Incidence, predictors and outcomes of Blunt Cardiac injury among Trauma patients presenting to emergency department in Tanzania

Abstract

ABSTRACT Background: Blunt cardiac injury (BCI) incidence varies due to non-specific presentation and lack of diagnostic clinical gold standard. Standard of care in BCI screening involves use of electrocardiogram (ECG), troponin and echocardiogram (ECHO) but is often not done in Low and Middle Income Country (LMIC) despite high trauma burden. It is therefore uncertain whether we should use scarce resources to screen for BCI in these entity of patients with BCI among polytrauma or isolated blunt chest trauma. Moreover, it was not known whether patients who have abnormal findings on these tests in Emergency Department (ED) will receive a definitive test like echocardiogram and/or cardiac monitoring once admitted. We therefore aimed to do this sudy with the goal of developing a standard algorithm to guide use of scarce resources in LMIC to target BCI screening. Objectives: To establish the incidence, predictors and outcomes (48hour and 7-day) of blunt cardiac injury among patients with polytrauma or isolated blunt chest injury who attended the Emergency Department of a Tertiary Hospital in Tanzania. Methods: Prospective observational cohort study between September 2023-June 2024, with consecutive enrollment of polytrauma or isolated blunt chest trauma patients from September 2023 to February 2024 at the ED of Muhimbili National Hospital and Muhimbili Orthopedic Insititute in Tanzania. BCI was defined as abnormal ECG and elevated troponin. All patients received ECG and if abnormal, troponin was done. Patients meeting BCI criteria were followed up at 48 hours and 7 days after disposition for death and composite adverse events (Intubation for airway protection and/or mechanical ventilation, hypotension, cardiorespiratory arrest resuscitated). Logistic regression analysis was performed to identify independent predictors of BCI. Results: Seventy three of 315 patients screened had BCI, an incidence of 23.2% [95% CI: 18.6 %- 28.2%]. BCI patients had a median age 31years (IQR: 22.5 – 39.5), and were predominantly male 65(89%). Most were polytrauma 68(93.2%) with 57 (78.1%) involved in motor traffic accidents. Twenty four-hour cardiac monitoring was performed in 30 (41.1%) patients while ECHO was performed in one. Mortality at 48hours was 6.8% and 9.6% at 7 days. Composite adverse events at 48hours and 7 days was 39.7% and 42.5% respectively. Tachycardia on ED arrival, initial presenting GCS 12 and lung contusion were independent predictors of BCI (p<0.05). Conclusion: There is a significant incidence of BCI among polytrauma/isolated blunt chest trauma in our setting, suggesting the need to include BCI screening and cardiac monitoring guidelines in our trauma algorithms. Predictors of tachycardia, initial presenting GCS 12 and lung contusion can be used to target screening to conserve resource use.