Ultrasonography in thoracic and abdominal stab wound injury: results from the FETTHA study

Background: While the role of Extended Focused Assessment with Sonography in Trauma (eFAST) is well defined in the management of severe blunt trauma, its performance in injuries caused by stab wounds has been poorly assessed.

Methods: Prospective single centre study which included all patients with stab wounds to the thorax or abdomen between December 2016 and December 2018. All patients underwent initial investigation with both eFAST and CT scan, except in cases of haemodynamic or respiratory instability, and in cases with a positive diagnosis by eFAST in which case surgery without CT scan was performed.

Results: Of the 200 consecutive patients included, 14 unstable patients underwent surgery immediately after eFAST. In these 14 patients, 9 had cardiac tamponade identified by eFAST and all were confirmed by surgery. In the remaining 186 patients, the median time between eFAST and CT scan was 30 min (IQR 20-49 min). Test characteristics (including 95% CI) for eFAST compared with reference standard of CT scan for detecting pneumothorax were as follows: sensitivity 77% (54%-92%), specificity 93% (90%-97%), positive predictive value (PPV) 60% (49%-83%), negative predictive value (NPV) 97% (93%-99%). Test characteristics (including 95% CI) for eFAST compared with CT scan for detecting haemothorax were as follows: sensitivity 97% (74%-99%), specificity 96% (92%-98%), PPV 83% (63%-93%) and NPV 99% (96%-100%). Finally, test characteristics (including 95% CI) for eFAST compared with CT scan for detecting haemoperitoneum were as follows: sensitivity 75% (35%-97%), specificity 97% (93%-99%), PPV 55% (23%-83%) and NPV 99% (96%-99%).

Conclusions: In patients admitted with stab wounds to the torso, eFAST was not sensitive enough to diagnose pneumothorax and haemoperitoneum, but performed better in the detection of cardiac tamponade and haemothorax than the other injuries. More robust multicentre studies are needed to better define the role of eFAST in this specific population.