Application of the Canadian Computed Tomography Head Rule to Patients With Minimal Head Injury.

STUDY OBJECTIVE: Two clinical decision rules, the Canadian CT Head Rule and the New Orleans Criteria, set the standard to guide clinicians in determining which patients with minor head trauma need computed tomography (CT) imaging. Both rules were derived with patients with minor head injury who had had a loss of consciousness or witnessed disorientation. No evidence exists for evaluating patients and need for CT imaging with minimal head injury; that is, patients who had a head injury but no loss of consciousness or disorientation and therefore would have been excluded from the Canadian CT Head Rule and New Orleans Criteria trials. We evaluate the Canadian CT Head Rule in patients with head injury without loss of consciousness or witnessed disorientation (minimal head injury). METHODS: We studied a prospective convenience sample of patients with minimal head injury who received head CTs as part of their evaluations in the emergency department (ED). Participants were enrolled after head CT was ordered, but before the physician received the imaging results. Physicians were surveyed on their clinical reasoning for ordering imaging in this low-risk cohort of patients. Physicians surveyed consisted of ED attending physicians and senior-level emergency medicine residents. Final patient disposition was recorded when it became available. Patients with positive CT findings had their medical records reviewed for specific disposition, admission length of stay, ICU stay, and any operative or procedural interventions. RESULTS: Two hundred forty patients with minimal head injury were enrolled. Five patients (2.1%) had head CTs that were positive for intracranial hemorrhage. All instances of intracranial hemorrhage occurred in patients who were at high or moderate risk by the Canadian CT Head Rule (2 high risk [age], 3 moderate risk [mechanism]). No patient with intracranial hemorrhage went to the ICU or underwent any intervention; the average hospital length of stay was 1.25 days. The Canadian CT Head Rule was 100% sensitive (95% confidence interval 40% to 100%) and 29% specific (95% confidence interval 23% to 35%) for the presence of intracranial hemorrhage. Physicians listed their own reassurance (24.6%), patient reassurance (24.2%), patient expectation (14.6%), and reduction of legal liability (11.7%) as the rationale for ordering head CT in patients with minimal head injury. Shared decisionmaking was used in 51% of cases. CONCLUSION: Risk of intracranial hemorrhage in patients with minimal head injury was very low, and even in patients found to have an intracranial hemorrhage, none had any serious adverse outcome (eg, death, intubation, prolonged hospitalization, surgical procedure). The Canadian CT Head Rule was 100% sensitive in this small cohort of patients with minimal head injury. Among our study cohort, which specifically included only patients who had CT scanning, applying the Canadian CT Head Rule may have reduced the need for CT, potentially saving costs and resources. However, because many patients with minimal head injury who present to the ED may not have CTs, it is unclear what effect the broad application of this rule would have on overall CT use. Providers' rationale for obtaining CT was multifactorial. These represent barriers that may need to be overcome before physicians are comfortable changing CT ordering patterns in this group of head injury patients.

Variability in Interpretation of Cardiac Standstill Among Physician Sonographers.

STUDY OBJECTIVE: Cardiac standstill on point-of-care ultrasonography has been widely studied as a marker of prognosis in cardiac arrest. Return of spontaneous circulation has been reported in as few as 0% and as many as 45% of patients with cardiac standstill. When explicitly documented, the definition of cardiac activity in these studies varied from any slight change in echogenicity of the myocardium to any kinetic cardiac activity. We hypothesize that the variability in research definitions of cardiac activity may affect interpretation of video clips of patients in cardiac arrest. The goal of this study is to assess the variability in interpretation of standstill among physician sonographers. METHODS: We surveyed physician sonographers at 6 conferences held at 3 academic medical centers in the Greater New York area. Survey respondents were allotted 20 seconds per slide to determine whether each of 15 video clips of patients in cardiac arrest were standstill or not. Data were collected anonymously with radio frequency remotes. RESULTS: There were 127 total participants, including faculty, fellows, and resident physicians specializing in emergency medicine, critical care, and cardiology. There was only moderate interrater agreement among all participants (α=0.47). This lack of agreement persisted across specialties, self-reported training levels, and self-reported ultrasonographic expertise. CONCLUSION: According to the results of our study, there appears to be considerable variability in interpretation of cardiac standstill among physician sonographers. Consensus definitions of cardiac activity and standstill would improve the quality of cardiac arrest ultrasonographic research and standardize the use of this technology at the bedside.

A novel method of assessing for lung sliding using Doppler imaging.

Ultrasound is an ideal modality in the emergency department (ED) to assess for pneumothorax given its rapid availability, portability, and repeatability to assess clinical status changes. Certain patient populations and clinical circumstances may present challenges to the performance of this examination. In this article, we review patterns of the presence or absence of lung sliding in the commonly utilized sonographic modes in the ED setting. We also describe a novel technique to evaluate lung sliding using tissue Doppler.

Reliability, Laterality and the Effect of Respiration on the Measured Corrected Flow Time of the Carotid Arteries.

BACKGROUND: Corrected flow time (FTc) measured via sonography of the carotid artery is a novel method that has shown promising results for predicting fluid responsiveness in shock states. It is a rapid and noninvasive examination that can be taught to emergency physicians with ease. However, its reliability has not been assessed, and the effects of several variables, including respiration and side of evaluation, are unclear. OBJECTIVES: The objectives were to compare carotid FTc during different phases of the respiratory cycle, (at end-inspiration and end-expiration), to compare FTc reproducibility among providers, and to compare FTc on the right and left sides in a given individual. METHODS: The FTc of both the right and left carotid arteries was measured in 16 healthy volunteers during an inspiratory hold and an expiratory hold. Examinations were completed by three sonographers blinded to previous results and were analyzed for reliability and reproducibility. RESULTS: Reliability and reproducibility were poor when comparing sonographers under all circumstances. No significant differences were found when comparing left vs. right sides of measurement regardless of respiratory phase. CONCLUSION: Although this method for predicting fluid responsiveness has many promising aspects, reproducibility between sonographers was found to be poor. No significant difference was found between the two sides of the body or respiratory phase.

Air and its Sonographic Appearance: Understanding the Artifacts.

BACKGROUND: Although air has traditionally been considered a barrier to sonographic imaging, when encountered in unusual settings it can serve as an important indicator of various pathologic states as well. Clinician recognition and thorough understanding of the characteristic pattern of artifacts generated by air are critical for making a number of important diagnoses. CASE SERIES: We present five emergency department cases in which air was visualized in a pathologic location. Pneumothorax, pneumoperitoneum, necrotizing fasciitis, or Fournier's gangrene, and subcutaneous emphysema and pneumomediastinum, can be rapidly and easily identified on ultrasound by the presence of air artifacts. The relevant sonographic findings are described and discussed in this article. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Due to its inherent impedance mismatch with other human tissues, air has a characteristic appearance on ultrasound that includes irregular hyperechoic structures, "dirty shadowing," A-lines, and decreased visualization of deeper structures. Knowledge of the sonographic appearance of air artifacts can assist the physician in making a diagnosis, selecting appropriate additional imaging, and enlisting specialist consultation.

Ultrasound-guided dorsal penile nerve block performed in a case of zipper entrapment injury.

Injury to the penis resulting from zipper entrapment is a painful condition that presents a unique anesthetic challenge to the emergency physician and may even require procedural sedation for removal. In this case report, we describe successful removal of zipper entrapment from the penis of a 34-year-old patient after the application of an ultrasound-guided dorsal penile nerve block. We discuss the anatomy, sonographic features, and steps required for the nerve block procedure. © 2017 Wiley Periodicals, Inc. J Clin Ultrasound 45:589-591, 2017.

Hand dominance in intravenous drug using patients does not affect peripheral venous access sites identified by ultrasound.

BACKGROUND: The peripheral veins in the arms and forearms of patients with a history of intravenous (IV) drug use may be sclerosed, calcified, or collapsed due to damage from previous injections. These patients may consequently require alternative, more invasive types of vascular access including central venous or intraosseous catheters. We investigated the relationship between hand dominance and the presence of patent upper extremity (UE) veins specifically in patients with a history of IV drug-use. We predicted that injection into the non-dominant UE would occur with a higher frequency than the dominant UE, leading to fewer damaged veins in the dominant UE. If hand dominance affects which upper extremity has more patent veins, providers could focus their first vascular access attempt on the dominant upper extremity. METHODS: Adult patients were approached for enrollment if they provided a history of IV drug use into one of their upper extremities. Each upper extremity was examined with a high frequency linear transducer in 3 areas: the antecubital crease, forearm and the proximal arm. The number of fully compressible veins ≥1.8 mm in diameter was recorded for each location. RESULTS: The mean vein difference between the numbers of veins in the dominant versus the non-dominant UE was -1.5789. At a .05 significance level, there was insufficient evidence to suggest the number of compressible veins between patients' dominant and non-dominant arms was significantly different (P = .0872.) CONCLUSIONS: The number of compressible veins visualized with ultrasound was not greater in the dominant upper extremity as expected. Practitioners may gain more information about potential peripheral venous access sites by asking patients their previous injection practice patterns.

Ultrasound for the evaluation of soft tissue foreign bodies before and after the addition of fluid to the surrounding interstitial space in a cadaveric model.

BACKGROUND: Point-of-care ultrasound may be used to facilitate foreign body (FB) localization and removal. We hypothesized that injection of normal saline adjacent to an FB may make it easier to detect. METHODS: The study was performed on one embalmed human cadaver. Potential FB sites were created of wood (24), metal (24), and null (24). Two sonographers evaluated each of the 72 sites both before and after a 25-gauge needle was inserted into each incision and 3 cc of normal saline was injected. Accuracy, sensitivity, and specificity were calculated both before and after injection of normal saline. Binomial tests were used to determine the statistical significance of FB detection before and after injection. A 2-tailed Student's t test was used to determine if there was a statistically significant difference between the 2 methods. RESULTS: Preinjection, 116 (81%) of the 144 interpretations (P≤ .001) were correct in their assessment of whether or not an FB was present, with a sensitivity of 81% (95% confidence interval [CI], 72%-88%) and a specificity of 79% (95% CI, 65%-90%). Postinjection, 119 (83%) of these 144 interpretations (P≤ .001) were correct in their assessment of whether or not an FB was present, with a sensitivity of 85% (95% CI, 77%-92%) and a specificity of 77% (95% CI, 63%-88%). This difference was not significant (P=.08; 95% CI, -0.04 to 0.01). DISCUSSION: Ultrasound was reasonably accurate, sensitive, and specific in identifying 1-cm metal and wood FBs. Although accuracy and sensitivity did improve after normal saline injection, this difference was not significant.

High Body Mass Index is Strongly Correlated with Decreased Image Quality in Focused Bedside Echocardiography.

BACKGROUND: There is a well-established relationship between obesity, as measured by body mass index (BMI), and overall health risk. The presence of body fat is a known limitation to ultrasound, but it is unknown whether any decrease in quality due to obesity limits the interpretability of focused bedside echocardiography (FBE). OBJECTIVES: To correlate obesity, as measured by BMI, with image quality and interpretability of (FBE) performed by an emergency physician. METHODS: We conducted a prospective observational study in a convenience sample of adults presenting to two academic emergency departments (EDs) and a bariatric surgery outpatient clinic. Twenty patients were enrolled in each of three BMI categories, <30, 30-39, and ≥40 kg/m(2). FBE was performed in multiple views in two positions. Images were rated for ability to discern the pericardial myocardial interface (PMI) and the endocardial border of the left ventricle (ELV). RESULTS: There were 23 males and 37 females enrolled. The median age was 49 years and the median BMI was 35.6 kg/m(2). There was a significant difference in the percentage of technically limited examinations between BMI categories for both PMI and ELV. There was an overall negative linear correlation between BMI and image quality for both PMI and ELV. CONCLUSION: There is an overall decrease in the quality of focused bedside echocardiographic images as BMI increases. This relationship exists for visualization of both the PMI and the ELV. Emergency physicians should be aware of the potential limitations of focused bedside echocardiography in this patient population.

The Inter-rater Reliability of Echocardiographic Diastolic Function Evaluation Among Emergency Physician Sonographers.

STUDY OBJECTIVES: In a patient with dyspnea and suspected CHF, the evaluation of diastolic function involves: tissue Doppler of the mitral annulus and 2) pulsed wave Doppler of the mitral inflow. We aimed to 1) determine the inter-rater reliability for overall diastolic function and 2) evaluate the reliability of the individual Doppler measurements. METHODS: A convenience sample of adult emergency department patients was prospectively enrolled by 8 EPs who had participated in a 1-hour didactic session. Patients were selected if they had a history of CHF or suspected abnormal diastolic function due to chronic hypertension. Diastolic function was considered to be abnormal if Tissue Doppler of the septal e' was <8 cm/s and if the lateral e' was <10 cm/s. In cases of discordance, the E/e' ratio was calculated with ≤8 considered normal and >8 considered abnormal. A Kappa coefficient. Bland-Altman plot and a fixed effect regression model were used in the analysis. RESULTS: Thirty-two patients were enrolled, and 3 (9.4%) were excluded due to technical inadequacy. The inter-rater reliability among sonographers for overall interpretation was very good: κ = 0.86 (95% CL [0.67, 1.0]). Based on the Bland-Altman plot, was no consistent bias between readers. There was no evidence to conclude that the readings differed among sonographers: septal e' (p = 0.77), lateral e' (p = 0.89) and E (p = 0.15). CONCLUSION: EP sonographers obtained similar Doppler measurements for diastolic function evaluation with very good inter-rater reliability for the assessment of overall diastolic function.

Foot pain and swelling after minor traumatic injury.

Necrotizing fasciitis is a rare bacterial infection of the fascia and surrounding soft tissue, which carries a mortality rate as high as 20%, even in well-appearing patients [1]. Classically, this diagnosis must be made with computed tomography or magnetic resonance,but recent literature shows that ultrasonography, readily available in the emergency department, may be adequate for diagnosis [2]. We present a case of a 48-year-old man who presented with a painful rash. We used his clinical presentation and ultrasound to make the diagnosis,which was later corroborated with plain radiograph findings. He was taken immediately to the operating room for extensive debridement.He was discharged 8 days later in good condition.

Point-of-care ultrasound differentiates pyomyositis from cellulitis.

Pyomyositis (PM) is an infection of skeletal muscle, often associated with an abscess. Patients typically have predisposing risk factors or are immune compromised. The disease is often misdiagnosed, mistreated,and goes undetected until late in the patient's clinical course.We present a case of a patient without obvious predisposing risk factors who complained of right thigh pain, swelling, redness, and fevers for 4 days.Point-of-care ultrasound revealed muscle edema and subcutaneous emphysema without signs of an overlying cellulitis. Point-of-care ultrasound consequently led to an earlier diagnosis of PM and directly affected the immediate patient care in the emergency department.

Preferences of air-blood-saline sonographic microbubble contrast agents among emergency medicine resident physicians.

INTRODUCTION: The placement of a central venous catheter (CVC) remains an important intervention in the care of critically ill patients in the emergency department, and bedside ultrasound can be used for procedural guidance as well as conformation of placement. Microbubble contrast-enhanced ultrasound may facilitate CVC tip position localization, and the addition of autologous blood can significantly increase its echogenicity. The purpose of this study was to describe the preferences of a group of resident physicians regarding the performance of various concentrations of air-blood-saline sonographic microbubble contrast agents. METHODS: Institutional Animal Care and Use Committee approved prospective study. A CVC was inserted into the right internal jugular vein of a 20-kg Yorkshire swine under general anesthesia. Contrast mixtures were created with air, saline, and varying amounts of blood and were injected while echocardiographic video clips were recorded and reviewed by 25 physician sonographers. RESULTS: All reading physicians reported increased overall echogenicity, a higher peak echogenicity, and greater personal preference for blood containing solutions. Nearly all reading physicians preferred the lower percentage blood containing mixtures over the higher percentage blood containing mixture. CONCLUSION: The inclusion of 1 to 3 parts of 10 of the patient's blood in the preparation of a sonographic contrast mixture increased the echogenicity of the contrast, resulted in better visualization of both the contrast and the endocardial border and was the preferred mixture among the resident physicians studied.

The baseline diameter of the inferior vena cava measured by sonography increases with age in normovolemic children.

OBJECTIVES: To evaluate normative sonographic measurements of the inferior vena cava (IVC) diameter in healthy pediatric patients. METHODS: We performed a prospective observational study of a convenience sample of healthy patients between the ages of 0 and 22 years presenting to a pediatric emergency department. Exclusion criteria included abnormal vital signs, pregnancy, or illnesses thought to influence volume status. During quiet respiration, the maximum and minimum IVC diameters were measured in the sagittal plane distal to the hepatic vein-IVC junction. As second measurements, the maximum diameters of the IVC and aorta were measured in the transverse plane distal to the insertion of the left renal vein into the IVC. RESULTS: From February 2013 through April 2014, 63 children (51% female; mean age, 11 years) were enrolled. There were 20 children in each age group of 2 to 7, 7 to 12, and 12 to 22 years. The correlations between IVC and aortic diameters as a function of age were calculated using the Spearman rank correlation coefficient. The correlation coefficients were all statistically significant (P < .001): sagittal maximum IVC diameter (0.81), sagittal minimum IVC diameter (0.79), transverse maximum IVC diameter (0.79), and transverse maximum aortic diameter (0.81). CONCLUSIONS: This pilot study of sonographic measurements of the IVC diameter in normovolemic children suggests a statistically significant positive correlation between age and IVC diameter. Future studies should focus on multicenter enrollment, children in the youngest age group, and the development of normative growth curves for the IVC by age, sex, and body mass index.

Two cases of heterotopic pregnancy: review of the literature and sonographic diagnosis in the emergency department.

We present 2 recent cases of heterotopic pregnancy in which bedside sonography performed by the treating emergency physician was used to identify the heterotopic pregnancy and facilitate prompt gynecologic intervention. The cases, the sonographic approach to the diagnosis of heterotopic pregnancy, and a review of the literature are presented.

The Ultrasound-Only Central Venous Catheter Placement and Confirmation Procedure.

The placement of a central venous catheter remains an important intervention in the care of critically ill patients in the emergency department. We propose an ultrasound-first protocol for 3 aspects of central venous catheter placement above the diaphragm: dynamic procedural guidance, evaluation for pneumothorax, and confirmation of the catheter tip location.

M-Mode Ultrasound Applications for the Emergency Medicine Physician.

BACKGROUND: M-mode or "motion" mode is a form of ultrasound imaging that is of high clinical utility in the emergency department. It can be used in a variety of situations to evaluate motion and timing, and can document tissue movement in a still image when the recording of a video clip is not feasible. OBJECTIVES: In this article we describe several straightforward and easily performed applications for the emergency physician to incorporate M-mode into his or her practice, including the evaluation for: 1) pneumothorax, 2) left ventricular systolic function, 3) cardiac tamponade, and 4) hypertrophic cardiomyopathy. DISCUSSION: The emergency physician and other point-of-care ultrasound providers can use this versatile function in the evaluation of patients for a number of critical cardiopulmonary diagnoses. CONCLUSION: A great deal of important information may be obtained with M-mode imaging through views and measurements that are relatively easy to obtain.

The endomyometrial thickness measurement for abnormal implantation evaluation by pelvic sonography.

Emergency physicians, obstetrician-gynecologists, and other medical specialists use pelvic sonography when caring for patients presenting with early pregnancy-related symptoms. A thin endomyometrial mantle and eccentric placement of a gestational sac should raise the suspicion for an abnormally implanted pregnancy. In such cases, an interstitial ectopic pregnancy or a cornual pregnancy, two clinically distinct entities, must be considered. This article reviews the literature and guidelines on the sonographic measurement of the endomyometrial mantle as a criterion for determining a pregnancy at risk for an abnormal implantation location. We sought to clarify the history and evolution of this measurement to determine what should be considered an abnormal measurement and to understand its diagnostic utility and management implications for the clinician using sonography.

Focused cardiac ultrasound diagnosis of thoracic aortic aneurysm: two cases.

BACKGROUND: Thoracic aortic aneurysms (TAAs) are less prevalent than abdominal aortic aneurysms. Symptomatic TAAs need to be identified quickly by the emergency physician (EP) since mortality rates increase dramatically once complications such as rupture or dissection occur. Compared with validated EP-performed ultrasound of the abdominal aorta, EP-performed focused cardiac ultrasound that includes evaluation of the thoracic aorta is relatively unreported. OBJECTIVE: Two cases illustrate EP-performed focused cardiac ultrasound and evaluation of the thoracic aorta for aneurysmal dilation. CASE  REPORTS: (1) A 60-year-old man presented to the emergency department (ED) after a blunt traumatic injury to his back while at work. During the focused cardiac ultrasound examination, the aortic outflow tract distal to the aortic valve appeared enlarged and the aortic root measured 5.49 cm. (2) An 82-year-old man with hypertension presented to the ED with 1 month of chest pain radiating to the back. The focused cardiac ultrasound examination demonstrated enlargement of the descending thoracic aorta at 4.82 cm. CONCLUSION: EPs performing focused cardiac ultrasound can visualize regions of the thoracic aorta that may reveal an aneurysm, particularly in the parasternal long axis view.