Ultrasonography in the management of blunt abdominal and thoracic trauma

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.

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

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

Focused Assessment with Sonography in Trauma (FAST): Experience of a Tertiary Hospital in Southeast Asia

Objective

This study compares the positive predictive value (PPV) and negative predictive value (NPV) of focused assessment with sonography in trauma (FAST) versus abdominal-pelvic computed tomography scans (CTAP) after blunt abdominal injury as well as the need for abdominal surgery. We also sought to determine if any false negative ultrasound studies were associated with significant morbidity. The results were compared with other studies.

Design

Retrospective cross-sectional study.

Setting

A tertiary hospital.

Methods

Cases were retrieved from the trauma registry and electronic medical records in a tertiary hospital in Singapore over a two year period from 1 January 2009 to 31 December 2010. Exclusion criteria included penetrating trauma and burns. The sonographic finding, computed tomography finding, and the outcome of the patients were retrieved. Diagnostic characteristics including predictive values were calculated.

Results

A total of 476 patients were enrolled. Four hundred fifty-nine patients had FAST performed with fifty (10.9%) being positive. Forty-nine patients (21.7%) out of 226 patients had CTAP which showed abnormalities and nineteen (4.0%) patients underwent surgery. Comparing FAST to detect abnormalities on CTAP, the PPV and NPV were 0.590 and 0.863 respectively. Comparing FAST with the need for surgery, the PPV and NPV were 0.280 and 0.990 respectively. Four patients (0.98%) had negative FAST but required surgery. There were no significant adverse outcomes or surgical intervention in patients with normal vital signs, normal initial physical examination and negative FAST findings but who did not have a CTAP.

Conclusions

In patients with an initial normal physical examination and negative FAST, emergent CTAP may be avoided. (Hong Kong j.emerg.med. 2014;21:230-236)

Current technology: laparoscopic surgery in trauma

There has been a rapid increase in the use of laparoscopy in general surgery over recent years. However in the field of trauma its role has not been defined and its regular use remains limited to a select group of enthusiasts. We present a review of the current literature on laparoscopic surgery in trauma including therapeutic procedures and a brief synopsis of the alternative methods of investigation for abdominal injury, and our interpretation of the current role of laparoscopic surgery in trauma today.

Ultrasound: the triage tool in the emergency department: using ultrasound first

Ultrasound in the emergency department has long been recognized as a powerful screening and diagnostic tool for both physicians and radiologists. In the emergency department, since time is of the essence, it becomes a critical tool in triaging patients. Over the years, ultrasound has gained several advantages over other modalities because of its non-ionizing radiation, portability, accessibility, non-invasive method and simpler learning curve. As a result, ultrasound has become one of the most frequently used diagnostic tools in the emergency department by non-radiologists. The value of ultrasound is implemented in every acute ailment in the emergency department such as trauma, acute abdomen, acute pelvic pain, acute scrotal pain, appendicitis in children and acute deep venous thrombosis. Our objective is to discuss the benefit of using ultrasound as the primary modality for each of these diseases.

Accuracy of FAST scan in blunt abdominal trauma in a major London trauma centre

INTRODUCTION

Blunt abdominal trauma (BAT) is a leading cause of morbidity and mortality. Rapid diagnosis and treatment with the Advanced Trauma Life Support guidelines are vital, leading to the development of Focused Assessment with Sonography in Trauma (FAST).

METHODS

A retrospective study carried out from January 2007-2008 on all patients who presented with BAT and underwent FAST scan. All patients subsequently had a CT scan within 2 h of admission or a laparotomy within two days. The presence of intra-peritoneal free fluid was interpreted as positive.

RESULTS

100 patients with BAT presented; 71 had complete data. The accuracy of FAST in BAT was 59.2%; in these 31 (43.7%) were confirmed by CT and 11 (15%) by laparotomy. There were 29 (40.8%) inaccurate FAST scans, all confirmed by CT. FAST had a specificity of 94.7% (95% CI: 0.75-0.99) and sensitivity of 46.2% (95% CI: 0.33-0.60). Positive Predictive Value of 0.96 (0.81-0.99) and Negative Predictive Value of 0.39 (0.26-0.54). Fisher's exact test shows positive FAST is significantly associated with Intra-abdominal pathology (p=0.001). Cohen's chance corrected agreement was 0.3. 21 out of 28 who underwent laparotomies had positive FAST results indicating accuracy of 75% (95% CI: 57%-87%).

CONCLUSION

Patients with false negative scans, requiring therapeutic laparotomy is concerning. In unstable patients FAST may help in triaging and identifying those requiring laparotomy. Negative FAST scans do not exclude abdominal injury. Further randomised control trials are recommended if the role of FAST is to be better understood.

Diagnostic accuracy of focused assessment with sonography for trauma (FAST) examinations performed by emergency medical technicians

OBJECTIVE

We aimed to assess the diagnostic accuracy of focused assessment with sonography for trauma (FAST) examinations when used by emergency medical technicians (EMTs) to detect the presence of free abdominal fluid.

METHODS

Six level 1 EMTs (similar to intermediate EMTs in the United States) who worked at a tertiary emergency department in Korea underwent an educational program consisting of two one-hour didactic lectures that included the principles of ultrasonography, the anatomy of the abdomen, and two hours of hands-on practice. After this educational session, the EMTs performed FAST examinations on a convenience sample of patients from July 1 to October 5, 2009. These patients also received an abdominal computed tomography (CT) scan regardless of their chief complaints. The CT findings served as the definitive standard and were interpreted routinely and independently by emergency radiologists who were blinded to the study protocol. In addition, the EMTs were blinded to the CT findings. A positive CT finding was defined as the presence of free fluid, as interpreted by the radiologist. The sensitivity, specificity, predictive values, and their 95% confidence intervals (CIs) were calculated. Informed consent was obtained from all participating patients.

RESULTS

Among the 1,060 eligible patients with abdominal CT scans, 403 patients were asked to participate in the study, and 240 patients agreed. Of these 240 patients, 80 (33.3%) had results showing the presence of free fluid. Fourteen patients had a significant amount of peritoneal cavity fluid, 15 had a moderate amount of peritoneal cavity fluid, and 51 had a minimal amount of peritoneal cavity fluid. Compared with the CT findings, the diagnostic performance of the FAST examination had a sensitivity of 61.3% (95% CI, 50.3%-71.2%), specificity of 96.3% (95% CI, 92.1%-98.3%), positive predictive value of 89.1% (95% CI, 77.0%-95.4%), and negative predictive value of 83.2% (95% CI, 76.9%-88.2%). For a significant or moderate amount of peritoneal cavity fluid, the sensitivity was considerably higher (86.2%).

CONCLUSION

EMTs in Korea showed a high diagnostic performance that was comparable to that of surgeons and physicians when detecting peritoneal cavity free fluid in a Korean emergency department setting. The validity of FAST examinations in prehospital care situations should be investigated further.

Eastern Association for the Surgery of Trauma practice management guidelines for hemorrhage in pelvic fracture--update and systematic review

BACKGROUND

Hemorrhage from pelvic fracture is common in victims of blunt traumatic injury. In 2001, the Eastern Association for the Surgery of Trauma (EAST) published practice management guidelines for the management of hemorrhage in pelvic trauma. Since that time there have been new practice patterns and larger experiences with older techniques. The Practice Guidelines Committee of EAST decided to replace the 2001 guidelines with an updated guideline and systematic review reflecting current practice.

METHODS

Building on the previous systematic literature review in the 2001 EAST guidelines, a systematic literature review was performed to include references from 1999 to 2010. Prospective and retrospective studies were included. Reviews and case reports were excluded. Of the 1,432 articles identified, 50 were selected as meeting criteria. Nine Trauma Surgeons, an Interventional Radiologist, and an Orthopedic Surgeon reviewed the articles. The EAST primer was used to grade the evidence.

RESULTS

Six questions regarding hemorrhage from pelvic fracture were addressed: (1) Which patients with hemodynamically unstable pelvic fractures warrant early external mechanical stabilization? (2) Which patients require emergent angiography? (3) What is the best test to exclude extrapelvic bleeding? (4) Are there radiologic findings which predict hemorrhage? (5) What is the role of noninvasive temporary external fixation devices? and (6) Which patients warrant preperitoneal packing?

CONCLUSIONS

Hemorrhage due to pelvic fracture remains a major cause of morbidity and mortality in the trauma patient. Strong recommendations were made regarding questions 1 to 4. Further study is needed to answer questions 5 and 6.

An overview of emergency ultrasound in the United States

BACKGROUND

As emergency ultrasound use explodes around the world, it is important to realize the path its development has taken and learn from trials and tribulations of early practitioners in the field.

METHODS

Approaches to education, scanning, documentation, and organization are also described.

RESULTS

Machines have reduced in price and once purchased further material costs are low. Staffing costs in terms of training, etc have yet to be assessed, but indications from elsewhere are that these are low. Length of stay in the emergency department dramatically decreases, thus increasing patient satisfaction while maintaining an even higher standard of care.

CONCLUSION

Emergency screening ultrasound is now a nationally accepted tool for the rapid assessment of the emergency patient.

Hollow viscus injury

BACKGROUND

Hollow viscus injuries are uncommon and occur in approximately 1% of all blunt trauma patients.

DISCUSSION

These injuries are often not suspected and are difficult to diagnosis. Morbidity and mortality are high, and a negative abdominal computed tomography is not sufficient to rule out these injuries in certain clinical scenarios.

CONCLUSION

Using a case-based approach, the epidemiology and diagnostic pathways to manage hollow viscus injuries are reviewed.

Are diagnostic peritoneal lavage or focused abdominal sonography for trauma safe screening investigations for hemodynamically stable patients after blunt abdominal trauma? A review of the literature

BACKGROUND

Assessment of patients in the emergency department who sustain blunt abdominal trauma represents a significant diagnostic challenge. Computed tomography (CT) is increasingly used as the principal investigation for these patients. A sensitive screening test could safely reduce the use of CT.

OBJECTIVES

To appraise the evidence supporting the use of diagnostic peritoneal lavage and focused abdominal sonography for trauma as screening tests in the emergency department to reduce the use of CT in the initial assessment of patients sustaining blunt abdominal trauma.

METHODS

A search of high-quality evidence resources was performed, followed by a hand search of the bibliographies of all relevant articles.

RESULTS

Altogether, 55 articles were found during the initial search, of which 23 were relevant. An additional 11 were found by hand searching. Six relevant original research articles were found.

CONCLUSION

Screening diagnostic peritoneal lavage and selective CT is a safe diagnostic strategy for the investigation of blunt abdominal trauma. Further research is needed to determine the role of focused abdominal sonography for trauma scanning in diagnostic protocols.

Evaluation of focussed assessment with sonography in trauma (FAST) by UK emergency physicians

OBJECTIVES

To evaluate the introduction of a focussed assessment with sonography in trauma (FAST) scan into the early assessment of trauma patients in the UK.

METHODS

The setting was an inner city teaching hospital emergency department (annual attendance 100,000). All patients aged 16 or over admitted to the resuscitation room after blunt trauma were included in a prospective observational study. Patients had a FAST scan performed at the end of the primary survey. Results were compared to results of other investigations, laparotomy, postmortem examination, or observation.

RESULTS

153 patients were entered into the study. The sensitivity of the FAST scan was 78% and specificity was 99%.

CONCLUSION

FAST is a highly specific "rule in" technique and is useful in the initial assessment of trauma patients. Emergency physicians can perform FAST after a brief training period.

[Medical imaging in the management of abdominal trauma]

There is a marked trend toward nonoperative management of abdominal trauma. This has been possible thanks to the advances in imaging and interventional techniques. Computed tomography (CT), angiography, and endoscopic retrograde cholangiopancreatography (ERCP) can guide the nonoperative management of abdominal trauma.

Usefulness of hand-held ultrasound devices in out-of-hospital diagnosis performed by emergency physicians

OBJECTIVE

To evaluate the usefulness of ultrasonographic examinations as a diagnostic tool for emergency physicians in out-of-hospital settings.

METHODS

Prospective study performed in a French teaching hospital. Eight emergency physicians given ultrasound training for out-of-hospital diagnosis of pleural, peritoneal, or pericardial effusion; deep venous thrombosis; and arterial flow interruption. After clinical examination, a probability of diagnosis ("clinical score") was assigned on visual analog scale from 0 (absent lesion) to 10 (present lesion). Clinical score between 3 and 7 was considered as clinically doubtful. After ultrasound examination, a second probability ("ultrasound score") was similarly determined. Potential usefulness of ultrasound examination was evaluated by calculating the absolute difference between clinical and ultrasound scores. Patients were followed up to determine final diagnosis: present or absent lesion. "Ultrasound usefulness score" (USS) was determined attributing a positive (when ultrasonography increased diagnostic accuracy) or a negative (when ultrasonography decreased diagnostic accuracy) value to the absolute difference between clinical and ultrasound scores.

RESULTS

One hundred sixty-nine patients were included and 302 ultrasound examinations performed. Median duration of examination was 6 minutes (5-10 minutes). The suspected lesion was found in 45 cases (17%). Mean USS was +2 (0-4). Ultrasonographic examination improved diagnostic accuracy (ie, positive USS) in 181 (67%) cases, decreased it (ie, negative USS) in 22 (8%) cases, and was not contributive (ie, USS was 0) in 67 (25%) cases. When initial diagnosis was uncertain (n = 115), diagnostic performance reached +4 (3-5) and ultrasonographic examination improved diagnostic accuracy in 103 (90%) cases.

CONCLUSION

Out-of-hospital ultrasonography increased diagnostic accuracy in out-of-hospital settings.

Ultrasonography for Interval Assessment in the Nonoperative Management of Hepatic Trauma

Abdominal ultrasonography (US) is gaining widespread acceptance as a valuable diagnostic tool in the initial evaluation of trauma victims. We investigated the utility of US as a follow-up radiologic study in nonoperative hepatic trauma. Patients with liver injury designated for non-operative management were prospectively studied over a 2-year period at our primary adult resource center for trauma. Computed tomography (CT) and radiologist-performed US were obtained at admission and at 1 week. The ability of US to detect lesions, fluid, and complications was evaluated by comparing with the corresponding CT. Twenty-five hepatic trauma patients in the study were successfully managed nonoperatively and had both initial and follow-up US and CT scans: 1 (4%) grade I, 5 (20%) grade II, 7 (28%) grade III, 7 (28%) grade IV, and 5 (20%) grade V. Four complications developed [biloma (3) and biliary fistula (1)] in 3 patients with grade IV injury and 1 with a grade II injury. Interval US appropriately detected a complication or confirmed the absence of complication in all (13/13, 100%) patients with low-grade (I–III) injury and only missed a small biloma in one patient with a grade IV injury. Interval US and CT agreement was 92 per cent for change in hemoperitoneum or parenchymal lesion. Ultrasonography is a convenient imaging modality in the evaluation of hepatic trauma. US is sufficient to detect or exclude complications in low-grade injuries. In high-grade injuries, US may be an adjunct to CT for definitive interval assessment.

Bedside Ultrasonography in the ICU

This is the second of a two-part review on the application of bedside ultrasonography in the ICU. In this part, the following procedures will be covered: (1) echocardiography and cardiovascular diagnostics (second part); (2) the use of bedside ultrasound to facilitate central-line placement and to aid in the care of patients with pleural effusions and intra-abdominal fluid collections; (3) the role of hand-carried ultrasound in the ICU; and (4) the performance of bedside ultrasound by the intensivist. The safety and utility of bedside ultrasonography performed by adequately trained intensivists has now been well demonstrated. This technology, as a powerful adjunct to the physical examination, will become an indispensable tool in the management of critically ill patients.

Hémothorax droit intarissable révélateur d'une plaie hépatique avec rupture diaphragmatique

We report a case of a woman with a blunt thoracic trauma and haemorrhagic shock after a road traffic accident. The clinical and complementary examinations revealed an isolated right haemothorax, which was compressive and uncontrollable. The source of bleeding was discovered with delay and during a surgical exploration: it was a liver injury with diaphragmatic rupture but without hepatic herniation and peritoneal effusion. The diagnostic features of blunt diaphragmatic rupture are discussed.

Critical concepts in abdominal injury

Missed intra-abdominal injuries are among the most frequent causes of potentially preventable trauma deaths. The evaluation and management of abdominal trauma is dependant on multiple factors, including mechanism of injury, location of injury, hemodynamic status of the patient, neurologic status of the patient, associated injuries, and institutional resources.

Fluid-filled bowel mimicking hemoperitoneum: a false-positive finding during sonographic evaluation for trauma

This case report describes a patient who presented to the Emergency Department (ED) after a high-speed motor vehicle crash (MVC), whose initial ultrasound examination was interpreted as being positive for fluid in Morison's pouch. Subsequent ultrasound examinations and computed tomography scans further delineated this finding to be fluid-filled bowel juxtaposed between the liver and right kidney. With greater implementation of ED ultrasound, it is important to identify entities that cause false-positive and false-negative examinations.

Gastrointestinal perforation in children due to blunt abdominal trauma in Hazara, Northern Pakistan

A retrospective study of 25 children with gastrointestinal perforation due to blunt abdominal trauma in a single region of Pakistan is presented. The age, sex, aetiology, site of perforation, abdominal and X-ray findings, associated injuries, surgical procedures and outcome were analysed. There were 20 boys and 5 girls: mean age was 10 years. The injuries were the result of road traffic accidents 12 (48%), falls 11 (44%) and 'struck by animals' two (8%). Associated injuries occurred in 19 (76%). On admission 20 (80%) patients had peritonitis while 18 (72%) had pneumoperitoneum. Mean time from trauma to admission was 10 hours and admission to operation was 5 hours. Ileum was the most common site of perforation. Simple closure was the most common surgical procedure. Complications occurred in nine (36%) patients--six (24%) died. Delay in presentation and operation was associated with increased morbidity and mortality. Frequent evaluation of the child and abdominal X-rays are still the important tools for early diagnosis of gastrointestinal perforation following blunt abdominal trauma.

Laparoscopic splenectomy for ruptured spleen: lessons learned from a case

Splenic rupture is a frequent consequence of blunt abdominal trauma. When nonsurgical management is not indicated, splenic rupture is usually an emergency requiring surgery. Removal of the spleen (splenectomy) or alternative conservative procedures (splenorraphy, partial splenectomy, and hemostatic collagen application) are surgical treatment options. Recently, laparoscopic conservative techniques have been proposed. Laparoscopic splenectomy for a ruptured spleen has been reported only in a single case, in which a hand-assisted technique was used. We present the first reported case, to our knowledge, of successful removal of a ruptured spleen by means of a totally laparoscopic technique. Adequate technical instrumentation, such as the endostapler, harmonic scalpel, and red cell-saving machine, in addition to extensive experience with routine splenectomy, were essential factors to ensure a safe and effective procedure.

Emergency ultrasound credentialling for focused assessment sonography in trauma and abdominal aortic aneurysm: A practical approach for Australasia

OBJECTIVE

Focused assessment with sonography for trauma and emergency ultrasound for abdominal aortic aneurysm are now practiced widely by non-radiologists in emergency departments worldwide. Various credentialling programs have been proposed for novice sonographers; however, their feasibility has been questioned. We adopted the Australasian College for Emergency Medicine (ACEM) credentialling process for emergency ultrasound to determine whether it is feasible for emergency physicians in the Australasian environment.

METHODS

Three full-time emergency medicine specialists and a post-Fellowship Examination trainee at Auckland Hospital undertook the credentialling process.

RESULTS

All four participants had sufficient scans to complete the process after 16 months. Accuracy for focused assessment with sonography for trauma, 90% (95% CI 83-95%), and abdominal aortic aneurysm, 99% (95% CI 90-100%), is similar to that previously reported.

CONCLUSION

The ACEM credentialling process for focused assessment with sonography for trauma and abdominal aortic aneurysm is practical and achievable for emergency medicine specialists working in the Emergency Department at Auckland Hospital. Further studies are necessary to determine whether this holds true for other major trauma centres in Australasia.

The hand-held FAST: experience with hand-held trauma sonography in a level-I urban trauma center

AIMS

To describe the effectiveness of a portable hand-held ultrasound machine when used by clinicians in the early evaluation and resuscitation of trauma victims.

METHODS

The study was a prospective evaluation in a level-I urban trauma center. The focussed assessment with sonography for trauma is a specifically defined examination for free fluid known as the focused assessment with sonography for trauma (FAST) exam. Seventy-one patients had a hand-held FAST (HHFAST) examination performed with a Sonosite 180, 2.4 kg ultrasound machine. Sixty-seven examinations were immediately repeated with a Toshiba SSH 140A portable floor-based machine. This repeat scan (formal FAST or FFAST) was used as a comparison standard between the devices for study purposes. Four patients had a HHFAST only, all with positive result, two being taken for immediate laparotomy, and two having a follow-up computed tomographic (CT) scan. Patient follow-up from other imaging studies, operative intervention, and clinical outcomes were also compared to the performance of each device.

RESULTS

There were 58 victims of blunt, and 13 of penetrating abdominal trauma. One examination was indeterminate using both machines. The apparent HHFAST performance yielded; sensitivity, specificity, positive predictive value, negative predictable value, and accuracy (S, S, PPV, NPV, A) of 83, 100, 100, 98, 98%. Upon review, a CT scan finding and benign clinical course found the HHFAST diagnosis to be correct rather than the FFAST in one case. Considering the ultimate clinical course of the patients, yielded a (S, S, PPV, NPV, A) of 78, 100, 100, 97, and 97% for the HHFAST and 75, 98, 86, 97, and 96% for the FFAST. Statistically, there was no significant difference in the actual performance of the HHFAST compared to the FFAST in this clinical setting.

DISCUSSION

Hand-held portable sonography can simplify early and accurate performance of FAST exams in victims of abdominal trauma.

Contrast-enhanced two- and three-dimensional sonography for evaluation of intra-abdominal hemorrhage

OBJECTIVE

To determine whether a contrast agent enhances sonographic detection of bleeding sites in the abdomen and whether contrast-enhanced three-dimensional sonography provides additional information compared with contrast-enhanced two-dimensional sonography.

METHODS

Bleeding sites were created within the livers (n = 3), spleens (n = 5), and kidneys (n = 3) of 3 dogs. A sonographic contrast agent with vascular and parenchymal enhancement capabilities was administered intravenously at a dose of 0.02 mL/kg. Before and after each contrast agent injection, the bleeding sites were imaged with two- and three-dimensional sonography in gray scale harmonic imaging and color flow modes. Sonographic findings were compared with gross pathologic findings.

RESULTS

Noncontrast-enhanced sonography was not able to show the specific location of the active bleeding in any of the organs evaluated. The contrast agent enhanced the sonographic detection of blood flow in normal vessels and extravasated blood from damaged vessels or organs in all cases. Intrasplenic and intrahepatic hematomas were better identified on delayed imaging sequences because there was marked enhancement of the normal parenchyma, whereas the hematomas remained unenhanced. Reconstructed three-dimensional sonography showed spatial relationships of the bleeding sites and surrounding structures. Gross pathologic findings were consistent with the contrast-enhanced sonographic results.

CONCLUSIONS

Contrast-enhanced sonography improves the detection and evaluation of abdominal bleeding sites. Contrast-enhanced three-dimensional sonography appears to provide additional information when compared with two-dimensional sonography.

Evaluating Blunt Abdominal Trauma with Sonography: A Cost Analysis

Ultrasonography (US) is becoming increasingly utilized in the United States for the evaluation of blunt abdominal trauma (BAT). The objective of this study was to assess the cost impact of utilizing US in the evaluation of patients with BAT in a major trauma center. All patients sustaining BAT during a 6-month period before US was used at our institution (Jan–Jun 1993) were compared to BAT patients from a recent period in which US has been utilized (Jan–Jun 1995). The numbers of US, computed tomography (CT), and diagnostic peritoneal lavage (DPL) were tabulated for each group. Financial cost for each of these procedures as determined by our finance department were as follows: US $96, CT $494, DPL $137. These numbers are representative of actual hospital expenditures exclusive of physician fees as calculated in 1994 U.S. dollars. Cost analysis was performed with t test and chi squared test, and significance was defined as P < 0.05. There were 890 BAT admissions in the 1993 study period and 1033 admissions in the 1995 study period. During the 1993 period, 642 procedures were performed on the 890 patients to evaluate the

abdomen: 0 US, 466 CT, and 176 DPL (see table). This compares to 801 procedures on the 1033 patients in 1995: 552 US, 228 CT, and 21 DPL. Total cost was $254,316 for the 1993 group and $168,501 for the 1995 group. Extrapolated to a 1-year period, a significant ( P < 0.05) cost savings of $171,630 would be realized. Cost per patient evaluated was significantly reduced from $285.75 in 1993 to $163.12 in 1995 ( P < 0.05). This represents a 43 per cent reduction in per patient expenditure for evaluating the abdomen. By effectively utilizing ultrasonography in the evaluation of patients with blunt abdominal trauma, a significant cost savings can be realized. This effect results chiefly from an eight-fold reduction in the use of DPL, and a two-fold reduction in the use of CT.

Diagnostic performance of trauma US in identifying abdominal or pelvic free fluid and serious abdominal or pelvic injury

RATIONALE AND OBJECTIVES

This study assessed the ability of a six-point trauma ultrasound (US) evaluation (a) to identify the presence of free fluid in the abdomen or pelvis, with computed tomography (CT) and laparotomy used as diagnostic standards and (b) to predict the presence of abdominal or pelvic injury, particularly injury requiring surgical intervention.

MATERIALS AND METHODS

Of 156 patients who underwent US evaluation for free fluid after sustaining blunt and penetrating trauma, 147 were entered into the prospective study and underwent follow-up CT and/or laparotomy (n = 79), in-hospital observation, or outpatient examination.

RESULTS

The sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy of US for identifying abdominal or pelvic free fluid were 69%, 100%, 100%, 95%, and 95%, respectively. The corresponding values for predicting abdominal and pelvic injury on the basis of free fluid status alone were 57%, 99%, 80%, 96%, and 95%, respectively. Performing repeated US examinations in patients with deteriorating clinical status decreased the false-negative rate by 50%, increasing the sensitivity for free fluid detection to 85% and the negative predictive value to 97%. Similarly, the sensitivity and negative predictive value for detection of injury increased to 71% and 97%, respectively. A learning curve was also observed, with 67% of the false-negative findings occurring in the first 3 months of the 19-month study.

CONCLUSION

A six-point trauma US evaluation can reliably identify abdominal and pelvic free fluid, which can be a reliable indicator of abdominal or pelvic injury. Scanning conditions must be optimized, and the approach to clinical management must be cautious.

2,576 ultrasounds for blunt abdominal trauma

BACKGROUND

Determination of intra-abdominal injury following blunt abdominal trauma (BAT) continues to be a diagnostic challenge. Ultrasound (US) has been described as a potentially useful diagnostic tool in this setting and is being used with increasing frequency in trauma centers. We determined the diagnostic capability of US in the evaluation of BAT.

METHODS

A retrospective analysis of our trauma US database was performed over a 30-month period. Computed tomographic scan, diagnostic peritoneal lavage, or exploratory laparotomy confirmed the presence of intra-abdominal injury.

RESULTS

During the study period, 8,197 patients were evaluated at the Ryder Trauma Center. Of this group, 2,576 (31%) had US in the evaluation of BAT. Three hundred eleven (12%) US exams were considered positive. Forty-three patients (1.7%) had a false-negative US; of this group, 10 (33%) required exploratory laparotomy. US had a sensitivity of 86%, a specificity of 98%, and an accuracy of 97% for detection of intra-abdominal injuries. Positive predictive value was 87% and negative predictive value was 98%.

CONCLUSION

Emergency US is highly reliable and may replace computed tomographic scan and diagnostic peritoneal lavage as the initial diagnostic modality in the evaluation of most patients with BAT.

Focused abdominal US in patients with trauma

PURPOSE

To evaluate the accuracy of focused abdominal ultrasonography (US) in detecting abdominal injuries that require in-hospital patient treatment in the setting of blunt abdominal trauma.

MATERIALS AND METHODS

One thousand ninety patients with blunt abdominal trauma were assessed with focused abdominal US within 30 minutes of arrival at the hospital. Focused abdominal US results were positive if intra- or retroperitoneal fluid was detected. Patients with negative US results and no other major injuries were observed in the emergency department for 12 hours before discharge. Patients who deteriorated clinically after negative initial US underwent repeat US and/or emergency abdominopelvic computed tomography (CT). Patients with positive or indeterminate US results underwent emergency abdominopelvic CT.

RESULTS

Nine hundred seventy-four (89%) patients had negative focused abdominal US results; eight of these underwent CT. Sixty-six (6%) had positive US results. Four (0.4%) had false-negative and 19 (1.7%) had false-positive US results. Twenty-seven (2.5%) had indeterminate US results; of these, five (18.5%) had positive CT results. One hundred twenty-four (11.4%) required emergency CT. After indeterminate cases were excluded, focused abdominal US had 94% sensitivity, 98% specificity, 78% positive predictive value, 100% negative predictive value, and 95% accuracy.

CONCLUSION

Focused abdominal US has a high negative predictive value for major abdominal injury in patients with blunt abdominal trauma.

Imaging in abdominal trauma

Prompt recognition and timely intervention both play a crucial role in managing patients with blunt abdominal trauma. In most cases of multiply injured patients, where physical examination is indeterminate, a rapid and accurate screening method is a valuable adjunct for care-providers. Through the years, different imaging techniques have been utilized for this purpose; among them are diagnostic peritoneal lavage (DPL), ultrasonography (US) and computed tomography (CT). Proponents of each modality have their own beneficial reasons for adopting that particular method of imaging. Needless to say, despite the high sensitivity and specificity values cited for each, all the methods have their own limitations. After having reviewed the advantages and disadvantages of these three modalities, this article suggests that there is not one single modality that is considered the best. Rather, all three can be complementary and the use of each can be appropriate for a particular subset of patients, given a particular clinical situation, and taking into account the resources available.

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.

Videolaparoscopia no trauma abdominal

A videolaparoscopia (VL) vem contribuindo de forma crescente, para diagnóstico e terapêutica de várias afecções cirúrgicas abdominais, introduzindo profundas mudanças na cirurgia contemporânea. Esse avanço incorporou-se também às urgências traumáticas, fazendo parte da avaliação diagnóstica e, às vezes, da terapêutica do trauma abdominal. Os autores apresentam uma revisão concisa da literatura sobre a VL no trauma, atualizando o tema e discutindo os aspectos mais relevantes das indicações, limitações e complicações do método.

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.

Ultrasound of blunt abdominal trauma

Widely accepted in Europe and Asia as a screening tool for blunt abdominal trauma, sonography is gradually gaining popularity among trauma and emergency physicians in the United States. Sonography has been shown to be comparable with DPL and CT for the detection of hemoperitoneum and superior to both modalities because of its rapidity, noninvasiveness, portability, and low cost. With its ability to demonstrate the amount of intraperitoneal hemorrhage within minutes of a patient's arrival, sonography may be considered the screening modality of choice for blunt abdominal trauma.

Hemoperitoneum as the sole indicator of abdominal visceral injuries: a potential limitation of screening abdominal US for trauma

PURPOSE

To determine, at screening ultrasonography, the prevalence, severity, and clinical outcome of clinically important abdominal visceral injuries, without associated hemoperitoneum, that result from blunt abdominal trauma.

MATERIALS AND METHODS

Computed tomography (CT) was performed at admission in 466 patients with visceral injury. A retrospective review was performed of findings from surgery and contrast material-enhanced spiral and conventional CT performed to verify abdominal visceral injuries in 467 (4%) of 11,188 patients with blunt trauma. These patients were admitted to a level 1 trauma center over 33 months to determine the presence of hemoperitoneum and to identify the grade of injury. Medical records of patients with abdominal visceral injury without hemoperitoneum were reviewed for the management required and for results of focused abdominal sonography for trauma (FAST).

RESULTS

A total of 575 abdominal visceral injuries were identified at CT and/or surgery. Findings of CT at admission (n = 156) and of surgery (n = 1) revealed no evidence of hemoperitoneum in 157 (34%) patients with abdominal visceral injury; 26 (17%) of whom also had negative FAST studies. Abdominal visceral injuries diagnosed in patients without hemoperitoneum included 57 (27%) of 210 splenic injuries, 71 (34%) of 206 hepatic injuries, 30 (48%) of 63 renal injuries, four (11%) of 35 mesenteric injuries, and two (29%) of seven pancreatic injuries. Surgical and/or angiographic intervention was required in 26 (17%) patients without hemoperitoneum.

CONCLUSION

Reliance on the presence of hemoperitoneum as the sole indicator of abdominal visceral injury limits the value of FAST as a screening diagnostic modality for patients who sustain blunt abdominal trauma.

Ultrasound: Impact on Diagnostic Peritoneal Lavage, Abdominal Computed Tomography, and Resident Training

Our objective was to determine the impact of abdominal ultrasound (US) on 1) the use of diagnostic peritoneal lavage (DPL) and abdominal computed tomography (ACT) for diagnosing blunt abdominal trauma (BAT) and on 2) surgical resident training. The study design was a retrospective chart review. Patients sustaining BAT who had ACT or DPL done during the 1-year period before the introduction of US (pre-US) were compared with those from a 1-year period beginning 6 months after US (post-US). Data collected included diagnostic modality, demographic data, mortality, associated injuries, length of stay, mechanism of injury, and number of exploratory laparotomies. Of 128 patients in the pre-US group, 35 patients (27%; P < 0.001) underwent DPL, 0 patients (0%; P < 0.001) received US, and 92 patients (72%) received ACT, with positive results for 31 patients (34%). Exploratory laparotomy was performed on 35 patients (27%) in the pre-US group. Of 140 patients in the post-US group, 8 patients (6%; P < 0.001) underwent DPL, 120 patients (85%; P < 0.001) received US, and 108 patients (77%) received ACT, with positive results for 44 patients (42%). Exploratory laparotomy was performed on 22 patients (15%; P < 0.001) in the post-US group. Resident experience with DPL before and after the introduction of US and availability of US for graduated residents was documented. Chi-square and Fisher's exact test were used for statistical analysis. Resident experience changed from 22 to 3 DPLs per year in the pre- and post-US groups, respectively. Ten per cent of graduating residents had US available for use after leaving this institution. US replaced DPL and resulted in slightly more positive ACT scans in assessing BAT at our institution. Paradoxically, only 10 per cent of graduating residents had US available after leaving this institution. Until the use of US for diagnosing BAT has widespread use in the community, we must question our adequacy of resident preparation for diagnosing BAT.

Focused abdominal sonogram for trauma: the learning curve of nonradiologist clinicians in detecting hemoperitoneum

BACKGROUND

The focused abdominal sonogram for trauma (FAST) has been used by surgeons and emergency physicians (CLIN) to screen reliably for hemoperitoneum after trauma. Despite recommendations for "appropriate training," ranging from 50 to 400 proctored examinations, there are no supporting data.

METHODS

We prospectively examined the initial FAST experience of CLIN in detecting hemoperitoneum by using diagnostic peritoneal lavage, computed tomography, and clinical findings as the diagnostic "gold standard."

RESULTS

241 patients had FAST performed by 12 CLIN (average, 20/CLIN; range, 2-43); 51 patients (21.2%) had hemoperitoneum and 17 patients (7.1%) required laparotomy. Initial experience with FAST by CLIN produced 35 true positives, 180 true negatives, 16 false negatives, and 3 false positives; sensitivity, 68%; specificity, 98%. Initial error rate was 17%, which fell to 5% after 10 examinations (chi2; p < 0.05).

CONCLUSION

Previous recommendations for the number of proctored examinations for individual nonradiologist clinician sonographers to develop competence are excessive.

Evaluation of the patient with blunt abdominal trauma: an evidence based approach

Patients with blunt abdominal trauma present a special challenge to the emergency physician. Physical examination is often unreliable, even if the patient is awake, and the frequent co-existence of head injury exacerbates this problem. This article examines the evidence basis of three diagnostic modalities in evaluating blunt abdominal trauma: DPL (the time-honored test); CT scanning (the current standard of care); and abdominal sonography (the emerging standard--especially for examination conducted in the trauma room). A proposed algorithm for the appropriate use of these modalities is also presented.

Prevalence and structure of ultrasound curricula in emergency medicine residencies

Emergency medicine (EM) residency program directors were surveyed to determine the presence and structure of curricula for teaching ultrasound to EM residents. For those EM programs without an ultrasound curriculum (USC), information was requested on plans to implement one within the next 12 months. Ninety of 116 (78%) EM programs replied to the survey. One-half of EM residencies surveyed have USCs, and another 30% plan to implement one in the near future.

A comparison of sonographic examinations for trauma performed by surgeons and radiologists

BACKGROUND

It has been demonstrated that surgeons and surgery residents, trained in the focused abdominal sonographic examination, are able to accurately and reliably evaluate trauma patients. Despite this, radiologists have objected to surgeon-performed sonography for several reasons. We set out to compare the accuracy of sonographic examinations performed by surgery residents and radiologists.

METHODS

A retrospective review of medical records of all trauma patients who received focused ultrasound examinations from January 1, 1995, through June 30, 1996, at one of two American College of Surgeons-verified Level I trauma centers in the same city was undertaken. Ultrasound examinations were performed by surgery residents at trauma center A (TCA) and by radiologists or radiology residents at trauma center B (TCB). Findings for each patient were compared with the results of computed tomography, diagnostic peritoneal lavage, operative exploration, or observation. Sensitivity, specificity, accuracy, positive predictive value, and negative predictive value were calculated for each group of patients. Comparison of patient charges for the trauma ultrasound examinations at each of the trauma centers was also made.

RESULTS

Patient populations at the two centers were similar except that the mean Injury Severity Score at TCB was higher than at TCA (11.74 vs. 9.6). Sensitivity, specificity, accuracy, or negative predictive value were not significantly different between the two cohorts. A significantly lower positive predictive value for examinations performed by surgery residents was noted and attributed to a lower threshold of the surgery residents to confirm their findings by computed tomography. Billing data revealed that the average charge for trauma sonography by radiologists (TCB) was $406.30. At TCA, trauma sonography did not generate a specific charge; however, a $20.00 sum was added to the trauma activation fee to cover ultrasound machine maintenance and supplies.

CONCLUSION

Focused ultrasound examination in the trauma suite can be as safely and accurately performed by surgery residents as by radiologists and radiology residents and should be a routine part of the initial trauma evaluation process.