Screening US for blunt abdominal trauma: a retrospective study.

PURPOSE

To assess the accuracy of screening US in patients with blunt abdominal trauma first admitted in the trauma centre of our general hospital.

MATERIALS AND METHODS

The reports of 864 abdominal US examinations of primary trauma patients (139 with major and 725 with minor injuries) obtained with standard protocols were retrieved. For each case, US reports were reviewed and compared to the best available reference standard. The accuracy of US was assessed by evaluating the method's overall ability to distinguish negative from positive cases by showing at least one of the lesions documented by the reference standard and its specific ability to depict injuries separately and independently.

RESULTS

US exhibited a satisfactory overall ability to distinguish negative from positive patients (91.5% sensibility and 97.5% specificity in major trauma patients vs. 73.3% sensibility and 98.1% specificity in minor trauma patients) and a satisfactory specific ability to depict injuries separately and independently in major trauma patients. Of the 21/864 false negative reports (5 in patients with major and 16 in cases with minor trauma), only one affected patient management, a major trauma case, by delaying an emergency laparotomy.

CONCLUSIONS

Its satisfactory accuracy for major trauma suggests that US could be employed not only to screen cases for emergency laparotomy but also as an alternative to screening CT. However, since major traumatic injuries generally carry an imperative indication for CT, especially as regards neurological, thoracic and skeletal evaluation, US has the not secondary task of performing a prompt preliminary examination using a simplified technique in the emergency room simultaneously with resuscitation.