Hemoperitoneum score helps determine need for therapeutic laparotomy

Usefulness of Multidetector Computed Tomography for the Initial Assessment of Blunt Abdominal Trauma Patients

BACKGROUND

The prompt detection and accurate localization of abdominal injuries are difficult. Some diagnostic modalities, including laboratory tests, ultrasound, and diagnostic peritoneal lavage (DPL) were used to evaluate patients with blunt abdominal trauma, with various advantages and pitfalls. We aimed to evaluate the risk and benefit of using multidetector computed tomography (MDCT) as an initial assessment tool for proper diagnosis and treatment planning of patients with blunt abdominal trauma.

METHODS

Two hundred fifty-two patients with blunt abdominal trauma were prospectively enrolled. Multidetector computed tomography was performed during resuscitation. The risk and benefit of using MDCT in the diagnosis and planning of treatment were analyzed.

RESULTS

The time required for a MDCT examination averaged 10.2 minutes. Of the studies done, 224 revealed abdominal injuries. Of those, 34 were performed in patients with unstable hemodynamic status without adverse effect. Prompt diagnosis and proper treatment were given according to the MDCT findings. A total of 43 (17.1%) MDCTs showed contrast extravasation. Active bleeding was confirmed in all and treated with transarterial embolization (30) or surgery (13). Another 58 patients sustained bowel, mesenteric, or pancreatic injuries (BMPI) necessitating laparotomy. The sensitivity, specificity, and accuracy of MDCT in identifying patients with active bleeding or BMPI were all 100%.

CONCLUSIONS

Multidetector computed tomography was useful as a second line initial assessment tool to identify injuries and determine treatment planning in blunt abdominal trauma patients. No increased risk was found if the facility is readily available, the protocol is well designed, and the patient is well prepared.

Surgeon-Performed Bedside Organ Assessment With Sonography After Trauma (BOAST): A Pilot Study From the WTA Multicenter Group

BACKGROUND

Although nonoperative management of solid organ injuries is a well-accepted practice, a rapid method to assess the progression of the injury, the early development of organ-related complications, and the frequency with which follow-up computed tomography (CT) scans are needed has yet to be determined. The use of ultrasound in this setting may provide information that would improve the rate of organ salvage and decrease the patient's morbidity. The objectives of this study were to determine whether surgeons could successfully use a bedside organ assessment with sonography after trauma (BOAST) examination to: (1) detect a solid organ injury; and (2) assess for changes in the size of the organ injury, an increase or decrease in hemoperitoneum, and the development of organ-related complications.

METHODS

A prospective, multicenter study was conducted using BOAST to evaluate patients undergoing nonoperative management of their solid organ injuries. Patients had to have: (1) a Focused Assessment for Sonography of Trauma (FAST) examination on admission; (2) a solid organ injury documented by an admission abdominal CT scan; and (3) the criteria for nonoperative management. BOAST was performed within 24 hours of admission and every 3 to 4 days to evaluate for an increase or decrease in hemoperitoneum [Ultrasound (US) heme score: from 0 = none to 3 = large], change in injury size, and organ-specific complications. BOAST results were compared with the radiologists' interpretation of the initial and follow-up CT scans, and with patient outcomes.

RESULTS

During a 22 month period, 126 patients sustained 135 solid organ injuries, 46 (34.1%) of these were seen by BOAST (Error rate = 66%). Serial US heme scores = 0 (no hemoperitoneum) were observed in 56 of 126 patients who had a combination of multi-system injury and a dropping Hgb, indicating that there was no further bleeding from the injured organ(s). Surgeons detected 13 of the 15 complications that were confirmed later by conventional imaging.

CONCLUSIONS

(1) BOAST has limitations in identifying solid organ injuries, especially those that are lower grade; (2) the US heme score is a valuable adjunct to the clinical examination in following patients with high-grade solid organ injuries and a dropping hemoglobin; and (3) although uncommon, organ-related complications may be identified using BOAST.

The fast is positive, now what? Derivation of a clinical decision rule to determine the need for therapeutic laparotomy in adults with blunt torso trauma and a positive trauma ultrasound

INTRODUCTION

The object of this study was to derive a clinical decision rule for therapeutic laparotomy among adult blunt trauma patients with a positive abdominal ultrasound for trauma (FAST) examination.

METHODS

We retrospectively reviewed the trauma registry and medical records of all critical trauma patients who underwent a FAST examination in the emergency department (ED) in a university Level I trauma center over a 3-year period. Blunt trauma patients aged >16 years who had a positive FAST examination (defined as the presence of intraperitoneal fluid) were eligible. We selected seven clinical and ultrasound variables available during ED resuscitation for analysis: age, presence of an episode of hypotension (systolic blood pressure <90 torr in the ED), presence of abdominal tenderness, chest injury, pelvic fracture, femur fracture, and FAST fluid location (right upper quadrant [RUQ] only; RUQ plus other location; other location only). The primary outcome variable was whether a laparotomy was performed and whether this laparotomy was needed to provide the definitive surgical intervention ("therapeutic laparotomy"). We analyzed the variables using binary recursive partitioning analysis to create a decision rule.

RESULTS

There were 2336 FAST examinations performed during the study period, resulting in 230 (9.8%) positive examinations in patients meeting inclusion criteria. There were 135 patients who had therapeutic laparotomies and 95 who did not need laparotomy. The groups were similar in baseline characteristics. In the recursive partitioning analysis, the first node in the decision tree was the presence of fluid in the RUQ. Of the 144 patients with RUQ fluid, 105 (73%, 95% confidence interval [CI] 64%-80%) required therapeutic laparotomy. Of the 86 patients without RUQ fluid, 30 (35%, 95% CI 25%-46%) nevertheless required therapeutic laparotomies, and the variables blood pressure, femur fracture, abdominal tenderness, and age further divided these patient into high- and low-risk groups. Of the 12 patients without RUQ fluid who had normal blood pressures, no femur fractures, no abdominal tenderness, and were aged 60 years and younger, none (95% CI 0%-22%) required therapeutic laparotomy. In conclusion, given a positive FAST examination, the presence of fluid in the RUQ is an important predictor of the need for therapeutic laparotomy.

CONCLUSION

In the absence of fluid in the RUQ, there are other clinical variables that may allow for the development of a clinical decision rule regarding the need for therapeutic laparotomy.

Association between compliance with methodological standards of diagnostic research and reported test accuracy: meta-analysis of focused assessment of US for trauma

PURPOSE

To study whether compliance with methodological standards affected the reported accuracy of screening ultrasonography (US) for trauma.

MATERIALS AND METHODS

Meta-analysis was conducted of prospective investigations in which US was compared with any diagnostic reference test in patients with suspected abdominal injury. Reports were retrieved from electronic databases without language restrictions; added information was gained with manual search. Two reviewers independently assessed methodological rigor by using 27 items contained in the Standards for Reporting of Diagnostic Accuracy (STARD) checklist and the Quality Assessment of Studies of Diagnostic Accuracy included in Systematic Reviews (QUADAS) instrument. Inconsistencies were resolved by means of consensus. Summary receiver operating characteristics and random-effects meta-regression were used to model the effect of methodological standards and other study features on US accuracy.

RESULTS

A total of 62 trials, which included a total of 18,167 participants, were eligible for meta-analysis. The average proportion of men or boys was 71.7%, the mean age was 30.6 years +/- 10.8 (standard deviation), and the mean injury severity score was 16.7 +/- 8.3. The prevalence of abdominal trauma was 25.1% (95% confidence interval [CI]: 21.1%, 29.1%). Pooled overall sensitivity and specificity of US were 78.9% (95% CI: 74.9%, 82.9%) and 99.2% (95% CI: 99.0%, 99.4%), respectively. Varying end points (hemoperitoneum or organ damage) did not change these results. US accuracy was much lower in children (sensitivity, 57.9%; specificity, 94.3%). Strong heterogeneity was observed in sensitivity, whereas specificity remained constant across trials. There was evidence of publication bias. Initial interobserver agreement with methodological standards ranged from poor (kappa = 0.03, independent verification of US findings) to perfect (kappa = 1.00, sufficiently short interval between US and reference test). By consensus, studies fulfilled a median of 13 methodological criteria (range, five to 20 criteria). In investigations that lacked individual methodological standards, researchers overestimated pooled sensitivity, with predicted differences of 9%-18%. The use of a single reference test, specification of the number of excluded patients, and calculation of CIs independently contributed to predicted sensitivity in a multivariate model. In 16 investigations (1309 subjects), a single reference test was used, which provided a combined sensitivity of 66.0% (95% CI: 56.2%, 75.8%).

CONCLUSION

Bias-adjusted sensitivity of screening US for trauma is low. Adherence to methodological standards included in appraisal instruments like STARD and QUADAS is crucial to obtain valid estimates of test accuracy.

Secondary ultrasound examination increases the sensitivity of the FAST exam in blunt trauma

INTRODUCTION

Approximately one third of stable patients with significant intra-abdominal injury do not have significant intraperitoneal blood evident on admission. We hypothesized that a delayed, repeat ultrasound study (Secondary Ultrasound--SUS) will reveal additional intra-abdominal injuries and hemoperitoneum.

METHODS

We performed a prospective observational study of trauma patients at our Level I trauma center from April 2003 to December 2003. Patients underwent an initial ultrasound (US), followed by a SUS examination within 24 hours of admission. Patients not eligible for a SUS because of early discharge, operative intervention or death were excluded. All US and SUS exams were performed and evaluated by surgical/emergency medicine house staff or surgical attendings.

RESULTS

Five hundred forty-seven patients had both an initial US and a SUS examination. The sensitivity of the initial US in this patient population was 31.1% and increased to 72.1% on SUS (p < 0.001) for intra-abdominal injury or intra-abdominal fluid. The specificity for the initial US was 99.8% and 99.8% for SUS. The negative predictive value was 92.0% for the initial US and increased to 96.6% for SUS (p = 0.002). The accuracy of the initial ultrasound was 92.1% and increased to 96.7% on the SUS (p < 0.002). No patient with a negative SUS after 4 hours developed clinically significant hemoperitoneum.

CONCLUSION

A secondary ultrasound of the abdomen significantly increases the sensitivity of ultrasound to detect intra-abdominal injury.

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

OBJECTIVE

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

DESIGN

Prospective study.

ANIMALS

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

PROCEDURE

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

RESULTS

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

CONCLUSIONS AND CLINICAL RELEVANCE

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

Ultrasound in abdominal trauma

This article reviews current issues regarding the Focused Assessment with Sonography for Trauma (FAST) examination. Technical performance issues, decision-making and practice algorithms, fluid volume and scoring systems, proficiency and training, and the role of the FAST in pediatric trauma are covered. This article examines the FAST examination from a practical, evidenced-based stand-point.

Establishment of a teaching animal model for sonographic diagnosis of trauma

BACKGROUND

Ultrasound is widely accepted as a valuable diagnostic tool for detecting intra-abdominal and intrathoracic bleeding in trauma patients. Nevertheless, many doctors are reluctant to use it because they do not have sufficient training. This study aimed to define intra-abdominal and intrathoracic fluid volumes that can be detected by sonography and their relation to fluid width in pigs to establish a clinically relevant animal model for teaching and training.

METHODS

Different volumes of normal saline were infused into the abdomen (50-2,000 mL) and chest (25-250 mL) in five anesthetized pigs. The maximum width of fluid as detected by ultrasound was recorded. The right upper quadrant, left upper quadrant, pelvis, and right paracolic section of the abdomen and right pleural cavity were studied. An experienced radiologist performed the studies. The effects on respiratory and cardiovascular functions were evaluated.

RESULTS

The sonographic findings in the pig were similar to those in humans. Up to 50 mL of intra-abdominal fluid and up to 25 mL of intrathoracic fluid could be detected by ultrasound. There was a significant correlation between the volume infused and the fluid width detected. The respiratory and cardiovascular monitoring of the animals showed that the infused intrathoracic volumes mimicked a survivable hemothorax.

CONCLUSION

The pig may serve as an excellent clinically relevant model with which to teach surgeons detection of different volumes of intra-abdominal and intrathoracic fluids. The value of this model as an educational tool has yet to be tested.

Splenic trauma: evaluation with contrast-specific sonography and a second-generation contrast medium: preliminary experience

OBJECTIVE

To report our experience in the assessment of splenic trauma with contrast-coded sonography and a second-generation contrast medium.

METHODS

From January to May 2002, 120 patients were studied with sonography for suspected splenic trauma. Twenty-five were selected for further imaging because of sonographic findings positive for splenic injury, findings positive for peritoneal fluid only, indeterminate findings, and negative findings with high clinical or laboratory suspicion. These patients underwent contrast-enhanced harmonic sonography and contrast-enhanced helical computed tomography.

RESULTS

Among the 25 patients studied, 6 had no spleen trauma at initial and follow-up evaluation. One patient had a hypoperfused spleen without parenchymal damage, and 18 had splenic injuries; these 19 patients were considered positive. Hemoperitoneum was identified by sonography, contrast-enhanced sonography, and contrast-enhanced computed tomography in 74% of the 19 positive cases. Perisplenic clots were recognized in 58% of the cases by computed tomography and in 42% by baseline and enhanced sonography. Splenic infarctions were found in 11% of cases by contrast-enhanced sonography and computed tomography; none was found by unenhanced sonography. Parenchymal traumatic lesions were identified in 12 of 18 patients with splenic injuries by unenhanced sonography, in 17 cases by contrast-enhanced sonography, and in all 18 cases by contrast-enhanced computed tomography. A minimal splenic lesion was found in the single patient with a false-negative contrast-enhanced sonographic finding. Contrast-enhanced sonography correlated appreciably better than unenhanced sonography in detecting injuries and in estimating their extent. Findings undetectable on unenhanced sonography were also noted: splenic hypoperfusion in 11% of positive cases on both contrast-enhanced sonography and contrast-enhanced computed tomography, contrast medium pooling in 21% of cases on both contrast-enhanced sonography and computed tomography, and contrast extravasation in 11% of cases on computed tomography and 5% on contrast-enhanced sonography.

CONCLUSIONS

Contrast-enhanced sonography is a promising tool in the assessment of splenic trauma. In institutions where sonography is used as the initial procedure, this technique may increase its effectiveness.

Predicting the need for laparotomy in pediatric trauma patients on the basis of the ultrasound score

BACKGROUND

It is possible to quantify the amount of hemoperitoneum seen on focused assessment with sonography for trauma (FAST) using a simple scoring system that had previously been shown to correlate with the need for subsequent laparotomy in adults. A score of 3 or greater was shown to be highly accurate in predicting the need for laparotomy. We hypothesized that this scoring system might also predict the need for laparotomy in pediatric trauma patients.

METHODS

We retrospectively reviewed all records for patients 15 years and younger who underwent FAST after blunt trauma. A "positive" ultrasound examination was defined as one containing free intraperitoneal fluid with or without solid organ injury. The ultrasound score (USS) was defined as the depth of the deepest pocket of fluid collection measured in centimeters plus the number of additional spaces where fluid was seen.

RESULTS

Thirty-eight (19.6%) of 193 patients who had FAST performed had positive ultrasound examinations. Thirty-seven patients with complete records were analyzed. There were no differences between patients with a USS < or = 3.0 and those with a USS > 3.0 in terms of admission pulse, Glasgow Coma Scale score, Injury Severity Score, or the proportion of patients who were initially hypotensive. One of 22 patients with a USS < or = 3.0 required therapeutic laparotomy versus 8 of 15 patients with a USS > 3.0 ( = 0.002). For a USS > 3.0, sensitivity, specificity, and accuracy in predicting therapeutic laparotomy were 89%, 75%, and 78%, respectively.

CONCLUSION

Ultrasound quantification of hemoperitoneum by a simple scoring system may serve as a useful adjunct to traditional clinical parameters in predicting the need for subsequent laparotomy in pediatric patients. Prospective validation with a larger study is required.

Surgeon-performed ultrasound imaging in acute surgical disorders

As the role of the general surgeon continues to evolve, the surgeon's use of ultrasound imaging will surely influence practice patterns, particularly for the evaluation of patients in the acute setting. With the use of real-time imaging, the surgeon receives "instantaneous" information to augment the physical examination, to narrow the differential diagnosis, or to initiate an intervention. With select ultrasound examinations, the surgeon can rapidly evaluate adult and pediatric patients with an acute abdomen, especially those patients who are hypotensive. In the hands of the surgeon, this noninvasive, bedside tool can assess more accurately the presence, depth, and extent of an abscess, confirm complete aspiration, or diagnose wound dehiscence before it is apparent on physical examination. Ultrasound imaging is so accurate for the diagnosis of pyloric stenosis that it has essentially replaced the upper gastrointestinal series in most institutions. The surgeon's use of ultrasound imaging to detect a pleural effusion has virtually supplanted the lateral decubitus radiograph. Furthermore, an ultrasound-guided thoracentesis not only facilitates the procedure but improves its safety. As surgeons become more facile with ultrasound imaging, it is anticipated that other uses will develop to further enhance its value for the assessment of patients in the acute setting.