Using Deep Learning to Detect the Presence and Location of Hemoperitoneum on the Focused Assessment with Sonography in Trauma (FAST) Examination in Adults.

Abdominal ultrasonography has become an integral component of the evaluation of trauma patients. Internal hemorrhage can be rapidly diagnosed by finding free fluid with point-of-care ultrasound (POCUS) and expedite decisions to perform lifesaving interventions. However, the widespread clinical application of ultrasound is limited by the expertise required for image interpretation. This study aimed to develop a deep learning algorithm to identify the presence and location of hemoperitoneum on POCUS to assist novice clinicians in accurate interpretation of the Focused Assessment with Sonography in Trauma (FAST) exam. We analyzed right upper quadrant (RUQ) FAST exams obtained from 94 adult patients (44 confirmed hemoperitoneum) using the YoloV3 object detection algorithm. Exams were partitioned via fivefold stratified sampling for training, validation, and hold-out testing. We assessed each exam image-by-image using YoloV3 and determined hemoperitoneum presence for the exam using the detection with highest confidence score. We determined the detection threshold as the score that maximizes the geometric mean of sensitivity and specificity over the validation set. The algorithm had 95% sensitivity, 94% specificity, 95% accuracy, and 97% AUC over the test set, significantly outperforming three recent methods. The algorithm also exhibited strength in localization, while the detected box sizes varied with a 56% IOU averaged over positive cases. Image processing demonstrated only 57-ms latency, which is adequate for real-time use at the bedside. These results suggest that a deep learning algorithm can rapidly and accurately identify the presence and location of free fluid in the RUQ of the FAST exam in adult patients with hemoperitoneum.

Test characteristics of focused assessment with sonography for trauma (FAST), repeated FAST, and clinical exam in prediction of intra-abdominal injury in children with blunt trauma.

PURPOSE: In children with blunt abdominal trauma (BAT), focused assessment of sonography in trauma (FAST) has been reported with low sensitivity, on the whole, in the detection of intra-abdominal injuries (IAI). The aim of the present study was to assess test characteristics of FAST using different strategies including repeated FAST (reFAST), and physical exam findings. METHODS: This retrospective study evaluated BAT pediatric patients with stable hemodynamics who underwent computed tomography (CT). Demographic data, initial physical examination, and results of FAST, reFAST (if done), and CT imaging were recorded. Different strategies of FAST were cross-tabulated with CT as the gold standard and test characteristics including sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were interpreted. RESULTS: 129 patients with a mean age of 8.6 ± 4.7 were studied and 74% were male. Comparing CT-positive and -negative groups, from the demographic and clinical findings, only positive physical exam (tenderness or ecchymosis) was significantly higher in the CT-positive group (59% vs. 17%; p < 0.01). In a multivariate analysis, positive FAST modality and clinical exam remained independent predictors for a positive CT result (likelihood ratios of 34.6 and 6.4, respectively). Out of the different diagnostic strategies for the prediction of IAI, the best overall performance resulted from the FAST-reFAST-tenderness protocol with sensitivity, specificity, PPV, NPV, and accuracy of 87%, 77%, 70%, 91%, and 81%. CONCLUSION: For children with blunt abdominal trauma, physical examination plus FAST and reFAST as needed, seems to have reasonable sensitivity, specificity, and accuracy in detecting intra-abdominal injuries and may reduce the need for CT scans.

Focused Assessment with Sonography in Trauma for Assessment of Injury in Military Settings: A Meta-analysis

Background: Non-invasive, rapid, and precise assessment of injury in the military settings is extremely important, yet difficult. Focused assessment with sonography in trauma (FAST) is being increasingly employed for assessing the location and severity of injury and guiding further treatment strategy. However, the evidence regarding the utility of FAST in the military settings is scattered. Aims: To evaluate the diagnostic performance of FAST in the assessment of injury in the military settings. Study Design: Meta-analysis. Methods: We identified all relevant papers via the PubMed, EMBASE, and Cochrane Library databases. We evaluated the quality of included studies by the Quality Assessment of Diagnostic Accuracy Studies-2 tool. We pooled the area under the curve (AUC), sensitivity, specificity, positive and negative likelihood ratios, and diagnostic odds ratio as the effect sizes, followed by evaluating the heterogeneity among the studies by p value and I2. Results: Among the 39 papers, a total of six papers were included. The sample size ranged from 15 to 396. The AUC of FAST for assessing the injury was 0.85. The pooled sensitivity, specificity, positive and negative likelihood ratios, and diagnostic odds ratio were 0.66, 0.98, 33.1, 0.34, and 97, respectively. The heterogeneity among the studies was statistically significant (p=0.006, I2=78%). Conclusion: FAST is potentially valuable for assessing injury in the military settings. Due to its high specificity, FAST may be appropriate to rule in significant injury. However, because of its poor sensitivity, the ability of FAST to rule out injury cannot be relied upon.

Diagnostic point-of-care ultrasound: assessment techniques for the pediatric trauma patient

Emergency ultrasound is performed at the point of care to quickly answer focused clinical questions. Over the last 25 years, the use of this technique has expanded rapidly. The use of emergency ultrasound in the pediatric setting is increasing because it does not expose the patient to ionizing radiation, as compared to computed tomography. Utilizing diagnostic point-of-care ultrasound for pediatric trauma patients in the emergency department can facilitate diagnosis at the bedside rather than sending the patient out of the department for another study. This supplement focuses on some of the common indications for diagnostic POCUS that may be useful in the setting of trauma, as found in the pediatric literature, or extrapolated from adult literature where pediatric evidence is scarce.

Focused assessment with sonography in trauma (FAST) for the regional anesthesiologist and pain specialist.

This article in our point-of-care ultrasound (PoCUS) series is dedicated to the role the focused assessment with sonography in trauma (FAST) exam plays for the regional anesthesiologist and pain specialists in the perioperative setting. The FAST exam is a well-established and extensively studied PoCUS exam in both surgical and emergency medicine literature with over 20 years demonstrating its benefit in identifying the presence of free fluid in the abdomen following trauma. However, only recently has the FAST exam been shown to be beneficial to the anesthesiologist in the perioperative setting as a means to identify the extravasation of free fluid into the abdomen from the hip joint following hip arthroscopy. In this article, we will describe how to obtain the basic FAST views (subcostal four-chamber view, perihepatic right upper quadrant view, perisplenic left upper quadrant view, and pelvic view in the longitudinal and short axis) as well as cover the relevant sonoanatomy. We will describe pathological findings seen with the FAST exam, primarily free fluid in the peritoneal space as well as in the pericardial sac. As is the case with any PoCUS skill, the application evolves with understanding and utilization by new clinical specialties. Although this article will provide clinical examples of where the FAST exam is beneficial to the regional anesthesiologist and pain specialist, it also serves as an introduction to this powerful PoCUS skill in order to encourage clinical practitioners to expand the application of the FAST exam within the scope of regional anesthesia and pain management practice.

A Potential Pitfall of Using Focused Assessment With Sonography for Trauma in Pediatric Trauma.

Prospective studies have shown sensitivities of 73% to 88% and specificities of 98% to 100% for using the focused assessment with sonography for trauma (FAST) examination to identify free fluid in adult trauma patients. However, the efficacy of FAST examinations for pediatric trauma patients has not been well defined, and studies looking at diagnostic performance have had varied results. We describe 3 cases of the potential pitfalls of the pediatric FAST examination in pediatric trauma patients using an advanced-processing ultrasound machine. We hypothesize several etiologies for these false-positive findings in the setting of advanced image-processing capabilities of point-of-care ultrasound. We also discuss the reevaluation of clinical algorithms and interpretation practices when using the FAST examination in pediatric trauma.

Calculated Decisions: Focused Assessment With Sonography for Trauma (FAST)

Focused Assessment with Sonography for Trauma (FAST) predicts the presence of pericardial or intra-abdominal injury after penetrating or blunt trauma.

The combined utility of extended focused assessment with sonography for trauma and chest x-ray in blunt thoracic trauma.

BACKGROUND: Portable chest x-ray (CXR) and extended focused assessment with sonography for trauma (EFAST) screen patients for thoracic injury in the trauma bay. It is unclear if one test alone is sufficient, if both are required, or if the two investigations are complementary. Study objectives were to define the combined diagnostic yield of EFAST and CXR among stable blunt thoracic trauma patients and to determine if a normal EFAST and CXR might obviate the need for computed tomography (CT) scan of the chest. METHODS: All blunt trauma patients 15 years or older presenting to LAC+USC Medical Center in 2016 were screened. Only patients who underwent CT thorax were included. Patients were excluded if they presented more than 24 hours after injury, were transferred, or if they did not undergo EFAST and CXR. Demographics, physical examination (PEx) of the thorax, injury data, investigations, procedures, and outcomes were collected. The EFAST, CXR, and PEx findings were compared to the gold standard CT thorax to calculate the diagnostic yield of each investigation and combinations thereof in the assessment for clinically significant thoracic injury. RESULTS: One thousand three hundred eleven patients met inclusion/exclusion criteria. Most common mechanisms of injury were motor vehicle collision (n = 385, 29%) and auto versus pedestrian trauma (n = 379, 29%). Mean Injury Severity Score was 11 (1-75), with mean Abbreviated Injury Scale chest score of 1.6 (1-6). The sensitivities of EFAST, CXR, and PEx, either individually or in combination, were less than 0.73 in the detection of clinically significant thoracic injury. The most common missed clinically significant injuries were sternal fractures, scapular fractures, clavicular fractures, and pneumothoraces. Motorcycle collisions and auto versus pedestrian traumas resulted in the highest rates of missed injury. CONCLUSION: Even in conjunction with the physical examination, the sensitivity of EFAST+CXR in the detection of clinically significant thoracic injury is low. Therefore, if clinical suspicion for injury exists after blunt thoracic trauma, a normal EFAST+CXR is insufficient to exclude injury and CT scan of the chest should be performed. LEVEL OF EVIDENCE: Diagnostic tests/criteria, level III.

Telepresent Focused Assessment With Sonography for Trauma Examination Training Versus Traditional Training for Medical Students: A Simulation-Based Pilot Study.

OBJECTIVES: Telepresent education is becoming an important modality in medical education, as it provides a means for instructors to lead education sessions via videoconferencing technologies. This study aimed to compare the effectiveness of telepresent ultrasound training versus traditional in-person ultrasound training. METHODS: Medical student cohorts were educated by either traditional in-person instruction or telementoring on how to perform a focused assessment with sonography for trauma (FAST) examination. Effectiveness was evaluated by pre- and post-multiple-choice tests (knowledge), confidence surveys, and summative simulation scenarios (hands-on FAST simulation). Formative simulation scenario debriefings were evaluated by each student using the Debriefing Assessment for Simulation in Healthcare student version (DASH-SV). RESULTS: Each method of instruction had significant increases in knowledge, confidence, and hands-on FAST simulation performance (P < .05). The collective increase in knowledge was greater for the in-person group, whereas the improvement in FAST examination performance during simulations was greater for the telementored group. Confidence gains were comparable between the groups. The DASH-SV scores were significantly higher for the in-person group for each criterion; however, both methods were deemed effective via median scoring. CONCLUSIONS: Telepresent education is a viable option for teaching the FAST examination to medical students.

Focused assessment with sonography in trauma: a review of concepts and considerations for anesthesiology.

The use of point-of-care ultrasound in trauma provides diagnostic clarity and routinely influences management. A scanning protocol known as the Focused Assessment with Sonography in Trauma (FAST) has been widely adopted by trauma providers of all specialties. The FAST exam addresses a broad array of pathologic conditions capable of causing instability, including hemoperitoneum, hemopericardium, hemothorax, and pneumothorax. The exam is an integral component to the primary assessment of injured patients and an iconic application of point-of-care ultrasound.This review article aims to summarize the application of the FAST exam with special consideration, where relevant, to anesthesiologists. The scope of the FAST exam, technical considerations, and clinical decision-making in trauma are explored.