Establishing the etiology of tachycardia in a trauma patient is often difficult. Pediatric trauma patients present an even tougher challenge. Cardiac contusion should be suspected when other more common traumatic injuries that produce hypoxia and blood loss are excluded. The diagnosis of cardiac contusion is notoriously difficult to make largely due to the controversy over the definition of the disease, and the lack of a true gold standard confirmatory test. Atrioventricular nodal reentrant tachycardia (AVNRT) is a common form of supraventricular tachycardia (SVT) that can also present a diagnostic challenge to emergency physicians. While electrophysiologic studies are the gold standard for confirming the diagnosis, there are certain aspects of the history, electrocardiogram (ECG), and responses to cardiac maneuvers that strongly suggest the diagnosis. We present the case of a pediatric trauma patient that presented with new onset AVNRT masquerading as cardiac contusion.

Introduction: Arterial lines are important for monitoring critically ill patients. They are placed most commonly in either femoral or radial sites, though there is little evidence to guide site preference.

Methods: This is an ambispective, observational, cohort study to determine variance in failure rates between femoral and radial arterial lines. This study took place from 2012 to 2016 and included all arterial lines placed in adult patients at a single institution. Causes of line failure were defined as inaccuracy, blockage, site issue, or accidental removal. The primary outcome was line failure by location. Secondary outcomes included time to failure and cause of failure.

Results: We evaluated 272 arterial lines over both arms of the study. Fifty-eight lines eventually failed (21.32%). Femoral lines failed less often in both retrospective (5.36% vs 30.71%) and prospective (5.41% vs. 25.64%) arms. The absolute risk reduction of line failure in the femoral site was 20.2% (95% confidence interval [3.7 - 36.2%]). Failures occurred sooner in radial sites compared to femoral. Infection was not a significant cause of removal in our femoral cohort.

Conclusion: Femoral arterial lines fail much less often then radial arterial lines. If placed preferentially in the femoral artery, one line failure would be prevented for every fourth line.