Ultrasonography for the initial evaluation of blunt abdominal trauma: A review of prospective trials

FAST and Furious About Quality: Impact of Continuous Review and Feedback on Point-of-Care Ultrasound Examinations

Background: Focused Assessment with Sonography in Trauma (FAST) examination is a point-of-care ultrasound study used to evaluate for abdominal hemorrhage, pneumothorax, or pericardial blood in trauma patients as an adjunct to their initial assessment. The quality of the image can be limited, and its diagnostic value is heavily dependent on operator skill. Our objective was to determine whether a standardized review process improved image quality and reduced incidence of nondiagnostic or insufficient imaging by 10% over a 6-month period. Study Design: Between July 1, 2021, and March 31, 2022, we evaluated 1106 trauma activations at our level II trauma center. Two exams per practitioner per month were reviewed by an emergency medicine trained traumatologist with specialized training in point-of-care ultrasound and board certification in echocardiography. Priority was given to exams on patients with known injuries identified on other studies. If there were no exams that matched these criteria, random exams were selected. Images were reviewed for image quality, diagnostic accuracy, and labeling with counseling given to the provider if indicated. Categorical variables were compared using chi squared analysis, while continuous non-normally distributed variables were compared using the Mann-Whitney U test. Results: A total of 305 FAST exams were reviewed (186 pre-intervention and 119 during intervention). Image quality improved from 46.3% (n = 31/65) to 79.0% (n = 94/119) (P < .01) with need for counseling falling from 63.1% (n = 41/65) pre-QI to 42.0% (n = 50/119) post-QI (P < .01). Incidence of detectable injury, BMI, ISS, and AIS body regions were consistent across the study period. This was seen in both the geriatric and non-geriatric cohorts despite a significant increase in ISS in the post-intervention geriatric patients.Discussion: A FAST review program is associated with improvement in image quality and decreased need for counseling of trauma providers.

Does Size Matter? A Prospective Study on the Feasibility of Using a Handheld Ultrasound Device in Place of a Cart-Based System in the Evaluation of Trauma Patients

BACKGROUND

As emergency physicians are looking at handheld devices as alternatives to the traditional, cart-based systems, concerns center around whether they are forsaking image quality for a lower price point and whether the handheld can be trusted for medical decision making.

OBJECTIVE

We aimed to determine the feasibility of using a handheld ultrasound device in place of a cart-based system during the evaluation of trauma patients using the Focused Assessment with Sonography for Trauma (FAST) examination.

METHODS

This was a prospective study of adult trauma patients who received a FAST examination as part of their evaluation. A FAST examination was performed using a cart-based machine and a handheld device. The results of the examinations were compared with computed tomography imaging. Images obtained from both ultrasound devices were reviewed by an expert for image quality.

RESULTS

A total of 62 patients were enrolled in the study. The mean (SD) time to perform a FAST examination using the handheld device was 307.3 (65.3) s, which was significantly less (p = 0.002) than the 336.1 (86.8) s with the cart-based machine. There was strong agreement between the examination results of the handheld and cart-based devices and between the handheld and computed tomography. Image quality scores obtained with the handheld device were lower than those from the cart-based system. Most operators and reviewers agreed that the images obtained from the handheld were adequate for medical decision making.

CONCLUSIONS

Data support that it is feasible to use the handheld ultrasound device for evaluation of the trauma patient in place of the cart-based system.

Multiorgan Point-of-Care Ultrasound Assessment in Critically Ill Adults

Traditional point-of-care ultrasound (POCUS) training highlights discrete techniques, single-organ assessment, and focused protocols. More recent developments argue for a whole-body approach, where the experienced clinician-ultrasonographer crafts a personalized POCUS protocol depending on specific clinical circumstances. This article describes this problem-based approach, focusing on common acute care scenarios while highlighting practical considerations and performance characteristics.

Initial Imaging of Pregnant Patients in the Trauma Bay-Discussion and Review of Presentations at a Level-1 Trauma Centre

Trauma is the leading non-obstetric cause of maternal and fetal mortality and affects an estimated 5-7% of all pregnancies. Pregnant women, thankfully, are a small subset of patients presenting in the trauma bay, but they do have distinctive physiologic and anatomic changes. These increase the risk of certain traumatic injuries, and the gravid uterus can both be the primary site of injury and mask other injuries. The primary focus of the initial management of the pregnant trauma patient should be that of maternal stabilization and treatment since it directly affects the fetal outcome. Diagnostic imaging plays a pivotal role in initial traumatic injury assessment and should not deviate from normal routine in the pregnant patient. Radiographs and focused assessment with sonography in the trauma bay will direct the use of contrast-enhanced computed tomography (CT), which remains the cornerstone to evaluate the potential presence of further management-altering injuries. A thorough understanding of its risks and benefits is paramount, especially in the pregnant patient. However, like any other trauma patient, if evaluation for injury with CT is indicated, it should not be denied to a pregnant trauma patient due to fear of radiation exposure.

Utility of ultrasound in managing acute medical conditions in space: a scoping review

BACKGROUND

In long-distance spaceflight, the challenges of communication delays and the impracticality of rapid evacuation necessitate the management of medical emergencies by onboard physicians. Consequently, these physicians must be proficient in tools, such as ultrasound, which has proven itself a strong diagnostic imaging tool in space. Yet, there remains a notable gap in the discourse surrounding its efficacy in handling acute medical scenarios. This scoping review aims to present an updated analysis of the evidence supporting the role of ultrasound in diagnosing acute conditions within microgravity environments.

METHODS

A systematic search was executed across three bibliographic databases: PubMed, EMBASE (Embase.com), and the Web of Science Core Collection. We considered articles published up to February 25, 2023, that highlighted the application of ultrasound in diagnosing acute medical conditions in either microgravity or microgravity-simulated settings. Exclusions were made for review papers, abstracts, and in-vitro studies.

RESULTS

After removing duplicates, and filtering papers by pre-determined criteria, a total of 15 articles were identified that discuss the potential use of ultrasound in managing acute medical conditions in space. The publication date of these studies ranged from 1999 to 2020. A relatively similar proportion of these studies were conducted either on the International Space Station or in parabolic flight, with one performed in supine positioning to simulate weightlessness. The included studies discuss acute pathologies, such as abdominal emergencies, decompression sickness, deep venous thrombosis, acute lung pathologies, sinusitis, musculoskeletal trauma, genitourinary emergencies, and ocular emergencies.

CONCLUSIONS

While ultrasound has shown promise in addressing various acute conditions, significant knowledge gaps remain, especially in gastrointestinal, cardiac, vascular, and reproductive emergencies. As we venture further into space, expanding our medical expertise becomes vital to ensure astronaut safety and mission success.

From diagnosis to therapy: the acute traumatic hemothorax - an orientation for young surgeons

Introduction

This review aims to provide an overview of diagnosing and managing traumatic haemothorax for young surgeons.

Content

Of 27,333 polytrauma patients in Germany in 2021, 35 % were admitted with thoracic trauma. In polytrauma patients, chest injuries are an independent negative predictor of 30-day mortality. These patients should be treated in an evidence-based and standardized manner to reduce mortality and morbidity. There are several methods of immediate diagnosis that should be used depending on hemodynamic stability. In addition to physical examination and chest X-ray, more specific techniques such as the eFAST protocol and Computed tomography (CT) of the chest  are available. Once the source of bleeding has been identified, acute treatment is given depending on hemodynamic stability. Thoracic drainage remains the gold standard in the initial management of hemothorax. If surgery is required because of an active source of bleeding, a hemothorax that has not been completely relieved, or associated injuries, either a minimally invasive or open approach can be used. The main focus is to stabilize the patient and avoid early and late complications.

Summary and Outlook

Rapid and prompt diagnosis and management of traumatic hemothorax is essential for patient outcome and should be taught to all young surgeons who are in direct contact with these patients.

Artificial intelligence evaluation of focused assessment with sonography in trauma

BACKGROUND

The focused assessment with sonography in trauma (FAST) is a widely used imaging modality to identify the location of life-threatening hemorrhage in a hemodynamically unstable trauma patient. This study evaluates the role of artificial intelligence in interpretation of the FAST examination abdominal views, as it pertains to adequacy of the view and accuracy of fluid survey positivity.

METHODS

Focused assessment with sonography for trauma examination images from 2015 to 2022, from trauma activations, were acquired from a quaternary care level 1 trauma center with more than 3,500 adult trauma evaluations, annually. Images pertaining to the right upper quadrant and left upper quadrant views were obtained and read by a surgeon or radiologist. Positivity was defined as fluid present in the hepatorenal or splenorenal fossa, while adequacy was defined by the presence of both the liver and kidney or the spleen and kidney for the right upper quadrant or left upper quadrant views, respectively. Four convolutional neural network architecture models (DenseNet121, InceptionV3, ResNet50, Vgg11bn) were evaluated.

RESULTS

A total of 6,608 images, representing 109 cases were included for analysis within the "adequate" and "positive" data sets. The models relayed 88.7% accuracy, 83.3% sensitivity, and 93.6% specificity for the adequate test cohort, while the positive cohort conferred 98.0% accuracy, 89.6% sensitivity, and 100.0% specificity against similar models. Augmentation improved the accuracy and sensitivity of the positive models to 95.1% accurate and 94.0% sensitive. DenseNet121 demonstrated the best accuracy across tasks.

CONCLUSION

Artificial intelligence can detect positivity and adequacy of FAST examinations with 94% and 97% accuracy, aiding in the standardization of care delivery with minimal expert clinician input. Artificial intelligence is a feasible modality to improve patient care imaging interpretation accuracy and should be pursued as a point-of-care clinical decision-making tool.

LEVEL OF EVIDENCE

Diagnostic Test/Criteria; Level III.

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.

Ultrasound Rounds: Anesthesiologist-Performed Intraoperative Point-of-Care Focused Assessment With Sonography in Trauma Examination Changes Surgical Management

Focused Assessment with Sonography in Trauma (FAST) examinations have been performed for decades by surgeons during initial patient presentation for emergency care and surgical planning, as well as for guiding resuscitation. This case highlights how use of intraoperative FAST examinations performed by anesthesiologists can dramatically change patient management. Use by anesthesiologists perioperatively is an important skill, although it is not widely practiced.

Focused Assessment with Sonography for Trauma (FAST)

The main cause of death in traumas is hypovolemic shock. Physical examination is limited to detect hemopericardium, hemoperitoneum, and hemopneumothorax. Computed tomography (CT) is the gold standard for traumatic injury evaluation. However, CT is not always available, is more expensive, and there are transportation issues, especially in hemodynamically unstable patients. In this scenario, a rapid, reproducible, portable, and noninvasive method such as ultrasound emerged, directed for detecting hemopericardium, hemoperitoneum, and hemopneumothorax, in a "point of care" modality, known as the focused assessment with sonography for trauma (FAST) protocol. With decades of experience, spread worldwide, and recommended by the most prestigious trauma care guidelines, FAST is a bedside ultrasound to be performed when accessing circulation issues of trauma patients. It is indicated to hemodynamically unstable patients with blunt abdominal trauma, with penetrating trauma of the thoracoabdominal transition (where there is doubt of penetrating the abdominal cavity) and for any patient with the cause of the instability unknown. There are four regions to be examined in the traditional FAST protocol: pericardium (to detect cardiac tamponade), right upper abdominal quadrant, left upper abdominal quadrant, and pelvis (to detect hemoperitoneum). The called extended FAST (e-FAST) protocol also searches the pleural spaces for hemothorax and pneumothorax. It is important to know the false positives and false negatives of the protocol, as well as its limitations. FAST/e-FAST protocol is designed to provide a simple "yes or no" answer regarding the presence of bleeding. It is not intended to quantify the bleeding nor evaluate organ lesions due to its limited accuracy for these purposes. Moreover, the amount of bleeding and/or the identification of organ lesions will not change patient's management: Hemodynamically unstable patients with positive FAST must go to the operating room without delay. CT should be considered for hemodynamically stable patients.

Use of point-of-care ultrasound and serial FAST as a monitoring tool for the removal of an ectopic chest tube in liver

Common complications of chest tube insertion are lung laceration, chest wall bleeding, improper tube positioning, and subcutaneous emphysema. However, a penetrating injury of the upper abdominal organs due to chest tube malposition is rare. A 33-year-old suffered multiple injuries in a road traffic accident. Due to the respiratory distress caused by right-sided hemothorax, an intercostal chest drain (ICD) was inserted, which drained 500 ml of venous blood, followed by hemodynamic instability. The post-procedural chest radiograph revealed a lower chest tube position within the liver shadow. As the patient was hemodynamically stable, it was decided to delay the removal of the ectopic ICD, and the patient was kept under close monitoring. After 7 days, ICD removal was done under ultrasound guidance, and a post-procedural serial-focused assessment with sonography for trauma (FAST) was done. Hepatic injury secondary to chest tube insertion is rare, and its management is not standardised. Point-of-care ultrasound has not been used before for the removal of an ectopic ICD. We managed the case conservatively because of the stable hemodynamic situation of the patient and to avoid invasive surgery as possible. Point-of-care ultrasound can be a valuable tool in these conditions where other imaging modalities such as CT are not available and help avoid surgery.

Pediatric Blunt Abdominal Trauma and Point-of-Care Ultrasound

ABSTRACT

Blunt abdominal trauma (BAT) accounts for most trauma in children. Although the focused assessment with sonography in trauma (FAST) is considered standard of care in the evaluation of adults with traumatic injuries, there is limited evidence to support its use as an isolated evaluation tool for intra-abdominal injury as a result of BAT in children. Although a positive FAST examination could obviate the need for a computed tomography scan before OR evaluation in a hemodynamically unstable patient, a negative FAST examination cannot exclude intra-abdominal injury as a result of BAT in isolation. In this article, we review the evaluation of BAT in children, describe the evaluation for free intraperitoneal fluid and pericardial fluid using the FAST examination, and discuss the limitations of the FAST examination in pediatric patients.

The Effectiveness of Self-Instructional Video vs. Classroom Teaching Method on Focused Assessment With Sonography in Trauma Among House Officers in University Hospital

Background: The aim of this study was to compare the effectiveness of self-instructional-video (SIV) and classroom training method (CTM) in learning Focus-Assessment with Sonography-in-Trauma (FAST) among house officers (HO).

Method: A randomized controlled study involving house officers working in the university hospital in Malaysia was conducted where participants were randomized into SIV group (intervention) and CTM group (control). Each group had to undergo a 4 h hands-on training. The intervention group has undergone self-training using the video material without any facilitation while the control group received lecture and hands-on training with facilitators. Participants' performance was assessed using a validated Objective Structured Clinical Examination checklist for landmark identification and interpretation of images generated. Learning preference and confidence level were also assessed.

Result: A total of 33 HO were enrolled in this study. Marks obtained in image acquisition by the intervention and control were 25.3 (SD = 5.3) and 25.6 (SD = 2.3) p > 0.05, respectively. While in image interpretation, the mean score for the intervention and control group was 10.3 (SD 1.7) and 9.8 (SD = 1.7) p > 0.05, respectively. Overall performance assessment, showed the intervention group obtained 35.6 (SD = 5.9) compared to control 35.3 (SD = 3.4), p > 0.05. Based on pre-specified determinant these scores difference falls within the 10% of non-inferiority margin. The absolute difference between both groups was 0.3 (CI = −3.75 to 3.21, p = 0.871), which proves non-inferiority but not superiority. In terms of learning preference and confidence to perform FAST, most of the participants preferred the control group approach.

Conclusion: The SIV method is as effective as the CTM for learning FAST among the house officers and served as an alternative to classroom teaching. However, this technique needs improvement in promoting their confidence and preference. Perhaps incorporating a feedback session after going through the SIV would improve the confidence.

Abdominal ultrasound augments the medical students' ability to identify free intraabdominal fluid

OBJECTIVE

Free intra-abdominal fluid describes an accumulation of free fluid in the peritoneal cavity. It has different etiologies, but it frequently constitutes a meaningful clinical sign. In this study, the authors interrogate whether abdominal ultrasound augments the medical students' ability to identify free intra-abdominal fluid.

METHODS

Thirty-one medical students without any previous formal ultrasound training were subjected to cognitive assessment before and after four and a half-hour of theoretical lecture and hands-on course about the diagnosis of free intra-abdominal fluid by physical examination and abdominal ultrasound. The hands-on sessions were done in healthy volunteers with a simulated peritoneal catheter and in patients treated with peritoneal dialysis with different amounts of dialysate in their cavity.

RESULTS

The cognitive assessment before and after the course increased from 6.7±2.3 to 11.6±1.1 points (p<0.0001). The sensitivity, specificity, and accuracy in the diagnosis of free intra-abdominal fluid were higher when students used abdominal ultrasound. The students agree with the inclusion of abdominal ultrasound in the diagnose of free intra-abdominal fluid in the undergraduate curriculum.

CONCLUSIONS

This study demonstrates that incorporating abdominal ultrasound is feasible and improves medical students' short-time competency in performing and interpreting the findings diagnostic of free intra-abdominal fluid.

The Utility of the Focused Assessment With Sonography in Trauma Examination in Pediatric Blunt Abdominal Trauma: A Systematic Review and Meta-Analysis

OBJECTIVE

To evaluate the utility of the Point of Care Ultrasound (POCUS) Focused Assessment with Sonography for Trauma (FAST) examination for diagnosis of intra-abdominal injury (IAI) in children presenting with blunt abdominal trauma.

METHODS

We searched medical literature from January 1966 to March 2018 in PubMed, EMBASE, and Web of Science. Prospective studies of POCUS FAST examinations in diagnosing IAI in pediatric trauma were included. Sensitivity, specificity, and likelihood ratios (LR) were calculated using a random-effects model (95% confidence interval). Study quality and bias risk were assessed, and test-treatment threshold estimates were performed.

RESULTS

Eight prospective studies were included encompassing 2135 patients with a weighted prevalence of IAI of 13.5%. Studies had variable quality, with most at risk for partial and differential verification bias. The results from POCUS FAST examinations for IAI showed a pooled sensitivity of 35%, specificity of 96%, LR+ of 10.84, and LR- of 0.64. A positive POCUS FAST posttest probability for IAI (63%) exceeds the upper limit (57%) of our test-treatment threshold model for computed tomography of the abdomen with contrast. A negative POCUS FAST posttest probability for IAI (9%) does not cross the lower limit (0.23%) of our test-treatment threshold model.

CONCLUSIONS

In a hemodynamically stable child presenting with blunt abdominal trauma, a positive POCUS FAST examination result means that IAI is likely, but a negative examination result alone cannot preclude further diagnostic workup for IAI. The need for computed tomography scan may be obviated in a subset of low-risk pediatric blunt abdominal trauma patients presenting with a Glasgow Coma Scale of 14 to 15, a normal abdominal examination result, and a negative POCUS FAST result.

Point-of-care ultrasound (POCUS) as the keystone investigation in undifferentiated dyspnoea

Dyspnoea is defined as a subjective perception of laboured breathing. It is a common cause of access to the emergency department (ED), it has a high rate of intensive care unit admission and a high mortality. The most common causes of dyspnoea in the adult include pneumonia, heart failure, chronic obstructive pulmonary disease, pulmonary embolism and asthma. Due to the high variety of dyspnoea's causes, the need for a rapid and accurate diagnosis puts the emergency physician in trouble. Moreover, standard tests such as chest radiography, B-type natriuretic peptide and d-dimer require time and may be less useful in patients with respiratory failure who require urgent therapy. Point-of-care ultrasound (POCUS) is rapid, non-invasive, repeatable and a useful tool in evaluating patients with acute and severe dyspnoea. This case report demonstrates the usefulness of POCUS in a patient with undifferentiated respiratory failure presenting to the ED.

FAST for blunt abdominal trauma: Correlation between positive findings and admission acid-base measurement

PURPOSE

This study aimed to determine any association between positive findings in ultrasonography examination and initial BD value with regard to diagnosis of intra-abdominal bleeding following blunt abdominal trauma.

METHODS

A prospective, multi-center study of consecutive adult patients was performed from April to September 2015. Demographics, initial vital signs and arterial BD were evaluated with respect to presence of any association with intra-abdominal bleeding and in-hospital mortality. FAST study was performed to find intra-abdominal bleeding. Receiver operating characteristic (ROC) curves tested the ability of BD to identify patients with intra-abdominal hemorrhage and probable mortality.

RESULTS

A total of 879 patients were included in final analysis. The mean (SD) age was 36.68 (15.7) years and 714 patients (81.2%) were male. According to multivariable analysis, statistically significant association was observed between negative admission BD and both intra-abdominal bleeding (OR 3.48, 95% CI 2.06-5.88, p<0.001) and in-hospital mortality (OR 1.55, 95% CI 1.49-1.63, p<0.001). ROC curve analysis demonstrated sensitivity of 92.7% and specificity of 22.1% for the best cut-off value of BD (-8mEq/L) to diagnose internal hemorrhage. Further, a cut-off value of -7mEq/L demonstrated significant predictive performance, 94.8% sensitivity and 53.6% specificity for in-hospital mortality.

CONCLUSION

This study revealed that arterial BD is an early accessible important marker to identify intra-abdominal bleeding, as well as to predict overall in-hospital mortality in patients with blunt abdominal trauma.

Contrast enhanced ultrasound of the kidneys: what is it capable of?

One of the many imaging uses of contrast enhanced ultrasound (CEUS) is studying a wide variety of kidney pathology, due to its ability to detect microvascular blood flow in real time without affecting renal function. CEUS enables dynamic assessment and quantification of microvascularisation up to capillary perfusion. The objective of this paper is to briefly refresh basic knowledge of ultrasound (US) contrast agents' physical properties, to study technical details of CEUS scanning in the kidneys, and to review the commonest renal indications for CEUS, with imaging examples in comparison to baseline unenhanced US and computed tomography when performed. Safety matters and limitations of CEUS of the kidneys are also discussed.

Development and evaluation of a novel, real time mobile telesonography system in management of patients with abdominal trauma: study protocol

BACKGROUND

Despite the use of e-FAST in management of patients with abdominal trauma, its utility in prehospital setting is not widely adopted. The goal of this study is to develop a novel portable telesonography (TS) system and evaluate the comparability of the quality of images obtained via this system among healthy volunteers who undergo e-FAST abdominal examination in a moving ambulance and at the ED. We hypothesize that: (1) real-time ultrasound images of acute trauma patients in the pre-hospital setting can be obtained and transmitted to the ED via the novel TS system; and (2) Ultrasound images transmitted to the hospital from the real-time TS system will be comparable in quality to those obtained in the ED.

METHODS

Study participants are three healthy volunteers (one each with normal, overweight and obese BMI category). The ultrasound images will be obtained by two ultrasound-trained physicians The TS is a portable sonogram (by Sonosite) interfaced with a portable broadcast unit (by Live-U). Two UTPs will conduct e-FAST examinations on healthy volunteers in moving ambulances and transmit the images via cellular network to the hospital server, where they are stored. Upon arrival in the ED, the same UTPs will obtain another set of images from the volunteers, which are then compared to those obtained in the moving ambulances by another set of blinded UTPs (evaluators) using a validated image quality scale, the Questionnaire for User Interaction Satisfaction (QUIS).

DISCUSSION

Findings from this study will provide needed data on the validity of the novel TS in transmitting live images from moving ambulances to images obtained in the ED thus providing opportunity to facilitate medical care of a patient located in a remote or austere setting.

Contrast-enhanced ultrasound performed under urgent conditions. Indications, review of the technique, clinical examples and limitations

Contrast-enhanced ultrasound (CEUS) is an imaging technique with various indications, most of which refer to scheduled examinations. However, CEUS can also be performed under urgent conditions for the investigation of many different clinical questions. This article reviews basic physics of ultrasound contrast agents and examines the commonest urgent clinical applications of CEUS. These include, among others, abdominal solid organ trauma and infarcts, scrotal and penile pathology and blood vessel imaging. Patients can be examined with a very short time delay at their bedside, without exposure to ionising radiation or risk of anaphylactic reaction and renal failure, while contraindications are minimal. CEUS technique is described for various urgent indications and imaging examples from our department's experience are presented. Safety matters and limitations of CEUS are also mentioned. Teaching Points • Contrast-enhanced ultrasound (CEUS) can be performed urgently for various clinical applications. • Abdominal indications include solid organ trauma and infarcts. • CEUS in abdominal organ trauma correlates well with CT and can replace it for patient follow-up. • CEUS images testicular torsion, infection and infarction, as well as testicular and penile trauma. • Blood vessels can be assessed with CEUS for obstruction, aneurysm, thrombosis and dissection.

Management of liver trauma

BACKGROUND

Blunt and penetrating liver trauma is common and often presents major diagnostic and management problems.

METHODS

A literature review was undertaken to determine the current consensus on investigation and management strategies.

RESULTS

The liver is the most frequently injured organ following abdominal trauma. Immediate assessment with ultrasound has replaced diagnostic peritoneal lavage in the resuscitation room, but computerised tomography remains the gold standard investigation. Nonoperative management is preferred in stable patients but laparotomy is indicated in unstable patients. Damage control techniques such as perihepatic packing, hepatotomy plus direct suture, and resectional debridement are recommended. Major complex surgical procedures such as anatomical resection or atriocaval shunting are now thought to be redundant in the emergency setting. Packing is also recommended for the inexperienced surgeon to allow control and stabilisation prior to transfer to a tertiary centre. Interventional radiological techniques are becoming more widely used, particularly in patients who are being managed nonoperatively or have been stabilised by perihepatic packing.

CONCLUSIONS

Management of liver injuries has evolved significantly throughout the last two decades. In the absence of other abdominal injuries, operative management can usually be avoided. Patients with more complex injuries or subsequent complications should be transferred to a specialist centre to optimise final outcome.

Management of liver trauma

BACKGROUND

Blunt and penetrating liver trauma is common and often presents major diagnostic and management problems.

METHODS

A literature review was undertaken to determine the current consensus on investigation and management strategies.

RESULTS

The liver is the most frequently injured organ following abdominal trauma. Immediate assessment with ultrasound has replaced diagnostic peritoneal lavage in the resuscitation room, but computerised tomography remains the gold standard investigation. Nonoperative management is preferred in stable patients but laparotomy is indicated in unstable patients. Damage control techniques such as perihepatic packing, hepatotomy plus direct suture, and resectional debridement are recommended. Major complex surgical procedures such as anatomical resection or atriocaval shunting are now thought to be redundant in the emergency setting. Packing is also recommended for the inexperienced surgeon to allow control and stabilisation prior to transfer to a tertiary centre. Interventional radiological techniques are becoming more widely used, particularly in patients who are being managed nonoperatively or have been stabilised by perihepatic packing.

CONCLUSIONS

Management of liver injuries has evolved significantly throughout the last two decades. In the absence of other abdominal injuries, operative management can usually be avoided. Patients with more complex injuries or subsequent complications should be transferred to a specialist centre to optimise final outcome.

Determining the accuracy of base deficit in diagnosis of intra-abdominal injury in patients with blunt abdominal trauma

BACKGROUND

Blunt abdominal trauma is a leading cause of morbidity and mortality among all age groups. A multiplicity of diagnostic modalities exists to evaluate the abdomen. We sought to assess the diagnostic performance of base deficit (BD) in identifying intra-abdominal injury in patients with blunt abdominal trauma.

METHODS

A prospective, nonrandomized series of patients with blunt abdominal trauma admitted into the 2 emergency departments was investigated from September 2007 to September 2008. Arterial blood samples were analyzed. According to BD, the patients were divided into 2 groups: group 1 who had a BD of -6 or lower and group 2 who had a BD more than -6. Ultrasonography, computed tomographic scan, or laparotomy was performed to find intra-abdominal injury. Follow-up at 7 days by telephone interview was obtained on patients who were discharged.

RESULTS

A total of 400 patients were enrolled, with a mean (SD) age of 34.8 ± 17.1 years. Two hundred sixty-eight (67%) of them were male. Seventy-six (19%) of patients had a BD of -6 or lower. Sixty-eight (17%) of them showed to have intra-abdominal injury with a BD of approximately -8.7 ± 3.2, compared with patients without intra-abdominal injury, -0.4 ± 0.1. Patients with a BD of -6 or lower achieved more laparotomy and blood transfusion compared with patients with a BD more than -6. On receiver operating characteristic curve analysis, the cutoff point of -6 was obtained with sensitivity and specificity of 88.2% and 95.2% and with positive and negative predictive values of 79% and 97.5%, respectively. None of outpatients had abdominal problem in telephone follow-up.

CONCLUSIONS

These data show that the BD is an early available important indicator to identify intra-abdominal injury in patients with blunt abdominal trauma, as well as a high transfusion requirement.

Findings and limitations of focused ultrasound as a possible screening test in stable adult patients with blunt abdominal trauma: a Greek study

Our objective is to underline the place of FAST (focus assessment by sonography for trauma) ultrasonography (US) in the investigation of blunt abdominal trauma. We retrospectively examined the ultrasound findings in 1,999 haemodynamically stable adult patients. These people were admitted to the emergency room (ER) for possible blunt abdominal trauma. All were stable at admission and a FAST ultrasound examination was made. Initial findings were compared with the clinical course after at least 24 h of observation time and CT results. Among the 1,999 US examinations, abnormalities were found in 109 (5.5%) cases. Among them, 102 had free peritoneal fluid, and in 58 examinations, ruptures, lacerations or haematomas were demonstrated. Despite its limitations, such as in cases involving uncooperative patients, excessive bowel gas, obesity and empty bladder, the FAST technique seems to be an accurate method to evaluate the possibility of abdominal blunt trauma in stable patients. Because of the high negative predictive value of the FAST technique in stable patients with blunt abdominal trauma, we recommend that a stable patient with negative ultrasound results at admission remain under close observation for at least 12 or preferably 24 h before being discharged.

Diffusion and practice of ultrasound in emergency medicine departments in Italy

INTRODUCTION

This paper reports data from a cognitive survey on the diffusion, practice and organization of ultrasound (US) in emergency medicine departments (EMDs) in Italy. The study was carried out by the Emergency Medicine Section of the Italian Society for Ultrasound in Medicine and Biology (SIUMB) in collaboration with the Italian Society for Emergency Medicine and Urgent Care (SIMEU).

METHODS

We created a questionnaire with 10 items, relating to 4 thematic areas. The questionnaires were administered from September 2007 to February 2008, by email, telephone or regular mail. In August 2008 the data were subjected to nonparametric statistical analysis (Spearman's Rho and Pearson's chi-square - software SPSS).

RESULTS

We analyzed 170 questionnaires from the EMDs of all Italian regions. A US scanner is present in 64.7% of the ERs, emergency US (E-US) is practiced only in 47.6% of the ERs, and only in 24% of these more than 60% of the ER team members have training in US. The diffusion of US in other operative units of the EMDs ranges from 8.2% to 26.5%.

DISCUSSION

The presence of a US scanner in the ER is essential for the practice and training and is correlated with the level of the EMD. The use of US appears to be less common in less equipped hospitals, regardless of the size of the ER and the availability of radiological services. Wider diffusion of US and greater integration with other services for the installment of the required equipment is to be hoped for.

Comparison of gray-scale contrast-enhanced ultrasonography with contrast-enhanced computed tomography in different grading of blunt hepatic and splenic trauma: an animal experiment

To compare the diagnostic value of contrast-enhanced ultrasonography (CEUS) with contrast-enhanced computed tomography (CECT) for the detection of different grading of solid organ injuries in blunt abdominal trauma in animals. A self-made miniature tools were used as models to simulate a blunt hepatic or splenic trauma in 16 and 14 anesthetized dogs, respectively. Baseline ultrasound, CEUS and CECT were used to detect traumatic injuries of livers and spleens. The degree of injuries was determined by CEUS according to the American Association for the Surgery of Trauma (AAST) scale and the results compared with injury scale based on CECT evaluation. CEUS showed 22 hepatic injury sites in 16 animals and 17 splenic injury sites in other 14 animals. According to AAST scale, 2 grade I, 4 grade II, 3 grade III, 5 grade IV and 2 grade V hepatic lesions were present in 16 animals; 2 grade I, 4 grade II, 6 grade III and 2 grade IV splenic lesions in 14 animals. On CECT scan, 21 hepatic and 17 splenic injuries were demonstrated. According to Becker CT scaling for hepatic injury, 1 grade I, 2 grade II, 4 grade III, 5 grade IV and 2 grade V hepatic injuries were present. On the basis of Buntain spleen scaling, 2 grade I, 5 grade II, 5 grade III, 2 grade IV splenic injuries were showed. After Spearman rank correlation analysis, the agreement of CEUS with CECT on the degree of hepatic and splenic injury is 93.3% and 92.9%, respectively. CT is currently considered as the reference method for grading blunt abdominal trauma, according to experiment results, CEUS grading showed high levels of concordance with CECT. CEUS can accurately determine the degree of injury and will play an important role in clinical application.

[Evidence-based diagnosis of abdominal trauma]

Abdominal trauma is a common cause of death particularly in patients up to 40 years of age. In order to reduce mortality a rapid radiologic diagnosis is essential. At present, sonography plays a role only in the evaluation of minor trauma and as a "focused assessment with sonography for trauma" (FAST) to clarify free intraperitoneal fluid immediately on admittance in severely injured patients. However, computed tomography has proven to be a potent tool for the triage of patients with abdominal trauma, because, based on the results of the CT scan, patients can be referred for laparotomy or safely classified for "wait and see" treatment. Therapeutic decisions are largely based on injury severity scores and the radiologist must be familiar with them as well as with the associated therapeutic consequences.

Focused assessment with sonography for trauma: the FAST scan

Focused assessment with sonography for trauma or focused abdominal sonography for trauma — the FAST scan, has become a useful modality for the initial evaluation of patients with blunt abdominal trauma. The technique is used to identify free fluid in the abdomen and pelvis and to detect the presence of a pericardial effusion. FAST can be performed by any trained individual, not necessarily a sonographer or radiologist, aiding in the immediate availability of this technique in the emergency situation. We will discuss the applications and sensitivity of this technique in trauma and review the potential pitfalls and limitations which need to be understood if this technique is to be safely applied. The use of FAST for the detection of pneumothoraces in trauma and other advances in FAST scanning, such as scoring systems and paediatric FAST are also reviewed.

Blunt abdominal trauma: diagnostic performance of contrast-enhanced US in children--initial experience

PURPOSE

To prospectively compare the sensitivity and specificity of ultrasonography (US) with those of contrast material-enhanced US in the depiction of solid organ injuries in children with blunt abdominal trauma, with contrast-enhanced computed tomography (CT) as the reference standard.

MATERIALS AND METHODS

The study protocol was approved by the ethics board, and written informed consent was obtained from parents. US, contrast-enhanced US, and contrast-enhanced CT were performed in 27 consecutive children (19 boys, eight girls; mean age, 8.9 years +/- 2.8 [standard deviation]) with blunt abdominal trauma to determine if solid abdominal organ injuries were present. Sensitivity, specificity, agreement, accuracy, number of lesions correctly identified, and positive and negative predictive values were determined for US and contrast-enhanced US, as compared with contrast-enhanced CT.

RESULTS

In 15 patients, contrast-enhanced CT findings were negative. Contrast-enhanced CT depicted 14 solid organ injuries in 12 patients. Lesions were in the spleen (n = 7), liver (n = 4), right kidney (n = 1), right adrenal gland (n = 1), and pancreas (n = 1). Contrast-enhanced US depicted 13 of the 14 lesions in 12 patients with positive contrast-enhanced CT findings and no lesions in the patients with negative contrast-enhanced CT findings. Unenhanced US depicted free fluid in two of 15 patients with negative contrast-enhanced CT findings and free fluid, parenchymal lesions, or both in eight of 12 patients with positive contrast-enhanced CT findings. Overall, the diagnostic performance of contrast-enhanced US was better than that of US, as sensitivity, specificity, and positive and negative predictive values were 92.2%, 100%, 100%, and 93.8%, respectively.

CONCLUSION

Contrast-enhanced US was almost as accurate as contrast-enhanced CT in depicting solid organ injuries in children.

Blunt abdominal trauma: back to clinical judgement in the era of modern technology

BACKGROUND AND METHODS

Abdominal trauma poses a diagnostic challenge to most trauma surgeons. This study evaluates a clinical scoring system in 476 blunt abdominal trauma patients treated by the author over a period of 92 months. Patients were sorted into three groups according to the score results. Priority I group (160 patients) was subjected to an immediate laparotomy. Priority II group (200 patients) was treated according to the results of auxiliary investigations. Priority III group (116 patients) was kept under observation. The treatment outcome was used as a gold standard for the evaluation of the results.

RESULTS

In priority I and III groups (276 cases) the management was only dependent on the proposed clinical score with a 100% specificity, 88% sensitivity, 90% positive predictive value, 100% negative predictive value and an overall accuracy of 94%.

CONCLUSIONS

This scoring system (CASS) is helpful in ensuring rapid diagnosis and treatment, reduces time, costs and mortality that may result from improper and/or delayed diagnosis.

Blunt abdominal trauma: emergency contrast-enhanced sonography for detection of solid organ injuries

OBJECTIVE

The objective of our study was to prospectively compare the diagnostic value of sonography and contrast-enhanced sonography with CT for the detection of solid organ injuries in blunt abdominal trauma patients.

SUBJECTS AND METHODS

Sonography, contrast-enhanced sonography, and CT were performed to assess possible abdominal organ injuries in 69 nonconsecutive hemodynamically stable patients with blunt abdominal trauma and a strong clinical suspicion of abdominal lesions. Sonography and contrast-enhanced sonography findings were compared with CT findings, the reference standard technique.

RESULTS

Thirty-two patients had 35 abdominal injuries on CT (10 kidney or adrenal lesions, seven liver lesions, 17 spleen lesions, and one retroperitoneal hematoma). Sixteen lesions were detected on sonography, and 32 were seen on contrast-enhanced sonography. The sensitivity and specificity of sonography were 45.7% and 91.8%, respectively, and the positive and negative predictive values were 84.2% and 64.1%, respectively. Contrast-enhanced sonography had a sensitivity of 91.4%, a specificity of 100%, and positive and negative predictive values of 100% and 92.5%, respectively.

CONCLUSION

Contrast-enhanced sonography was found to be more sensitive than sonography and almost as sensitive as CT in the detection of traumatic abdominal solid organ injuries. It can therefore be proposed as a useful tool in the assessment of blunt abdominal trauma.

Randomized controlled clinical trial of point-of-care, limited ultrasonography for trauma in the emergency department: the first sonography outcomes assessment program trial

STUDY OBJECTIVE

Annually, 38 million people are evaluated for trauma, the leading cause of death in persons younger than 45 years. The primary objective is to assess whether using a protocol inclusive of point-of-care, limited ultrasonography (PLUS), compared to usual care (control), among patients presenting to the emergency department (ED) with suspected torso trauma decreased time to operative care.

METHODS

The study was a randomized controlled clinical trial conducted during a 6-month period at 2 Level I trauma centers. The intervention was PLUS conducted by verified clinician sonographers. The primary outcome measure was time from ED arrival to transfer to operative care; secondary outcomes included computed tomography (CT) use, length of stay, complications, and charges. Regression models controlled for confounders and analyzed physician-to-physician variability. All analyses were conducted on an intention-to-treat basis. Results are presented as mean, first-quartile, median, and third-quartile, with multiplicative change and 95% confidence intervals (CIs), or percentage with odds ratio and 95% CIs.

RESULTS

Four hundred forty-four patients with suspected torso trauma were eligible; 136 patients lacked consent, and attending physicians refused enrollment of 46 patients. Two hundred sixty-two patients were enrolled: 135 PLUS patients and 127 controls. There were no important differences between groups. Time to operative care was 64% (48, 76) less for PLUS compared to control patients. PLUS patients underwent fewer CTs (odds ratio 0.16) (0.07, 0.32), spent 27% (1, 46) fewer days in hospital, and had fewer complications (odds ratio 0.16) (0.07, 0.32), and charges were 35% (19, 48) less compared to control.

CONCLUSION

A PLUS-inclusive protocol significantly decreased time to operative care in patients with suspected torso trauma, with improved resource use and lower charges.

Ultrasound detection of blunt urological trauma: a 6-year study

The objective of this study was to assess the utility of emergency ultrasonography in the detection of blunt urological injury. A retrospective review was conducted of all consecutive emergency blunt trauma ultrasonograms (US) obtained at a level I trauma centre from January 1995 to January 2001. Among the 4320 emergency ultrasonograms performed, 596 patients (14%) had intraabdominal injury and, of these, 99 patients (17%) had urological injuries. The sensitivity of ultrasound for all urological injuries was 67%, and specificity was 99.8%. For isolated urological injuries, sensitivity and specificity were 55.6 and 99.8%, respectively. Ultrasound was most accurate in the detection of grade III renal injuries, identifying 14/15 (93%), and 13 underwent laparotomy. For isolated urological injuries, 15 of 25 (60%) patients with a true-positive US underwent laparotomy compared to 3 of 20 (15%) with a false-negative US. Isolated urological injury was significantly associated with an ultrasonographic pattern of free fluid in the left upper quadrant and the left pericolic gutter (odds ratio=55.1; P<0.001), followed by isolated fluid in the left pericolic gutter (odds ratio=8.6; P=0.04). Although emergency ultrasonography is useful in the triage of patients with blunt urological trauma, it may miss significant urological injury requiring further intervention. As most renal injuries may be managed non-operatively, further studies such as contrast-enhanced CT or angiography should be obtained in the stable patient with suspected blunt urological injury.

A systematic review finds that diagnostic reviews fail to incorporate quality despite available tools

BACKGROUND AND OBJECTIVE

To review existing quality assessment tools for diagnostic accuracy studies and to examine to what extent quality was assessed and incorporated in diagnostic systematic reviews.

METHODS

Electronic databases were searched for tools to assess the quality of studies of diagnostic accuracy or guides for conducting, reporting or interpreting such studies. The Database of Abstracts of Reviews of Effects (DARE; 1995-2001) was used to identify systematic reviews of diagnostic studies to examine the practice of quality assessment of primary studies.

RESULTS

Ninety-one quality assessment tools were identified. Only two provided details of tool development, and only a small proportion provided any indication of the aspects of quality they aimed to assess. None of the tools had been systematically evaluated. We identified 114 systematic reviews, of which 58 (51%) had performed an explicit quality assessment and were further examined. The majority of reviews used more than one method of incorporating quality.

CONCLUSION

Most tools to assess the quality of diagnostic accuracy studies do not start from a well-defined definition of quality. None has been systematically evaluated. The majority of existing systematic reviews fail to take differences in quality into account. Reviewers should consider quality as a possible source of heterogeneity.

Reevaluation of ultrasonography for solid-organ injury in blunt abdominal trauma

OBJECTIVE

To reevaluate the usefulness of ultrasonography for detecting and classifying solid-organ injuries from blunt abdominal trauma by comparing ultrasonography with computed tomography (CT) and laparotomy.

METHODS

Six hundred four patients with blunt abdominal trauma were examined by both B-mode ultrasonography and CT for a study period of 14 years. The ultrasonographic examiners were divided into 2 groups depending on their experience with ultrasonography. The ultrasonographic results were then compared with CT and surgical findings. This was a retrospective study.

RESULTS

In 198 patients, solid-organ injuries were identified on CT, laparotomy, or both. Sensitivity values in group A (experts) were 87.5% for hepatic injuries, 85.4% for splenic injuries, 77.6% for renal injuries, and 44.4% for pancreatic injuries. Sensitivity values in group B were 46.2% for hepatic injuries, 50.0% for splenic injuries, and 44.1% for renal injuries. The detection rates in group A were 80% to 100% for different types of hepatic injuries except superficial injuries (20%) and 70% to 100% for different types of splenic injuries. The detection rates for renal parenchymal and pancreatic duct injuries were 53.3% and 80%, respectively. The detection rates for injuries requiring intervention were 86.1% in group A and 66.7% in group B.

CONCLUSIONS

The sensitivity of ultrasonography with the use of CT and surgical findings as reference standards decreased compared with our prior study. However, ultrasonography was found to enable experienced examiners to detect and classify parenchymal injuries efficiently, despite disadvantages in detecting superficial and vascular injuries. Ultrasonography should be used to explore not only free fluid but also solid-organ injuries.

Blunt Abdominal Injury in the Pregnant Patient: Detection with US

PURPOSE

To determine the accuracy of ultrasonography (US) for the detection of blunt intraabdominal injury in pregnant patients and to compare differences between pregnant and nonpregnant patients of childbearing age.

MATERIALS AND METHODS

A retrospective review of results of all consecutive emergency blunt trauma US examinations performed at a level I trauma center from January 1995 to June 2002 was conducted. Data on demographics, free fluid location, and patient outcome were collected. Injuries were determined on the basis of results of computed tomography and/or laparotomy. The Student t test was used to detect differences between continuous variables, and chi(2) analysis was used to evaluate differences between proportions.

RESULTS

A total of 2319 US examinations for blunt trauma were performed in girls and women between the ages of 10 and 50 years. There were 328 pregnant patients, 23 of whom had intraabdominal injury. The mean age of the pregnant patients was 24.7 years +/- 6.1 (standard deviation) (age range, 14-42 years). In pregnant patients, the sensitivity of US was 61% (14 of 23 patients), the specificity was 94.4% (288 of 305 patients), and the accuracy was 92.1% (302 of 328 patients). Pregnant patients were significantly more likely to have sustained injuries from assault (odds ratio: 2.6, P < .001). The most common pattern of free fluid accumulation detected at US in pregnant patients was that of fluid in the left and right upper quadrants and pelvis (n = 4, 29%); the second most common pattern was one of isolated pelvic fluid (n = 3, 21%).

CONCLUSION

For detection of intraabdominal injury, US was less sensitive in pregnant patients than in nonpregnant patients but was highly specific in both subgroups. The sensitivity of US was highest in pregnant patients during the first trimester.

Controversies in emergency radiology. CT versus ultrasound in the evaluation of blunt abdominal trauma

There has been controversy regarding ultrasonography (US) versus CT in blunt abdominal trauma (BAT). Each modality has its strengths and weaknesses. US is fast and allows resuscitative efforts to proceed while the patient is being scanned. However, the sensitivity of US is inferior to that of CT, and there is user variability. CT is better at determining the extent, type, and grade of injury, resulting in a more tailored therapeutic plan and safe conservative management of many patients. However, CT involves ionizing radiation, cannot be performed portably, and requires only visual monitoring while scanning. Given each modality's strengths and weaknesses we conclude that CT is the preferred examination when the BAT patient is stable or moderately stable, enough to be taken to CT. If a BAT patient is unstable, US is beneficial in screening for certain injuries or large hemoperitoneum prior to an exploratory laparotomy.

Sonographic patterns of intraperitoneal hemorrhage associated with blunt splenic injury

OBJECTIVE

To determine the correlation between sonographic detection of free fluid in the left upper quadrant and blunt splenic injury.

METHODS

A retrospective review was conducted of all consecutive emergency blunt trauma sonograms obtained at a level I trauma center from January 1995 to January 2001. Data were collected on demographics, free fluid location, and patient outcome. Injuries were determined from computed tomography, diagnostic peritoneal lavage, laparotomy, or a combination thereof.

RESULTS

A total of 4320 blunt trauma sonograms were obtained, and 596 patients (14%) had intra-abdominal injuries. The mean age was 33.7 +/- 19.1 years (range, 1-95 years), with 294 (49%) male and 302 (51%) female. There was no statistical difference between age, sex, or mechanism for all subgroups. There were 409 true-positive, 187 false-negative, 88 false-positive, and 3636 true-negative findings. Sensitivity of sonography for detecting all intra-abdominal injuries was 68%, and specificity was 97.6%; sensitivity for detecting isolated splenic injuries was 73.8%. Locations of free fluid in patients with nonsplenic injuries were compared with those in patients with splenic injuries. Isolated left upper quadrant free fluid was significantly associated with splenic injury (odds ratio = 3.0; P = .002), followed by diffuse free fluid (odds ratio = 2.1; P = .005). A subanalysis of isolated splenic injuries also revealed a significant association with left upper quadrant free fluid (odds ratio = 3.1; P = .007) and diffuse free fluid (odds ratio = 2.7; P = .0007).

CONCLUSIONS

Free fluid in the left upper quadrant is significantly associated with splenic injury. This finding should triage patients more rapidly to computed tomography, angiography, embolization, and laparotomy.

Emergency department spirometric volume and base deficit delineate risk for torso injury in stable patients

Background

We sought to determine torso injury rates and sensitivities associated with fluid-positive abdominal ultrasound, metabolic acidosis (increased base deficit and lactate), and impaired pulmonary physiology (decreased spirometric volume and PaO₂/FiO₂).

Methods

Level I trauma center prospective pilot and post-pilot study (2000–2001) of stable patients. Increased base deficit was < 0.0 in ethanol-negative and ≤ -3.0 in ethanol-positive patients. Increased lactate was > 2.5 mmol/L in ethanol-negative and ≥ 3.0 mmol/L in ethanol-positive patients. Decreased PaO₂/FiO₂ was < 350 and decreased spirometric volume was < 1.8 L.

Results

Of 215 patients, 66 (30.7%) had a torso injury (abdominal/pelvic injury n = 35 and/or thoracic injury n = 43). Glasgow Coma Scale score was 14.8 ± 0.5 (13–15). Torso injury rates and sensitivities were: abdominal ultrasound negative and normal base deficit, lactate, PaO₂/FiO₂, and spirometric volume – 0.0% & 0.0%; normal base deficit and normal spirometric volume – 4.2% & 4.5%; chest/abdominal soft tissue injury – 37.8% & 47.0%; increased lactate – 39.7% & 47.0%; increased base deficit – 41.3% & 75.8%; increased base deficit and/or decreased spirometric volume – 43.8% & 95.5%; decreased PaO₂/FiO₂ – 48.9% & 33.3%; positive abdominal ultrasound – 62.5% & 7.6%; decreased spirometric volume – 73.4% & 71.2%; increased base deficit and decreased spirometric volume – 82.9% & 51.5%.

Conclusions

Trauma patients with normal base deficit and spirometric volume are unlikely to have a torso injury. Patients with increased base deficit or lactate, decreased spirometric volume, decreased PaO₂/FiO₂, or positive FAST have substantial risk for torso injury. Increased base deficit and/or decreased spirometric volume are highly sensitive for torso injury. Base deficit and spirometric volume values are readily available and increase or decrease the suspicion for torso injury.

Electron paramagnetic resonance analysis of transferrin-bound iron in animal models of blunt trauma

BACKGROUND

Blood iron sequestration is known to be implicated in the systemic acute-phase response to trauma injury. The objective of the present research was to assess the effect of iron sequestration in animal models of blunt trauma by means of electron paramagnetic resonance spectroscopy of iron in complex with transferrin, a main iron-transporting protein in blood, and to correlate this effect with the extent of induced injury.

METHODS

Two animal models of blunt trauma were explored in the present study. Blunt trauma in the rat model was produced by exposure of 14 animals to blast overpressure (BOP) (at peak BOP of either 86 +/- 5 kPa or 112 +/- 2 kPa) generated in a shock tube. Blunt trauma in the porcine model was produced by impact of high-speed projectiles made from a rubber-tipped, plastic composite weighing 28.64 +/- 0.12 g (mean +/- SEM, n = 8) with a length of approximately 6 cm and a diameter of approximately 4 cm. The projectiles were propelled by compressed helium onto eight animals at a velocity of 101.8 +/- 3.8 m/s (mean +/- SEM, n = 8) at the point of impact. Each experiment was accompanied by a pathology assessment using an injury scoring system developed for blunt trauma injuries to derive a severity score for whole-body involvement. Amounts of transferrin-bound iron (TRF-[Fe3+]) in whole blood and blood plasma samples were measured using quantitative electron paramagnetic resonance spectroscopy. The observed alterations in the amounts of blood TRF-[Fe3+] were correlated with estimated injury score ratios in each animal.

RESULTS

Blunt trauma produced by either BOP exposure of rats or projectile impacts in pigs was accompanied by TRF-[Fe3+] sequestration observed in both blood and blood plasma. The amount of TRF-[Fe3+] in blood was shown to have inverse correlation with the extent of injury (Pearson r = -0.90 in the rat model and r = -0.93 in the porcine model) estimated by injury score ratios and was not dependent on location of the injury (lung, liver, spleen, or jejunum).

CONCLUSION

The presented data suggest that assessment of TRF-[Fe3+] in blunt trauma can provide a good deal of information on severity of injury. The response of TRF-[Fe3+] can be considered as a potential surrogate marker of the systemic alterations in blunt trauma and, therefore, warrants further investigation in a human pilot study.

The focused abdominal sonography for trauma scan: pearls and pitfalls

OBJECTIVE

To review the state-of-the-art use of sonography in evaluating the patient with trauma.

METHODS

We reviewed our experience in performing more than 5000 sonographic examinations in the patient with trauma. The recent experience of other publications advocating newer applications of sonography in the patient with trauma are discussed and presented in a pictorial fashion.

RESULTS

The main focus of sonography in the patient with trauma has been in performance of the focused abdominal sonography for trauma scan. The focused abdominal sonography for trauma scan is usually performed in the patient with blunt abdominal trauma and is used to check for free fluid in the abdomen or pelvis. There are certain pitfalls that need to be avoided and certain limitations of the focused abdominal sonography for trauma scan that need to be recognized. These pitfalls and limitations are reviewed. More recently, sonography has been used to detect certain solid-organ injuries that have a variety of appearances. Thus, sonography may be used to localize the specific site of injury in these patients. More recently, sonography has been used to evaluate thoracic abnormalities in patients with trauma, including pleural effusions, pneumothoraces, and pericardial effusions.

CONCLUSIONS

The use of sonography in evaluating the patient with trauma has rapidly expanded in the past decade. Those using sonography in this group of patients should be aware of its many uses but also its potential pitfalls and limitations.

Blunt abdominal trauma in children: evaluation with emergency US

PURPOSE

To assess the accuracy of emergency abdominal ultrasonography (US) in the detection of both hemoperitoneum and parenchymal organ injury in children.

MATERIALS AND METHODS

Imaging findings were recorded prospectively in 744 consecutive children who underwent emergency US from January 1995 to October 1998; free fluid and parenchymal abnormalities of specific organs were also noted. Patients with intraabdominal injuries were identified retrospectively. Computed tomographic (CT) findings, intraoperative findings, and clinical outcome were compared with the initial US findings. Sensitivity, specificity, and positive and negative predictive values were calculated for patients who underwent CT, laparotomy, or both after US.

RESULTS

Seventy-five (10%) of 744 patients had intraabdominal injuries, and US depicted free fluid in 42 of them. US had 56% sensitivity, 97% specificity, 82% positive predictive value, and 91% negative predictive value for detection of hemoperitoneum alone. US helped identify parenchymal abnormalities that corresponded to actual organ injury without accompanying free fluid in nine patients (12%). Inclusion of identification of parenchymal organ injury at US increased the sensitivity of US to 68%, with an accuracy of 92%.

CONCLUSION

US for blunt abdominal trauma in children is highly accurate and specific, but moderately sensitive, for detection of intraabdominal injury.

Sonographic assessment of blunt abdominal trauma: a 4-year prospective study

PURPOSE

Emergency abdominal sonography has become a common modality worldwide in the evaluation of injuries caused by blunt trauma. The sensitivity of sonography in the detection of hemoperitoneum varies, and little is known about the accuracy of sonography in the detection of injuries to specific organs. The purpose of this study was to determine the overall accuracy of sonography in the detection of hemoperitoneum and solid-organ injury caused by blunt trauma.

METHODS

From January 1995 to October 1998, 3,264 patients underwent emergency sonography at our institution to evaluate for free fluid and parenchymal abnormalities of specific organs caused by blunt trauma. All patients with intra-abdominal injuries (IAIs) were identified, and their sonographic findings were compared with their CT and operative findings, as well as their clinical outcomes.

RESULTS

Three hundred ninety-six (12%) of the 3,264 patients had IAIs. Sonography detected free fluid presumed to represent hemoperitoneum in 288 patients (9%). The sonographic detection of free fluid alone had a 60% sensitivity, 98% specificity, 82% positive predictive value, and 95% negative predictive value for diagnosing IAI. The accuracy was 94%. Seventy patients (2%) had parenchymal abnormalities identified with sonography that corresponded to actual organ injuries. The sensitivity of the sonographic detection of free fluid and/or parenchymal abnormalities in diagnosing IAI was 67%.

CONCLUSIONS

Emergency sonography to evaluate patients for injury caused by blunt trauma is highly accurate and specific. The sonographic detection of free fluid is only moderately sensitive for diagnosing IAI, but the combination of free fluid and/or a parenchymal abnormality is more sensitive.

Evaluating the quality of systematic reviews in the emergency medicine literature

STUDY OBJECTIVE

The objective of this study was to examine the scientific quality of systematic reviews published in 5 leading emergency medicine journals.

METHODS

MEDLINE and EMBASE databases were electronically searched to identify published systematic reviews. Searches were only conducted in emergency medicine journals during the past 10 years; 4 of the journals were also hand searched. Potential reviews were assessed independently by 2 reviewers for inclusion. Data regarding methods were extracted from each review independently by 2 reviewers. All systematic reviews were retrieved and rated for quality by using the 10 questions from the overview quality assessment questionnaire.

RESULTS

Twenty-nine reviews were identified from more than 100 citations. The overall scientific quality of the systematic reviews was low (mean score, 2.7; 95% confidence interval 2.1 to 3.2; maximum possible score, 7.0). Selection and publication biases were rarely addressed in this collection of reviews. For example, the search strategies were only identified in 9 (31%) reviews, whereas independent study selection (6 [21%]) and quality assessment of included studies (9 [31%]) were infrequently performed. Overall, the majority of reviews had extensive flaws, and only 3 (10%) had minimal flaws.

CONCLUSION

The results of the study indicate that many of the systematic reviews published in the emergency medicine literature contain major flaws; reviews with poor methodology may limit the validity of reported results. Further efforts should be made to improve the design, reporting, and publication of systematic reviews in emergency medicine.

Does the presence of ultrasound really affect computed tomographic scan use? A prospective randomized trial of ultrasound in trauma

OBJECTIVE

There is a paucity of evidence demonstrating that emergency department (ED) ultrasound changes clinical practice in trauma patients. We hypothesized that the presence of ultrasound would affect clinical decision making as evidenced through abdominal computed tomographic (CT) scan use in blunt multiple trauma patients.

METHODS

This study used a prospective randomized format in an urban county ED with Level II trauma center status (ED census, 72,000 patients per year). Participants were patients with multiple blunt injuries meeting trauma center triage criteria. Patients were randomized to receive either abdominal ultrasound or no ultrasound (control) during initial ED resuscitation. The primary outcome variable was use of abdominal CT scan in patients with and without ultrasound.

RESULTS

Two hundred eight patients were enrolled. The mean age was 40 +/- 18 years, and 62% were men. Mechanism of injury was motor vehicle crash, 56%; automobile versus pedestrian, 18%; motorcycle crash, 16%; falls, 10%; and other, 10%. One hundred four ultrasound and 104 control patients were analyzed. There were no apparent differences between ultrasound and control groups in demographics, injury type, or Injury Severity Score. Fifty-four of 104 (52%) of the control group received abdominal CT scans versus 37 of 104 (36%) abdominal CT scans for the ultrasound group; mean difference in proportions was 15.9 (p < 0.01; 95% confidence interval, 2.6-29.1).

CONCLUSION

In this trial, the routine use of abdominal ultrasound in the evaluation of patients with multiple blunt injuries resulted in significantly fewer abdominal CT scans being obtained. A larger trial is needed to more clearly define the clinical and financial impact of ultrasound in the management of blunt abdominal trauma.

Absent peritoneal fluid on screening trauma ultrasonography in children: a prospective comparison with computed tomography

BACKGROUND

Although the accuracy of focused abdominal sonography for trauma (FAST) in adults has been demonstrated, results of this technique in children have been conflicting with few comparisons against computed tomography (CT), the imaging gold standard.

METHODS

A total of 160 hemodynamically stable pediatric trauma victims referred for abdominal CT initially underwent rapid screening sonography looking for free fluid. Both studies were interpreted in blinded fashion.

RESULTS

Forty-four of the 160 patients had an intraabdominal injury on CT, 24 (55%) of which had normal screening sonography. Fifteen of the 44 (34%) had no free fluid on either modality. Accuracy of sonography compared with CT was 76% with a negative predictive value 81%.

CONCLUSIONS

Sonography for free fluid alone is not reliable to exclude blunt intraabdominal injury in hemodynamically stable children given the considerable percentage of injured patients without free fluid. J Pediatr Surg 36:565-569.