Emergency focussed assessment with sonography in trauma (FAST) and haemodynamic stability

Abstract

Background: Focussed assessment with sonography in trauma (FAST) has assumed a key role in the rapid non-invasive assessment of thoracoabdominal trauma and assists in decreasing disposition time. This study evaluates FAST's efficacy with respect to haemodynamic stability in a South African emergency department (ED).

Methods: Data were collected prospectively by four emergency medicine doctors trained in emergency ultrasonography. FAST scans were performed by one ED doctor and timings, scan result and disposition were recorded. Patient haemodynamic stability was assessed by the emergency doctor performing the scan; subjectively at the time of scanning and objectively using calculation of the shock index. All scan results were subsequently verified by a second ED doctor in a blinded fashion and by CT scanning or operative intervention when clinically indicated.

Results: 166 FAST scans were conducted of which 36 (21.7%) were positive. Mean age was 30.6 years (SD 12.8). 74.1% of patients sustained blunt traumatic injury. Doctors' subjective haemodynamic stability assessments had higher specificity, sensitivity and predictive values than shock index alone. Haemodynamic instability and a positive FAST result were significantly related (p=0.004). Sensitivities and specificities of FAST scans for blunt and penetrating trauma were 93.1% and 100%, and 90.0% and 100%, respectively. Corresponding values for pneumothoraces were 84.6% and 100%.

Discussion: This study showed a valuable role for FAST in all traumas, particularly in haemodynamic compromise. As an addition to the physician's repertoire of bedside assessment tools, it improves diagnostic capabilities in comparison with simple haemodynamic assessments alone.

Keywords: Trauma; clinical assessment; emergency department; non invasive; ultrasound.