Ultrasound in the evaluation and management of blunt abdominal trauma

Serial Trauma Abdominal Ultrasound in Children (STAUNCH): A Pilot Study

BACKGROUND

Ultrasound has established utility within pediatric emergency medicine and has an added benefit of avoiding excessive radiation exposure. The serial focused assessment with sonography in trauma (sFAST) examination is a potential alternative to improve pediatric trauma evaluation. We sought to evaluate the accuracy of sFAST in pediatric patients with blunt abdominal trauma.

METHODS

We performed a multicenter, retrospective observational study of electronic medical records, trauma registry data, and image archiving records of previous sFAST examinations. Examinations from pediatric patients (18 years or younger) who presented to an emergency department with blunt abdominal trauma were eligible for inclusion as long as the period between the first and second FAST was at least 30 minutes but no more than 24 hours. Demographic data and patient and outcomes were collected.

RESULTS

Data collected from 3 institutions found a total of 38 sFAST performed between July 2017 and September 2021 on eligible patients. Of these, there were 6 (15.4%) FAST examinations that were positive after an initial negative or indeterminate interpretation. The overall sensitivity and specificity of sFAST were 66.7% (95% confidence interval 22.3-95.7%) and 93.8% (79.2-99.3%), respectively.

CONCLUSIONS

This pilot study found that sFAST can enhance blunt trauma evaluation and improve sensitivity and diagnostic accuracy. More data are needed to determine how sFAST can be utilized in pediatric patients with blunt abdominal trauma.

The effect of e-learning on point-of-care ultrasound education in novices

BACKGROUND

Current studies assessed the learning efficacy of e-learning in ultrasound (US) training using questionnaires, or simulation in well-controlled conditions. This study investigates the effect of e-learning on the clinical US performance of the first postgraduate year (PGY-1) residents.

METHODS

In this prospective observational study, we enrolled PGY-1 and second postgraduate year (PGY-2) residents. The e-learning was introduced on the first day and each PGY-1 was authorized to access the e-learning platform. The point-of-care ultrasound (PoCUS) curriculum for the focused assessment of sonography for trauma (FAST) was conducted on the 7^th day for PGY-1 and the objective structured clinical examination (OSCE) followed. The PGY-2 received bedside one-to-one random learning before the study and did not have the authorization to access the e-learning. The FAST examinations performed by the PGY-1 and PGY-2 were collected on the 30th day. The clinical FAST performance was assessed by the instructor not involved in the curriculum and blinded to the use of e-learning, including numbers, image quality, and diagnostic accuracy between PGY-1 e-learning users, non-users, and the PGY-2.

RESULTS

One hundred and seventy PGY-1 with 736 FAST examinations and 53 PGY-2 residents with 134 examinations were included. Seventy PGY-1 used e-learning with a median time spent of 13.2 mins (IQR, 6.5-21.1 mins) at the first access. The PGY-2 had more PoCUS experience than the PGY-1, however, the 70 e-learning users performed more FAST examinations than the PGY-2 (median [IQR], 4 [2-6] vs. 2 [1-3], p = 0.0004) and had better image quality than the PGY-2 (3 [3-3.2] vs. 3 [2.7-3], p = 0.044). There were no significant differences in the diagnostic accuracy between the PGY-1 and PGY-2.

CONCLUSIONS

E-learning has a positive effect on US learning. The PGY-1 users had comparable performance with the PGY-2 and even better image acquisition although the PGY-2 had more PoCUS experience.

TRIAL REGISTRATION

NCT03738033 at ClinicalTrials.gov.

Surgical management of severe pediatric blunt abdominal trauma

A 3-year-old male patient was brought to the Emergency Department with a traumatic blunt lesion in the liver. Due to hemodynamic instability and a severe lesion of a grade IV liver injury shown on the CT, the chosen conduct was to perform a hepatorrhaphy with oxidized cellulose.

The Pregnant Trauma Patient

Trauma is the leading non-obstetric cause of maternal death. Optimal management of the pregnant trauma patient requires a multidisciplinary approach. The anaesthetist and critical care physician play a pivotal role in the entire continuum of fetomaternal care, from initial assessment, resuscitation and intraoperative management, to postoperative care that often involves critical care support and patient transfer. Primary goals are aggressive resuscitation of the mother and maintenance of uteroplacental perfusion and fetal oxygenation by the avoidance of hypoxia, hypotension, hypocapnia, acidosis and hypothermia. Recognizing and understanding the mechanisms of injury, the factors that may predict fetal outcome, and the pathophysiological changes that can result from trauma, will allow early identification and treatment of fetomaternal injury. This in turn should improve morbidity and mortality. A framework for the acute care of the pregnant trauma patient is presented.

Bedside Ultrasonography at Emergency Department - “New Kids on the Block” and “Echoes of Future”

Bedside ultrasonography is increasingly being performed by emergency physician in Hong Kong. Nearly every Accident and Emergency department in Hong Kong is equipped with an ultrasound machine. Ultrasonographic examination is a powerful clinical tool as it is non-invasive, safe, reliable and inexpensive. It has a high diagnostic accuracy in an experience hand. The practice of performing ultrasonography by local emergency physician is just at the early stage. This article aims to review the characteristic, scope and limitation of bedside ultrasonography at emergency department setting. The issue of training and certification, cost effectiveness and medico-legal implication of this tool is also discussed. The goal of bedside ultrasonography program in Hong Kong is to provide round the clock ultrasound examination and interpretation by well-trained and qualified emergency physician. Establishment of the scope of emergency ultrasound examination and implementation of quality improvement audit on the services is necessary. Training and research in the area of ultrasound imaging should be encouraged. With the maturation of our specialty and the effort of our local emergency physicians, bedside emergency ultrasonography will soon emerge as the “Echoes of the future”.

FOCUSED ASSESSMENT WITH SONOGRAPHY AS AN AID FOR THE DIAGNOSIS OF GASTROINTESTINAL PERFORATION IN A BOBCAT ( FELIS RUFUS )

A 10-yr-old female spayed bobcat (Felis rufus) presented with a 3-day history of lethargy, anorexia, and two episodes of vomiting. An emergency field visit was scheduled to perform abdominal radiography and ultrasonography. The bobcat was assessed to be approximately 5-10% dehydrated, on the basis of decreased skin turgor and tacky mucous membranes. Free peritoneal gas, reduced abdominal serosal detail, and an abnormal-appearing right-sided intestinal segment were identified in the abdominal radiographs. However, the emergency field clinicians were not knowledgeable of these abnormalities, because the radiographs could not be processed in the field. During an initial complete abdominal ultrasound evaluation, a nondependent hyperechoic interface with reverberation artifact suggestive of intestinal or free gas and focal intestinal changes indicative of marked enteritis or peritonitis were identified. Free peritoneal fluid was not present on initial examination. In a focused abdominal sonography for trauma (FAST) scan, made after subcutaneous fluid administration, a small volume of anechoic free fluid was present in the peritoneal space. With ultrasound guidance, the fluid was aspirated and appeared grossly turbid. This fluid was subsequently confirmed as septic suppurative effusion, secondary to a foreign body-associated intestinal perforation. The use of a FAST scan is well described in human medicine, and to a limited degree in veterinary literature. This case represents a novel application of FAST scanning in an emergency field setting in a nontraumatized patient. This case report illustrates the utility of the FAST scan in yielding critical clinical information after fluid resuscitation in a zoological setting.

False-positive focused abdominal sonography in trauma in a hypotensive child: case report

We report a case of a false-positive focused abdominal sonography in trauma (FAST) examination in a persistently hypotensive pediatric trauma patient, performed 12 hours after the trauma, suspected to be caused by massive fluid resuscitation leading to ascites. While a positive FAST in a hypotensive trauma patient usually indicates hemoperitoneum, this case illustrates that the timing of the FAST examination relative to the injury, as well as clinical evolution including the volume of fluid resuscitation, need to be considered when interpreting the results of serial and/or late FAST examinations.

The efficacy and value of emergency medicine: a supportive literature review

Study objectives

The goal of this study was to identify publications in the medical literature that support the efficacy or value of Emergency Medicine (EM) as a medical specialty and of clinical care delivered by trained emergency physicians. In this study we use the term "value" to refer both to the "efficacy of clinical care" in terms of achieving desired patient outcomes, as well as "efficiency" in terms of effective and/or cost-effective utilization of healthcare resources in delivering emergency care. A comprehensive listing of publications describing the efficacy or value of EM has not been previously published. It is anticipated that the accumulated reference list generated by this study will serve to help promote awareness of the value of EM as a medical specialty, and acceptance and development of the specialty of EM in countries where EM is new or not yet fully established.

Methods

The January 1995 to October 2010 issues of selected journals, including the EM journals with the highest article impact factors, were reviewed to identify articles of studies or commentaries that evaluated efficacy, effectiveness, and/or value related to EM as a specialty or to clinical care delivered by EM practitioners. Articles were included if they found a positive or beneficial effect of EM or of EM physician-provided medical care. Additional articles that had been published prior to 1995 or in other non-EM journals already known to the authors were also included.

Results

A total of 282 articles were identified, and each was categorized into one of the following topics: efficacy of EM for critical care and procedures (31 articles), efficacy of EM for efficiency or cost of care (30 articles), efficacy of EM for public health or preventive medicine (34 articles), efficacy of EM for radiology (11 articles), efficacy of EM for trauma or airway management (27 articles), efficacy of EM for using ultrasound (56 articles), efficacy of EM faculty (34 articles), efficacy of EM residencies (24 articles), and overviews and editorials of EM efficacy and value (35 articles).

Conclusion

There is extensive medical literature that supports the efficacy and value for both EM as a medical specialty and for emergency patient care delivered by trained EM physicians.

Portable ultrasonography in mass casualty incidents: The CAVEAT examination

Ultrasonography used by practicing clinicians has been shown to be of utility in the evaluation of time-sensitive and critical illnesses in a range of environments, including pre-hospital triage, emergency department, and critical care settings. The increasing availability of light-weight, robust, user-friendly, and low-cost portable ultrasound equipment is particularly suited for use in the physically and temporally challenging environment of a multiple casualty incident (MCI). Currently established ultrasound applications used to identify potentially lethal thoracic or abdominal conditions offer a base upon which rapid, focused protocols using hand-carried emergency ultrasonography could be developed. Following a detailed review of the current use of portable ultrasonography in military and civilian MCI settings, we propose a protocol for sonographic evaluation of the chest, abdomen, vena cava, and extremities for acute triage. The protocol is two-tiered, based on the urgency and technical difficulty of the sonographic examination. In addition to utilization of well-established bedside abdominal and thoracic sonography applications, this protocol incorporates extremity assessment for long-bone fractures. Studies of the proposed protocol will need to be conducted to determine its utility in simulated and actual MCI settings.

Free abdominal fluid without obvious solid organ injury upon CT imaging: an actual problem or simply over-diagnosing?

Whereas a non-operative approach for hemodynamically stable patients with free intraabdominal fluid in the presence of solid organ injury is generally accepted, the presence of free fluid in the abdomen without evidence of solid organ injury not only presents a challenge for the treating emergency physician but also for the surgeon in charge. Despite recent advances in imaging modalities, with multi-detector computed tomography (CT) (with or without contrast agent) usually the imaging method of choice, diagnosis and interpretation of the results remains difficult. While some studies conclude that CT is highly accurate and relatively specific at diagnosing mesenteric and hollow viscus injury, others studies deem CT to be unreliable. These differences may in part be due to the experience and the interpretation of the radiologist and/or the treating physician or surgeon.A search of the literature has made it apparent that there is no straightforward answer to the question what to do with patients with free intraabdominal fluid on CT scanning but without signs of solid organ injury. In hemodynamically unstable patients, free intraabdominal fluid in the absence of solid organ injury usually mandates immediate surgical intervention. For patients with blunt abdominal trauma and more than just a trace of free intraabdominal fluid or for patients with signs of peritonitis, the threshold for a surgical exploration - preferably by a laparoscopic approach - should be low. Based on the available information, we aim to provide the reader with an overview of the current literature with specific emphasis on diagnostic and therapeutic approaches to this problem and suggest a possible algorithm, which might help with the adequate treatment of such patients.

The value of focused assessment with sonography in trauma examination for the need for operative intervention in blunt torso trauma: a rebuttal to “emergency ultrasound-based algorithms for diagnosing blunt abdominal trauma (review)”, from the Cochrane Collaboration

Background and significance

The Cochrane Database of Systematic Reviews published a manuscript critical of the use of the FAST examination. The reference is Stengel D. Bauwens K. Sehouli J. Rademacher G. Mutze S. Ekkernkamp A. Porzsolt F. Emergency ultrasound-based algorithms for diagnosing blunt abdominal trauma. Cochrane Database of Systematic Reviews. (2):CD004446, 2005. UI: 15846717. The stated objective was the assessment of the “efficiency and effectiveness” of ultrasound-inclusive evaluative algorithms in patients with suspected blunt abdominal trauma (BAT). The primary outcome measures explored were Mortality, CT and DPL use, and laparotomy rates. Little or no benefit was seen and the conclusion was that “there is insufficient evidence from randomized controlled trials to justify promotion” of FAST in patients with BAT. While the review used the same rigorous methods employed in all Cochrane Reviews, it appears that several serious flaws plagued the manuscript. The finest methodological rigor cannot yield usable results, if it is not applied to a clinically relevant question. In a world of increasingly conservative management of BAT, do we need FAST, a rapid, repeatable screening modality at the point-of-care to visualize any amount of free fluid or any degree of organ injury? The obvious answer is no. However, quantifying the value of FAST to predict the need for immediate operative intervention (OR) is essential.

Methods

To rebut this recurrent review, a systematic literature review was conducted using verbatim methodologies as described in the Cochrane Review with the exception of telephone contacts. Data were tabulated and presented descriptively.

Results

Out of 487 citations, 163 articles were fully screened, 11 contained prospectively derived data with FAST results, patient disposition and final diagnoses, and a description of cases considered false negatives or false positives. Of the 2,755 patients, 448 (16%) went to the OR. There were a total of 5 patients with legitimately false-negative diagnoses made based on the FAST: 3 involving inadequate scans and 2 of blunt trauma-induced small bowel perforations without hemoperitoneum.

Conclusion

The FAST examination, adequately completed, is a nearly perfect test for predicting a “Need for OR” in patients with blunt torso trauma.

ED ultrasound in hepatobiliary disease

To evaluate the diagnostic accuracy of gallbladder ultrasound performed by emergency physicians (EPUS) in patients with right upper quadrant (RUQ) and epigastric (EPI) pain, adults>18 years of age with RUQ or EPI pain were prospectively evaluated by physical examination, laboratory data, and EPUS followed by a blinded radiology department ultrasound (RADUS). Diagnostic categories included: "normal gallbladder"; "uncomplicated symptomatic cholelithiasis" (uncomplicated SCL; stones present but symptoms and signs relieved and no abnormal blood-work); or "complicated symptomatic cholelithiasis" (CSCL; stones and positive symptoms and signs including abnormal blood-work). Final Emergency Department patient assessments based on the RADUS were compared to the EPUS. Over 2-years, 127 patients were enrolled. The sensitivity of the EPUS for detecting stones was 94% (positive predictive value 99%; specificity 96%; negative predictive value 73%). In conclusion, the EPUS is a highly sensitive and reliable indicator of the presence of gallstones.

Ultrasound-assisted paracentesis performed by emergency physicians vs the traditional technique: a prospective, randomized study

STUDY OBJECTIVE

To determine if emergency center ultrasound (ECUS) can be of value to emergency physicians in the evaluation of possible ascites and accompanying decisions to perform emergent paracentesis.

METHODS

During a 7-month period, patients suspected of having ascites and potentially requiring paracentesis were prospectively entered into a randomized study in an urban public hospital emergency center (>140 000 annual visits). Patients were randomized to receive paracentesis using the traditional or the bedside ECUS-assisted technique. Indications for paracentesis included known liver disease and obvious ascites as well as suspected ascites or suspected subacute bacterial peritonitis. Participating physicians had received a minimum of 1 hour of formal didactic ultrasound training that included gallbladder, renal, vascular, and bladder studies as well as the focused abdominal sonography for trauma examination for trauma and the detection of ascites. A portable Terason 2000 laptop ultrasound machine with a 5-MHz probe was used to scan the patients. Data collected included the patients' characteristics, estimation of ascitic fluid volume, number of attempts made to obtain fluid, speed of paracentesis, and the operator's overall evaluation of the ECUS-assisted technique, if used.

RESULTS

Of 100 enrolled patients, 56 received the ECUS-assisted technique. Of 42 patients with ascites, 40 (95%) were successfully aspirated and 14 (25%) did not receive paracentesis because no ascites or insignificant amount of ascites was visualized. One patient was noted to have a large cystic mass in the left lower quadrant and another patient had a ventral hernia. Of the 44 patients randomized to the traditional technique, 27 (61%) were successfully aspirated. In 17 (39%) of these patients, fluid could not be obtained using traditional methods. Of these 17 failed attempts by traditional methods, 15 patients received ECUS in a "break" from the study protocol. Ascitic fluid was obtained in 13 of these 15 patients; of the 2 remaining patients, 1 did not have enough fluid to be sampled and the other had no fluid visualized.

CONCLUSION

Ninety-five percent (P=.0003) of the patients who were randomized in the ECUS group and in whom a needle paracentesis was performed had ascitic fluid successfully obtained, as compared with the traditional method group.

Evaluation of blunt abdominal trauma: current practice in Taiwan

OBJECTIVE

To gain an overview of the current practice of different major institutions in Taiwan in the evaluation of abdominal injuries. A further comparison was made between general surgeons and emergency physicians in this aspect.

METHOD

A telephone survey was conducted of all emergency departments of 58 major institutions (14 medical centres, 44 district hospitals) that are capable of providing definitive care for trauma victims in Taiwan in June 2002. Respondents were asked to select the diagnostic modality of choice in the evaluation of a haemodynamically abnormal blunt trauma victim with suspected intra-abdominal injuries. In the same study period, this particular telephone scenario was also used to survey 109 individual doctors (45 emergency physicians, 64 general surgeons).

RESULTS

Most respondents preferred ultrasound (also known as focused assessment with sonography for trauma or "FAST") instead of diagnostic peritoneal lavage (DPL) because DPL is invasive and most doctors in Taiwan have limited experience in performing DPL or interpreting the results.

CONCLUSIONS

It seems reasonable to devote greater resources for emergency departments to incorporate a FAST based algorithm into their initial management of trauma victims, and to improve training in its use. It is also suggested that future ATLS teaching in Taiwan should include didactic material on FAST.

Evaluation of a focused assessment with sonography for trauma protocol to detect free abdominal fluid in dogs involved in motor vehicle accidents

OBJECTIVE

To establish a focused assessment with sonography for trauma (FAST) protocol in dogs, determine whether FAST can be performed by veterinary clinicians without extensive ultrasonographic experience, and assess the frequency of free fluid (as determined via FAST) in the abdominal cavity of dogs following motor vehicle accidents (MVAs).

DESIGN

Prospective study.

ANIMALS

100 client-owned dogs evaluated within 24 hours of an MVA.

PROCEDURE

Dogs were placed in lateral recumbency for the FAST examination. To detect fluid in the abdomen, 2 ultrasonographic views (transverse and longitudinal) were obtained at each of 4 sites (just caudal to the xiphoid process, on the midline over the urinary bladder, and at the left and right flank regions).

RESULTS

In the 100 dogs evaluated via FAST, free abdominal fluid was detected in 45 dogs. In 40 of those 45 dogs, abdominocentesis was performed; hemoperitoneum and uroperitoneum were diagnosed in 38 and 2 dogs, respectively. Compared with dogs that had no free abdominal fluid detected via FAST, dogs that had free abdominal fluid detected via FAST had significantly higher heart rates and serum lactate concentrations and significantly lower PCVs and total solid concentrations.

CONCLUSIONS AND CLINICAL RELEVANCE

Results indicate that FAST is a simple and rapid technique that can be performed on dogs in an emergency setting to detect intra-abdominal free fluid and can be performed by veterinary clinicians with minimal previous ultrasonographic experience.

Residents should not independently perform focused abdominal sonography for trauma after 10 training examinations

OBJECTIVES

To assess whether 10 focused abdominal sonography for trauma (FAST) examinations could be used as a minimum standard for training, as suggested previously.

METHODS

This was a retrospective review of patients with abdominal trauma who underwent resident-performed FAST examinations before surgical or Department of Radiology evaluation.

RESULTS

Six hundred ninety-eight patients were examined by resident-performed FAST followed by reference standard evaluations. Four hundred twelve patients were evaluated by residents who previously performed 10 FAST examinations; 154 were evaluated by 29 residents performing their 11th through 30th examinations; and 258 were evaluated by 10 residents performing their 31st and subsequent examinations. The results of resident-performed FAST for intraperitoneal free fluid were as follows: 11 to 20 examinations--sensitivity, 73.9% (95% confidence interval, 51.3%-88.9%); specificity, 98.8% (92.5%-99.9%); true-positive findings, 17; true-negative, 81; false-positive, 1; false-negative, 6; total patients, 105; 21 to 30 examinations--sensitivity, 100% (73.2%-100%); specificity, 97.1% (83.3%-99.9%); true-positive, 14; true-negative, 34; false-positive, 1; false-negative, 0; total patients, 49; 31 and more examinations--sensitivity, 94.8% (88.6%-97.9%); specificity, 98.6% (94.5%-99.8%); true-positive, 110; true-negative, 140; false-positive, 2; false-negative, 6; total patients, 258.

CONCLUSIONS

The suggestion that 10 examinations could be used as a minimum standard for training in FAST examinations was not validated.

FAST (focused assessment with sonography in trauma) accurate for cardiac and intraperitoneal injury in penetrating anterior chest trauma

OBJECTIVE

To evaluate the FAST (focused assessment with sonography in trauma) examination for determining traumatic pericardial effusion and intraperitoneal fluid indicative of injury in patients with penetrating anterior chest trauma.

METHODS

An observational prospective study was conducted over a 30-month period at an urban level I trauma center. FAST was performed in the emergency department by emergency physicians and trauma surgeons. FAST results were recorded before review of patient outcome as determined by 1 or more of the following: thoracotomy, laparotomy, pericardial window, cardiologic echocardiography, diagnostic peritoneal lavage, computed tomography, and serial examinations.

RESULTS

FAST was undertaken in 32 patients with penetrating anterior chest trauma: 20 (65%) had stab wounds, and 12 (35%) had gunshot wounds. Sensitivity of FAST for cardiac injury (n = 8) in patients with pericardial effusion was 100% (95% confidence interval, 63.1%-100%); specificity was 100% (95% confidence interval, 85.8%-100%). The presence of pericardial effusion determined by FAST correlated with the need for thoracotomy in 7 (87.5%) of 8 patients (95% confidence interval, 47.3%-99.7%). One patient with a pericardial blood clot on cardiologic echocardiography was treated nonsurgically. FAST had 100% sensitivity for intraperitoneal injury (95% confidence interval, 63.1%-100%) in 8 patients with views indicating intraperitoneal fluid but without pericardial effusion, again with no false-positive results, giving a specificity of 100% (95% confidence interval, 85.8%-100%). This prompted necessary laparotomy in all 8.

CONCLUSIONS

In this series of patients with penetrating anterior chest trauma, the FAST examination was sensitive and specific in the determination of both traumatic pericardial effusion and intraperitoneal fluid indicative of injury, thus effectively guiding emergent surgical decision making.

Sensitivity in detecting free intraperitoneal fluid with the pelvic views of the FAST exam

The multiple-view focused assessment with sonography for trauma (FAST) exam is an integral tool in the assessment of blunt abdominal trauma. A prospective observational study was performed to compute the average minimum volume of detectable intraperitoneal fluid with the pelvic views of the FAST exam. All adult patients from October 1999 to May 2001, who presented to the ED with blunt abdominal trauma and underwent a clinically indicated diagnostic peritoneal lavage (DPL), were candidates for admission to the pelvic ultrasound study. In the supine position, patients were administered lavage fluid in 100 cc increments until the examiner detected the fluid on ultrasound. An independent reviewer also examined the hard-copy ultrasound images for fluid detection. Patients were excluded if they had (1) a positive DPL for hemoperitoneum (defined as 10 cc of gross blood or >100,000 red blood cells/mL), (2) a positive initial ultrasound for free fluid, or (3) lacked sufficient hard-copy ultrasound images. The mean minimal volume of fluid needed for pelvic ultrasound detection by the examiner and reviewer was 157 and 129 cc (n = 7), respectively. The median quantity of fluid for ultrasound detection by both the examiner and reviewer was 100 cc. The pelvic views of the FAST exam identified a significantly smaller quantity of intraperitoneal fluid than previous studies of the right upper quadrant single-view exam.

Imaging modalities in obstetrics and gynecology

The practicing emergency physician often encounters diagnostic dilemmas involving the choice of the most appropriate radiologic study to evaluate patients in the emergency department. In addition, the uncertainty of potentially harmful fetal effects of radiation in the pregnant patient may add unnecessary delay and concern in the workup of obstetric emergencies. An emergency physician's in-depth understanding of the strengths, limitations, and potentially harmful effects of radiologic studies allows the safest and most appropriate studies to be ordered for the gynecologic and obstetric population. With the explosion of interest and growing level of expertise in focused emergency department ultrasonography during the last decade, the practicing emergency physician should add this skill to his or her armamentarium in the future. Many emergency physicians are already comfortable in using radiologic technologies in their daily practice and have discovered how quickly vital and specific information can be obtained.

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.

Ultrasound detection of blunt splenic injury

The purpose of this study was to determine the sensitivity of emergency ultrasound (US) for the detection of blunt splenic injury (BSI), and to describe sonographic parenchymal patterns. Over 3 years, 2138 emergency US were performed, and 162 patients had BSI. CT was performed for 76 patients, and there were 86 laparotomies. Seventy patients (43%) had concomitant intraabdominal injuries. Ultrasound detected free fluid in 109 patients (67%), and parenchymal injury in 31 patients (19%). There were 48 false negative US (30%). Sonographic patterns included a diffuse heterogeneous appearance, hyperechoic and hypoechoic perisplenic crescents, and discrete hypoechoic or hyperechoic areas within the spleen. Overall sensitivity of US for detection of BSI was 69%, but was 86% for grade III or higher injuries. Ultrasound is most sensitive for the detection of grade III or higher BSI based on the presence of haemoperitoneum. Ultrasound may also identify BSI on the basis of parenchymal abnormality, with a diffuse heterogeneous pattern most commonly encountered. Sonographic evaluation for both free fluid and parenchymal injury improves sensitivity of US.

Management of traumatically injured patients in the emergency department observation unit

An EDOU may be an ideal setting for the short-term monitoring and treatment of certain acutely injured patients. The patients choosen for observation, and the diagnostic studies used, will be specific to a particular institution's availability and expertise. Pathways should be developed in conjunction with all services caring for these patients.

Blunt abdominal trauma: screening us in 2,693 patients

PURPOSE

To evaluate the accuracy of screening abdominal ultrasonography (US) in patients with blunt abdominal trauma.

MATERIALS AND METHODS

Patients with blunt abdominal trauma underwent US. The abdomen and pelvis were scanned for free fluid, the visceral organs were assessed for heterogeneity, and duplex US was performed if necessary. Empty bladders were filled with 200-300 mL of sterile saline through a Foley catheter. US findings were considered positive if free fluid was present or if parenchymal abnormalities that could be consistent with trauma were detected. Screening US results were compared with findings of diagnostic peritoneal lavage, repeat US, computed tomography (CT), cystography, surgery, and/or autopsy and/or the clinical course.

RESULTS

Findings from 2,693 US examinations were evaluated and were positive in 145 of 172 patients with injuries (sensitivity, 84%) and 64 (89%) of 72 patients who ultimately underwent laparotomy with surgical repair of injuries. False-negative findings were retroperitoneal injury, bowel injury, and intraperitoneal solid organ injury without hemoperitoneum. No patient with false-negative findings died. Specificity of US was 96% (2,429 of 2,521 patients), and overall accuracy was 96% (2,574 of 2,693 patients). Positive predictive value was 61% (145 of 237 patients), and negative predictive value was 99% (2,429 of 2,456 patients).

CONCLUSION

Abdominal US is useful in screening for injury in patients with blunt abdominal trauma, and its use represents a notable change in institutional practice. Diagnostic peritoneal lavage is rarely performed, and CT is used when screening US findings are positive, when injury is clinically suspected despite negative US findings, or when US is not available.

Ultrasonography by emergency physicians in patients with suspected cholecystitis

This article investigates the use of bedside abdominal ultrasonography (BAU) performed by emergency physicians (EPs) to screen patients for cholelithiasis and cholecystitis. In this prospective study EPs performed BAU on 116 patients. Agreement between BAU and formal abdominal ultrasound (FUS) performed in the radiology department for detecting cholelithiasis and cholecystitis was determined using Kappa statistics. Test characteristics of BAU for detecting cholelithiasis and acute cholecystitis were calculated. Agreement between BAU and FUS was 0.71 for cholelithiasis and 0.46 for acute cholecystitis. Test characteristics of BAU for cholelithiasis were sensitivity 92%, specificity 78%, positive predictive value (PPV) 86%, negative predictive value (NPV) 88%. Test characteristics of BAU for acute cholecystitis compared with clinical follow-up were sensitivity 91%, specificity 66%, PPV 70%, NPV 90%. BAU may be used to exclude cholelithiasis and is sensitive for cholecystitis. However, when EPs with limited experience identify cholecystitis a confirmatory test is warranted before cholecystectomy.

Role of emergency medicine physicians in US performed in patients in the emergency department: how substantial is their participation?

PURPOSE

To determine the extent to which emergency medicine physicians have assumed responsibility for performing and interpreting ultrasonographic (US) studies in emergency departments (EDs) in the United States.

MATERIALS AND METHODS

The national 1997 Medicare Part B database was searched by using standard US procedure codes, location codes, and physician specialty codes. The authors determined how many US studies were performed in EDs and what percentage of those studies were performed by emergency medicine physicians, radiologists, or other physicians.

RESULTS

During 1997, 234,820 ED US studies within nine major examination categories were performed in Medicare patients nationwide. Emergency medicine physicians performed 1,551 (0.7%) of these studies. When echocardiographic examinations were excluded, emergency medicine physicians performed 458 (0.2%) of the remaining total of 196,158 studies.

CONCLUSION

Although emergency medicine physicians have claimed to be actively involved in ED US on a broad scale, the data reveal that their involvement in 1997 was minimal. This raises doubt as to whether they can properly train their residents to perform US or maintain their own competence at acceptable levels.

Ultrasound and other imaging technologies in the intensive care unit

As technology advances, more imaging and procedures are performed at the bedside on critically ill patients in ICUs, thereby eliminating the risks of transporting patients. These imaging techniques can serve as diagnostic and therapeutic tools in treating the acute and chronic consequences of injured, critically ill patients. One area of growth is ultrasonography. Critical care applications of ultrasonography are expanding, and the learning curve of surgeons and intensivists performing some of these studies is improving. Ultrasonography can supplement physical examination and provide useful "real-time" information on nearly every body cavity. Other imaging technology is also available in a portable form, enabling imaging directly at the bedside. Images are now becoming readily and easily available with the advancement of teleradiology. Some of the imaging modalities are still in development, and their clinical effectiveness is being studied. In the future, more uses of these various imaging technologies may become evident and cost-effective.

Diagnostic evaluation of patients with blunt abdominal trauma: a decision analysis

OBJECTIVES

Using decision analysis, to compare the expected utility (EU) of diagnostic peritoneal lavage (DPL), computed tomography (CT), and ultrasonography (US) to determine the optimal modality for the evaluation of blunt abdominal trauma (BAT) in hemodynamically stable adults.

METHODS

Data points for the decision analysis were obtained from three sources: 1) prevalence of BAT and the sensitivity and specificity of each diagnostic modality were determined through a criteria-based review of the literature; 2) rate of BAT necessitating immediate intervention, perioperative complication rate, and operative mortality rate were calculated using data from the authors' institution's trauma registry; and 3) outcome utilities were determined by telephone survey of adults in a random sample of households in the region. The decision tree was constructed and evaluated in standard fashion. For each diagnostic modality, the authors calculated the EU using the minimum, mean, and maximum sensitivity and specificity across a range of prevalence. Mean outcome utilities were used for each branch of the tree when calculating the EU.

RESULTS

The EU of CT was consistently lower than the EUs of DPL and US at all levels of prevalence. However, the rank order of the EUs of US and DPL varied with the prevalence of BAT. When the prevalence was <30%, the EU of US was higher than that for DPL. When the prevalence was 30-40%, the EUs were similar. When the prevalence was >40%, the EU of US was less than that of DPL.

CONCLUSIONS

Among institutions operating under constraints similar to those used in this model, the optimal diagnostic modality for the evaluation of BAT can be determined based on the sensitivity and specificity of the modality at their institution and the prevalence of BAT in their patient population.

A preliminary evaluation of emergency ultrasound in the setting of an emergency medicine training program

In this article we seek to evaluate the diagnostic accuracy of emergency physicians performing emergency ultrasonography in the setting of an emergency medicine training program. A prospective observational study was performed at an inner city Level I trauma center with an emergency medicine residency training program. From July 1994 to December 1996 a convenience sample of ultrasound exams was recorded. The diagnostic quality ("acceptable or technically limited") was determined by a board-certified cardiologist or radiologist with fellowship training in ultrasonography. The emergency department interpretations were then compared to those of the blinded cardiologist or radiologist. Four hundred and fifty-six ultrasound examinations were videotaped and entered into the study; 408 (89%) of the studies performed were determined to be "acceptable." The diagnostic accuracy (sensitivity, specificity, positive and negative predictive values) of these studies were as follows: cardiac, to rule out effusion (n = 67; 0.83, 0.98, 0.88, 0.98); transabdominal, to rule out abdominal aortic aneurysms (AAA), cholelithiasis, or free peritoneal fluid (n = 263; 0.91, 0.89, 0.88, 0.92); renal, to rule out hydronephrosis (n = 45; 0.94, 0.96, 0.94, 0.96); pelvic, to rule in intrauterine pregnancy (n = 33; 1.0, 0.90, 0.96, 1.0). The 48 "technically limited studies" included: 39 transabdominal (33 gallbladder, 1 abdominal aortic aneurysm, 5 free peritoneal fluid), 6 cardiac, 2 renal, and 1 pelvic ultrasound. This study suggests that emergency physicians with a minimal amount of training display acceptable technical skill and interpretive acumen in their approach to emergency ultrasonography.

Serial abdominal ultrasound in the setting of trauma

Ultrasound is gaining wide acceptance in Emergency Medicine as an inexpensive and accurate examination modality. One of the leading uses of this technology is in the initial assessment of the trauma patient, where the ultrasound examination is often used to determine the need for immediate laparotomy or further diagnostic study. We present a series of four patients, all of whom sustained blunt or penetrating abdominal trauma. In each case, the initial screening abdominal ultrasound was negative for free intraperitoneal (i.p.) fluid but, when repeated by the same practitioner, became positive. These cases demonstrate the need for serial ultrasounds in evaluating the patient with abdominal trauma. Future studies of trauma ultrasound should investigate the utility of serial sonographic examinations.

A comparison of emergency medicine ultrasound training with guidelines of the Society for Academic Emergency Medicine

STUDY OBJECTIVES

To compare the current state of emergency medicine residency ultrasound training with guidelines for that training from the Society for Academic Emergency Medicine (SAEM).

METHODS

A brief questionnaire was sent to program directors from 119 emergency medicine residency programs in the United States. Responses were compared with the SAEM guidelines for clinical experience (150 total ultrasounds) and didactic experience (40 hours of didactic instruction).

RESULTS

The overall response rate was 92%. Seventy-six (69%) of the programs own an ultrasound machine (ownership defined as 24-hour availability and complete discretion over use). Of these, 12 (16%) indicated that their average 1998 graduate had done at least 150 total ultrasound scans during residency, although none of the programs had average numbers that exceeded the minimum guidelines for all 4 procedure categories. Information on didactic curriculum was available from 74 ultrasound-owning programs: the duration was 0 to 20 hours in 49 (66%), 20 to 40 hours in 19 (26%), and 40 to 100 hours in 6 (8%). Only 1 program's average graduate met or exceeded the SAEM guidelines for both didactic and clinical training.

CONCLUSION

Most emergency medicine residency programs own at least 1 ultrasound machine, with more than half of these obtaining their first machine within the past 3 years. Only 1 program currently meets SAEM training guidelines.

Should UK emergency physicians undertake diagnostic ultrasound examinations?

From the published evidence there is no doubt that emergency physicians in America can undertake focused ultrasound examinations and that, by extrapolation, this would also be the case for UK emergency physicians. If this skill is to become part of the diagnostic armamentarium of the emergency physician, however, it needs to be demonstrated to be cost effective compared with the alternatives already available to the hospital. Trials to test for this benefit should adopt a hospital and not an emergency department perspective if the results are to influence health policy and specialty training.

Bowel and mesenteric injury: evaluation with emergency abdominal US

PURPOSE

To assess emergency ultrasonography (US) for detection of bowel and mesenteric injury from blunt trauma.

MATERIALS AND METHODS

For 3 years, prospective data on all patients undergoing emergency US were recorded. Patients with bowel and mesenteric injury were identified, and physical examination, laboratory, computed tomographic (CT), and intraoperative findings were compared with prospective data.

RESULTS

From January 1995 to January 1998, emergency US was performed in 1,686 patients; 71 patients had bowel and mesenteric injury. Forty-one examinations were true-positive (i.e., with free fluid), and 30 were false-negative. Twenty-five of the 41 patients with true-positive US results had concomitant injuries that may have accounted for the free fluid, including liver, spleen, pancreas, gallbladder, kidney, and/or bladder injuries. The remaining 16 patients had isolated bowel and mesenteric injury. Bowel and mesenteric damage was identified intraoperatively in 70 patients. Twenty-nine of 30 patients with false-negative US examinations had abdominal tenderness. Sixteen patients with false-negative US results had bowel and mesenteric injury that was detected 12 or more hours after initial scanning.

CONCLUSION

Free fluid in the abdomen is not detected in the majority of patients with isolated bowel and mesenteric injury. For clinical suspicion of bowel and mesenteric injury, observation, serial physical abdominal examination, and CT may be helpful in diagnosing this condition.

Intravascular gas as an incidental finding at US after blunt abdominal trauma

PURPOSE

To describe the occurrence and importance of intravascular gas at ultrasonography (US) during the initial examination of patients after blunt abdominal trauma.

MATERIALS AND METHODS

Reports of all abdominal US examinations performed at one institution for blunt trauma from October 1995 through June 1996 were reviewed. The charts of patients with intravascular gas were examined to determine the mechanism of injury, associated findings, and clinical outcome.

RESULTS

A total of 730 patients underwent abdominal US examinations during the 9 months of study; five had intravascular gas demonstrated. Two patients had portal venous gas, one had hepatic venous gas, and two had inferior vena caval gas. Four of the five patients were involved in motor vehicle accidents, and one had been assaulted. In patients in whom follow-up studies were obtained, there was no evidence of intravascular gas at US or computed tomography. No cause was found at imaging or clinical examination.

CONCLUSION

Intravascular gas may occur as a transient incidental finding after blunt abdominal trauma.

Ultrasonography by emergency physicians in patients with suspected ureteral colic

We performed a prospective study of patients with suspected ureteral colic to evaluate the test characteristics of bedside renal ultrasonography (US) performed by emergency physicians (EPs) for detecting hydronephrosis, and to evaluate how US can be used to predict the likelihood of nephrolithiasis. Thirteen EPs performed US, recorded the presence of hydronephrosis, and made an assessment of the likelihood of nephrolithiasis. All patients underwent i.v. pyelography (IVP) or unenhanced helical computed tomography (CT). There were 126 patients in the study: 84 underwent IVP; 42 underwent helical CT. Test characteristics of bedside US for detecting hydronephrosis were: sensitivity 72%, specificity 73%, positive predictive value (PPV) 85%, negative predictive value (NPV) 54%, accuracy 72%. The PPV and NPV for the ability of the EP to predict nephrolithiasis after performing US were 86% and 75%, respectively. We conclude that bedside US performed by EPs may be used to detect hydronephrosis and help predict the presence of nephrolithiasis.

Computed tomography for evaluating blunt abdominal trauma in the low-volume nondesignated trauma center: the procedure of choice?

BACKGROUND

Scepticism has been expressed regarding the accuracy of computed tomography for evaluating patients with blunt abdominal trauma in low-volume institutions. Diagnostic peritoneal lavage has been suggested as a more reliable method, and recently ultrasound has been proposed as a quick alternative. We sought to determine the accuracy of computed tomography at our low-volume center, which lacks 24-hour, in-house computed tomography dedicated radiologists.

METHODS

A prospective case series of patients who had computed tomographic evaluation requested for suspected blunt abdominal trauma were enrolled over a 1-year study period.

RESULTS

Fifty-five patients were enrolled. Injuries were identified in 12 patients, six of whom required intervention. The diagnostic accuracies for the detection of injury were 86% and 90.5% for radiology residents and attending radiologists, respectively. The likelihood ratios for the detection of an injury requiring intervention were identical for both groups of interpreters and were 0.17 for negative result and 35.6 for positive result.

CONCLUSION

The accuracy of computed tomography for evaluating blunt abdominal trauma at a low-volume institution is comparable to that reported from higher-volume centers and may be the procedure of choice, averting the expected higher incidence of nontherapeutic laparotomy attendant with more widespread application of diagnostic peritoneal lavage and the missed injuries that may be expected from the occasional ultrasonographer.

Trauma in pregnancy

Over the past 60 years, trauma has become the leading cause of morbidity and mortality in the pregnant patient. The emotional and physiological challenges of treating two patients simultaneously adds to an already stressful situation. Resuscitation of the pregnant trauma patient is discussed from the prehospital setting to disposition. Also discussed are non-invasive monitoring tools, such as tocodynanomometry and ultrasonography.