Focused Ultrasonography in Cardiac Arrest

Rapid diagnostic tools available to the emergency physician caring for cardiac arrest patients are limited. Focused ultrasound (US), and in particular, focused echocardiography, is a useful tool in the evaluation of patients in cardiac arrest. It can help identify possible causes of cardiac arrest like tamponade and pulmonary embolism, which can guide therapy. US can also yield prognostic information, with lack of cardiac activity being highly specific for failure to achieve return of spontaneous circulation. US may also be used to aid in procedural guidance. Recently, focused transesophageal echocardiography has been used in the emergency department setting.

The Utility of Transvaginal Ultrasound After Intrauterine Pregnancy Identification on Transabdominal Ultrasound in Emergency Department Patients

Introduction

Ultrasonography has an important role in the evaluation of Emergency Department (ED) patients presenting with early pregnancy complaints. Both transabdominal (TAUS) and transvaginal ultrasound (TVUS) can be utilized. While TVUS generally allows for greater detail, it is unclear how much added benefit exists in performing TVUS once an intrauterine pregnancy (IUP) has been identified on TAUS.

Methods

This was a retrospective study utilizing Radiology Department ultrasound examinations obtained in first trimester pregnancy ED patients during a consecutive four month period in 2019. Studies wherein both TAUS and TVUS were both performed were included. Two ED physicians with specialized training in point of care ultrasound reviewed only the TAUS images from these studies. Their findings were compared to the Radiologist interpretation, which was inclusive of both TAUS and TVUS components of the study.

Results

108 studies met inclusion criteria. Amongst these, 82 had IUP's identified on the radiologist report. 69 studies had an IUP identified by ED physician review of the TAUS images, with 1 false positive. Each case of intrauterine fetal demise (IUFD) was identified on ED physician review of TAUS. Two ectopic pregnancies were present, neither of which was mistaken for IUP on ED physician TAUS review. There were 15 studies with subchorionic hemorrhage and 3 studies with an ovarian cyst noted on the radiologist report.

Conclusion

Following the identification of an IUP on TAUS, the added diagnostic value of TVUS amongst this cohort of ED patients was low. Given the added time and cost of TVUS, selective instead of routine usage should be encouraged.

POINT-OF-CARE ULTRASOUND FOR GUIDANCE OF CLOSED REDUCTION OF FIFTH METACARPAL NECK (BOXER'S) FRACTURE

BACKGROUND

Ultrasound has been used previously in fracture identification, analgesia delivery, and fracture reduction for patients in the emergency department. It has not been previously described as a tool for the guidance of closed fracture reduction in fifth metacarpal neck fractures ("boxer's fractures").

CASE REPORT

A 28-year-old man presented with hand pain and swelling after punching a wall. Point-of-care ultrasound revealed a significantly angulated fifth metacarpal fracture, which was confirmed with a subsequent hand x-ray study. After an ultrasound-guided ulnar nerve block, closed reduction was performed. Ultrasound was used to assess reduction and ensure improvement in bony angulation during the closed reduction attempts. Post-reduction x-ray study confirmed improved angulation and adequate alignment. Why Should an Emergency Physician Be Aware of This? Point-of-care ultrasound has previously had efficacy in fracture diagnosis and anesthesia delivery for fifth metacarpal fractures. Ultrasound can also be used at the bedside to assist in the determination of adequate fracture reduction when performing closed reduction of a boxer's fracture.

A Narrative Review of the Uses of Ultrasound in the Evaluation, Analgesia, and Treatment of Distal Forearm Fractures

BACKGROUND

Distal forearm fractures are a commonly encountered injury in the emergency department (ED), accounting for 500,000 to 1.5 million visits and 17% of ED fractures. The evaluation and management of these fractures frequently employs x-ray studies, conscious sedation, closed reduction, and splinting. Point-of-care ultrasound (POCUS) can offer significant benefit in the diagnosis and management of these common injuries.

OBJECTIVE OF THE REVIEW

To review the clinical utility of POCUS in the diagnosis of distal forearm fractures, as well as to demonstrate the performance of ultrasound-guided analgesia delivery and ultrasound-guided reduction technique.

DISCUSSION

The initial evaluation of forearm injuries frequently includes x-ray studies. However, multiple studies have shown ultrasound to be sensitive and specific for distal radius fractures, with the added value of detecting soft tissue injuries missed by conventional radiography. POCUS may also facilitate analgesia through the use of ultrasound-guided hematoma blocks, which removes the need for conscious sedation prior to manipulation. Finally, POCUS can be used after manipulation to assess cortical realignment of the bone fragments and spare the patient multiple reduction attempts and repeat radiographs.

CONCLUSION

Distal forearm fractures are common, and the emergency physician should be adept with the evaluation and management of these injuries. POCUS can be a reliable modality in the detection of these fractures and can be used to facilitate analgesia and augment success of reduction attempts. These techniques may decrease length of stay, improve patient pain, and decrease reduction attempts.

Comparison of the Quality of Echocardiography Imaging Between the Left Lateral Decubitus and Supine Positions

Introduction It is commonly taught that positioning the patient in the left lateral decubitus (LLD) position will improve transthoracic echocardiography (TTE) image quality. Despite this, no previous studies have been performed that study this practice. Our goal was to quantify the difference in image quality of TTE views between the supine and LLD positions.  Methods This was a prospective study in a single academic Emergency Department (ED) of a convenience sample of 30 patients. Three separate ED physicians performed TTE views in both the supine and LLD position on each patient. The order of position was randomized. Images were then reviewed on a previously validated TTE image quality scale by two blinded ED physicians with specialized training in ultrasound. The scale used a 0 to 5 (highest quality) metric for quality assessment. Interpretability of right ventricular and left ventricular function was also assessed. Results The mean image quality for the supine position was 2.85 (standard deviation {SD} 1.1) and 3.05 (SD 1.2) for the LLD position (p=0.044). In the subset of parasternal and apical windows, the mean quality for the supine position was 2.87 (SD 1.1) and 3.23 (SD 1.1) for the LLD position (p=0.003). The number of studies in which right ventricular function was interpretable was significantly higher in the LLD position (62% versus 42%, p=0.044). Conclusions There was a statistically significant increase in image quality when TTE was performed in the LLD position as compared to supine. This was especially pronounced in the apical four and parasternal windows.

Point-of-Care Ultrasound Identifies Pyomyositis Secondary to Intramuscular Testosterone Injection: Report of Two Cases

BACKGROUND

Intramuscular (i.m.) injections are a commonly utilized route for medication delivery. Intramuscular-associated soft tissue infections are rare and can include pyomyositis and i.m. abscess. Intramuscular testosterone injections have not been previously implicated in causing pyomyositis. Point-of-care ultrasound is an important bedside tool that can identify pyomyositis and differentiate this infection from more common entities such as cellulitis.

CASE REPORTS

We present two cases of i.m. testosterone-associated pyomyositis. In both cases, the physical examination features were consistent with simple cellulitis. However, point-of-care ultrasound evaluation revealed changes consistent with pyomyositis in each case. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Although uncommon, i.m. injections such as testosterone carry a risk of soft tissue infection. As demonstrated in the above cases, ultrasound can be helpful in making the differentiation between simple cellulitis and pyomyositis. The emergency physician should be cognizant of this complication of therapeutic i.m. injections, as well as the diagnostic efficacy of point-of-care ultrasound in evaluating the extent and location of the soft tissue infection.

Fatal Abdominal Compartment Syndrome Due to Constipation: A Case Report

Introduction

Abdominal compartment syndrome (ACS) is a rare condition in which increased intra-abdominal pressure causes multiorgan dysfunction through decreased perfusion. Causes of this condition are variable, and early recognition is critical for favorable patient outcomes. Measurement of bladder pressure is recommended for diagnosis.

Case Report

A 64-year-old female on clozapine with a two-year history of chronic constipation presented to the emergency department in extremis with a protuberant abdomen. After resuscitative measures, computed tomography showed a dilated, stool-filled colon with a decompressed inferior vena cava and decreased perfusion. She died despite surgical decompression.

Conclusion

Severe constipation is a rare cause of ACS, and there is a lack of evidence-based guidelines. Options for bedside decompression are limited. To reduce morbidity and mortality in this population, early recognition of ACS is imperative. Initial interventions should support hemodynamics and respiration. Definitive management is surgical decompression.

Ultrasound-Guided Talonavicular Arthrocentesis

BACKGROUND

Joint arthrocentesis is a commonly performed procedure by the emergency physician (EP). Point of care ultrasound (POCUS) has demonstrated promise in identifying joint effusions and guiding arthrocentesis procedures. EP-performed talonavicular joint arthrocentesis has not been previously described in the literature. We present a case in which an isolated talonavicular joint effusion was identified and then subsequently aspirated using POCUS.

CASE REPORT

A 65-year-old man presented with atraumatic right ankle pain. On arrival, he was noted to have diffuse warmth and edema around the ankle and midfoot. POCUS was performed to evaluate for an ankle joint effusion, which was not present. The ultrasound was then moved distally, where a talonavicular joint effusion was noted. Inflammatory markers were found to be elevated. A magnetic resonance imaging scan revealed an isolated talonavicular joint effusion without additional acute findings. POCUS was then used to perform an arthrocentesis, which revealed monosodium urate crystals consistent with an initial episode of gouty arthritis. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: POCUS provides the EP with an efficient tool to diagnose joint effusions and guide arthrocentesis procedures. The foot is composed of several small joints where ultrasound can be particularly helpful. Similar to the ankle joint, these joints can be afflicted with pyogenic infections and crystalline arthropathies. To our knowledge, we present the first report of EP-performed talonavicular arthrocentesis guided by POCUS. The approach to this joint and technique for arthrocentesis are presented.

Point-of-care hip ultrasound leads to expedited results in emergency department patients with suspected septic arthritis

BACKGROUND

The evaluation of septic hip arthritis often incorporates the utilization of hip ultrasonography to determine the presence of a hip joint effusion, as well as to guide arthrocentesis. Point-of-care (POC) hip ultrasound has previously been demonstrated to be accurate when performed by the emergency physician. Time to diagnosis and subsequent intervention in septic arthritis (SA) is critical to favorable outcomes.

METHODS

Retrospective single-center study of all emergency department (ED) patients who had a POC or radiology hip ultrasound or arthrocentesis as part of their ED evaluation for SA in a 3-year period. We investigated the difference in time to obtain hip ultrasonography results and the time to arthrocentesis between radiology and emergency physician-performed studies in cases of suspected septic hip arthritis.

RESULTS

Seventy-four patients met inclusion criteria. The median time to hip ultrasound completion was 68 (interquartile range [IQR], 38.8-132) minutes in the emergency physician-performed ultrasound group versus 208.5 (IQR, 163.8-301.3) minutes for the radiology group (P < 0.001). A total of 17 patients had a hip arthrocentesis performed. Time to arthrocentesis was 211 (IQR 141.3-321.5) minutes in the emergency physician-performed arthrocentesis group and 602 (IQR 500-692) minutes in the radiology arthrocentesis (P < 0.001).

CONCLUSION

There was a statistically shorter time to ultrasound result and arthrocentesis when POC hip ultrasound was utilized by the emergency physician. Given that unfavorable outcomes in SA are associated with delay in treatment, further study is warranted to determine if emergency physician-performed hip ultrasound and arthrocentesis could lead to improved patient-centered clinical end points.

Can Ultrasound Identify Traumatic Knee Arthrotomy in a Cadaveric Model?

BACKGROUND

Traumatic arthrotomy of the knee (TAK) involves the violation of the knee capsule. TAK differs from simple lacerations because it requires operative management to prevent resultant septic arthritis. The diagnostic test of choice in the emergency department is the saline load test (SLT). SLT sensitivity ranges from 34% to 99%, depending on volume used. Computed tomography (CT) is a possible alternative, using intra-articular air as a diagnostic marker. Ultrasound can identify air in various tissues, given its highly echogenic nature.

OBJECTIVE

We sought to determine the sensitivity and specificity of ultrasound for detecting intra-articular air in cadaveric knee joints.

METHODS

Soft embalmed cadavers were utilized. The knees were block randomized to having 1 mL of air injected into the joint or sham skin injection. Two blinded, expert operators scanned the knees with a high-frequency linear transducer. The sensitivity and specificity were calculated.

RESULTS

Twenty knees were included. Knees that had any prior dissection were excluded from analysis. Ten knees were randomized for air injection. The pooled sensitivity was 0.65 (95% confidence interval [CI] 0.41-0.85) with a specificity of 0.75 (95% CI 0.48-0.93). Mean time taken was 143 s.

CONCLUSIONS

Ultrasound may have utility in evaluation of TAK. There were limitations. Some knees had effusions with echogenic material present, which could have led to false-positive results. It is also unknown how much air is typical of TAK. One milliliter was used based on previous work with CT. The use of ultrasound for diagnosis of TAK warrants further study.

Utilizing ECG-Based Heartbeat Classification for Hypertrophic Cardiomyopathy Identification

Hypertrophic cardiomyopathy (HCM) is a cardiovascular disease where the heart muscle is partially thickened and blood flow is (potentially fatally) obstructed. A test based on electrocardiograms (ECG) that record the heart electrical activity can help in early detection of HCM patients. This paper presents a cardiovascular-patient classifier we developed to identify HCM patients using standard 10-second, 12-lead ECG signals. Patients are classified as having HCM if the majority of their recorded heartbeats are recognized as characteristic of HCM. Thus, the classifier's underlying task is to recognize individual heartbeats segmented from 12-lead ECG signals as HCM beats, where heartbeats from non-HCM cardiovascular patients are used as controls. We extracted 504 morphological and temporal features—both commonly used and newly-developed ones—from ECG signals for heartbeat classification. To assess classification performance, we trained and tested a random forest classifier and a support vector machine classifier using 5-fold cross validation. We also compared the performance of these two classifiers to that obtained by a logistic regression classifier, and the first two methods performed better than logistic regression. The patient-classification precision of random forests and of support vector machine classifiers is close to 0.85. Recall (sensitivity) and specificity are approximately 0.90. We also conducted feature selection experiments by gradually removing the least informative features; the results show that a relatively small subset of 264 highly informative features can achieve performance measures comparable to those achieved by using the complete set of features.

Identifying Hypertrophic Cardiomyopathy Patients by Classifying Individual Heartbeats from 12-lead ECG Signals

Test based on electrocardiograms (ECG) that record the heart electrical activity can help in early detection of patients with hypertrophic cardiomyopathy (HCM) where the heart muscle is partially thickened and blood flow is (potentially fatally) obstructed. This paper presents a cardiovascular-patient classifier we developed to identify HCM patients using standard 10-seconds, 12-lead ECG signals. Patients are classified as having HCM if the majority of the heartbeats are recognized as HCM. Thus, the classifier's underlying task is to recognize individual heartbeats segmented from 12-lead ECG signals as HCM beats, where heartbeats from non-HCM cardiovascular patients are used as controls. We extracted 504 morphological and temporal features - both commonly used and newly-developed ones - from ECG signals for heartbeat classification. To assess classification performance, we trained and tested a random forest classifier and a support vector machine classifier using 5-fold cross validation. The patient-classification precision and F-measure of both classifiers are close to 0.85. Recall (sensitivity) and specificity are approximately 0.90. We also conducted feature selection experiments by gradually removing the least informative features; the results show that a relatively small subset of 304 highly informative features can achieve performance measures comparable to that achieved by using the complete set of features.