Diagnosing poststernotomy mediastinitis in the ED

Poststernotomy mediastinitis (PSM), the severe chest wall and mediastinal infection that may arise at any time after a sternotomy, causes significant morbidity and mortality globally. Late recognition and diagnosis are the major contributors to a poor outcome. This review focuses on recent advances in diagnosing PSM (particularly after cardiovascular surgery) at the earliest opportunity--in the emergency department.

Morbidity and mortality of PSM, especially when associated with numerous other complications, remain unaltered high. Careful history taking and clinical examination remain the mainstays of a preliminary diagnosis. No specific signs are indicative of PSM alone. Procalcitonin as a biomarker and neutrophil volume distribution width obtained during a complete blood count with differential, assessed in the clinical context, offer interesting prospects of obtaining a speedy and accurate diagnosis. Adjunctive diagnostic imaging modalities such as contrast-enhanced computed tomography can differentiate PSM from postcardiac injury syndrome and other causes of vague chest pain some time after sternotomy with increasing accuracy.

The speed and accuracy of diagnosing PSM have improved with recent advances in imaging and laboratory methodologies. In the symptomatic patient with a closed sternotomy wound or scar, with either fever (>38°C) or sternal instability, together with well-described signs on contrast-enhanced computed tomography, in whom other life-threatening causes of chest pain have been excluded, the diagnosis of PSM can be made without awaiting the outcome of microbiological confirmation. Nevertheless, there still remain significant research opportunities for clinicians and scientists to improve the early diagnostic accuracy of PSM.