National risk factors for blunt cardiac injury: Hemopneumothorax is the strongest predictor

Cardiac Trauma: A Review of Penetrating and Blunt Cardiac Injuries

Cardiac injuries pose challenging diagnostic and management dilemmas. Cardiac trauma can be classified by mechanism into blunt and penetrating injuries. Penetrating trauma has an overall higher mortality and is more likely to require operative intervention. Due to the lethality of any cardiac injury, prompt diagnosis and treatment is critical for survival. The initial management of suspected cardiac injury should start with Advanced Trauma Life Support (ATLS) protocols followed shortly by directed diagnosis and management, which usually begins with a focused assessment with sonography in trauma (FAST) examination. In contrast to traditional ATLS protocols, some centers have adopted an assessment of "circulation before "airway" and "breathing"; however, this is an evolving concept. In this article, we provide an overview on the management of penetrating and blunt cardiac injuries, including use of physical exam, laboratory tests, imaging, and surgery.

Re-evaluating the Use of High Sensitivity Troponin to Diagnose Blunt Cardiac Injury

INTRODUCTION

Blunt cardiac injury (BCI) can be challenging diagnostically, and if misdiagnosed, can lead to life-threatening complications. Our institution previously evaluated BCI screening with troponin and electrocardiogram (EKG) during a transition from troponin I to high sensitivity troponin (hsTnI), a more sensitive troponin I assay. The previous study found an hsTnI of 76 ng/L had the highest capability of accurately diagnosing a clinically significant BCI. The aim of this study was to determine the efficacy of the newly implemented protocol.

METHODS

Patients diagnosed with a sternal fracture from March 2022 to April 2023 at our urban level-1 trauma center were retrospectively reviewed for EKG findings, hsTnI trend, echocardiogram changes, and clinical outcomes. The BCI cohort and non-BCI cohort ordinal measures were compared using Wilcoxon's two-tailed rank sum test and categorical measures were compared with Fisher's exact test. Youden indices were used to evaluate hsTnI sensitivity and specificity.

RESULTS

Sternal fractures were identified in 206 patients, of which 183 underwent BCI screening. Of those screened, 103 underwent echocardiogram, 28 were diagnosed with clinically significant BCIs, and 15 received intervention. The peak hsTnI threshold of 76 ng/L was found to have a Youden index of 0.31. Rather, the Youden index was highest at 0.50 at 40 ng/L (sensitivity 0.79 and specificity 0.71) for clinically significant BCI.

CONCLUSIONS

Screening patients with sternal fractures for BCI using hsTnI and EKG remains effective. To optimize the hsTnI threshold, this study determined the hsTnI threshold should be lowered to 40 ng/L. Further improvements to the institutional protocol may be derived from multicenter analysis.

Risk factors and outcomes in pediatric blunt cardiac injuries

PURPOSE

Unlike adults, less is known of the etiology and risk factors for blunt cardiac injury (BCI) in children. Identifying risk factors for BCI in pediatric patients will allow for more specific screening practices following blunt trauma.

METHODS

A retrospective review was performed using the Trauma Quality Improvement Program (TQIP) database from 2017 to 2019. All patients ≤ 16 years injured following blunt trauma were included. Demographics, mechanism, associated injuries, injury severity, and outcomes were collected. Univariate and multivariate regression was used to determine specific risk factors for BCI.

RESULTS

Of 266,045 pediatric patients included in the analysis, the incidence of BCI was less than 0.2%. The all-cause mortality seen in patients with BCI was 26%. Motor-vehicle collisions (MVCs) were the most common mechanism, although no association with seatbelt use was seen in adolescents (p = 0.158). The strongest independent risk factors for BCI were pulmonary contusions (OR 15.4, p < 0.001) and hemothorax (OR 8.9, p < 0.001).

CONCLUSIONS

Following trauma, the presence of pulmonary contusions or hemothorax should trigger additional screening investigations specific for BCI in pediatric patients.

Evaluating the Utility of High Sensitivity Troponin in Blunt Cardiac Injury

INTRODUCTION

Screening for blunt cardiac injury (BCI) includes obtaining a serum troponin level and an electrocardiogram for patients diagnosed with a sternal fracture. Our institution has transitioned to the use of a high sensitivity troponin I (hsTnI). The aim of this study was to determine whether hsTnI is comparable to troponin I (TnI) in identifying clinically significant BCI.

MATERIALS AND METHODS

Trauma patients presenting to a level I trauma center over a 24-mo period with the diagnosis of sternal fracture were screened for BCI. Any initial TnI more than 0.04 ng/mL or hsTnI more than 18 ng/L was considered positive for potential BCI. Clinically significant BCI was defined as a new-bundle branch block, ST wave change, echocardiogram change, or need for cardiac catheterization.

RESULTS

Two hundred sixty five patients with a sternal fracture were identified, 161 underwent screening with TnI and 104 with hsTnI. For TnI, the sensitivity and specificity for detection of clinically significant BCI was 0.80 and 0.79, respectively. For hsTnI, the sensitivity and specificity for detection of clinically significant BCI was 0.71 and 0.69, respectively. A multivariate analysis demonstrated the odds ratio for significant BCI with a positive TnI was 14.4 (95% confidence interval, 3.9-55.8, P < 0.0001) versus an odds ratio of 5.48 (95% confidence interval 1.9-15.7, P = 0.002) in the hsTnI group.

CONCLUSIONS

The sensitivity of hsTnI is comparable to TnI for detection of significant BCI. Additional investigation is needed to determine the necessity and interval for repeat testing and the need for additional diagnostic testing.

Factors Associated with Cardiac/Pericardial Injury among Blunt Injury Patients: A Nationwide Study in Japan

The lack of established diagnostic criteria makes diagnosing blunt cardiac injury difficult. We investigated the factors associated with blunt cardiac injury using the Japan Trauma Data Bank (JTDB) in a multicenter observational study of blunt trauma patients conducted between 2004 and 2018. The primary outcome was the incidence of blunt cardiac/pericardial injury. Multivariable logistic regression analysis was used to identify factors independently associated with blunt cardiac injuries. Of the 228,513 patients, 1002 (0.4%) had blunt cardiac injury. Hypotension on hospital arrival (adjusted odds ratio (AOR) 4.536, 95% confidence interval (CI) 3.802–5.412), thoracic aortic injury (AOR 2.722, 95% CI 1.947–3.806), pulmonary contusion (AOR 2.532, 95% CI 2.204–2.909), rib fracture (AOR 1.362, 95% CI 1.147–1.618), sternal fracture (AOR 3.319, 95% CI 2.696–4.085). and hemothorax/pneumothorax (AOR 1.689, 95% CI 1.423–2.006)) was positively associated with blunt cardiac injury. Regarding the types of patients, car drivers had a higher rate of blunt cardiac injury compared to other types of patients. Driving a car, hypotension on hospital arrival, thoracic aortic injury, pulmonary contusion, rib fracture, sternal fracture, and hemothorax/pneumothorax were positively associated with blunt cardiac injury.

Blunt Cardiac Injury in Patients With Sternal Fractures

Background

Blunt cardiac injury (BCI) is a possible consequence of sternal fractures (SF). There is a scarcity of studies addressing BCI in patients with different types of SF and with pre-existing cardiac conditions. The goal of this study was to delineate diagnostic patterns of BCI in different cohorts of SF patients.

Methods

This retrospective cohort study included 380 blunt trauma patients admitted to two level 1 trauma centers between January 2015 and March 2020 with radiologically confirmed SF. Electrocardiography, cardiac enzymes and echocardiography were evaluated for BCI diagnosis. Analyzed variables included: age, comorbidities, injury severity score, Glasgow coma score, type of SF (isolated, combined, displaced), incidence of traumatic brain injury, co-injuries, retrosternal hematoma, intensive care unit admissions, hospital lengths of stay, and mortality.

Results

In 380 SF patients there were 250 (66%) females and 130 (34%) males and the mean age was 63 years old. Electrocardiography was done in all patients, cardiac enzymes in 234 (62%) and echocardiography in 181 (48%). BCI was diagnosed in 19 (5%) of patients, all having combined SF. BCI patients had higher injury severity score (mean 18.4) and 14 (74%) had pulmonary co-injuries. Multivariable analysis confirmed pulmonary co-injuries as a statistically significant predictor of BCI (p<0.001). BCI patients compared to no BCI patients had all three tests (electrocardiography, cardiac enzymes and echocardiography) performed statistically more often (90% vs 36%, p<0.001). SF patients with pre-injury cardiac comorbidities had similar incidence of BCI as without cardiac comorbidities (5% vs 6%, p=0.6). In SF patients with traumatic brain injury, cardiac enzymes (troponin, creatine kinase) were elevated significantly more often compared to patients without traumatic brain injury (58% vs 38%, p=0.02). SF displacement or retrosternal hematoma presence were not associated with BCI. Mortality in SF patients with BCI versus without was not statistically different (16 vs 9%, p=0.4).

Conclusions

Blunt cardiac injury is rare in patients with SF. Higher degree of BCI suspicion must be applied in combined SF patients, especially those with pulmonary co-injuries. Cardiac comorbidities did not affect the rate of BCI. Echocardiography for BCI diagnosis is essential in SF patients with traumatic brain injury, as cardiac enzymes may be less informative, however is less important in isolated SF patients. Performing all three diagnostic tests in combined SF patients improves the accuracy of BCI diagnosis.

Identification of a small pericardial effusion on contrast-enhanced computed tomography indicating cardiac perforation and pericardial injury following blunt trauma: A case report

Blunt trauma may cause cardiac perforation requiring emergency surgical repair. Cardiac perforations are usually diagnosed by the presence of a pericardial effusion on echocardiography. However, cardiac perforations and pericardial effusions are sometimes too small to detect, resulting in underdiagnosis. In this case report, we describe a 22-year-old man who was involved in a traffic accident, admitted in a state of shock, and was initially treated for tension pneumothorax and liver and spleen injuries. His initial computed tomography scans revealed a small region of enhancement, corresponding to a small pericardial effusion, indicative of a cardiac perforation. Thus, an emergency median sternotomy was performed. He was diagnosed with perforation of the left atrial ear and right atrium, which were repaired surgically. His liver and spleen injuries were also treated, and the patient was discharged 44 days after admission. The detection of a small pericardial effusion on enhanced computed tomography enabled rapid diagnosis of a cardiac perforation and ensured emergency surgical repair could be performed as soon as possible.

Learning objectives

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To acknowledge the difficulty of diagnosing cardiac perforation in patients with pericardial injury, based on conventional signs of blunt cardiac injury, such as sternal fracture, serum cardiac enzymes, and hemothorax.

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To recognize that a small pericardial effusion on enhanced computed tomography scans is an important finding that should raise suspicion of cardiac perforation and pericardial injury.