Cardiac vasoplegia syndrome: pathophysiology, risk factors and treatment.

Vasoplegia syndrome is a well known complication after cardiac surgery and has a significant morbidity and mortality. It is characterized by profound vasodilation and loss of systemic vascular resistance leading to hypotension. The pathogenesis of vasoplegia involves the activation of contact, coagulation and complement systems and the activation of leukocytes, platelets and endothelial cells resulting in an imbalance in the regulation of the vascular tone leading to postcardiac surgery vasoplegia. Multiple risk factors have been identified that help predict vasoplegia. Treatment requires mainly vasopressors, but hypotension can be refractory to vasopressors. Some studies suggest that methylene blue can reverse refractory hypotension in these patients and may prevent the development of the syndrome, but more studies are needed with this drug. In this review, we will discuss the pathophysiology of the vasoplegia syndrome and associated risk factors for this complication and briefly outline current therapeutic strategies.