to provide information concerning the gestational age of the pregnancy and the fetal heart rate. Ultrasound has a major role in the diagnosis and management of the patient with a suspected ectopic pregnancy.