Causes, Predictors, and Treatment of Vasoplegia in Cardiac Surgery: A Narrative Review

Vasoplegia is a form of distributive shock that commonly occurs after cardiac surgery involving cardiopulmonary bypass. Although a formal definition does not exist, it is generally characterized by low systemic vascular resistance with a maintained or elevated cardiac index that tends to be resistant to treatment with fluid or vasopressor. Postoperative vasoplegia in cardiac surgery patients is associated with increased morbidity and mortality. This article reviews the current understanding of the pathophysiology of vasoplegia in cardiac surgery, including risk factors for its development, and evolving strategies for prediction, diagnosis, and treatment. Prominent preoperative risk factors include patient demographics (older age, male sex, elevated body mass index), comorbid conditions (heart failure with reduced ejection fraction, chronic kidney disease, anemia, infective endocarditis, hemodynamic instability, thyroid dysfunction, diabetes mellitus, tobacco use), medications (renin-angiotensin-aldosterone axis blockers, calcium channel blockers, beta-blockers, inotropes, antiplatelets and anticoagulants, amiodarone, diuretics, anesthetic agents), and the type of surgical procedure performed. Prominent intraoperative risk factors include the use of cardiopulmonary bypass, blood product transfusion, and poor temperature control. Multiple biomarkers and dynamic monitoring systems are being studied as predictors for the development of vasoplegia. An overview of available treatments is presented along with up-to-date evidence supporting their use in multimodal vasopressor regimens.