Bowel and mesenteric injury: evaluation with emergency abdominal US

Surgical intervention for blunt bowel and mesenteric injury: indications and time intervals

PURPOSE

Decision making in management of blunt bowel and mesenteric injury (BBMI) is difficult. This study aimed to identify indicators for laparotomy and appropriate time intervals to surgery.

METHODS

We retrospectively reviewed our hospital's trauma registry to identify patients with a diagnosis of BBMI from February 2011 to July 2017. Patients requiring therapeutic surgical treatment (OM group) were compared with those who did not (NOM group). Preoperative risk factors for surgery (with p < 0.1 by univariate analysis) were integrated in a multivariate logistic regression model. In the OM group, we identified relevant factors for time intervals to surgical interventions.

RESULTS

Among 2808 trauma patients admitted to our hospital, 83 (3.0%) had bowel and mesenteric injury; 6 patients with penetrating trauma, 2 lethal, untreated cases, and 2 patients who underwent exploratory laparotomy were excluded. Finally, 73 patients (47 males), with a mean Injury Severity Score (ISS) of 23, were included. Results from univariate analysis identified three relevant factors between the OM and NOM groups: ISS score (p = 0.036), hemodynamic instability (p = 0.041), and free air (p = 0.0018). Multivariate analysis revealed one relevant factor, free air (p = 0.0002). Short intervals between hospital admission and intervention were associated with 7-day mortality (p = 0.029), hemodynamic instability (p = 0.0009), focused assessment with sonography for trauma positive (p < 0.0001), and mesenteric extravasation (p = 0.012).

CONCLUSIONS

Early surgical intervention is essential in cases of hemodynamically unstable BBMI and bowel perforation with free air; nevertheless, it is associated with high mortality. We suggest that prompt transport along with early intervention could significantly lessen mortality.

A big mesenteric rupture after blunt abdominal trauma: A case report and literature review

INTRODUCTION

A blunt abdominal trauma especially in organs less commonly injured (such as small bowel and mesentery injury), are difficult to diagnose.

PRESENTATION OF CASE

We report a case of a blunt abdominal trauma, in a 43 year old male presented in the Emergency Department after a truck vehicle accident. He sustained a chest injury, a pelvic fracture and diffuse abdominal tenderness. The patient had tachycardia (120 pulses/min) and normal blood pressure (120/90mmHg). The computed tomography (CT) showed only free fluid. We placed two chest tubes (due to pneumothorax and hemothorax at both sides) and the patient went to the operating room (OP). An external pelvic osteosynthesis was performed first and then we did an exploratory laparotomy, which revealed a big mesenteric rupture. Finally, an enterectomy (circa 2m) with a fist stage side to side anastomosis was performed.

DISCUSSION

Mesentery and bowel injury constitutes 3-5% of blunt abdominal injuries. The main diagnostic challenge is to identify lesions that require surgery. Diagnostic delay over 8h can lead to high morbidity and mortality rates. Laparotomy is the standard of care in hemodynamically unstable patients.

CONCLUSION

In polytrauma cases with abdominal pain and unclear CT findings the decision to proceed with exploratory laparotomy is better than a conservative treatment, because any surgical delay can lead to severe complications.

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

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

Computed tomographic imaging in the pediatric patient with a seatbelt sign: still not good enough

PURPOSE

Considering the improvements in CT over the past decade, this study aimed to determine whether CT can diagnose HVI in pediatric trauma patients with seatbelt signs (SBS).

METHODS

We retrospectively identified pediatric patients with SBS who had abdominopelvic CT performed on initial evaluation over 5 1/2years. Abnormal CT was defined by identification of any intra-abdominal abnormality possibly related to trauma.

RESULTS

One hundred twenty patients met inclusion criteria. CT was abnormal in 38/120 (32%) patients: 34 scans had evidence of HVI and 6 showed solid organ injury (SOI). Of the 34 with suspicion for HVI, 15 (44%) had small amounts of isolated pelvic free fluid as the only abnormal CT finding; none required intervention. Ultimately, 16/120 (13%) patients suffered HVI and underwent celiotomy. Three patients initially had a normal CT but required celiotomy for clinical deterioration within 20h of presentation. False negative CT rate was 3.6%. The sensitivity, specificity and accuracy of CT to diagnose significant HVI in the presence of SBS were 81%, 80%, and 80%, respectively.

CONCLUSIONS

Despite improvements in CT, pediatric patients with SBS may have HVI not evident on initial CT confirming the need to observation for delayed manifestation of HVI.

LEVEL OF EVIDENCE

Level II Study of a Diagnostic Test.

Hollow viscus injury due to blunt trauma: A review

Blunt abdominal trauma results in injury to the bowel and mesenteries in 3-5% of cases. The injuries are polymorphic including hematoma, seromuscular tear, perforation, and ischemia. They preferentially involve the small bowel and may result in bleeding and/or peritonitis. An urgent laparotomy is necessary if there is evidence of active bleeding or peritonitis at the initial examination, but these situations are uncommon. The main diagnostic challenge is to promptly and correctly identify lesions that require surgical repair. Diagnostic delay exceeding eight hours before surgical repair is associated with increased morbidity and probably with mortality. Because of this risk, the traditional therapeutic approach has been to operate on all patients with suspected bowel or mesenteric injury. However, this approach leads to a high rate of non-therapeutic laparotomy. A new approach of non-operative management (NOM) may be applicable to hemodynamically stable patients with no signs of perforation or peritonitis, and is being increasingly employed. This attitude has been described in several recent studies, and can be applied to nearly 40% of patients. However, there is no consensual agreement on which criteria or combination of clinical and radiological signs can insure the safety of NOM. When NOM is decided upon at the outset, very close monitoring is mandatory with repeated clinical examinations and interval computerized tomography (CT). Larger multicenter studies are needed to better define the selection criteria and modalities for NOM.

Is pneumoperitoneum the terra ignota in ultrasonography?

In most cases, pneumoperitoneum is caused by gastrointestinal perforation, which usually requires surgical treatment. Many authors believe that ultrasound imaging of pneumoperitoneum is at least as effective as conventional radiography, or even that its efficacy is superior. In such a situation, it is imperative to make this modality one of the main tools in the diagnostic arsenal of emergency medicine. This is the main aim of this paper. First, ultrasound anatomy of so-called thoracic-abdominal border is discussed. The equipment requirements emphasize that the diagnostic process can be conducted with the simplest portable US scanner, even without the Doppler mode. The technique of a US examination, the aim of which is to detect, free air in the peritoneal cavity is also simple and conducted with the patients lying down, either in the supine or lateral position. A convex transducer with the frequency of 3.5-5 MHz is applied above the lower intercostal spaces on the right and left side, to the epigastric region below the xiphoid process and in various sites of the abdominal wall. The most effective examination, however, is conducted in the left lateral position via the right intercostal spaces. The differential diagnosis on the right side under the diaphragm should include the presence of a subdiaphragmatic abscess with gas and a hepatic abscess with a similar content as well as transposition of the colon in between the diaphragm and the liver (Chilaiditi syndrome). It seems that the inclusion of a US examination to the E-FAST method in order to detect free gas in the peritoneal cavity is justified since it is a sign of gastrointestinal perforation in numerous cases, and is clinically as relevant as the presence of free fluid.

Ischemic colitis due to a mesenteric arteriovenous malformation in a patient with a connective tissue disorder

Ischemic colitis is a rare, life-threatening, consequence of mesenteric arteriovenous malformations. Ischemia ensues from a steal phenomenon through shunting, and may be compounded by the resulting portal hypertension. Computed tomographic angiography is the most common first-line test because it is quick, non-invasive, and allows for accurate anatomic characterization. Also, high-resolution three-dimensional images can be created for treatment planning. Magnetic resonance angiography is similarly sensitive for vascular mapping. Conventional angiography remains the gold standard for diagnosis and also allows for therapeutic endovascular embolization. Our patient underwent testing using all three of these modalities. We present the first reported case of this entity in a patient with a vascular connective tissue disorder.

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.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

Evaluation of gastrointestinal injury in blunt abdominal trauma "FAST is not reliable": the role of repeated ultrasonography

Background

To determine the diagnostic Accuracy of Focused Assessment Sonography for Trauma (FAST) and repeated FAST in the patients with blunt abdominal trauma.

Methods

In this retrospective study we collected the data of all patients from September 2007 to July 2011 with gastrointestinal injury. The intraoperative outcome was compared with FAST technique and the repeated or delayed sonography.

Results

A total number of 1550 patients with blunt abdominal trauma underwent FAST in a period of 4 years in our hospital. Eighty-eight (5.67%) patients were found to have gastrointestinal injury after exploratory laparotomy. Fifty-five (62.5%) patients had isolated gastrointestinal injury and 33 (37.5%) patients had concomitant injury to the other solid organs. In those with isolated gastrointestinal injury, the sensitivity of FAST was 38.5%. Repeated ultrsonography was performed in 34 patients with false negative initial FAST after 12-24 hours. The sensitivity of repeated ultrasonography in negative initial FAST patients in detection of gastrointestinal injury was 85.2% (95% CI, 68.1%, and 94.4%).

Conclusion

Repeated sonography after 12 to 24 hours in patients with negative initial FAST but sustain abdominal symptom can facilitated a diagnosis of GI tract injury and can be as effective method instead of Computed tomography in developing country.

Is the FAST exam reliable in severely injured patients?

INTRODUCTION

Highly sensitive and accurate for the detection of injuries requiring intervention in haemodynamically unstable patients, FAST may underestimate intra-abdominal injuries in stable patients with blunt abdominal trauma. Diminished accuracy of ultrasound has been reported in different cohorts of multiple injured patients. We hypothesised that multiple injured patients with a high Injury Severity Score (ISS) will have a decreased accuracy of FAST for the assessment of blunt abdominal trauma.

METHODS

Data from the trauma registry of a Level 1 trauma centre were retrospectively reviewed. All haemodynamically stable blunt trauma patients who underwent both FAST and CT scan of abdomen from January 1, 2000 to January 1, 2005 were included in the cohort. All patients were divided into three groups according to their ISS: Group 1 included patients with an ISS from 1 to 14, Group 2 included patients with an ISS from 16 to 24, and Group 3 consisted of patients with ISS>or=25.

RESULTS

3181 patients with blunt abdominal trauma included into the study were divided into the three groups according to the ISS. The mean ISS was 7.9+/-3.97, 19.6+/-2.48 and 41.3+/-11.95 in Groups 1, 2 and 3, respectively. The accuracy of ultrasound was 90.6% in the group of patients with the highest ISS (>or=25) compared with 97.5 and 97.1 for Groups 1 and 2 (p<0.001). Similarly, ultrasound had a significantly lower sensitivity, specificity, PPV and NPV for patients in Group 3 compared with the first two groups (p<0.001). There was a significantly lower sensitivity in Group 2 compared with Group 1 (p<0.001), but no differences in specificity, accuracy, PPV or NPV were demonstrated.

CONCLUSION

Patients with high ISS are at increased risk of having ultrasound-occult injuries and have a lower accuracy of their ultrasound examination than patients with low and moderate ISS.

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

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

Management of blunt bowel and mesenteric injuries: Experience at the Alfred hospital

BACKGROUND

The incidence of blunt bowel and mesenteric injury (BBMI) has increased recently in blunt abdominal trauma, possibly due to an increasing number of high-speed motor accidents and the use of seat belts.

OBJECTIVE

Our aim was to identify the factors determining the time of surgical intervention and how they affect the outcome of the patient with BBMI. This was achieved by reviewing our experience as a major Victorian trauma service in the management of bowel and mesenteric injuries and comparing this to the experiences reported in the literature.

METHODS

A retrospective study reviewing 278 consecutive patients who presented to the Alfred trauma center with blunt bowel and mesenteric injuries over a 6-year period.

RESULTS

The patient cohort comprised 278 patients with BBMI (66% were male, 34% were female), of whom 80% underwent a laparotomy, 17% were treated conservatively and 3% were diagnosed post-mortem. In terms of time from admission to laparotomy, 67% were treated within 0-4 h, 9% within 4-8 h, 3% within 8-12 h, 10% within 12-24 h, 4% within 24-48 h and 7% at >48 h. A focused abdominal sonography for trauma (FAST) was performed in 86 patients, of whom 51% had a positive FAST, 44% had a negative FAST and 4% had an equivocal FAST. Overall, 13% of the patient cohort did not have a FAST. Computerized tomography (CT) scans were undertaken preoperatively in 68% of the patients, revealing free gas (22% of patients), bowel-wall thickening (31%), fat and mesenteric stranding or hematoma (38%) and free fluid with no solid organ injury (43%).

CONCLUSION

The timing of surgical intervention in cases of BBMI is mostly determined by the clinical examination and the results of the helical CT scan findings. The FAST lacks sensitivity and specificity for identifying bowel and mesenteric trauma. A delayed diagnosis of > 48 h has a significantly higher bowelrelated morbidity but not mortality.

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.

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

PURPOSE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

The Utility of Sonography for the Triage of Blunt Abdominal Trauma Patients to Exploratory Laparotomy

OBJECTIVE

The purpose of this study was to assess the utility of focused abdominal sonography for trauma (FAST) in the triage of hypotensive and normotensive blunt abdominal trauma patients to exploratory laparotomy.

MATERIALS AND METHODS

Data entered in a trauma registry database were retrospectively reviewed and were correlated with medical records, radiology reports, and surgical laparotomy reports. In the setting of blunt abdominal trauma, hypotensive patients were compared with normotensive patients who underwent FAST.

RESULTS

During the 6-year study period, 4,029 patients with blunt abdominal trauma underwent sonography, 122 of whom were hypotensive on arrival and underwent FAST. Of 87 hypotensive patients with positive findings on FAST, 69 (79%) were taken directly to exploratory laparotomy without the need for CT. In predicting the need for therapeutic laparotomy in hypotensive patients, the sensitivity of FAST was 85%, specificity was 60%, and accuracy was 77%. Of the 3,907 normotensive patients, 3,584 had negative FAST findings, whereas 323 had positive FAST findings. In normotensive patients, the sensitivity of FAST was 85%, specificity was 96%, and accuracy was 96%. In the combined patient population (all hypotensive and normotensive patients), 4,029 patients with blunt abdominal trauma underwent sonography: 3,619 had negative and 410 had positive FAST findings. In all patients regardless of blood pressure, the sensitivity of FAST was 85%, specificity was 96%, and accuracy was 95%.

CONCLUSION

Hypotensive patients screened in the emergency department with positive FAST findings may be triaged directly to therapeutic laparotomy, depending on the results of the sonography examination, without the need for CT.

The Management of Blunt Abdominal Trauma Patients with Computed Tomography Scan Findings of Free Peritoneal Fluid and No Evidence of Solid Organ Injury

Modalities available for the diagnosis of blunt abdominal traumatic (BAT) injuries include focused abdominal sonography for trauma, diagnostic peritoneal lavage, and computed tomography (CT) of the abdomen/pelvis. Hollow viscous and/or mesenteric injury (HVI/MI) can still be challenging to diagnose. Specifically, there is debate as to the proper management of BAT when CT findings include free peritoneal fluid but no evidence of solid organ injury (SOI). Our objective was to determine the incidence of HVI/MI and to evaluate the management of BAT patients with CT findings of peritoneal fluid without evidence of SOI. An Institutional Review Board-approved retrospective chart review was conducted of all BAT patients with peritoneal fluid on CT admitted to Kern Medical Center from January 1, 2003 to July 31, 2004. A total of 2651 trauma admissions yielded 79 patients. Fourteen of these had no evidence of SOI. Nonoperative management was successful in only 2 of these 14, whereas 12 required an operation, with 11 being therapeutic. Trigger to operate and time from presentation to laparotomy was hypotension in three patients (164 minutes), signs of HVI/MI on CT in two patients (235 minutes), diaphragm injury on CT in one patient (95 minutes), and for peritoneal signs in six patients (508 minutes). In BAT patients with peritoneal fluid on CT without evidence of SOI, there should be a high suspicion of HVI/MI. Relying on increasing abdominal tenderness to trigger laparotomy can result in delayed treatment.

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

OBJECTIVE

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

SUBJECTS AND METHODS

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

RESULTS

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

CONCLUSION

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

Sonography as the primary screening method in evaluating blunt abdominal trauma

PURPOSE

The radiological evaluation of patients with blunt abdominal trauma can be done with either ultrasound (US) or computed tomography (CT) with strategies varying considerably among institutions. We evaluated the efficacy of our current strategy in which US is used at our hospital as the primary screening tool for patients with blunt abdominal trauma.

METHODS

We retrospectively analysed all patients admitted to our hospital with possible blunt abdominal trauma who underwent abdominal US, abdominal CT and/or a laparotomy during the initial trauma assessment from 1998 until 2002 (n = 1149).

RESULTS

Nine-hundred sixty-one of the 1149 patients had a negative US, of which 922 were true negative, resulting in a negative predictive value of 96%. A CT of the abdomen was performed in 7%. In 1.7% there was delayed diagnosis with no significant additional morbidity. Fourteen of the 103 laparotomies (14%) were non-therapeutic; in 5 of these cases the patients underwent non-therapeutic laparotomy despite the performance of a CT. Seven were emergency operations.

CONCLUSIONS

In our practice, the use of US for the evaluation of acute blunt abdominal trauma is adequate, with a high negative predictive value, a small number of delayed diagnoses, and an acceptable rate of non-therapeutic laparotomies.

Blunt Abdominal Injury in the Pregnant Patient: Detection with US

PURPOSE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

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

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

Blunt Abdominal Trauma: Clinical Value of Negative Screening US Scans

PURPOSE

To assess clinical and surgical outcomes in patients with blunt abdominal trauma and negative screening ultrasonographic (US) scans.

MATERIALS AND METHODS

From a database of 4,000 patients who underwent screening US for suspected blunt abdominal trauma at a level 1 trauma center, the authors retrospectively identified 3,679 patients with negative US findings. In these patients, outcome was determined by means of retrospective review of the trauma registry and all radiologic, surgical, and autopsy reports. In patients with false-negative findings at screening US, all imaging studies and medical charts were also reviewed. Proportions were statistically compared by means of the Pearson chi(2) and Fisher exact tests. Monte Carlo estimation was applied when expected frequencies were low.

RESULTS

Among the 3,679 patients with negative findings at screening US, 99.9% (n = 3,641) had no injuries (true-negative findings). Differences in true-negative rates as a function of year (P >.5) or time of day (P >.3) were not significant. Among the 3,641 patients with true-negative findings, 93.6% (n = 3,407) required no additional tests and 6.4% (n = 234) underwent computed tomography or other tests. The percentage of patients who underwent additional tests was significantly higher in the 1st year of the study (19.2%) than in subsequent years (all comparisons, P <.001). Thirty-eight patients had false-negative US findings for abdominal injury. The injuries that were missed in 24 patients were nonsurgical (those that were treated successfully without intervention or were considered minor at autopsy) and those in 14 patients were surgical (required surgical intervention). Cumulatively, 65 injuries were missed. The six most common injuries included retroperitoneal hematoma (n = 13) and injuries in the spleen (n = 10), liver (n = 9), kidney (n = 8), adrenal gland (n = 8), and small bowel (n = 7). Twenty-five of the 38 patients had no or trace hemoperitoneum. Mean diagnostic delay until recognition of missed injury was 16.8 hours +/- 4.3 (standard error of the mean). The missed injury was identified within 12 hours in 19 of the 38 patients and within 24 hours in 34.

CONCLUSION

The combination of negative US findings and negative clinical observation virtually excludes abdominal injury in patients who are admitted and observed for at least 12-24 hours.

Ultrasonographic findings in dogs and cats with gastrointestinal perforation

A retrospective study was performed to evaluate the sonographic features of gastrointestinal (GI) perforation in dogs and cats. Sonographic findings in 19 animals (14 dogs and 5 cats) included regional bright mesenteric fat (19), peritoneal effusion (16), fluid-filled stomach or intestines (12), GI wall thickening (11), presence of free air (9), loss of GI wall layering (9), regional lymphadenopathy (8), reduced GI motility (7), pancreatic changes (4), corrugated intestines (4), presence of a mass (3), presence of a foreign body (3), and mineralization of the gastric wall (1). In 14 patients, "perforation" was listed as a differential diagnosis by the sonographer. Abdominal radiographs and radiographic reports were available for 14 patients. Radiographic findings were decreased serosal detail (12), free air (8), peritoneal contrast medium (1), and suspected foreign body (1). GI perforation was listed as radiographic diagnosis in eight patients, seven of which had evidence of pneumoperitoneum, and one had leakage of contrast material on an upper GI study. In 9/14 patients with radiography, "GI perforation" was listed as a sonographic diagnosis. In three patients in which free air was diagnosed sonographically, radiographs were either not available (2) or the presence of free air was not detected at presentation (1). Peritoneal fluid analysis was performed in nine patients, five of which were identified as septic inflammation, and the remaining four were classified as neutrophilic inflammation with no etiologic agent identified. The histologic or surgical diagnoses were as follows: three intestinal surgical dehiscence; one percutaneous endoscopic gastrostomy tube site leakage; one duodenal adenocarcinoma; one ileocolic lymphoma; one trichobezoar; one ascarid impaction; and one bobby pin foreign body. In the remaining 10 patients, a focal area of gastric/intestinal ulceration or transmural necrosis with perforation was identified without evidence of an underlying cause.

Pathophysiology and management of bowel and mesenteric injuries due to blunt trauma

Injuries to the bowel and mesentery are uncommon in blunt trauma and rarely occur in isolation. Delay to diagnosis has a significant impact on morbidity and mortality. The literature tends to focus on the diagnosis of hollow viscus and mesenteric injury, with little written on its management. Studies are usually retrospective with a paucity of comparative trials. The use of computerized tomography (CT) scanning in blunt abdominal trauma has overshadowed other reports. Early-generation scanners had a relatively poor sensitivity in detecting bowel-related injuries, but the CT scan is now the primary modality for imaging stable patients. However radiological signs can be subtle and should be regarded as complementary to meticulous clinical assessment.

Blunt abdominal trauma: should US be used to detect both free fluid and organ injuries?

PURPOSE

To evaluate abdominal ultrasonography (US) for indirect (with free fluid analysis only) and direct (with free fluid and parenchymal analysis) detection of organ injury in patients with blunt abdominal trauma, with findings at computed tomography (CT) and/or surgery as the standard of diagnosis.

MATERIALS AND METHODS

Abdominal US was performed at hospital admission in consecutive patients with blunt abdominal trauma. The presence of free peritoneal fluid and organ injury were recorded and compared with results of abdominal CT in all hemodynamically stable patients. When US results were considered false-negative for free fluid or organ injury compared with CT results, repeat US was performed within 6 hours. Admission and second US results were compared with CT and/or surgical results to determine sensitivity, specificity, negative predictive value, and positive predictive value of US with regard to the presence of free intraperitoneal fluid and/or organ injury.

RESULTS

Two hundred five hemodynamically stable patients underwent abdominal US and CT. CT revealed free fluid in 83 patients and organ injury in 99. Thirty-one (31%) of 99 patients with organ injury did not have free fluid at CT. Three (10%) of the 31 patients required surgery or angiographic embolization. The sensitivity of admission US was 93% (77 of 83 cases) for the diagnosis of free fluid, 41% (39 of 99) for directly demonstrating organ injury, and 72% (71 of 99) for suggesting organ injury by means of both free fluid and organ analysis. At second US, these sensitivities were 96% (80 of 83 cases), 55% (54 of 99) and 84% (83 of 99), respectively.

CONCLUSION

US is highly sensitive for the detection of free intraperitoneal fluid but not sensitive for the identification of organ injuries. In hemodynamically stable patients, the value of US is mainly limited by the large percentage of organ injuries that are not associated with free fluid.

Clinical importance of intraperitoneal fluid in patients with blunt intra-abdominal injury

The purpose of this study was to determine the prevalence of intraperitoneal fluid (IF) in blunt trauma patients with intra-abdominal injuries, to determine the rate of exploratory laparotomy in patients with and without IF, and to identify the location of this IF. We retrospectively reviewed the records of 604 patients with intra-abdominal injuries after blunt trauma who were admitted to a level 1 trauma center over a 42-month period. Patients were considered to have intra-abdominal injuries if an injury to the spleen, liver, urinary tract, pancreas, adrenal glands, gallbladder, or gastrointestinal tract was identified on abdominal computed tomography (CT) or at exploratory laparotomy. Patients were considered to have IF if fluid was identified on abdominal CT or during exploratory laparotomy. In patients undergoing abdominal CT or abdominal ultrasound (US), the specific location of the IF was identified. Four hundred forty-three (73%, 95% confidence interval [CI] 69 - 77%) of the 604 patients with intra-abdominal injuries had IF. Patients with IF had an increased risk of laparotomy (344/443 [78%] v 44/161 [27%], odds ratio = 9.2, 95% CI 6.1-13.9). Of the 539 patients undergoing abdominal CT or abdominal US, IF was identified in 389 (72%) and was visualized in the following locations: 258 of 389 (66%) in Morison's pouch, 216 of 389 (56%) in the left upper quadrant, 187 of 389 (48%) in the pelvis, and 139 of 390 (36%) in paracolic gutters. Three patients with IF visualized solely in the paracolic gutters underwent laparotomy. The majority of patients with intra-abdominal injuries have IF, and these patients are more likely to undergo laparotomy. Morison's pouch is the most common location for IF to be detected with radiologic imaging. However, visualization of the paracolic gutters with abdominal US may detect IF in patients with intra-abdominal injuries that would otherwise not be detected by US.

Late presentation of small bowel obstruction following blunt abdominal trauma

BACKGROUND

Motor vehicle accidents have increasingly become a major cause of serious blunt abdominal and chest injury, the pattern and mechanism of which has changed in recent years largely due to seatbelt legislation.

AIM

A case of blunt abdominal and chest trauma is reported which resulted in a mesenteric tear--the small bowel subsequently herniated through and strangulated.

CONCLUSION

This case highlights the need for clinical suspicion, serial physical examination and early surgery in the management of these injuries.

The focused abdominal sonography for trauma scan: pearls and pitfalls

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

From the RSNA refresher courses: focused abdominal US for trauma

Focused abdominal ultrasonography (US) has been introduced in Europe as a method to evaluate blunt abdominal trauma. The main focus of the examination is detection of free fluid in the abdomen secondary to injury of the abdominal organs. The examination takes only a few minutes to perform. In the authors' experience, trauma patients in unstable condition and in whom significant free fluid is detected are immediately taken to the operating room for surgical exploration without undergoing computed tomographic (CT) correlation. The authors have also used US to identify the specific site of organ injury. Injuries to solid organs such as the liver, spleen, and kidney that are identified with US usually appear heterogeneous or hyperechoic. A hematoma surrounding the injured organ may appear echogenic or hypoechoic. However, pitfalls of focused abdominal US for trauma include failure to show contained solid-organ injuries; injuries to the diaphragm, pancreas, and adrenal gland; and some bowel injuries. Thus, negative findings at US do not exclude an intraperitoneal injury, and close clinical observation or CT is warranted.

Free fluid on abdominal computed tomography without solid organ injury after blunt abdominal injury does not mandate celiotomy

BACKGROUND

Mandatory celiotomy has been proposed for all patients with unexplained free fluid on abdominal computed tomography (CT) scanning after blunt abdominal injury. This recommendation has been based upon retrospective data and concerns over the potential morbidity from the late diagnosis of blunt intestinal injury. This study examined the rate of intestinal injury in patients with free fluid on abdominal CT after blunt abdominal trauma.

METHODS

This study was a multicenter prospective series of all patients with blunt abdominal trauma admitted to four level I trauma centers over 22 months. Data were collected concurrently at the time of patient enrollment and included demographics, injury severity score, findings on CT scan, and presence or absence of blunt intestinal injury. This database was specifically queried for those patients who had free fluid without solid organ injury.

RESULTS

In all, 2,299 patients were evaluated. Free fluid was present in 265. Of these, 90 patients had isolated free fluid with only 7 having a blunt intestinal injury. Conversely, 91% of patients with free fluid did not. All patients with free fluid were observed for a mean of 8 days (95% confidence interval 6.1 to 10.4, range 1 to 131). There were no missed injuries.

CONCLUSIONS

Free fluid on abdominal CT scan does not mandate celiotomy. Serial observation with the possible use of other adjunctive tests is recommended.

Ultrasound detection of blunt splenic injury

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

Concomitant Blunt Enteric Injuries with Injuries of the Liver and Spleen: A Dilemma for Trauma Surgeons

Prompt identification of enteric injuries after blunt trauma remains problematic. With the increased utilization of nonoperative management of blunt abdominal trauma gastrointestinal disruptions may escape timely detection and repair. The purpose of this study was to evaluate blunt enteric injuries requiring operative repair in adult patients and the association of concomitant hepatic and/or splenic injuries. Over a 10-year period (January 1990 through December 1999) 1648 patients suffered blunt liver, spleen, and/or enteric injuries, with 87 (5.3%) of these requiring operative repairs of the enteric injury. These patients had enteric injury only (EI) (60.9%; 53 of 87), concomitant enteric/splenic injury (ESI) (10.3%; 9 of 87), concomitant enteric/hepatic injury (EHI) (13 8%-12 of 87), and enteric/hepatic/splenic injury (EHSI) 14.9% (13 of 87). A delay in treatment of >8 hours from presentation of EI compared with either EHI or ESI was not significantly different between the two groups. EHSI had exploratory laparotomy more expeditiously related to hemodynamic instability. Mortality rates were higher with EHI related to hemorrhagic shock and/or severe traumatic brain injury. Morbidity was not related to a delay in diagnosis until the period of delay was greater than 24 hours. The nonoperative management of blunt solid organ injury does not delay the detection and treatment of concomitant bowel injuries compared with isolated blunt enteric injuries. Occult enteric injury with solid organ injury has a low incidence and represents a continuing challenge to the clinical acumen of the trauma surgeon.

Diagnostic techniques in assessing vessels of the gastrointestinal tract

Vascular disorders of the gastrointestinal tract include a variety of different underlying diseases, thus requiring different and, in many cases, more than one imaging procedure. Only a knowledge of the newest developments in vascular imaging techniques with all the possibilities and limits will ensure a time- and cost-effective, accurate and reliable diagnosis. In many acute cases and also as a screening procedure, ultrasound in combination with colour Doppler and duplex sonography, plays an important role in setting the right course for further imaging techniques, and can provide the correct diagnosis in many cases.Depending on the most prominent symptoms and the expected disease, the right choice of technique saves valuable time. Computed tomography (CT) and magnetic resonance imaging (MRI) are cross-sectional imaging techniques that not only demonstrate lesion vascularization, but also provide information about neighbouring structures and complications in an understandable and demonstrable way. The use of angiography as an invasive tool should be limited to cases where a high temporal and spatial resolution is necessary to make the diagnosis or where therapeutic interventions are also likely to be performed within the same setting. For the diagnosis of gastrointestinal vascular diseases, often no generally valid recommendation can be given, since the impact of all imaging techniques will depend on the examiner's experience, the technical equipment and on their 24-h availability in a hospital. This chapter tries to give some information about the inherent limits and indications of the different imaging techniques, as well as the newest study results concerning the most frequent vascular diseases of the gastrointestinal tract.

Blunt abdominal trauma: screening us in 2,693 patients

PURPOSE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

2,576 ultrasounds for blunt abdominal trauma

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Focused abdominal sonography for trauma (FAST) in children with blunt abdominal trauma

BACKGROUND

Focused abdominal sonography for trauma (FAST) has been well reported in adults, but its applicability in children is less well established. We decided to test the hypothesis that FAST and computed tomography (CT) are equivalent imaging studies in the setting of pediatric blunt abdominal trauma.

METHODS

One hundred seven hemodynamically stable children undergoing CT for blunt abdominal trauma were prospectively investigated using FAST. The ability of FAST to predict injury by detecting free intraperitoneal fluid was compared with CT as the imaging standard.

RESULTS

Thirty-two patients had CT documented injuries. There were no late injuries missed by CT. FAST detected free fluid in 12 patients. Ten patients had solid organ injury but no free fluid and, thus, were not detected by FAST. The sensitivity of FAST relative to CT was only 0.55 and the negative predictive value was only 0.50.

CONCLUSION

FAST has insufficient sensitivity and negative predictive value to be used as a screening imaging test in hemodynamically stable children with blunt abdominal trauma.