The Advantages of Using FAST

Focused Assessment with Sonography in Trauma (FAST) has largely replaced DPL which, while sensitive, is regarded as invasive, compromising other investigations and time consuming. 

The advantage of FAST is that it can be repeated as many times as necessary. It can be carried out during clinical assessment, within minutes of the patient arriving and before any other investigation, such as CT, can be organized. It can also be carried out on an unstable patient where a CT requires the patient to be stable. 

As in most aspects of emergency medicine ultrasound it should be operated on a ‘rule in’, not a rule out principle, i.e. there is no such thing as a normal FAST. This is important when communicating findings to colleagues. It is appropriate to say that free fluid has not been seen, but this should be qualified by the statement that this does not mean that bleeding is not occurring.