Usefulness of CT-scan in the management of chest stab trauma: a prospective observational study

The management of chest stab wounds necessitates to perform an efficient imaging strategy. Compared to chest X-ray, computed tomography (CT) scan has a higher sensitivity. Nevertheless, the utility of diagnosing occult injuries remains controversial. Previous studies reported very different rates of management modifications induced by CT-scan. Indeed, no study specifically addressed the issue of ruling out traumatic diaphragmatic injury (TDI) in the specific population of chest stab trauma. The aim of the study was to evaluate the rate of thoracic procedures induced or guided by the results of thoracic CT-scan in the specific population of chest stab wounds. Secondary objective was to evaluate the utility of CT-scan for the diagnosis of TDI.

We conducted a prospective observational study. All consecutive patients referred to the acute care unit were included. We recorded the general characteristics of patients, the localization of wounds, all imaging tests, the final injury diagnosis, and the patients' management. We compared patients with modifications of management induced by CT-scan results to other patients. We evaluated the performance of CT-scan for the diagnosis of TDI by calculating its sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV).

153 patients were included. There were 92 patients with normal chest X-ray. 67 of them received a CT-scan. 34 (51%) patients had an abnormal CT-scan, including 19 (21%) patients with thoracic new findings, with 3 (4.5%) modification of management. There were 50 patients who had an abnormal chest X-ray. 31 of them received a CT-scan, and 31 (100%) had an abnormal CT-scan, including 19 thoracic new findings, with 11 (36%) modifications of management. The diagnostic performance of CT-scan for TDI was: sensitivity 50%; specificity 95%; NPV 72%; PPV 88%.

In chest stab trauma, CT-scans may be unnecessary outside the thoracoabdominal zone when chest X-ray is normal. In other cases, CT-scan seems to have an impact on the decision-making. In case of thoracoabdominal wounds, CT-scan helps to detect intra-abdominal injuries. The performance of CT-scan to diagnose TDI is not high enough to reliably rule out all TDI.