The Chaos of Triage: A Model for Early Exclusion of Cardiac Injury in Chest Gunshot Wound Patients

Abstract IntroductionHeart injury caused by thoracic gunshot wounds (GSW) is especially life-threatening and require prompt diagnosis and treatment. Heart injury is especially life-threatening and requires prompt diagnosis and treatment. During the pre-hospital phase and initial triage in the emergency department (ED), early recognition of a patient with heart GSW is difficult but important. The purpose of this study was to evaluate the predictability of heart injury in patients with chest GSWs. MethodsThe National Trauma Data Bank was queried for patients with chest GSW treated at all US trauma centres from July 1, 2009, to June 30, 2016. Patients with and without heart injuries (ICD-9: 861.00-03, 861.10-13) were compared and analyzed. Multivariate logistic regression was performed to evaluate independent factors of heart injury which could be obtained during the pre-hospital or triage phase only. Step-backward selection was used to establish a model for such patients. We used the receiver operating characteristic (ROC) curve to test the accuracy of this model and Youden’s J statistic to find the cutoff value of sensitivity/specificity. Level 1 trauma registry data from Stroger Hospital of Cook County (July 1, 2016, to June 30, 2017) was used for external validation of this prediction model.Results47,044 patients with chest GSW were evaluated in the ED and 8.6% of them had heart injuries. The mortality rates of patients without cardiac injury versus those with cardiac injury were 9.0% (3864/42997) and 21.7% (879/4047) respectively. Patients with heart injuries were significantly younger (28.4 vs. 29.3, p<0.001), had lower SBP (34.7 vs. 103.8 mmHg, p<0.001), had lower GCS (5.1 vs. 11.2, p<0.001) and a higher probability of apnea (58.3% vs. 14.7%, p<0.001), higher rate of pulselessness (59.9% vs. 12.0%, p<0.001), and more self-inflicted injuries (9.7% vs. 8.5%, p<0.001) than patients without heart injuries. The cutoff values of SBP and GCS for prediction of heart injury were 61mmHg (AUC: 0.783) and 5.5 (AUC: 0.768) respectively. Integration of six independent factors (age, SBP, GCS, apnea, lack of pulse and suicide intent) with multivariate logistic regression showed an AUC: 0.823 and specificity of 88.8% in the heart injury prediction model. External validation with the local database showed 95.6% specificity.ConclusionEarly diagnosis of heart injury is important in the management of patients with chest GSWs. Our model has high specificity and can be beneficial for early triage of cardiac injury in patients with GSW to the chest.