Vasoplegic syndrome

A condition characterized by low blood pressure and reduced vascular resistance

Vasoplegic syndrome is a medical condition characterized by severe hypotension (low blood pressure) and decreased systemic vascular resistance (SVR), often occurring after cardiac surgery. It is a form of distributive shock and can be life-threatening if not promptly treated.

Pathophysiology

Vasoplegic syndrome is primarily caused by the excessive production of nitric oxide and other vasodilators, leading to widespread vasodilation and reduced vascular tone. This results in a significant drop in blood pressure and inadequate perfusion of vital organs. The condition is often associated with the use of cardiopulmonary bypass during cardiac surgery, which can trigger inflammatory responses and endothelial dysfunction.

Diagnosis

The diagnosis of vasoplegic syndrome is typically based on clinical criteria, including persistent hypotension despite adequate fluid resuscitation and normal or elevated cardiac output. Hemodynamic monitoring may reveal low systemic vascular resistance and high cardiac index. Laboratory tests may show elevated levels of inflammatory markers and vasodilators.

Treatment

The management of vasoplegic syndrome involves the use of vasopressors to restore vascular tone and maintain adequate blood pressure. Commonly used vasopressors include norepinephrine and vasopressin. In some cases, methylene blue is administered as it inhibits the nitric oxide-cyclic GMP pathway, thereby reducing vasodilation. Fluid resuscitation and optimization of cardiac output are also crucial components of treatment.

Prognosis

The prognosis of vasoplegic syndrome depends on the severity of the condition and the timeliness of treatment. Early recognition and aggressive management can improve outcomes, but severe cases may lead to multiple organ dysfunction and increased mortality.

Related pages

• Cardiac surgery
• Distributive shock
• Nitric oxide

References

• Argenziano, M., et al. (1998). "Vasoplegic syndrome after cardiac surgery: a clinical and biochemical study." The Annals of Thoracic Surgery, 66(2), 914-920.
• Levin, M. A., et al. (2009). "Vasoplegia during cardiopulmonary bypass: pathophysiology and treatment." The Journal of Extra-Corporeal Technology, 41(1), 16-24.

External links

• Vasoplegic Syndrome: A Review - National Center for Biotechnology Information

Gross pathology of a normal brain and a brain of a patient treated with methylene blue before death.