O42 – Use of Computed Tomography to Diagnose Aspiration in Trauma Patients

Author(s):

Vanessa Fawcett, Joseph Cuschieri, Heemun Kwok, David Carlbom, Joel Gross, Heather Evans, University of Washington

Background: While aspiration is linked to the development of respiratory complications following injury, the diagnosis remains challenging.

Hypothesis: Chest computed tomographic (CT) scans can contribute to the diagnosis of aspiration and the prediction of poor clinical outcomes in trauma patients.

Methods: We employed an existing dataset of ventilated adult trauma patients prospectively assessed for clinical evidence of aspiration during intubation. Patients who underwent chest CT imaging within 24 hours of hospital arrival were included in the analysis. A single radiologist, blinded to the clinical condition of the patients, retrospectively reviewed the CT images. Using the following pre-determined scoring system, the likelihood of aspiration was assessed: 0=None, 1=Possible, 2=Probable, 3=Definite. Descriptive statistics and univariate analyses were used to compare patient characteristics, injury severity, and outcome by CT aspiration score (CTAS).

Results: 163 patients met the inclusion criteria. There were no differences in patient characteristics when compared by CTAS. Higher CTAS was associated with higher injury severity scores (mean group ISS 17.0±3.3 vs 21.8±1.5 vs 27.9±2.7 vs 45.0±5.0, p<0.01 by ANOVA), especially severe thoracic injuries (mean group maximum thoracic AIS 0.5±0.2 vs 1.4±0.2 vs 2.2±0.3 vs 2.7±0.9, p<0.01 by ANOVA). Table 1 displays patient outcomes. Patients with higher CTAS showed a trend towards increased hospital and ICU length of stay (LOS). As CTAS increased, the likelihood of developing pneumonia also increased. Using ordered logistic regression controlling for maximum thoracic AIS, we observed that evidence of clinical aspiration predicted CTAS (p<0.001).

Conclusions: In the absence of an established gold standard, our chest CT aspiration score provides a new approach to the diagnosis of aspiration in trauma patients. The strong relationship between thoracic AIS scores and evidence of aspiration on chest CT reflects the challenge of discrimination between pulmonary aspiration and chest injury. However, higher CTAS was associated with worse clinical outcomes, including higher rates of pneumonia, reinforcing the negative impact of early injury-associated events.