What does ultrasonography miss in blunt trauma patients with a low Glasgow Coma Score (GCS)?

Background: The role of ultrasound (US) as a screening tool for the evaluation of blunt abdominal trauma is still controversial. Determining the types of missed injuries and the accuracy of US in patients with a low GCS will improve the evaluation of these blunt trauma patients.
Methods: Prospectively collected data from the trauma registry of a Level I trauma center was reviewed.
Results: 7,952 patients were included in the study. US examination had an accuracy of 89%, sensitivity of 77%, specificity of 97%, positive predictive value (PPV) of 78%, and negative predictive value (NPV) of 98%. GCS correlated with ISS and base deficit levels. US examination had a significantly lower accuracy in patients with a low GCS and in women.
Conclusion: The sensitivity and specificity of US examination is similar in those with normal and low GCS. Therefore ultrasonographic examination may be considered a good screening tool for the evaluation of patients with blunt abdominal trauma, but its accuracy is diminished in patients with a low GCS. Further imaging may be warranted in these patients.