Oral contrast solution and computed tomography for blunt abdominal trauma: a randomized study

Single Center Retrospective Review of Post-laparotomy CT Abdomen and Pelvis Findings and Trends

Purpose

To identify common findings visualized on CT following damage control laparotomy, including post-surgical changes and additional injuries, and to determine change in frequency of post-laparotomy CT at our institution over time.

Methods

Single institution, IRB-Exempt, retrospective review of the University of Kentucky trauma registry from 1/2006 to 2/2019 for all trauma patients undergoing exploratory laparotomy initially and subsequently undergoing CT of the abdomen and pelvis within 24 hours. Operative findings from surgical operation notes and findings reported on post-laparotomy CT were recorded, including vascular and solid organ injuries, operative changes, free intraperitoneal fluid/air, and retroperitoneal findings. Next steps in management were also recorded.

Results

In total 1,047 patients underwent exploratory laparotomy initially at our institution between 1/2006-2/2019. Of those, only 96 had a diagnostic CT of the abdomen and pelvis within 24 h after initial surgery, first occurring in 2010. Among these 96, there were 71 blunt and 25 penetrating injuries. Most common injuries recognized during exploratory laparotomy were bowel/mesentery (55), spleen (34), and liver (26). Regarding CT findings, all patients (96/96, 100%) had residual pneumoperitoneum, 84/96 (87.5%) had residual hemoperitoneum, 36/96 (37.5%) noted post-surgical changes or additional injuries to the spleen, 36/96 (37.5%) to the bowel/mesentery, and 32/96 (33.3%) to the liver, and 34/96 (35.4%) were noted to have pelvic fractures. After CT, 31/96 (32.3%) went back to the OR for relook laparotomy and additional surgical intervention and 7/96 (7.3%) went to IR for embolization. Most common procedures during relaparotomy involved the bowel (8) and solid organs (6).

Conclusions

CT examination within 24 h post damage control laparotomy was exceedingly rare at our institution prior to 2012 but has steadily increased. Frequency now averages 20.5% yearly. Damage control laparotomy is an uncommon clinical scenario; however, knowledge of frequent injuries and common post-operative changes will aid in radiologist detection of additional injuries helping shape next step management and provide adequate therapy.

Endoscopic Diagnosis and Management of Gastrointestinal Trauma

Trauma affects all sociodemographic profiles and is a major cause of morbidity and mortality particularly in patients less than forty years of age. A variety of endoscopic tools and techniques initially used for iatrogenic etiologies (post-operative bile or pancreatic duct leaks, intra-procedural perforation) have been adopted for use in the gastrointestinal trauma victim. The purpose of this review is to highlight a variety of gastrointestinal traumatic complications where endoscopy can serve a complement and/or definitive management strategy.

Use of Enteric Contrast Material for Abdominopelvic CT in Penetrating Traumatic Injury in Adults: Comparison of Diagnostic Accuracy Systematic Review and Meta-Analysis

BACKGROUND. Scarce evidence exists on the diagnostic benefit of enteric contrast administration for abdominopelvic CT performed in the setting of penetrating trauma. OBJECTIVE. The purpose of this systematic review and meta-analysis is to compare the diagnostic accuracy of CT using enteric contrast material with that of CT not using enteric contrast material in penetrating traumatic abdominopelvic injury in adults. EVIDENCE ACQUISITION. A protocol was registered a priori (PROSPERO CRD42019139613). MEDLINE and EMBASE databases were searched until June 25, 2019. Studies were included that evaluated the diagnostic accuracy of abdominopelvic CT either with or without enteric (oral and/or rectal) contrast material in patients presenting with penetrating traumatic injury. Relevant study data metrics and risk of bias were assessed. Bivariate random-effects meta-analyses and meta-regression modeling were performed to assess and compare diagnostic accuracies. EVIDENCE SYNTHESIS. From an initial sample of 829 studies, 12 studies were included that reported on 1287 patients with penetrating injury (389 with confirmed bowel, mesenteric, or other abdominopelvic organ injury). The enteric contrast material group (seven studies; 506 patients; 124 patients with confirmed penetrating injury) showed a sensitivity of 83.8% (95% CI, 73.7-90.5%) and specificity of 93.8% (95% CI, 83.6-97.8%). The group without enteric contrast administration (six studies; 781 patients; 265 patients with confirmed penetrating injury) showed a sensitivity of 93.0% (95% CI, 86.8-96.4%) and a specificity of 90.3% (95% CI, 81.4-95.2%). No statistically significant difference was identified for sensitivity (p = .07) or specificity (p = .37) between the groups with and without enteric contrast material according to meta-regression. Nine of 12 studies showed risk of bias in at least one QUADAS-2 domain (most frequently limited reporting of blinding of radiologists or lack of blinding of radiologists, insufficient clinical follow-up for the reference standard, and limited reporting of sampling methods). CONCLUSION. The use of enteric contrast material for CT does not provide a significant diagnostic benefit for penetrating traumatic injury. CLINICAL IMPACT. Eliminating enteric contrast administration for CT in penetrating traumatic injury can prevent delays in imaging and surgery and reduce cost.

Article Commentary: Evolving Colon Injury Management: A Review

The colon is the second most commonly injured intra-abdominal organ in penetrating trauma. Management of traumatic colon injuries has evolved significantly over the past 200 years. Traumatic colon injuries can have a wide spectrum of severity, presentation, and management options. There is strong evidence that most non-destructive colon injuries can be successfully managed with primary repair or primary anastomosis. The management of destructive colon injuries remains controversial with most favoring resection with primary anastomosis and others favor colonic diversion in specific circumstances. The historical management of traumatic colon injuries, common mechanisms of injury, demographics, presentation, assessment, diagnosis, management, and complications of traumatic colon injuries both in civilian and military practice are reviewed. The damage control revolution has added another layer of complexity to management with continued controversy.

Imaging of blunt bowel and mesenteric injuries: Current status

Blunt abdominal trauma often presents a diagnostic challenge. Clinical examination demonstrates low reliability in detecting abdominal injury (16 %) when there is a history of head injury or loss of consciousness. This can prove detrimental, as delays in the diagnosis of traumatic bowel injury of 8 h or less can result in increased morbidity and mortality, as well as prolonged hospitalization. Although hemodynamically unstable patients will require an urgent laparotomy following clinical assessment, MDCT is the modality of choice for comprehensive imaging of blunt abdominal trauma in hemodynamically stable patients. Despite the use of MDCT, blunt injury to the bowel and mesentery, which accounts for up to 5% of injuries in cases of trauma, may be difficult to detect. The use of a constellation of direct and indirect signs on MDCT can help make the diagnosis and guide clinical management. Direct signs on MDCT, such as bowel wall discontinuity, and extraluminal gas may assist in the diagnosis of traumatic bowel injury. However, these signs are not sensitive. Therefore, the astute radiologist may have to rely on indirect signs of injury, such as free fluid, bowel wall thickening, and abnormal bowel wall enhancement to make the diagnosis. This review will focus on MDCT imaging findings of bowel and mesenteric injuries secondary to blunt abdominal trauma.

Duodeno-pancreatic and extrahepatic biliary tree trauma: WSES-AAST guidelines

Duodeno-pancreatic and extrahepatic biliary tree injuries are rare in both adult and pediatric trauma patients, and due to their anatomical location, associated injuries are very common. Mortality is primarily related to associated injuries, but morbidity remains high even in isolated injuries. Optimal management of duodeno-bilio-pancreatic injuries is dictated primarily by hemodynamic stability, clinical presentation, and grade of injury. Endoscopic and percutaneous interventions have increased the ability to non-operatively manage these injuries. Late diagnosis and treatment are both associated to increased morbidity and mortality. Sequelae of late presentations of pancreatic injury and complications of severe pancreatic trauma are also increasingly addressed endoscopically and with interventional radiology procedures. However, for moderate and severe extrahepatic biliary and severe duodeno-pancreatic injuries, immediate operative intervention is preferred as associated injuries are frequent and commonly present with hemodynamic instability or peritonitis. The aim of this paper is to present the World Society of Emergency Surgery (WSES) and American Association for the Surgery of Trauma (AAST) duodenal, pancreatic, and extrahepatic biliary tree trauma management guidelines.

Pneumoperitoneum

Pneumoperitoneum, usually seen as free air under the diaphragm, is a finding that can be seen on plain abdominal radiographs, signifying a leakage of air, usually from a perforation in the gastrointestinal tract. There are several other potential pathways from other body compartments for air to enter the abdominal cavity. Pneumoperitoneum does not always signify bowel rupture, as it can also result from pneumomediastinum and pneumothorax, and in patients who are being mechanically ventilated. Patient history and physical examination can assist in a preliminary diagnosis before diagnostic imaging. Plain chest/abdominal radiograph or computed tomographic scan of the abdomen can be diagnostic of pneumoperitoneum. Surgical versus nonsurgical conservative observation is determined on the basis of the cause and amount of free air.

Using Body Mass Index and Bioelectric Impedance Analysis to Assess the Need for Positive Oral Contrast Agents Before Abdominopelvic CT

OBJECTIVE

The objective of this study was to determine whether body fat percentage, measured using a portable handheld bioelectric impedance analysis (BIA) device, and body mass index (BMI, weight in kilograms divided by the square of height in meters) can estimate the amount of intraabdominal and intrapelvic fat and thereby predict the need for oral contrast material before abdominopelvic CT.

SUBJECTS AND METHODS

A prospective, institutional review board-approved study consisting of 101 patients who presented to the emergency department of a level I trauma center was conducted between June 1, 2016, and July 19, 2016. A medical student calculated patients' BMI and obtained body fat measurements from a handheld BIA device. Three fellowship-trained and board-certified radiologists who were blinded to the collected data then assigned a score of 1-5 on the basis of the amount of intraabdominal and intrapelvic fat seen on CT images. A McNemar test was used to compare overall sensitivity and specificity of this method, and a weighted Fleiss kappa score was used to determine interobserver variability between the three radiologists.

RESULTS

Nearly all (97%) of the patients with high BMI (BMI ≥ 25) had sufficient amounts of intraabdominal and intrapelvic fat to allow delineation of anatomic structures without the use of oral contrast material. Of the patients with low BMI (BMI ≤ 21), 83% had inadequate amounts of fat to separate intraabdominal and intrapelvic structures. For patients with intermediate BMIs (21 < BMI < 25), BIA-determined body fat percentage of 30% or more can be used to predict whether a patient will have sufficient intraabdominal and intra-pelvic fat to obviate oral contrast material for CT.

CONCLUSION

Using BIA in addition to BMI accurately predicts amount of intraabdominal and intrapelvic fat. This information may help guide the decision to use oral contrast material in patients presenting for abdominopelvic CT.

Utility of CT oral contrast administration in the emergency department of a quaternary oncology hospital: diagnostic implications, turnaround times, and assessment of ED physician ordering

PURPOSE

To compare studies with and without oral contrast on performance of multidetector computed tomography (CT) and the order to CT examination turnaround time in cancer patients presenting to the emergency department (ED). To the best of our knowledge, oral contrast utility has not previously been specifically assessed in cancer patients presenting to the emergency department.

MATERIALS & METHODS

Retrospective review of CT abdomen examinations performed in oncology patients presenting to the emergency department during one month. CT examinations performed with and without oral contrast were rated by two consensus readers for degree of confidence and diagnostic ability. Correlations were assessed for primary cancer type, age, sex, chief complaint/examination indication, body mass index, intravenous contrast status, repeat CT examination within 4 weeks, and disposition. Turnaround times from order to the start of the CT examination were calculated.

RESULTS

The studied group consisted of 267 patients (127 men and 140 women) with a mean age of 56 years and a mean body mass index of 27.8 kg/m². One hundred sixty CT examinations were performed without oral contrast, and 107 CT examinations were performed with oral contrast. There was no significant difference between cases with oral contrast and cases without oral contrast in the number of cases rated as "improved confidence" (odds ratio [OR] 0.54, 95% confidence interval [CI] 0.23-1.31, P = 0.17), "improved diagnosis" (OR 0.58, 95% CI 0.20-1.64, P = 0.3), "impaired confidence" (OR 3.92, 95% CI 0.46-33.06, P = 0.21), or "impaired diagnosis" (OR 2.63, 95% CI 0.29-23.89, P = 0.39). The turnaround time in the group receiving oral contrast (mean, 141 min; standard deviation, 49.8 min) was significantly longer than that in the group not receiving oral contrast (mean, 109.2 min; standard deviation, 64.8 min) with a mean difference of 31.8 min (P < 0.0001).

CONCLUSION

On the basis of our findings and prior studies, targeted rather than default use of oral contrast shows acceptable diagnostic ability in the emergency setting for oncology patients. Benefit from oral contrast use is suggested in scenarios such as suspected fistula/bowel leak/abscess, hypoattenuating peritoneal disease, prior bowel surgery such as gastric bypass, and the absence of intravenous contrast administration. Improvement through the use of targeted oral contrast administration also supports the emergency department need for prompt diagnosis and disposition.

Effects of oral contrast on dose in abdominopelvic computed tomography with pure iterative reconstruction

AIM

To assess the effect of neutral (NC) and positive (PC) oral contrast use on patient dose in low-dose abdominal computed tomography (CT).

METHODS

Low-dose clinically indicated CTs were performed on 79 Crohn’s patients (35 = PC, 1 L 2% gastrografin; 44 = NC, 1.5 L polyethylene glycol). Scanner settings for both acquisitions were identical apart from 25 s difference in intravenous contrast timing. Body mass index (BMI), scan-ranges, dose-length product and size-specific dose estimated were recorded. Data was reconstructed with pure model-based iterative reconstruction. Image quality was objectively and subjectively analysed. Data analysis was performed with Statistical Package for Social Scientists.

RESULTS

Higher doses were seen in neutral contrast CTs (107.60 ± 78.7 mGy.cm, 2.47 ± 1.21 mGy vs 85.65 ± 58.2 mGy.cm, 2.18 ± 0.96 mGy). The difference was significant in 2 of 4 BMI groups and in those that had both NC and PC investigations. Image-quality assessment yielded 6952 datapoints. NC image quality was significantly superior (P < 0.001) (objective noise, objective signal to noise ratio, subjective spatial resolution, subjective contrast resolution, diagnostic acceptability) at all levels. NC bowel distension was significantly (P < 0.001) superior.

CONCLUSION

The use of polyethylene glycol as a neutral OC agent leads to higher radiation doses than standard positive contrast studies, in low dose abdominal CT imaging. This is possibly related to the osmotic effect of the agent resulting in larger intraluminal fluid volumes and resultant increased overall beam attenuation.

Pediatric Trauma: Current Concepts and Treatments

Injured children represent a complex management problem for the trauma surgeon. Physiologic and psychological factors have been shown to influence outcome; however, more importantly, injury patterns and treatment algorithms differ from those recommended for adults. Children often do well after major injuries, but surgeons must use appropriate treatment to maximize the physiologic responses and the innate healing abilities of the growing child. Historically, surgeons have defined childhood as prepubertal, but a child's physiologic response to injury extends well into the third decade of life, making treatment of a 20-year-old similar to that of a 10-year-old, rather than that of a 40-year-old. The distribution of pediatric trauma facilities across the country has limited the access of the injured child to these centers. Adult centers more often serve as the first and definitive treatment provider for children. This article reviews the current concepts of trauma treatments for children. It is hoped that the adult trauma surgeons caring for injured children might gain information that will be of assistance in their daily practice.

Lower radiation exposure from body CT imaging for trauma at a dedicated pediatric hospital

PURPOSE

We compare radiation exposure from body CT imaging for blunt trauma performed at outside hospitals (OH) versus our children's hospital (CH).

METHODS

We performed a retrospective chart review of all children transferred to our facility for management of trauma after undergoing a body CT scan at an OH from June 2011 to August 2013. Radiation from OH images was compared to our CH by matching to age, gender, and nearest date. Radiation measures included dose length product (DLP), computed tomography dose index (CTDI), and size-specific dose estimate (SSDE).

RESULTS

Fifty-one children were transferred from 39 OH. Abdomen/pelvis and chest/abdomen/pelvis imaging was performed in 30 and 21 children, respectively. Demographics are shown in Table 1. Results are illustrated in Tables 2 and 3. Contrast was utilized in 45 (1 oral, 41 IV, 3 both) and 51 (49 IV, 2 both). CT scans were performed at OH and CH, respectively (P=0.03).

CONCLUSIONS

Children receive significantly less radiation exposure with body CT imaging for blunt trauma when performed at our dedicated CH. CT scans were significantly more likely to be ordered with appropriate contrast at our CH.

Assessment and treatment of the trauma patient in shock

High-volume crystalloid resuscitation is associated with increased length of stay, ICU and ventilator days, and organ failure and infection rates. Rapid evaluation of a hemodynamically unstable trauma patient is vital to diagnosis and treatment of the cause of shock. CT scanning should be used liberally in trauma patients to effect decreased mortality. Nonoperative management and catheter-based interventions are becoming the standard of care in appropriately selected patients with solid organ injuries.

Blunt bowel and mesenteric injuries detected on CT scan: who is really eligible for surgery?

BACKGROUND

There is no consensually accepted approach to the management of blunt bowel and mesenteric injuries. Surgery is required urgently in the case of bowel perforation or haemodynamic instability, but several patients can be treated non-operatively. This study aimed to identify the risk factors for surgery in an initial assessment.

METHODS

We retrospectively reviewed the medical charts and computed tomography (CT) scans of adult patients presenting with a blunt abdominal trauma to our centre between the years 2004 and 2011. We included only patients with a CT scan showing suspected injury to the mesentery or bowel.

RESULTS

There were 43 patients (33 males and 10 females), with a mean Injury Severity Score (ISS) of 22. The most frequently suspected injuries based on a CT scan were mesenteric infiltrations in 40 (93 %) patients and bowel wall thickening in 22 (51 %) patients. Surgical therapy was required for 23 (54 %) patients. Four factors were independently associated with surgical treatment: a free-fluid peritoneal effusion without solid organ injury [adjusted odds ratio (OR) = 14.4, 95 % confidence interval (CI) [1.9-111]; p = 0.015], a beaded appearance of the mesenteric vessels (OR = 9 [1.3-63]; p = 0.027), female gender (OR = 14.2 [1.3-159]; p = 0.031) and ISS >15 (OR = 6.9 [1.1-44]; p = 0.041). Surgery was prescribed immediately for 11 (26 %) patients and with delay, after the failure of initially conservative treatment, for 12 (28 %) patients. The presence of a free-fluid peritoneal effusion without solid organ injury was also an independent risk factor for delayed surgery (OR = 9.8 [1-95]; p = 0.048).

CONCLUSIONS

In blunt abdominal trauma, the association of a bowel and/or mesenteric injury with a peritoneal effusion without solid organ injury on an initial CT scan should raise the suspicion of an injury requiring surgical treatment. Additionally, this finding should lead to a clinical discussion of the benefit of explorative laparotomy to prevent delayed surgery. However, these findings need validation by larger studies.

Use of positive oral contrast agents in abdominopelvic computed tomography for blunt abdominal injury: meta-analysis and systematic review

OBJECTIVES

To determine whether positive oral contrast agents improve accuracy of abdominopelvic CT compared with no, neutral or negative oral contrast agent.

METHODS

Literature was searched for studies evaluating the diagnostic performance of abdominopelvic CT with positive oral contrast agents against imaging with no, neutral or negative oral contrast agent. Meta-analysis reviewed studies correlating CT findings of blunt abdominal injury with positive and without oral contrast agents against surgical, autopsy or clinical outcome allowing derivation of pooled sensitivity and specificity. Systematic review was performed on studies with common design and reference standard.

RESULTS

Thirty-two studies were divided into two groups. Group 1 comprised 15 studies comparing CT with positive and without oral contrast agents. Meta-analysis of five studies from group 1 provided no difference in sensitivity or specificity between CT with positive or without oral contrast agents. Group 2 comprised 17 studies comparing CT with positive and neutral or negative oral contrast agents. Systematic review of 12 studies from group 2 indicated that neutral or negative oral contrasts were as effective as positive oral contrast agents for bowel visualisation.

CONCLUSIONS

There is no difference in accuracy between CT performed with positive oral contrast agents or with no, neutral or negative oral contrast agent.

KEY POINTS

• There is no difference in the accuracy of CT with or without oral contrast agent. • There is no difference in the accuracy of CT with Gastrografin or water. • Omission of oral contrast, utilising neutral or negative oral contrast agent saves time, costs and decreases risk of aspiration.

Multidetector CT of blunt abdominal trauma

The morbidity, mortality, and economic costs resulting from trauma in general, and blunt abdominal trauma in particular, are substantial. The "panscan" (computed tomographic [CT] examination of the head, neck, chest, abdomen, and pelvis) has become an essential element in the early evaluation and decision-making algorithm for hemodynamically stable patients who sustained abdominal trauma. CT has virtually replaced diagnostic peritoneal lavage for the detection of important injuries. Over the past decade, substantial hardware and software developments in CT technology, especially the introduction and refinement of multidetector scanners, have expanded the versatility of CT for examination of the polytrauma patient in multiple facets: higher spatial resolution, faster image acquisition and reconstruction, and improved patient safety (optimization of radiation delivery methods). In this article, the authors review the elements of multidetector CT technique that are currently relevant for evaluating blunt abdominal trauma and describe the most important CT signs of trauma in the various organs. Because conservative nonsurgical therapy is preferred for all but the most severe injuries affecting the solid viscera, the authors emphasize the CT findings that are indications for direct therapeutic intervention.

The Role of Repeat Computed Tomography Scan in the Evaluation of Blunt Bowel Injury

The precise role of repeat abdominal computed tomography (CT) imaging in the diagnosis and management of bowel injury is unclear. We reviewed 540 patients with blunt abdominal trauma managed at a Level II trauma center over a 5-year period to better define the role of repeat imaging. One hundred patients had a repeat abdominal CT scan within 72 hours of admission. These patients were young with multisystem injuries (mean ± standard deviation age, 34 ± 15 years; Injury Severity Score, 21 ± 12; Glasgow Coma Score [GCS], 12 ± 5). There were 14 patients with bowel injuries. All bowel-injured patients survived without abdominal morbidity. Time to repeat CT was shortest in the bowel injured group (20 ± 10 hours). The repeat CT was most helpful in patients with significant closed head injury (mean GCS, 3 ± 1) and in those with occult bowel injury. The repeat scan resulted in a change in clinical management in 26 patients. Regarding the presence of bowel perforation, the follow-up scan enhanced sensitivity from 30 to 82 per cent. The repeat abdominal CT is best used selectively in patients with blunt abdominal trauma and can provide clinically useful information to exclude bowel injury.

Rate of intra-abdominal injury after a normal abdominal computed tomographic scan in adults with blunt trauma

OBJECTIVE

The objective of this study is to determine the rate of intra-abdominal injury (IAI) in adults with blunt abdominal trauma after a normal abdominal computed tomographic (CT) scan. We hypothesize that the risk of subsequent IAI is so low that hospital admission and observation for possible IAI are unnecessary.

METHODS

We conducted a prospective, observational cohort study of adults (>18 years) with blunt trauma who underwent abdominal CT scanning in the emergency department. Computed tomographic scans were obtained with intravenous contrast but no oral contrast. Abnormalities on abdominal CT included all visualized IAIs or any finding suggestive of possible IAI. Patients were followed up to determine the presence or absence of IAI and the need for therapeutic intervention if IAI was identified.

RESULTS

Of the 3103 patients undergoing abdominal CT, 2734 (88%) had normal CT scans. The median age was 39 years (interquartile range, 26-51 years); and 2141 (78%) were admitted to the hospital. Eight (0.3%; 95% confidence interval, 0.1%-0.6%) were identified with IAIs after normal abdominal CT scans including the following injuries: pancreas (5), liver (4), gastrointestinal (2), and spleen (2). Five underwent therapy at laparotomy. Abdominal CT had a likelihood ratio (+) of 20.9 (95% confidence interval, 17.7-24.8) and likelihood ratio (-) of 0.034 (0.017-0.068).

CONCLUSION

Adult patients with blunt torso trauma and normal abdominal CT scans are at low risk for subsequently identified IAI. Thus, hospitalization for evaluation of possible IAI after a normal abdominal CT scan is unnecessary in most cases.

CT imaging of blunt traumatic bowel and mesenteric injuries

Delayed diagnosis of a bowel or mesenteric injury resulting in hollow viscus perforation leads to significant morbidity and mortality from hemorrhage, peritonitis, or abdominal sepsis. The timely diagnosis of bowel and mesenteric injuries requiring operative repair depends almost exclusively on their early detection by the radiologist on computed tomography examination, because the clinical signs and symptoms of these injuries are not specific and usually develop late. Therefore, the radiologist must be familiar with the often-subtle imaging findings of bowel and mesenteric injury that will allow for appropriate triage of a patient who has sustained blunt trauma to the abdomen or pelvis.

Clinical policy: critical issues in the evaluation of adult patients presenting to the emergency department with acute blunt abdominal trauma

This clinical policy from the American College of Emergency Physicians is an update of the 2004 clinical policy on the critical issues in the evaluation of adult patients presenting to the emergency department with acute blunt abdominal trauma. A writing subcommittee reviewed the literature as part of the process to develop evidence-based recommendations to address 4 key critical questions: (1) In a hemodynamically unstable patient with blunt abdominal trauma, is ultrasound the diagnostic modality of choice? (2) Does oral contrast improve the diagnostic performance of computed tomography (CT) in blunt abdominal trauma? (3) In a clinically stable patient with isolated blunt abdominal trauma, is it safe to discharge the patient after a negative abdominal CT scan result? (4) In patients with isolated blunt abdominal trauma, are there clinical predictors that allow the clinician to identify patients at low risk for adverse events who do not need an abdominal CT? Evidence was graded and recommendations were based on the available data in the medical literature related to the specific clinical question.

Small bowel perforation due to blunt trauma to an inguinal hernia: a case report and literature review

We report the case of a 41-year-old man with a known right inguinal hernia presenting with groin pain following a fall while dog walking. Operative findings showed a small bowel perforation affecting the loop of bowel in the hernial sac. Bowel perforations caused by blunt abdominal injury in patients with an inguinal hernia is a rare and not well recognised problem, and are confined to a handful of case reports in the surgical literature.

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

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

Primary pan-computed tomography for blunt multiple trauma: can the whole be better than its parts?

Single-pass, whole-body computed tomography (pan-CT) was proposed in the late 1990s as a new concept for the diagnostic work-up of severely injured patients. Since its introduction, it has led to considerable debate among clinicians and scientists, triggered by concerns about its immediate safety, questionable therapeutic advantages and exposure to radiation. However, it was recently shown that pan-CT scanning may be associated with a reduction in trauma mortality. In this article, we provide an overview of current knowledge of the value of this compelling concept. The diagnostic accuracy of multidetector row CT (MDCT) for clearing various anatomical regions in trauma patients is, at best, unclear. Little is known about the accuracy of pan-CT as a whole, which weakens statements about its effectiveness and prevents inferences about survival advantages. This last point may be explained by a stage-migration or "Will Rogers" phenomenon: Pan-CT increases injury severity by detecting lesions that would not have been recognized by conventional methods but still do not affect treatment decisions, thus artificially lowering the ratio of observed to expected deaths. In order to maintain the credibility of pan-CT technology for trauma, a rigorous, large-scale evaluation of its accuracy is required. Such an evaluation requires consensus about the definition of true and false positive and negative findings in the setting of blunt multiple trauma. In addition, triage criteria need to be refined to increase specificity and reduce the number of unnecessary scans.

Blast injuries

Health-care providers are increasingly faced with the possibility of needing to care for people injured in explosions, but can often, however, feel undertrained for the unique aspects of the patient's presentation and management. Although most blast-related injuries (eg, fragmentation injuries from improvised explosive devices and standard military explosives) can be managed in a similar manner to typical penetrating or blunt traumatic injuries, injuries caused by the blast pressure wave itself cannot. The blast pressure wave exerts forces mainly at air-tissue interfaces within the body, and the pulmonary, gastrointestinal, and auditory systems are at greatest risk. Arterial air emboli arising from severe pulmonary injury can cause ischaemic complications-especially in the brain, heart, and intestinal tract. Attributable, in part, to the scene chaos that undoubtedly exists, poor triage and missed diagnosis of blast injuries are substantial concerns because injuries can be subtle or their presentation can be delayed. Management of these injuries can be a challenge, compounded by potentially conflicting treatment goals. This Seminar aims to provide a thorough overview of these unique primary blast injuries and their management.

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.

CT evaluation of placental abruption in pregnant trauma patients

The purpose of the study was to assess the possibility of placental injury detection on computed tomography (CT) in pregnant trauma patients. The images and dictated reports of 44 CT scans of pregnant women who presented to the University of California Irvine Medical Center (UCIMC) from 2003 to 2008 for traumatic abdominal conditions were reviewed for placental abruption. Performances of original dictated reports, an untrained reviewer, and a trained reviewer (who was trained on 22 non-traumatic scans) were compared. Of the 66 pregnant women who received abdominal CT scans, 44 sustained abdominal trauma. Seven suffered placental abruptions, all of which were identified on CT. Sensitivity and specificity were 100% and 79.5%, respectively, for the untrained reviewer, 100% and 82.1% for the trained reviewer, and 42.9% and 89.7% for the original dictated reports. Placental abruptions are often overlooked on CT scan. Sensitivity may be improved by systematic evaluation of the placenta and specificity by training on normal placental morphology.

Emergency department imaging: current practice

PURPOSE

To provide a snapshot of the demographics of radiologists providing coverage for emergency departments (EDs) and current imaging practices in EDs in the United States.

METHODS

An online survey was created with Views Flash 3 software (Cogix, Monterey, California). Random e-mail addresses from a variety of databases were chosen. A total of 678 surveys were sent over a 9-month period.

RESULTS

One hundred ninety-two radiology groups (28%) responded to the survey. Forty-one groups (21%) had designated emergency radiology divisions. Sixty-three groups (33%) were using computed tomographic (CT) coronary angiography in the ED workup of chest-pain. Thirty-five groups (18%) were using "triple-rule-out scans" (ie, a single CT scan to rule out coronary artery disease, pulmonary embolism, and aortic dissection). Multiplanar reconstructions of chest, abdominal, and pelvic CT images were routinely performed by 95 groups (49%). Forty-four percent used reformatted CT images instead of conventional radiographs in the workup of cervical spine trauma, and 68 groups (35%) used reformations in thoracic and lumbar spine trauma. Ninety groups (47%) did not use oral contrast for blunt abdominal trauma CT scanning. Sixty-seven respondents (35%) preferred computed tomography to evaluate for acute appendicitis in the setting of pregnancy. Forty percent of imaging equipment located within the EDs was CT scanners. The majority of the groups still communicated unexpected findings via telephone (49%).

CONCLUSION

New imaging practices for the evaluation of entities such as chest pain, spine trauma, and abdominal pain and trauma are emerging in EDs. As one plans ED development, these trends should be considered.

Blunt abdominal trauma: current imaging techniques and CT findings in patients with solid organ, bowel, and mesenteric injury

Imaging plays a critical role in the evaluation of patients with blunt abdominal trauma. In most institutions, computed tomography (CT) is the modality of choice when evaluating such patients. The purpose of this review is to highlight current techniques in trauma imaging and to review CT findings associated with solid organ, bowel, mesenteric, and diaphragmatic injury. In particular, emphasis is placed on the use of multidetector CT technology (MDCT), especially 64-row detector CT. The role of various techniques, including the use of oral and intravenous contrast, as well as the potential benefit of delayed imaging, is discussed.

Outcomes of management in stable children with intra-abdominal free fluid without solid organ injury after blunt abdominal injury

BACKGROUND

The optimal management of hemodynamically stable children without solid-organ injury and with intra-abdominal free fluid on computed tomographic (CT) scan is highly debatable. The possibility of hollow viscus injury in this setting has led many to propose mandatory exploration. We think that stable children with intra-abdominal fluid without solid organ injury can be managed nonoperatively.

METHODS

The charts of all children less than 18 years of age who had an abdominopelvic CT scan after a blunt abdominal trauma between January 2001 and July 2004 were queried. Patient demographics, mechanism of injury, vital signs, physical examination, laboratory data, CT findings, and outcomes of management were reviewed.

RESULTS

There were 37 pediatric patients identified during the study period who met the selection criteria. Twenty were boys and 17 were girls. Thirty-one patients had a small amount of fluid and six had a moderate amount of fluid. The most common mechanism of injury was motor vehicle crash (MVC). Thirty-one patients were successfully managed nonoperatively. Six patients received an exploratory laparotomy. Intraoperative findings included mesenteric injuries with or without ischemic bowel. There were no cases of hollow viscus perforation.

CONCLUSIONS

Nonoperative management of stable patients with small amounts of free fluid in the absence of significant abdominal findings is appropriate in the pediatric population. Increasing amounts of tenderness elicited on physical examination correlates well with the presence of more than a small amount of fluid. The presence of seat belt sign and more than a small amount of fluid may be associated with an increased likelihood of operative intervention.

[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.

Computed tomography without oral contrast solution for blunt diaphragmatic injuries in abdominal trauma

OBJECTIVE

The aim of this study was to estimate the sensitivity, specificity, and positive predictive value (PPV) of computed tomography (CT) without oral contrast for diaphragm injuries (DIs) in blunt abdominal trauma.

METHODS

We prospectively enrolled 500 consecutive "trauma-one" patients who received CT imaging and interpretation (CT-Read1) of the abdomen within 45 minutes of their arrival from July 2000 to December 2001. All patients were imaged without oral contrast but with intravenous contrast. Computed tomographic images were reviewed within 24 hours of admission by research radiologists (CT-Read2) blinded to CT-Read1. True DIs were determined hierarchically by either laparotomy or autopsy.

RESULTS

There were 9 patients with laparotomy or autopsy-proven blunt DIs; 8 of these injuries involved the left hemidiaphragm. The CT-Read1 correctly detected only 6 of 9 blunt DIs, thus missing 3 DIs. One of these involved the right hemidiaphragm, whereas the other 2 were left sided. There were no false-positive findings with CT-Read1 for blunt DI. The sensitivity and specificity of CT imaging with respect to DI were 66.7% (95% CI, 29.9%-92.5%) and 100% (95% CI, 99.2%-100%), respectively. The PPV for the test was 1.00 (95% CI, 0.65-1.00).

CONCLUSION

Although the low number of blunt DIs in this study limits its general applicability, CT imaging of the diaphragm without oral contrast appears to perform within the range of reported imaging techniques using oral contrast. Still, CT scanning appears to have an unsatisfactorily low sensitivity to be reliably used in eliminating the diagnosis of blunt DI.

Blunt Abdominal Trauma: Performance of CT without Oral Contrast Material

PURPOSE

To retrospectively evaluate multi-detector row computed tomography (CT) without oral contrast material for depiction of bowel and mesenteric injuries that require surgical repair in patients with blunt abdominal trauma.

MATERIALS AND METHODS

The investigational review board approved the study. Informed consent was waived. CT reports for October 2001 to September 2003 were reviewed and 1082 patients were identified who had undergone abdominopelvic CT with a multi-detector row scanner and without oral contrast material. Findings were divided into four categories: negative, solid organ injury with or without hemoperitoneum, free fluid only, and suspected bowel or mesenteric injury. Sensitivity, specificity, positive predictive value, and negative predictive value were calculated by comparing CT findings with laparotomy reports and hospital course.

RESULTS

CT findings were no intraabdominal injury (n = 932), solid organ injury only (n = 102), free fluid only (n = 34), and suspected bowel or mesenteric injury (n = 14). CT findings in patients suspected of having bowel or mesenteric injury were pneumoperitoneum with other secondary findings (n = 4), mesenteric hematoma and bowel wall abnormality (n = 2), mesenteric hematoma only (n = 4), and bowel wall thickening only (n = 4). In 11 patients, bowel or mesenteric injury was proved surgically. Thus, the study included 1066 true-negative, nine true-positive, two false-negative, and five false-positive results. Based on these data, sensitivity was 82% (95% confidence interval [CI]: 52%, 95%), specificity was 99% (95% CI: 98%, 99%), positive predictive value was 64% (95% CI: 39%, 83%), and negative predictive value was 99% (95% CI: 98%, 99%) for depiction of bowel and mesenteric injuries.

CONCLUSION

Multi-detector row CT without oral contrast material is adequate for depiction of bowel and mesenteric injuries that require surgical repair. Results are comparable with previously reported data for single-detector row helical CT with oral contrast material.

Performance of helical computed tomography without oral contrast for the detection of gastrointestinal injuries

STUDY OBJECTIVE

We describe the performance of helical abdominal computed tomography (CT) scan without oral contrast for the detection of blunt gastrointestinal injuries.

METHODS

We retrospectively reviewed the records of a consecutive series of patients who underwent helical abdominal CT scanning for evaluation of blunt intra-abdominal injury and were admitted to a Level I trauma center from May 1996 to September 2001. Abdominal CT scans were performed with intravenous contrast but without oral contrast. Patients were considered to have gastrointestinal injuries if an injury was identified to the gastrointestinal tract from the duodenum to the sigmoid colon or associated mesentery and considered to have major gastrointestinal injuries if gastrointestinal perforation, active mesenteric hemorrhage, or mesenteric devascularization occurred. All gastrointestinal injuries were confirmed by laparotomy, autopsy, or additional imaging studies.

RESULTS

Six thousand fifty-two patients underwent abdominal CT scan (mean age 35.5 +/- 21.1 years), and 106 (1.8%) patients had gastrointestinal injuries identified by laparotomy, autopsy, or additional (nonabdominal CT) imaging studies. Abdominal CT scan result was abnormal in 91 (86%; 95% confidence interval [CI] 78% to 92%) of the 106 patients with gastrointestinal injuries and revealed findings suggestive of gastrointestinal injury in 81 (76%; 95% CI 67% to 84%) patients. Abdominal CT scan demonstrated findings suggestive of gastrointestinal injury in 58 of 64 (91%; 95% CI 81% to 96%) patients with major gastrointestinal injuries. Two hundred thirty-eight (4.0%) patients had findings suspicious for gastrointestinal injuries on abdominal CT scan, but gastrointestinal injury was never confirmed.

CONCLUSION

Helical abdominal CT scan without oral contrast identified nearly three fourths of patients with blunt gastrointestinal injuries who were selected for abdominal CT scanning. Sensitivity of this diagnostic test improves in the subset of patients with major gastrointestinal injuries.

The role of computed tomography in diagnosis of blunt intestinal and mesenteric trauma (BIMT)

Blunt intestinal mesenteric trauma (BIMT) is a rare injury with a high morbidity and mortality. It is a diagnostic dilemma for Trauma Surgeons and Emergency Physicians. This study was undertaken to assess the role of computed tomography (CT) in BIMT. Data were analyzed from 1995 to 2002. Thirty-six cases of BIMT were identified: 16 isolated and 20 non-isolated injuries. Initial CT scan was abnormal in 74% (17 out of 23), and 83% on retrospect (2 additional cases). CT scans were abnormal (initial and repeat) in 96% (22 out of 23). The most common abnormalities were free fluid (78%), mesenteric stranding or edema (39%), bowel wall hematoma, or edema (30%). Free air was seen in 31% and oral contrast extravasation in 15% of cases of bowel perforation. CT scan findings in BIMT can be subtle and non-specific. Suspicion of BIMT warrants close observation and probably further diagnostic testing.

Multidetector Computed Tomography and Blunt Thoracoabdominal Trauma

Computed tomography has had an increasing role in the evaluation of patients after blunt trauma. Important findings in thoracic trauma include acute traumatic aortic injury, pneumothorax, hemothorax, pulmonary contusions and lacerations, mediastinal hematoma, and diaphragmatic rupture. The solid abdominal viscera may lacerate; infarct; or suffer vascular, ductal, or pyelocalyceal disruption. The bladder and intestines may rupture. In abdominal pelvic trauma, the direction of applied force often results in an identifiable constellation of injuries. This article reviews how multidetector computed tomography (MDCT) is used in the trauma patient. Technical advances of increased cephalocaudad coverage speed and improved z-axis resolution intrinsic to MDCT, together with effective contrast utilization, make MDCT invaluable in the setting of trauma.

Computed tomographic scanning without oral contrast solution for blunt bowel and mesenteric injuries in abdominal trauma

BACKGROUND

Computed tomographic (CT) scanning using intravenous and oral contrast material has traditionally been advocated for the evaluation of intra-abdominal injury, including blunt bowel and mesenteric injuries (BBMIs). The necessity of oral contrast in detecting these injuries has recently been called into question. The purpose of this study was to determine the sensitivity and specificity of CT scanning without oral contrast for BBMIs.

METHODS

We prospectively enrolled 500 consecutive blunt trauma patients who received CT imaging and interpretation (CT-Read1) of the abdomen from July 2000 to November 2001. All patients were imaged without oral contrast, but with intravenous contrast. CT images were reviewed within 24 hours of admission by a research radiologist (CT-Read2) blinded to CT-Read1. For study purposes, true BBMI was determined to be present if either laparotomy or autopsy identified bowel or mesenteric injury, or both CT-Read2 and the hospital discharge summary described bowel or mesenteric injury. Three-month telephone follow-up was also completed.

RESULTS

CT-Read1 detected 19 of 20 bowel and mesenteric injuries. CT-Read1 missed one duodenal perforation. There were two patients with false-positive interpretations of CT-Read1 for bowel injury. The sensitivity and specificity of CT imaging for the detection of BBMIs were 95.0% and 99.6%, respectively.

CONCLUSION

CT imaging of the abdomen without oral contrast for detection of BBMIs compares favorably with CT imaging using oral contrast.