Diagnostic evaluation of patients with blunt abdominal trauma: a decision analysis

FAST for blunt abdominal trauma: Correlation between positive findings and admission acid-base measurement

PURPOSE

This study aimed to determine any association between positive findings in ultrasonography examination and initial BD value with regard to diagnosis of intra-abdominal bleeding following blunt abdominal trauma.

METHODS

A prospective, multi-center study of consecutive adult patients was performed from April to September 2015. Demographics, initial vital signs and arterial BD were evaluated with respect to presence of any association with intra-abdominal bleeding and in-hospital mortality. FAST study was performed to find intra-abdominal bleeding. Receiver operating characteristic (ROC) curves tested the ability of BD to identify patients with intra-abdominal hemorrhage and probable mortality.

RESULTS

A total of 879 patients were included in final analysis. The mean (SD) age was 36.68 (15.7) years and 714 patients (81.2%) were male. According to multivariable analysis, statistically significant association was observed between negative admission BD and both intra-abdominal bleeding (OR 3.48, 95% CI 2.06-5.88, p<0.001) and in-hospital mortality (OR 1.55, 95% CI 1.49-1.63, p<0.001). ROC curve analysis demonstrated sensitivity of 92.7% and specificity of 22.1% for the best cut-off value of BD (-8mEq/L) to diagnose internal hemorrhage. Further, a cut-off value of -7mEq/L demonstrated significant predictive performance, 94.8% sensitivity and 53.6% specificity for in-hospital mortality.

CONCLUSION

This study revealed that arterial BD is an early accessible important marker to identify intra-abdominal bleeding, as well as to predict overall in-hospital mortality in patients with blunt abdominal trauma.

Iterative reconstruction improves image quality and preserves diagnostic accuracy in the setting of blunt solid organ injuries

This study aims to investigate the effect of iterative reconstruction (IR) on MDCT image quality and radiologists' ability to diagnose and grade blunt solid organ injuries. One hundred (100) patients without and 52 patients with solid organ injuries were scanned on a 64-slice MDCT scanner using reference 300 mAs, 120 kVp, and fixed 75 s delay. Raw data was reconstructed using filtered back projection (FBP) and three levels of iterative reconstruction (Philips iDose levels 2, 4, and 6). Four emergency radiologists, blinded to the reconstruction parameters and original interpretation, independently reviewed each case, assessed image quality, and assigned injury grades. Each reader was then asked to determine if they thought that IR was used and, if so, what level. There was no significant difference in diagnostic accuracy between FBP and the various IR levels or effect on the detection and grading of solid organ injuries (p > 0.8). Images reconstructed using iDose level 2 were judged to have the best overall image quality (p < 0.01). The radiologists had high sensitivity in detecting if IR was used (80 %, 95 % CI 76-84 %). IR performed comparably to FBP with no effect on radiologist ability to accurately detect and grade blunt solid organ injuries.

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.

Abdominal Trauma in Combat

Evaluating and managing patients with abdominal trauma remains one of the most challenging, resource-intensive and satisfying aspects of combat care. It demands a thorough understanding of the pathophysiology of trauma and shock, excellent clinical acumen and the ability to think and operate rationally in a chaotic milieu.

Determining the accuracy of base deficit in diagnosis of intra-abdominal injury in patients with blunt abdominal trauma

BACKGROUND

Blunt abdominal trauma is a leading cause of morbidity and mortality among all age groups. A multiplicity of diagnostic modalities exists to evaluate the abdomen. We sought to assess the diagnostic performance of base deficit (BD) in identifying intra-abdominal injury in patients with blunt abdominal trauma.

METHODS

A prospective, nonrandomized series of patients with blunt abdominal trauma admitted into the 2 emergency departments was investigated from September 2007 to September 2008. Arterial blood samples were analyzed. According to BD, the patients were divided into 2 groups: group 1 who had a BD of -6 or lower and group 2 who had a BD more than -6. Ultrasonography, computed tomographic scan, or laparotomy was performed to find intra-abdominal injury. Follow-up at 7 days by telephone interview was obtained on patients who were discharged.

RESULTS

A total of 400 patients were enrolled, with a mean (SD) age of 34.8 ± 17.1 years. Two hundred sixty-eight (67%) of them were male. Seventy-six (19%) of patients had a BD of -6 or lower. Sixty-eight (17%) of them showed to have intra-abdominal injury with a BD of approximately -8.7 ± 3.2, compared with patients without intra-abdominal injury, -0.4 ± 0.1. Patients with a BD of -6 or lower achieved more laparotomy and blood transfusion compared with patients with a BD more than -6. On receiver operating characteristic curve analysis, the cutoff point of -6 was obtained with sensitivity and specificity of 88.2% and 95.2% and with positive and negative predictive values of 79% and 97.5%, respectively. None of outpatients had abdominal problem in telephone follow-up.

CONCLUSIONS

These data show that the BD is an early available important indicator to identify intra-abdominal injury in patients with blunt abdominal trauma, as well as a high transfusion requirement.

Advances in Abdominal Trauma

Emergency practitioners routinely encounter patients who suffer from abdominal trauma, be it blunt or penetrating. These injuries are often confounded by altered mental status, distracting injuries, or lack of historical information, and may present challenges in management. However, in the last several years new approaches to the diagnosis and management of abdominal trauma, including bedside ultrasound, newer generation computed tomography scans, laparoscopy, and the ability for selected nonoperative management expedite identification of life threatening injury and offer new options in 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.

Trauma in the anticoagulated patient

An increasing number of people are taking anticoagulants for the prophylaxis of thromboembolic disease. This may cause problems when they attend hospital following trauma. Patients may also develop spontaneous bleeding that may have similar effects to bleeding after an injury.

This article discusses the risks of bleeding (especially in head injury); the risks of stopping anticoagulation; how anticoagulation should be reversed and how anticoagulation should affect the approach to the head-injured patient.

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.

Evaluation of blunt abdominal trauma: current practice in Taiwan

OBJECTIVE

To gain an overview of the current practice of different major institutions in Taiwan in the evaluation of abdominal injuries. A further comparison was made between general surgeons and emergency physicians in this aspect.

METHOD

A telephone survey was conducted of all emergency departments of 58 major institutions (14 medical centres, 44 district hospitals) that are capable of providing definitive care for trauma victims in Taiwan in June 2002. Respondents were asked to select the diagnostic modality of choice in the evaluation of a haemodynamically abnormal blunt trauma victim with suspected intra-abdominal injuries. In the same study period, this particular telephone scenario was also used to survey 109 individual doctors (45 emergency physicians, 64 general surgeons).

RESULTS

Most respondents preferred ultrasound (also known as focused assessment with sonography for trauma or "FAST") instead of diagnostic peritoneal lavage (DPL) because DPL is invasive and most doctors in Taiwan have limited experience in performing DPL or interpreting the results.

CONCLUSIONS

It seems reasonable to devote greater resources for emergency departments to incorporate a FAST based algorithm into their initial management of trauma victims, and to improve training in its use. It is also suggested that future ATLS teaching in Taiwan should include didactic material on FAST.

Hollow visceral injury after blunt lower thoracic and abdominal trauma

The early diagnosis of hollow viscous injury after blunt abdominal trauma remains a challenge for physicians in the Emergency Department, although the early diagnosis of hollow viscous injury decreases morbidity and mortality. After a description of two cases of hollow viscous injury after blunt abdominal trauma, a literature review is performed concerning the indications and limitations of diagnostic imaging modalities. Focused abdominal sonography for trauma, computed tomography scan and diagnostic peritoneal lavage are described. On the basis of the review a proposal for maximal diagnostic accuracy is made.

Systematic review and meta-analysis of emergency ultrasonography for blunt abdominal trauma

BACKGROUND

How precise and reliable is ultrasonography as a primary tool for injury assessment in blunt abdominal trauma?

METHODS

A systematic review and meta-analysis were conducted of prospective clinical trials of ultrasonography for blunt abdominal trauma. Publications were retrieved by structured searching among databases, review articles and major text books. Authors and experts in the field were contacted for original and unpublished data. For statistical analysis, summary receiver operating characteristic curves (SROCs) were computed using weighted and robust regression models, with Q* denoting the shoulder of the curve. Post-test probabilities were calculated as a function of pooled likelihood ratios (LRs).

RESULTS

Thirty of 123 trials enrolling 9047 patients were eligible for final analysis. With respect to targeting organ lesions, ultrasonography showed a summary Q* value of 0.91 (inverse variance weights, 95 per cent confidence interval (c.i.) 0.76-1.07); negative predictive values ranged from 0.72 to 0.99. A similar SROC slope was calculated for screening for free fluid (Q* = 0.89 (95 per cent c.i. 0.73-1.05)). Ultrasonography detects the presence of organ lesions, but fails to exclude abdominal injuries (random effects negative LR 0.23 (95 per cent c.i. 0.18-0.28)). Given a pretest probability of 50 per cent for blunt abdominal injury, a post-test probability of nearly 25 per cent remains in the case of a negative sonogram.

CONCLUSION

Despite its high specificity, ultrasonography has an unexpectedly low sensitivity for the detection of both free fluid and organ lesions. In clinically suspected abdominal trauma, another assessment (e.g. helical computed tomography) must be performed regardless of the initial ultrasonographic findings.