Objective: The study sought to assess the test performance characteristics of clinical judgement in the evaluation of stable blunt chest trauma patients compared with chest radiography (CXR) in the determination of significant intra-thoracic injury.
Methods: We prospectively enrolled all adult patients (older than 16 years) who were considered to have stable blunt chest trauma over a six-month period (May 1−October 31, 2009). We defined the latter as patients who were unintubated, normotensive (systolic blood pressure > 90 mm Hg) and without hypoxia (oxygen saturation > 95% at room air). Patients eligible for the study were sent for anteroposterior (AP) CXRs which were then interpreted by the same consultant radiologist throughout the study period. Both test (clinical judgement) and disease status (CXR) were assigned and correlated as binary measures. We compared the test performance characteristics such as sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and diagnostic likelihood ratios of clinical judgement to CXR findings in the determination of significant intra-thoracic injury.
Results: During the six-month period, data were collected from 77 eligible stable blunt chest trauma patients (age over 16 years). Fifty-nine patients (76.6%) were male. Nine patients (11.7%) were radiologically confirmed to have significant blunt chest injuries including rib fractures, pneumothorax and an isolated case of pulmonary contusion. All nine (11.7%) patients had a positive (abnormal) radiograph for rib fractures. In addition, three (3.9%) of them also had both rib fracture and pneumothoraces and one (1.3%) had both a rib fracture and pulmonary contusion. Clinical judgement for the diagnosis of significant blunt chest injuries matched with the CXR finding with 95%confidence intervals (CIs): sensitivity 100% (95% CI 66.4, 100), specificity 32.4% (95% CI 21.5, 44.8), prevalence 11.7%, PPV 16.4% (95% CI 7.77, 28.8), NPV 100% (95% CI 84.6, 100), DLR+ 1.48 (95% CI 1.25, 1.74).
Conclusion: The majority of patients who sustained blunt chest injuries and were assessed as stable patients do not require CXR routinely. This study revealed that physicians in the local Emergency Department may be over-utilizing CXR for patients who have stable blunt chest trauma.