Original article
William T. Thorwarth award paper
The Role of Negative CT of the Abdomen and Pelvis in the Decision to Admit Adults From the Emergency Department After Blunt Trauma

https://doi.org/10.1016/j.jacr.2005.06.013Get rights and content

Rationale and Objectives

Computed tomography (CT) is widely used in the initial evaluation of blunt trauma patients and is associated with a high rate of negative imaging. A described benefit of negative imaging is prompt discharge. This study examined a single level 1 trauma center to determine whether adult blunt trauma patients are discharged from the emergency department (ED) after negative CT of the abdomen and pelvis (CT AP).

Materials and Methods

The authors retrospectively created a data set of adult blunt trauma patients who received CT AP in the ED from August to November 2003. Statistical analysis of admission rates on the basis of positivity or negativity on CT AP was performed to determine if the test influenced admission rates. Additional subgroup analysis was made between the patients admitted with negative CT AP and those who were discharged from the ED.

Results

Two thirds (316/469) had negative CT AP. Whereas 80.4% of the patients (254/316) with negative CT AP were admitted, 98.0% (148/151) with positive CT AP were admitted, a statistically significant difference in admission rate (P < .0001). The vast majority (208/254, 81.9%) of patients with negative CT AP were admitted for extra-abdominal injuries. There was no statistical difference in the characteristics of a subgroup of 45 patients who were admitted without any documented injuries from the group discharged from the ED in terms of age, gender, comorbidity, Glasgow Coma Scale score, or intoxication.

Conclusion

Under current practice, negative CT AP after blunt trauma results in a statistically significant decrease in admissions.

Introduction

The technology available to clinicians today is increasingly more sensitive than the tools available to prior generations. These sensitive tools allow physicians to provide better care to patients. Improvements in quality almost always are accompanied by increased cost, which must be weighed against the benefit provided by a test [1]. In the case of blunt trauma, the established benefits of positive computed tomography (CT) have resulted in the widespread use of CT as a screening tool of trauma patients in emergency departments (EDs) [2, 3, 4, 5, 6, 7].

However, the value of a negative examination is not as defined. In 1998, Livingston et al [8] published a multi-institutional prospective trial in the Journal of Trauma demonstrating that admission for observation after negative abdominal CT in blunt abdominal trauma patients was not necessary. They postulated that the adoption of this policy into clinical practice would result in a substantial benefit to the medical system in terms of cost and resource utilization, without resulting in harm to individual patients.

Our study used a retrospectively created cohort of trauma patients in a single busy level 1 trauma center to determine if these benefits of negative imaging have translated into clinical practice. We hypothesized that negative CT of the abdomen and pelvis (CT AP), in the setting of blunt trauma, would be associated with a significantly lower admission rate.

Section snippets

Materials and methods

Our medical center is an 821-bed, level 1 trauma center, as designated by the state of North Carolina. Over the past 5 years, the number of trauma evaluations has been steadily increasing. In 2002, 2,169 adult trauma patients were evaluated, and in 2003, 2,410 adult trauma patients were evaluated. Using the picture archiving and communication system at our institution, a retrospective data set of patients who received CT AP in the ED was created.

The data set consists of all patients scanned by

Results

A search of the picture archiving and communication system database for patients who received CT scans of the abdomen and pelvis from August 1, 2003 to November 30, 2004, for trauma-related indications yielded 527 patients. The final group of 469 patients was created after excluding 8 patients for evaluation more than 24 hours after the traumatic event, 2 patients for penetrating trauma, 1 for an incomplete medical record, and 47 for age less than 18 years. Our medical center has a separate

Discussion

In the era before the common availability of body CT and ultrasound in the emergency room, the principal diagnostic tools used to evaluate for blunt trauma injuries were limited. These included the physical examination; laboratory and radiographic examinations, including excretory urography and angiography; exploratory laparotomy; and clinical observation. Computed tomography was initially used in blunt trauma patients in whom physical examinations were unreliable or difficult to obtain.

Conclusion

At our institution, negative CT AP in the ED evaluation of adult blunt trauma patients did result in a significantly lower admission rate, an important benefit of the test. Our evaluation of the current trauma literature suggests that the considerable information provided by rapid and thorough CT scanning of adult blunt trauma patients, whether the results are positive or negative, outweighs the costs and risks associated with the increase in technology utilization.

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    Editor’s Note: The Thorwarth Award is presented by the ACR at the AUR Annual Meeting for the best paper submitted on health economics.

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