Quantitative sensitivity of ultrasound in detecting free intraperitoneal fluid

Image Segmentation and Machine Learning for Detection of Abdominal Free Fluid in Focused Assessment With Sonography for Trauma Examinations: A Pilot Study

The objective of this pilot study was to test the feasibility of automating the detection of abdominal free fluid in focused assessment with sonography for trauma (FAST) examinations. Perihepatic views from 10 FAST examinations with positive results and 10 FAST examinations with negative results were used. The sensitivity and specificity compared to manual classification by trained physicians was evaluated. The sensitivity and specificity (95% confidence interval) were 100% (69.2%-100%) and 90.0% (55.5%-99.8%), respectively. These findings suggest that computerized detection of free fluid on abdominal ultrasound images may be sensitive and specific enough to aid clinicians in their interpretation of a FAST examination.

A Clinical Experience of Ectopic Pregnancies with Initial Free Intraperitoneal Fluid

INTRODUCTION

Extra-uterine pregnancy or Ectopic Pregnancy (EP) is a major health problem for pregnant women, presenting as a potentially life-threatening emergency in the first trimester. There are three major options for the treatment of EP: expectant management, surgical treatment and medical management. The presence of free intraperitoneal fluid in EP-diagnosed patients is crucial for treatment planning and evaluation.

AIM

To compare the outcomes of both the expectant man-agement and medical treatment with methotrexate (MTX) in ectopic pregnancies with free intraperitoneal fluid.

MATERIALS AND METHODS

This retrospective cohort study inclu-ded a total of 91 ectopic pregnancies with or without rupture in which the women had initial free intraperitoneal fluid and were haemodynamically stable. Serial β-HCG measurements were used to assess the outcome of expectant management and medical treatment with MTX. For the statistical analysis, the SPSS statistical software package, version 22.0 (Chicago, IL, USA), was used. For the quantitative variables that were not distributed normally, the Kruskal-Wallis test and the Mann-Whitney U test were performed for the evaluation of differences between the groups.

RESULTS

It was observed that the success rate with expectant management was 81% (initial β HCG concentration 626±443 mIU/mL). With a single dose of MTX, it was 76% (initial β HCG concentration 2124±1647 mIU/mL) and with a total single or double dose of MTX, it was 88% (initial β HCG concentration 2252±78 mIU/mL) from among EP with or without rupture in women with initial free intraperitoneal fluid during diagnosis. There was no significant difference between the groups with regard to ultrasonography findings.

CONCLUSION

Expectant management or medical treatment with methotrexate should be the first line treatment for ectopic pregnancies with initial free intraperitoneal fluid, albeit with rupture, in patients who are haemodynamically stable, along with β-HCG follow-up.

Sonographic evaluation for intra-abdominal hemorrhage after cesarean delivery

PURPOSE

To evaluate whether intra-abdominal hemorrhage is visible on a modified focused assessment with sonography for trauma (FAST) examination in stable obstetrics patients after a nonemergent cesarean delivery.

METHODS

This was a prospective observational study of patients who underwent nonemergent cesarean delivery at a single institution. Patients provided written informed consent to participate in the study preoperatively and underwent a modified FAST examination in the recovery room within 2 hours of completion of surgery. A sonographic examination was considered positive for hemorrhage if an anechoic pocket consistent with free fluid was present.

RESULTS

One hundred patients underwent suprapubic and bilateral upper-quadrant sonographic evaluations. The mean (±SD) time of the evaluation was 74.2 ± 36 minutes after the end of surgery. Among the 100 sonographic examinations of each upper quadrant, 194 (97.0%) were negative, 5 (2.5%) were indeterminate, and 1 (0.5%) was positive for fluid. All suprapubic sonographic examinations were considered inadequate.

CONCLUSIONS

Sonographic evaluation immediately after cesarean delivery is feasible in most patients and was overwhelmingly negative for intra-abdominal hemorrhage in a group of patients who did not require reoperation or unexpected blood transfusion.

Diagnostic imaging of blunt abdominal trauma in pediatric patients

Trauma is a leading cause of morbidity and mortality in childhood, and blunt trauma accounts for 80-90 % of abdominal injuries. The mechanism of trauma is quite similar to that of the adults, but there are important physiologic differences between children and adults in this field, such as the smaller blood vessels and the high vasoconstrictive response, leading to the spreading of a non-operative management. The early imaging of children undergoing a low-energy trauma can be performed by CEUS, a valuable diagnostic tool to demonstrate solid organ injuries with almost the same sensitivity of CT scans; nevertheless, as for as urinary tract injuries, MDCT remains still the technique of choice, because of its high sensitivity and accuracy, helping to discriminate between an intra-peritoneal form a retroperitoneal urinary leakage, requiring two different managements. The liver is the most common organ injured in blunt abdominal trauma followed by the spleen. Renal, pancreatic, and bowel injuries are quite rare. In this review we present various imaging findings of blunt abdominal trauma in children.

Pocket ultrasound device as a complement to physical examination for ascites evaluation and guided paracentesis

The pocket ultrasound device (PUD) is a new tool that may be of use in the early detection of ascites. Abdominal ultrasound-guided paracentesis has been reported to decrease the rate of complications due to the procedure, but must be performed in a healthcare setting; this new tool may be a useful on an ambulatory basis. The aim of this study was to determine the diagnostic usefulness of the PUD in the diagnosis of ascites and the safety of guided paracentesis. We conducted a retrospective study that included adult patients suspected of having ascites and in whom an evaluation was performed with the PUD to identify it. Concordance with abdominal ultrasound (AUS) was determined with the Kappa coefficient. Sensitivity (Se), specificity (Sp) and likelihood ratios (LR) were determined and compared with physical examination, AUS, computed tomography and procurement of fluid by paracentesis. Complications resulting from the guided paracentesis were analyzed. 89 participants were included and 40 underwent a paracentesis. The PUD for ascites detection had 95.8 % Se, 81.8 % Sp, 5.27 +LR and 0.05 -LR. It had a concordance with AUS of 0.781 (p < 0.001). Technical problems during the guided paracentesis were present in only two participants (5 %) and three patients (7.5 %) developed minor complications that required no further intervention. There were no severe complications or deaths. This study suggests that the PUD is a reliable tool for ascites detection as a complement to physical examination and appears to be a safe method to perform guided paracentesis.

Contrast-enhanced ultrasound (CEUS) in blunt abdominal trauma

Baseline ultrasound is essential in the early assessment of patients with a huge haemoperitoneum undergoing an immediate abdominal surgery; nevertheless, even with a highly experienced operator, it is not sufficient to exclude parenchymal injuries. More recently, a new ultrasound technique using second generation contrast agents, named contrast-enhanced ultrasound (CEUS) has been developed. This technique allows all the vascular phase to be performed in real time, increasing ultrasound capability to detect parenchymal injuries, enhancing some qualitative findings, such as lesion extension, margins and its relationship with capsule and vessels. CEUS has been demonstrated to be almost as sensitive as contrast-enhanced CT in the detection of traumatic injuries in patients with low-energy isolated abdominal trauma, with levels of sensitivity and specificity up to 95%. Several studies demonstrated its ability to detect lesions occurring in the liver, spleen, pancreas and kidneys and also to recognize active bleeding as hyperechoic bands appearing as round or oval spots of variable size. Its role seems to be really relevant in paediatric patients, thus avoiding a routine exposure to ionizing radiation. Nevertheless, CEUS is strongly operator dependent, and it has some limitations, such as the cost of contrast media, lack of panoramicity, the difficulty to explore some deep regions and the poor ability to detect injuries to the urinary tract. On the other hand, it is timesaving, and it has several advantages, such as its portability, the safety of contrast agent, the lack to ionizing radiation exposure and therefore its repeatability, which allows follow-up of those traumas managed conservatively, especially in cases of fertile females and paediatric patients.

Focused abdominal sonography for trauma in the clinical evaluation of children with blunt abdominal trauma

Introduction

In pediatric care, the role of focused abdominal sonography in trauma (FAST) remains ill defined. The objective of this study was to assess the sensitivity and specificity of FAST for detecting free peritoneal fluid in children.

Methods

The trauma registry of a single level I pediatric trauma center was queried for the results of FAST examination of consecutive pediatric (<18 years) blunt trauma patients over a period of 36 months, from January 2010 to December 2012. Demographics, type of injuries, FAST results, computerized tomography (CT) results, and operative findings were reviewed.

Results

During the study period, 543 injured pediatric patients (mean age 8.2 ± 5 years) underwent FAST examinations. In 95 (17.5 %) FAST was positive for free peritoneal fluid. CT examination was performed in 219 (40.3 %) children. Positive FAST examination was confirmed by CT scan in 61/73 (83.6 %). CT detected intra-peritoneal fluid in 62/448 (13.8 %) of the patients with negative FAST results. These findings correspond to a sensitivity of 50 %, specificity of 88 %, positive predictive value (PPV) of 84 %, and a negative predictive value (NPV) of 58 %. In patients who had negative FAST results and no CT examination (302), no missed abdominal injury was detected on clinical ground. FAST examination in the young age group (<2 years) yielded lower sensitivity and specificity (36 and 78 % respectively) with a PPV of only 50 %.

Conclusions

This study shows that although a positive FAST evaluation does not necessarily correlate with an IAI, a negative one strongly suggests the absence of an IAI, with a high NPV. These findings are emphasized in the analysis of the subgroup of children less than 2 years of age. FAST examination tempered with sound clinical judgment seems to be an effective tool to discriminate injured children in need of further imaging evaluation.

Do we really rely on fast for decision-making in the management of blunt abdominal trauma?

INTRODUCTION

The Focused Assessment with Sonography in Trauma examination (FAST) is currently taught and recommended in the ATLS(®), often as an addendum to the primary survey for patients with blunt abdominal trauma. Although it is non-invasive and rapidly performed at bedside, the utility of FAST in blunt abdominal trauma has been questioned. We designed this study to examine our hypothesis that FAST is not an efficacious screening tool for identifying intra-abdominal injuries.

METHODS

We performed a retrospective chart review of all patients with confirmatory diagnosis of blunt abdominal injuries with CT and/or laparotomy for a period of 1.5 years (from 7/2009 to 11/2010). FAST was performed by ED residents and considered positive when free intra-abdominal fluid was visualized. Abdominal CT, or exploratory laparotomy findings were used as confirmation of intra-abdominal injury.

RESULTS

A total of 1671 blunt trauma patients were admitted to and evaluated in the Emergency Department during a 1½ year period and 146 patients were confirmed intra-abdominal injuries by CT and/or laparotomy. Intraoperative findings include injuries to the liver, spleen, kidneys, and bowels. In 114 hemodynamically stable patients, FAST was positive in 25 patients, with a sensitivity of 22%. In 32 hemodynamically unstable patients, FAST was positive in 9 patients, with a sensitivity of 28%. A free peritoneal fluid and splenic injury are associated with a positive FAST on univariate analysis, and are the independent predictors for a positive FAST on multiple logistic regression.

CONCLUSION

FAST has a very low sensitivity in detecting blunt intraabdominal injury. In hemodynamically stable patients, a negative FAST without a CT may result in missed intra-abdominal injuries. In hemodynamically unstable blunt trauma patients, with clear physical findings on examination, the decision for exploratory laparotomy should not be distracted by a negative FAST.

[Examination concepts and procedures in emergency ultrasonography]

As a point-of-care tool, emergency sonography has the potential to rule out or to confirm a diagnosis in the context to the leading symptom of critically ill persons. Extended focused assessment with sonography for trauma (E-FAST) and focused echo entry level (FEEL) are examples of algorithms that have been developed for this purpose. Echoscopy is another form of point-of-care sonography that is used at the bedside. It helps to answer simple questions (yes/no) and allows follow-up examinations to be made with little effort. Point-of-care sonography does not compete with normal standardized sonography because it is not able to answer medical questions in a sophisticated manner.

From FAST to E-FAST: an overview of the evolution of ultrasound-based traumatic injury assessment

Ultrasound is a ubiquitous and versatile diagnostic tool. In the setting of acute injury, ultrasound enhances the basic trauma evaluation, influences bedside decision-making, and helps determine whether or not an unstable patient requires emergent procedural intervention. Consequently, continued education of surgeons and other acute care practitioners in performing focused emergency ultrasound is of great importance. This article provides a synopsis of focused assessment with sonography for trauma (FAST) and the extended FAST (E-FAST) that incorporates basic thoracic injury assessment. The authors also review key pitfalls, limitations, controversies, and advances related to FAST, E-FAST, and ultrasound education.

Diagnostic accuracy of secondary ultrasound exam in blunt abdominal trauma

Background:

In stable patients with blunt abdominal trauma, accurate diagnosis of visceral injuries is crucial.

Objectives:

To determine whether repeating ultrasound exam will increase the sensitivity of focused abdominal sonography for trauma (FAST) through revealing additional free intraperitoneal fluid in patients with blunt abdominal trauma.

Patients and Methods:

We performed a prospective observational study by performing primary and secondary ultrasound exams in blunt abdominal trauma patients. All ultrasound exams were performed by four radiology residents who had the experience of more than 400 FAST exams. Five routine intraperitoneal spaces as well as the interloop space were examined by ultrasound in order to find free fluid. All patients who expired or were transferred to the operating room before the second exam were excluded from the study. All positive ultrasound results were compared with intra-operative and computed tomography (CT) findings and/or the clinical status of the patients.

Results:

Primary ultrasound was performed in 372 patients; 61 of them did not undergo secondary ultrasound exam; thus, were excluded from the study.Three hundred eleven patients underwent both primary and secondary ultrasound exams. One hundred and two of all patients were evaluated by contrast enhanced CT scan and 31 underwent laparotomy. The sensitivity of ultrasound exam in detecting intraperitoneal fluid significantly increased from 70.7% for the primary exam to 92.7% for the secondary exam. Examining the interloop space significantly improved the sensitivity of ultrasonography in both primary (from 36.6% to 70.7%) and secondary (from 65.9% to 92.7%) exams.

Conclusions:

Performing a secondary ultrasound exam in stable blunt abdominal trauma patients and adding interloop space scan to the routine FAST exam significantly increases the sensitivity of ultrasound in detecting intraperitoneal free fluid.

Bedside US imaging in multiple trauma patients. Part 1: US findings and techniques

OBJECTIVES

The aim of this review article is to present the current views and visions of the role of ultrasound (US) in the management of patients with multiple trauma. The article is divided into two parts. Part 1 (US findings and techniques) will mainly deal with the technical aspects of US imaging in trauma patients and is written also for educational purposes. Part 2 (pathophysiology and US imaging in trauma patients) will deal with integration of US in the clinical and pathophysiological management of multiple trauma patients.

METHODS

A non-systematic review of the literature through PubMed search (restricted to the last 10 years) of original articles and review articles.

RESULTS

80 publications were selected for Part 1. Of these 80 articles, the author selected 50 according to personal criteria on the basis of their innovative or original contents (48 original articles and 2 literature review articles); 19 articles were furthermore extracted from the references of the selected publications. The information extracted from these 69 publications was organized into sections dealing with different fields of applications of US imaging in multiple trauma patients.

CONCLUSIONS

US imaging in trauma has evolved from the initial use, i.e., early diagnosis of peritoneal effusion (focused abdominal sonography for trauma), to a wider use known as resuscitative ultrasonography, and is today considered as an extension of physical examination to implement a more effective approach to clinical problems and increase the timeliness and safety of interventions.

[Management of penetrating abdominal trauma: what we need to know?]

Penetrating traumas are rare in France and mainly due to stabbing. Knives are less lethal than firearms. The initial clinical assessment is the cornerstone of hospital care. It remains a priority and can quickly lead to a surgical treatment first. Urgent surgical indications are hemorrhagic shock, evisceration and peritonitis. Dying patients should be immediately taken to the operating room for rescue laparotomy or thoracotomy. Ultrasonography and chest radiography are performed before damage control surgery for hemodynamic unstable critical patients. Stable patients are scanned by CT and in some cases may benefit from non-operative strategy. Mortality remains high, initially due to bleeding complications and secondarily to infectious complications. Early and appropriate surgery can reduce morbidity and mortality. Non-operative strategy is only possible in selected patients in trained trauma centers and with intensive supervision by experienced staff.

Accuracy of Focused Assessment with Sonography for Trauma (FAST) in Blunt Trauma Abdomen-A Prospective Study

Focused assessment with sonography for trauma (FAST) is a limited ultrasound examination, primarily aimed at the identification of the presence of free intraperitoneal or pericardial fluid. In the context of blunt trauma abdomen (BTA), free fluid is usually due to hemorrhage, bowel contents, or both; contributes towards the timely diagnosis of potentially life-threatening hemorrhage; and is a decision-making tool to help determine the need for further evaluation or operative intervention. Fifty patients with blunt trauma abdomen were evaluated prospectively with FAST. The findings of FAST were compared with contrast-enhanced computed tomography (CECT), laparotomy, and autopsy. Any free fluid in the abdomen was presumed to be hemoperitoneum. Sonographic findings of intra-abdominal free fluid were confirmed by CECT, laparotomy, or autopsy wherever indicated. In comparing with CECT scan, FAST had a sensitivity, specificity, and accuracy of 77.27, 100, and 79.16 %, respectively, in the detection of free fluid. When compared with surgical findings, it had a sensitivity, specificity, and accuracy of 94.44, 50, and 90 %, respectively. The sensitivity of FAST was 75 % in determining free fluid in patients who died when compared with autopsy findings. Overall sensitivity, specificity, and accuracy of FAST were 80.43, 75 and 80 %, respectively, for the detection of free fluid in the abdomen. From this study, we can safely conclude that FAST is a rapid, reliable, and feasible investigation in patients with BTA, and it can be performed easily, safely, and quickly in the emergency room with a reasonable sensitivity, specificity, and accuracy. It helps in the initial triage of patients for assessing the need for urgent surgery.

Bedside ultrasonography in the pediatric emergency department: the focused assessment with sonography in trauma examination uncovers an occult intra-abdominal tumor

We present a case of a 3-year-old male with history of minor trauma, who was brought in by ambulance from the playground where he had an acute mental status change and was noted to be hypotensive on initial evaluation. History and examination did not indicate a clear etiology of his symptoms. Point-of-care emergency ultrasonography revealed free fluid in the abdomen and expedited the care of the child's unexpected intra-abdominal hemorrhage from an occult abdominal tumor. This case demonstrates the ability of practitioners to expedite and focus care with the use of rapid assessment with ultrasonography in the pediatric emergency department.

Does the size of the hemoperitoneum help to discriminate the bleeding source and guide therapeutic decisions in blunt trauma patients with pelvic ring fracture?

BACKGROUND

In blunt trauma patients with a hemoperitoneum and a pelvic injury, multiple sources of active bleeding may exist. The purpose of this study was to determine whether the size of the hemoperitoneum helps to establish the bleeding source and guide therapeutic decisions in patients with pelvic fractures.

METHODS

The charts of patients with pelvic fractures admitted to a trauma intensive care unit from January 2005 to December 2009 were reviewed retrospectively. The hemoperitoneum size was defined by semiquantitative analysis (minimal/none, moderate, and large) using the Federle score on computed tomographic scan or during laparotomy. Active peritoneal hemorrhages requiring immediate laparotomy were compared according to hemoperitoneum size.

RESULTS

Of 185 patients, hemoperitoneum did not occur in 116 patients, moderate in 43, and large in 26. Among 102 patients (55%) who were hypotensive (systolic blood pressure <90 mm Hg) on admission, 27 needed therapeutic laparotomy and 15 needed pelvic embolization. Laparotomy (39% vs. 2%) and pelvic embolization (22% vs. 4%) were required significantly more often in patients with hemoperitoneum (moderate or large) than those without hemoperitoneum. The positive predictive value for an active peritoneal hemorrhage derived from qualitative analysis of the hemoperitoneum (moderate or large) was 39% (4% in hypotensive patients and 40% in those requiring pelvic embolization). The corresponding values for large hemoperitoneum only (semiquantitative analysis) were 62%, 70%, and 67%, respectively.

CONCLUSION

In patients with pelvic fractures, hemoperitoneum does not mean peritoneal injury requiring hemostatic procedure. Semiquantitative analysis of the hemoperitoneum improves predictability of peritoneal hemorrhage than qualitative analysis of hemoperitoneum. However, there remains numerous false-positives even in presence of large hemoperitoneum associated with hypotension.

Ultrasonographic diagnosis of abdominal free fluid: accuracy comparison of emergency physicians and radiologists

OBJECTIVE

Blunt abdominal trauma is a diagnostic challenge for emergency physicians and ultrasonography is one of the diagnostic tools used in this type of injuries. The aim of this study was to evaluate the diagnostic value of ultrasonographies performed by emergency physicians and radiologists.

METHODS

This prospective diagnostic study was performed in the emergency departments of two trauma centers in Iran during a period of 12 months. The subjects were all patients with blunt abdominal trauma that were candidated for abdominopelvic computed tomography (CT) scanning in our emergency departments. The results of focused assessment with sonography for trauma (FAST) performed by emergency physicians and radiologists were compared blindly with the results of CT scans performed by radiologists. The sensitivity, specificity, and predictive values of diagnosis for different abdominal anatomic areas were calculated.

RESULTS

In total, 450 patients undergoing FAST and CT scanning were studied. The sensitivity of radiologists' diagnoses for Morison's, splenorenal, perivesical, and pleural effusion areas were, respectively, 88.0, 70.0, 38.0, and 30.0 %. The corresponding values for emergency physicians' diagnoses were, respectively, 82.0, 60.0, 28.0, and 30.0 %. The specificity of radiologists' diagnoses in the mentioned areas were, respectively, 98.9, 100, 93.1, and 100 %, and for emergency physicians, they were, respectively, 98.9, 100, 96.0, and 100 %.

CONCLUSION

Emergency physicians showed a promising performance in applying FAST in blunt abdominal trauma. The specificity of ultrasonographic diagnosis in the emergency physicians group and the radiologists group were comparable, while radiologists showed a higher performance regarding the sensitivity of the ultrasonographic diagnosis.

False-negative FAST examination: associations with injury characteristics and patient outcomes

STUDY OBJECTIVE

Focused assessment with sonography in trauma (FAST) is widely used for evaluating patients with blunt abdominal trauma; however, it sometimes produces false-negative results. Presenting characteristics in the emergency department may help identify patients at risk for false-negative FAST result or help the physician predict injuries in patients with a negative FAST result who are unstable or deteriorate during observation. Alternatively, false-negative FAST may have no clinical significance. The objectives of this study are to estimate associations between false-negative FAST results and patient characteristics, specific abdominal organ injuries, and patient outcomes.

METHODS

This was a retrospective cohort study including consecutive patients who presented to an urban Level I trauma center between July 2005 and December 2008 with blunt abdominal trauma, a documented FAST, and pathologic free fluid as determined by computed tomography, diagnostic peritoneal lavage, laparotomy, or autopsy. Physicians blinded to the study purpose used standardized abstraction methods to confirm FAST results and the presence of pathologic free fluid. Multivariable modeling was used to assess associations between potential predictors of a false-negative FAST result and false-negative FAST result and adverse outcomes.

RESULTS

During the study period, 332 patients met inclusion criteria. Median age was 32 years (interquartile range 23 to 45 years), 67% were male patients, the median Injury Severity Score was 27 (interquartile range 17 to 41), and 162 (49%) had a false-negative FAST result. Head injury was positively associated with false-negative FAST result (odds ratio [OR] 4.9; 95% confidence interval [CI] 1.5 to 15.7), whereas severe abdominal injury was negatively associated (OR 0.3; 95% CI 0.1 to 0.5). Injuries to the spleen (OR 0.4; 95% CI 0.24 to 0.66), liver (OR 0.36; 95% CI 0.21 to 0.61), and abdominal vasculature (OR 0.17; 95% CI 0.07 to 0.38) were also negatively associated with false-negative FAST result. False-negative FAST result was not associated with mortality (OR 0.89; 95% CI 0.42 to 1.9), prolonged ICU length of stay (relative risk 0.88; 95% CI 0.69 to 1.12), or total hospital length of stay (relative risk 0.92; 95% CI 0.76 to 1.12). However, patients with false-negative FAST results were substantially less likely to require therapeutic laparotomy (OR 0.31; 95% CI 0.19 to 0.52).

CONCLUSION

Patients with severe head injuries and minor abdominal injuries were more likely to have a false-negative than true-positive FAST result. On the other hand, patients with spleen, liver, or abdominal vascular injuries are less likely to have false-negative FAST examination results. Adverse outcomes were not associated with false-negative FAST examination results, and in fact patients with false-negative FAST result were less likely to have a therapeutic laparotomy. Further studies are needed to assess the strength of these findings.

Controversies in the management of splenic trauma

BACKGROUND

The technologic innovations of the last three decades, coupled with a deeper understanding of the immunologic role of the spleen, have significantly shifted the management of splenic injuries towards non-operative approaches. However, there continuous to be a wide range of practice patterns related to the non-operative management of splenic injuries, from which the authors infer a gap between the best available evidence and its translation into practice. We sought to explore ongoing areas of controversy in the non-operative management of splenic trauma with the aim of further elucidating why these controversies continue to exist.

METHODS

We explored areas of ongoing controversy in the management of splenic injury though a series of iterative surveys. We invited 70 experts in trauma care from ten countries around the world to participate. Areas of controversy explored included: indications and frequency for in-hospital and follow-up imaging, definitions of failure of non-operative management, indications for angioembolisation and non-operative management in special populations (i.e. elderly, concomitant traumatic brain injury, penetrating trauma).

RESULTS

A 49% response rate was obtained. Even though a wide range of practice patterns were identified, no controversies were identified in areas that do not involve the adoption of new technologies. In areas where practice pattern variation was observed, the strong influence of the local environment was constantly identified as an impediment to changes in practice.

CONCLUSIONS

We have identified that barriers present within local practice environments are the major driving forces behind controversies in the non-operative management of splenic injuries.

Ultrasonographic evaluation of the free intraperitoneal fluid in asymptomatic children

BACKGROUND

Free intraperitoneal fluid can be an important sign in an abdominal inflammatory process or abdominal trauma. It is often present in children with abdominal pain, but it is a nonspecific finding. A minimal amount of free intraperitoneal fluid is considered normal.

OBJECTIVE

The purpose of this study was to evaluate the incidence, location and volume of free fluid in the abdomen and pelvis in a population of asymptomatic children.

MATERIALS AND METHODS

In this prospective study, we performed clinically indicated abdominal and pelvic sonography, using high-resolution transducers, in 200 asymptomatic children: 104 (52%) girls, 96 (48%) boys; ages 6 days-15 years (mean 3 years 8 months). US studies were performed and prospectively evaluated by two experienced pediatric radiologists. Patients with any condition that could result in the accumulation of free intraperitoneal fluid as well as postpubertal girls were excluded from the study.

RESULTS

Free intraperitoneal fluid was seen in 12 children (6%), only in the pelvis. Fluid volume never exceeded 1 ml.

CONCLUSION

Our study suggests that 1 ml or less of free intraperitoneal fluid detected in the pelvis is probably insignificant.

Accuracy of conventional imaging of penetrating torso injuries in the trauma resuscitation room

OBJECTIVES

Chest X-ray (CXR), abdominal ultrasound, cardiac ultrasound, and abdominal X-ray are the most frequently used imaging modalities to radiologically evaluate patients with penetrating torso trauma. The aim of this study was to evaluate the accuracy of these imaging modalities.

METHODS

From January 2001 until January 2005, all consecutive patients with penetrating torso injuries presenting at the emergency department of a level 1 trauma center were included. Imaging modalities (chest/abdominal X-ray, abdominal/cardiac ultrasound), were compared retrospectively with a 'gold standard' (i.e. computed tomography or surgery within 2 h after arrival) or outcome of conservative treatment. The accuracy of the imaging modalities was calculated.

RESULTS

Three hundred and eighteen patients were included. On the basis of 299 CXRs, the sensitivity for diagnosing pneumothorax, hemothorax, and subcutaneous emphysema was 71, 63, and 61%, respectively. The sensitivity of abdominal ultrasound (N = 229) to detect free abdominal fluid and/or intra-abdominal injury was 65%. The specificity, positive predictive value, negative predictive value, and accuracy of the two imaging modalities to detect any of the diagnoses mentioned were >or=87%. Cardiac ultrasound (N = 31) did not show any false positive or negative results for detecting cardiac effusion. Pneumoperitoneum was not seen on abdominal X-ray in eight of 11 patients with perforation of a hollow organ.

CONCLUSION

Despite high specificity, positive predictive value, and negative predictive value, a considerable number of lesions remain undetected after CXR and abdominal ultrasound because of moderate-to-inadequate sensitivity. Abdominal X-ray hardly provides additional information. Careful clinical monitoring of patients is mandatory, particularly when computed tomography scan or operative treatment is not indicated.

Endoscopic ultrasound-guided paracentesis of ascitic fluid: a morphologic study with ultrasonographic correlation

BACKGROUND

Endoscopic ultrasound (EUS)-guided fine needle aspiration (FNA) has been widely used for the diagnosis of primary and metastatic gastrointestinal (GI) and non-GI malignancies. Few studies have been published to evaluate the accuracy and the cytologic features of EUS-guided paracentesis in the diagnosis and staging of malignant neoplasms.

METHODS

All EUS-guided paracenteses of ascitic fluid performed at the University of California Irvine Medical Center (UCIMC) from January 2003 to February 2006 were retrospectively retrieved. Corresponding EUS findings, cytology and histology slides, and follow-up information were reviewed.

RESULTS

One hundred one (101) cases were found. Two smears were submitted in 11 cases because of the scanty amount of fluid aspirated. In the remaining cases, 5 mL or less of fluid were aspirated in 56 patients, and, of 9 who had prior computed tomography (CT), ascitic fluid was not seen in 6. The cytologic diagnoses were as follows: 17 were positive for adenocarcinoma, 1 positive for metastatic small-cell carcinoma of the lung, 1 positive for diffuse large-cell lymphoma, 3 suspicious for adenocarcinoma, 1 suspicious for plasmacytoma, 4 atypical epithelial cells, and 74 negative. Cell block was available in 80 cases and immunohistochemical stains were performed in 71 cases to confirm the diagnosis. Six patients had peritoneal biopsy. The sensitivity, specificity, positive and negative predictive values, and diagnostic accuracy were 80%, 100%, 100%, 95%, and 96%, respectively.

CONCLUSIONS

EUS-guided paracentesis is a valuable aid in the cytologic diagnosis of malignant ascites. It is particularly useful when no abnormality is identified by CT.

Adrenal injury following blunt abdominal trauma

BACKGROUND

Adrenal injury secondary to abdominal trauma is quite rare because the adrenal gland is located deep in the retroperitoneum and is well cushioned by surrounding soft tissues. This report presents our experiences of managing patients with adrenal injury following abdominal blunt trauma.

METHODS

The medical records of 11 patients who had been treated for adrenal gland injury between January 1998 and June 2009 were retrospectively reviewed.

RESULTS

Of the 11 patients, nine were male and two were female and the mean age was 31.5 years. The causes of trauma were motor vehicle accident (8 cases) and fall (3 cases). The majority of injuries occurred on the right side (8 cases), two were on the left side, and one patient had bilateral injury. Three cases presented as isolated adrenal gland injuries, and eight were combined with other internal organ injuries. The most common coinjured organ was the liver, followed by the kidney. The most useful diagnostic modality was computed tomography (CT). Ten cases were treated successfully using conservative management, while one required a left partial adrenalectomy and splenectomy due to active bleeding.

CONCLUSIONS

Adrenal injury due to blunt abdominal trauma is extremely rare. The majority of cases can be diagnosed using CT. Most cases involve the right side and can be treated successfully using conservative management. Surgery is required only in cases of active bleeding.

Accuracy of peritoneal fluid measurements by transvaginal ultrasonography

OBJECTIVE

To assess the accuracy of the assessment of peritoneal fluid volumes of up to 1 L by transvaginal ultrasonography and to re-evaluate the formula used to calculate total volume from the dimensions of the largest pocket.

METHODS

Patients (n = 13) enrolled for a minor laparoscopic procedure were prospectively recruited. At the end of the procedure, with the patient in the 30 degrees anti-Trendelenburg position, Ringer's lactate was instilled into the abdomen in discrete steps up to 1 L. Following equilibration the diameters of the single pocket of fluid were measured by transvaginal ultrasonography in order to calculate the volume, and regression models were used to determine the relationship between this and the instilled volume. The body mass index (BMI) of the patient was evaluated as a parameter for predicting the instilled volume more accurately.

RESULTS

The intra-abdominal fluid volume could be calculated from the measured volume using a quadratic regression equation with an overall coefficient of variation of 19%. In individual patients, changes in volume could be assessed with a coefficient of variation of 7.3%. BMI was not found to be a significant parameter in relating the measured to the instilled volume.

CONCLUSION

Transvaginal ultrasound in a standardized setting can accurately estimate the volume of peritoneal fluid, with the accuracy consistent for small and large volumes. Changes in peritoneal fluid volume over time in the same individual can be measured more accurately than the total volume present.

An Evidence-Based Approach for Integrating Bedside Ultrasound Into Routine Practice in the Assessment of Undifferentiated Shock

Undifferentiated hypotension remains a central diagnostic and therapeutic challenge in emergency and critical care medicine. Increasingly, bedside ultrasound conducted by intensivists and emergency medicine providers is assuming a central role in diagnosis and resuscitation of hypotension. This review discusses sample algorithms for the bedside ultrasonographic assessment of undifferentiated shock and outlines an evidence-based framework for the intensivist seeking to incorporate bedside ultrasound into daily clinical practice. The literature regarding specific applications including cardiac, thoracic, pulmonary, and vascular assessment is briefly reviewed, as is the evidence pertaining to effective implementation, training, credentialing, and ongoing quality assurance.

The RUSH exam: Rapid Ultrasound in SHock in the evaluation of the critically lll

The RUSH exam (Rapid Ultrasound in SHock examination), presented in this article, represents a comprehensive algorithm for the integration of bedside ultrasound into the care of the patient in shock. By focusing on a stepwise evaluation of the shock patient defined here as "Pump, Tank, and Pipes," clinicians will gain crucial anatomic and physiologic data to better care for these patients.

Ultrasound in trauma

Point-of-care ultrasound is well suited for use in the emergency setting for assessment of the trauma patient. Currently, portable ultrasound machines with high-resolution imaging capability allow trauma patients to be imaged in the pre-hospital setting, emergency departments and operating theatres. In major trauma, ultrasound is used to diagnose life-threatening conditions and to prioritise and guide appropriate interventions. Assessment of the basic haemodynamic state is a very important part of ultrasound use in trauma, but is discussed in more detail elsewhere. Focussed assessment with sonography for Trauma (FAST) rapidly assesses for haemoperitoneum and haemopericardium, and the Extended FAST examination (EFAST) explores for haemothorax, pneumothorax and intravascular filling status. In regional trauma, ultrasound can be used to detect fractures, many vascular injuries, musculoskeletal injuries, testicular injuries and can assess foetal viability in pregnant trauma patients. Ultrasound can also be used at the bedside to guide procedures in trauma, including nerve blocks and vascular access. Importantly, these examinations are being performed by the treating physician in real time, allowing for immediate changes to management of the patient. Controversy remains in determining the best training to ensure competence in this user-dependent imaging modality.

Ultrasound performed by radiologists-confirming the truth about FAST in trauma

BACKGROUND

For hemodynamically stable patients with suspected abdominal injuries, the diagnostic accuracy of computed tomographic scans remains unmatched. Focused assessment with sonography for trauma (FAST) is useful in trauma evaluation to identify intraabdominal fluid early in the unstable patient. In skilled hands, sensitivity is shown to be close to 100%. However, some recent studies have questioned its sensitivity in subgroups at risk of bleeding. In most studies, hemodynamic markers of instability have been limited to hypotension. The purpose of this study was to determine the sensitivity and specificity of initial FAST for detection of hemoperitoneum in the potentially unstable patient as judged by objective hemodynamic parameters available early during resuscitation.

METHODS

Prospective observational study at a major European trauma center. FAST was performed in trauma patients by the trauma team radiologist. The study population consisted of the subgroup deemed potentially unstable on arrival as defined by systolic blood pressure < or =90 mm Hg, pulse rate > or =120, or base deficit > or =8. Results were compared with one of the following reference standards: computed tomographic scan, diagnostic peritoneal lavage, exploratory laparotomy, or observation.

RESULTS

One hundred and four patients constituted the study group. There were 75 true-negative, 10 false-negative, 16 true-positive, and 3 false-positive FAST results. Sensitivity and specificity were 62% and 96%, positive and negative predictive values 84% and 89%, respectively, and overall accuracy was 88%.

CONCLUSION

A negative initial FAST in hemodynamically unstable patients, even in the hands of radiologists, cannot reliably exclude intraabdominal bleeding. These patients should undergo additional diagnostic tests to exclude intraperitoneal hemorrhage.

Focused abdominal sonography for trauma in the emergency department for blunt abdominal trauma

BACKGROUND

Blunt abdominal trauma (BAT) is a diagnostic challenge to the emergency physician (EP). The introduction of bedside ultrasound provides another diagnostic tool for the EP to detect intra-abdominal injuries.

AIMS

To evaluate the performance of EP in a local emergency department in Hong Kong to perform the 'focused abdominal sonography for trauma' (FAST) in BAT patients.

METHODS

This was a retrospective cohort study including all the trauma team cases in a 36-month period in the emergency department of a public hospital in Hong Kong. The results of FAST scans were analyzed and compared with CT scans when the FAST was positive or followed by a period of clinical observation when the FAST was negative. Descriptive statistics and sensitivity, specificity, and predictive values were calculated.

RESULTS

There was a total of 273 cases, and FAST scans were performed in 242 cases. The sensitivity and specificity were 86% and 99%, respectively. The negative predictive value was 0.98, while the positive predictive value was 0.94. The overall accuracy was 97%.

CONCLUSIONS

The performance of the EP in using FAST scans in BAT patients was encouraging. The high specificity (99%), positive predictive value (0.98), and likelihood ratio for positive tests (86) make it a good 'rule in' tool for BAT patients. The high negative predictive value also makes the FAST scan a useful screening tool. However, ultrasound examination is operator dependent, and FAST scan has its own limitations. For negative FAST scan cases, we recommend a period of monitoring, serial FAST scans, or further investigations, such as CT scan or peritoneal lavage.

Hepatic Trauma

Hepatic injuries are one of the most common abdominal injuries following either blunt or penetrating trauma. CT scanning has revolutionized the treatment algorithm for these patients. The majority of patients are successfully treated with nonoperative management, but surgeons should have a clear understanding of the indications for operative intervention. An array of techniques including operative, interventional, and endoscopic, are often required for management of advanced grade hepatic injuries.

Multidisciplinary approach for patients with pelvic fractures and hemodynamic instability

The hemodynamically unstable patient with a pelvic fracture presents a diagnostic and therapeutic challenge. The care of these patients requires a unique multidisciplinary approach with input and expertise from many different specialists. An understanding of pelvic anatomy and fracture patterns can help guide the diagnostic evaluation and treatment plan. The initial management of these patients must focus on rapid airway and hemorrhage control while preparing for ongoing blood loss. Rapid temporary fracture stabilization with simple bedside modalities is crucial in limiting additional blood loss. An exhaustive search must also be performed to evaluate for concomitant injuries that commonly accompany major pelvic fractures and the treatment of these other injuries must be appropriately prioritized. For patients who are unresponsive to standard resuscitation and bedside attempts at limiting hemorrhage, angiographic embolization is often utilized as the next step to attain hemodynamic stability. The key to successful management of these patients lies in the careful coordination of different specialists and the expertise that each brings to the clinical care of the patient.

Current Role of Emergency US in Patients with Major Trauma

In patients with major trauma, focused abdominal ultrasonography (US) often is the initial imaging examination. US is readily available, requires minimal preparation time, and may be performed with mobile equipment that allows greater flexibility in patient positioning than is possible with other modalities. It also is effective in depicting abnormally large intraperitoneal collections of free fluid, which are indirect evidence of a solid organ injury that requires immediate surgery. However, because US has poor sensitivity for the detection of most solid organ injuries, an initial survey with US often is followed by a more thorough examination with multidetector computed tomography (CT). The initial US examination is generally performed with a FAST (focused assessment with sonography in trauma) protocol. Speed is important because if intraabdominal bleeding is present, the probability of death increases by about 1% for every 3 minutes that elapses before intervention. Typical sites of fluid accumulation in the presence of a solid organ injury are the Morison pouch (liver laceration), the pouch of Douglas (intraperitoneal rupture of the urinary bladder), and the splenorenal fossa (splenic and renal injuries). FAST may be used also to exclude injuries to the heart and pericardium but not those to the bowel, mesentery, and urinary bladder, a purpose for which multidetector CT is better suited. If there is time after the initial FAST survey, the US examination may be extended to extra-abdominal regions to rule out pneumothorax or to guide endotracheal intubation, vascular puncture, or other interventional procedures.

[The significance of delayed diagnosis of lesions in multiply traumatised patients. A study of 1,187 shock room patients]

BACKGROUND

Multislice computed tomography (CT) technology has improved the diagnosis of relevant lesions within the phase of primary treatment of severely injured patients. The lack of time in this phase and the complexity of the multiple injuries there is still a risk that lesions will be missed at this stage. The purpose of this study was to evaluate the incidence, causes, implications and significance when injuries are not diagnosed until later.

METHODS

The data were documented prospectively in the context of a quality management system for the care of severely injured patients in a primary urban trauma centre. Missed injuries were defined as any lesions that had not been recognised by the time the patient was admitted to the ICU.

RESULTS

During a 44-month period 1,187 (ISS 21+/-17) patients were enrolled in the study, all of whom were admitted from May 1998 to April 2002 after attending the emergency room. In total 64 (4.9%) missed injuries were detected in 58 (ISS 30+/-16) patients; 26 of the 64 missed injuries were located on the torso, 8 injuries in the head and neck region, and 30 on the arms and legs. The missed injuries were categorised as follows: 1. Lesion not seen in diagnostics (n=15). 2. Incomplete diagnostics (n=8). 3. Primarily unsuspicuous examination (n=35). 4. Diagnostics interrupted due to hemodynamic instability (n=6).

CONCLUSION

Despite intensified and standardised diagnostic procedures prescribed for use in trauma centres, injuries are still missed in severely injured patients. About 30% of lesions that are not diagnosed until after the patient has left the emergency room have clinically significant, but not lethal, consequences for the patient. Great importance attaches to the follow-up investigation on the intensive care station, so that lesions that have initially been overlooked can be diagnosed and treated as soon as possible so as to keep the complication rate low.

Identification and Resuscitation of the Trauma Patient in Shock

This article focuses on rapid diagnosis and treatment of the patient suffering from trauma-related shock, including early identification of patients at risk for occult hypoperfusion. Resuscitation strategies (delayed resuscitation, damage control resuscitation), end points of resuscitation, and the role of blood products and pro-coagulants for resuscitation are discussed.

Multislice computed tomography in blunt abdominal trauma

Blunt abdominal trauma is a frequent finding in patients with multiple trauma, and is associated with significant morbidity and mortality. Multislice computed tomography (MSCT), allowing for multiplanar reconstructions and three-dimensional images, has become the imaging modality of choice for these patients. MSCT is indicated in all haemodynamically stable patients with suspected blunt abdominal trauma. A `focussed CT' algorithm, as recommended by the Advanced Trauma Life Support (ATLS®) program, may be useful for patients with isolated abdominal trauma who are conscious and cooperative. For unconscious patients with or without multiple trauma `unfocussed' whole-body MSCT algorithms should be used, as these lead to earlier as well as more accurate diagnosis. MSCT allows for rapid diagnosis of abdominal and retroperitoneal injuries and for grading of solid organ injuries. Active haemorrhage may be detected with accuracy similar to angiography. Even bowel, diaphragmatic and bladder injuries, where CT used to miss a significant number of injuries, can be diagnosed with high accuracy by the new generation of MSCT scanners.