Test characteristics of focused assessment of sonography for trauma for clinically significant abdominal free fluid in pediatric blunt abdominal trauma

Identification of blunt abdominal injuries in children

BACKGROUND

The use of computed tomography (CT) to screen for injuries in pediatric blunt abdominal trauma (BAT) is increasing, concurrent with increasing concern over long-term risk of radiation-associated malignancies. We proposed to determine features that could be identified in the early assessment of these patients, which can predict the likelihood of clinically important intra-abdominal injuries warranting imaging by CT. We further queried if these were discrepant from factors associated with the decision to obtain an abdominal CT.

METHODS

Data of patients admitted with BAT to one of two Level I pediatric trauma centers were reviewed retrospectively. Clinical, laboratory, radiographic, and epidemiologic data were collected. Logistic regression was used to determine associations between pre-CT findings and ultimate diagnoses of "notable" or "clinically important" intra-abdominal injuries. Similar analyses were performed to determine which findings were associated with actually receiving an abdominal CT scan.

RESULTS

Of 571 patients, 37% had a notable intra-abdominal injury and 18% a clinically important intra-abdominal injury. After adjusting for all covariates, hematuria (gross or microscopic), elevated serum alanine aminotransferase, and documentation of clinically concerning abdominal findings upon examination remained significant predictors (odds ratio (OR), 3.5; 95% confidence interval [CI], 1.8-6.8; OR, 10.9; 95% CI, 2.5-47, respectively) of a clinically important injury. Undergoing a CT head and the presence of hematuria were significantly associated with obtaining a CT of the abdomen (OR, 3.4; 95% CI, 1.5-7.7; OR, 2.9; 95% CI, 1.1-7.3, respectively), while concerning abdominal findings and decreased Glasgow Coma Scale (GCS) score were not.

CONCLUSION

Clinical variables may be used to predict intra-abdominal injuries after pediatric BAT that may warrant imaging with CT scanning. Combined with findings from similar studies, it may be possible to derive and validate a decision-making rule both sensitive and specific in predicting the need for abdominal CT scanning in these patients.

LEVEL OF EVIDENCE

Prognostic study, level III.

Emerging concepts in pediatric emergency radiology

Radiologic studies are a vital component in the workup and diagnosis of disease. An appropriate radiographic study will accurately rule in or rule out disease with the least possible harm. Special considerations are necessary for the imaging of children. Current trends in pediatric imaging support the increased use of ultrasound and magnetic resonance imaging to decrease radiation exposure. In this review, we highlight some of the emerging concepts in the radiographic workup of pediatric disease, with a focus on decreasing ionizing radiation, increasing ultrasound use, and using clinical decision rules to identify children who do not need imaging.

The role of focused abdominal sonography for trauma (FAST) in pediatric trauma evaluation

PURPOSE

With increasing concerns about radiation exposure, we questioned whether a structured program of FAST might decrease CT use.

METHODS

All pediatric trauma surgeons in our level 1 pediatric trauma center underwent formal FAST training. Children with potential abdominal trauma and no prior imaging were prospectively evaluated from 10/2/09 to 7/31/11. After physical exam and FAST, the surgeon declared whether the CT could be eliminated.

RESULTS

Of 536 children who arrived without imaging, 183 had potential abdominal trauma. FAST was performed in 128 cases and recorded completely in 88. In 48% (42/88) the surgeon would have elected to cancel the CT based on the FAST and physical exam. One of the 42 cases had a positive FAST and required emergent laparotomy; the others were negative. The sensitivity of FAST for injuries requiring operation or blood transfusion was 87.5%. The sensitivity, specificity, PPV, and NPV in detecting pathologic free fluid were 50%, 85%, 53.8%, and 87.9%.

CONCLUSIONS

True positive FAST exams are uncommon and would rarely direct management. While the negative FAST would have potentially reduced CT use due to practitioner reassurance, this reassurance may be unwarranted given the test's sensitivity.

Sonographic Detection of Abdominal Free Fluid: Emergency Residents vs Radiology Residents

Background

Focused assessment with sonography for trauma (FAST) has become a part of initial examinations in trauma care at emergency departments (ED).

Objectives

The goal of the present study was to evaluate the accuracy of FASTs performed by emergency residents (ER) in detection of abdominal free fluid following blunt trauma.

Materials and Methods

In this study, the reports of ERs performing FASTs on 286 admitted patients following blunt trauma were compared with those of radiology residents (RR) in relation to presence of abdominal free fluid. In addition, the reports of the two resident groups were compared with the final abdominal outcome, based on the results of abdominal computed tomography (CT) and clinical follow up.

Results

The ERs had reported abdominal free fluid in 20 (6.9%) patients while RRs performing FAST had positive results in 22 (7.6%) patients. The reports of FASTs revealed significant correlation between the two resident groups (P < 0.001). ERs performing FASTs had 90% sensitivity and 98.5% specificity in comparison to RRs sonography reports. Furthermore, ER-performed FASTs had 96.5% accuracy in relation to final outcome.

Conclusions

Following training, ED residents can perform FAST with high accuracy and specificity, similar to RR residents, in patients with blunt abdominal trauma.

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

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

Use of emergency ultrasound in United States pediatric emergency medicine fellowship programs in 2011

OBJECTIVES

The purpose of this study was to evaluate the use of and training in emergency ultrasound (US) in pediatric emergency departments (EDs) with pediatric emergency medicine (EM) fellowship programs. We hypothesized that emergency US use and pediatric EM fellow training have become widespread and that more structured training is being offered.

METHODS

A survey instrument was sent via e-mail to all 69 United States pediatric EM fellowship directors or associate directors in the spring of 2011. We used descriptive summary statistics and χ(2) tests to determine characteristics associated with having a formal emergency US training program for pediatric EM fellows.

RESULTS

The survey response rate was 87% (60 of 69). Among responding programs, 40 (67%) resided within a children's hospital (versus general ED). Fifty-one (85%) were designated level 1 pediatric trauma centers. Fifty-seven programs (95%) endorsed the use of emergency US in their EDs. Fifty-three (88%) provided at least some emergency US training to fellows, and 42 (70%) offered a structured emergency US rotation. Training has existed for a median of 3 years (interquartile range, 2-4 years). Twenty-eight programs (67%) with emergency US rotations provided fellow training in the both a general ED as well as a pediatric ED. There were no hospital or program level factors statistically associated with having a formal training program for pediatric EM fellows.

CONCLUSIONS

As of 2011, nearly all pediatric EDs with pediatric EM fellowship programs use emergency US. Pediatric EM fellowship programs provide emergency US training to their fellows, with a structured rotation being offered by most of these programs.

Blunt abdominal trauma in children

PURPOSE OF REVIEW

This review will examine the current evidence regarding pediatric blunt abdominal trauma and the physical exam findings, laboratory values, and radiographic imaging associated with the diagnosis of intra-abdominal injuries (IAI), as well as review the current literature on pediatric hollow viscus injuries and emergency department disposition after diagnosis.

RECENT FINDINGS

The importance of the seat belt sign on physical examination and screening laboratory data remains controversial, although screening hepatic enzymes are recommended in the evaluation of nonaccidental trauma to identify occult abdominal organ injuries. Focused Assessment with Sonography for Trauma (FAST) has modest sensitivity for hemoperitoneum and IAI in the pediatric trauma patient. Patients with concern for undiagnosed IAI, including bowel injury, may be considered for hospital admission and serial abdominal exams without an increased risk of complications, if an exploratory laparotomy is not performed emergently.

SUMMARY

Although the FAST exam is not recommended as the sole screening tool to rule out IAI in hemodynamically stable trauma patients, it may be used in conjunction with the physical exam and laboratory findings to identify children at risk for IAI. Children with a normal physical exam and normal abdominal CT may not require routine hospitalization after blunt abdominal trauma.