Diagnosis and Management of Vasoplegia in Temporary Mechanical Circulatory Support: A Narrative Review

Refractory vasodilatory shock, or vasoplegia, is a pathophysiologic state observed in the intensive care unit and operating room in patients with a variety of primary diagnoses. Definitions of vasoplegia vary by source but are qualitatively defined clinically as a normal or high cardiac index and low systemic vascular resistance causing hypotension despite high-dose vasopressors in the setting of euvolemia. This definition can be difficult to apply to patients undergoing mechanical circulatory support (MCS). A large body of mostly retrospective literature exists on vasoplegia in the non-MCS population, but the increased use of temporary MCS justifies an examination of vasoplegia in this population. MCS, particularly extracorporeal membrane oxygenation, adds complexity to the diagnosis and management of vasoplegia due to challenges in determining cardiac output (or total blood flow), lack of clarity on appropriate dosing of noncatecholamine interventions, increased thrombosis risk, the difficulty in determining the endpoints of adequate volume resuscitation, and the unclear effects of rescue agents (methylene blue, hydroxocobalamin, and angiotensin II) on MCS device monitoring and function. Care teams must combine data from invasive and noninvasive sources to diagnose vasoplegia in this population. In this narrative review, the available literature is surveyed to provide guidance on the diagnosis and management of vasoplegia in the temporary MCS population, with a focus on noncatecholamine treatments and special considerations for patients supported by extracorporeal membrane oxygenation, transvalvular heart pumps, and other ventricular assist devices.

Updates in the Management of Perioperative Vasoplegic Syndrome

Vasoplegic syndrome occurs relatively frequently in cardiac surgery, liver transplant, major noncardiac surgery, in post-return of spontaneous circulation situations, and in pateints with sepsis. It is paramount for the anesthesiologist to understand both the pathophysiology of vasoplegia and the different treatment strategies available for rescuing a patient from life-threatening hypotension.

Vasoplegic syndrome in cardiac surgery: Definitions, pathophysiology, diagnostic approach and management

Vasoplegic syndrome is a state of vasopressor resistant systemic vasodilation in the presence of a normal cardiac output. Its definition, pathophysiology, risk factors, diagnosis and therapeutic approach will be reviewed in this paper. It occurs frequently during cardiac surgery and is associated with high morbidity and mortality. A search in the LILACS, MEDLINE, and GOOGLE SCHOLAR databases was conducted to find the most relevant papers during the last 18 years. Prompt identification and diagnosis of patients at risk must be undertaken in order to implement an optimal therapeutic approach. This latter includes early treatment with vasopressors with different mechanisms of action.

[Vasoplegic Syndrome after Aortic Valve Replacement]

We report a case of vasoplegic syndrome (VS) after aortic valve replacement in a 65 year old male with aortic stenosis. The patient developed hypotension after separation from cardiopulmonary bypass (CPB). Transesophageal echocardiography revealed well-maintained cardiac function and normal prosthetic valve function. However, his cardiac index was 3.0 l x min(-1) x m(-2) and systemic vascular resistance index (SVRI) was 1100 dynes x sec(-1) x cm(-5) x m(-2). Diagnosing VS, norepinephrine administration was commenced. Since his respiratory status was good, the patient was extubated on the day of surgery. Two days after surgery, catecholamines were discontinued with the stabilization of his circulatory status. However, his respiratory status showed gradual deterioration, and he was re-intubated. Chest X-ray showed bilateral pleural effusion, which was treated by drainage and fluid restriction. With this, his oxygenation improved and he could be extubated 5 days after surgery. Vasoplegic syndrome is a potentially life-threatening complication following cardiac surgery. Hypotension at the time of separation from CPB can be due to multiple factors. Despite an incidence rate of 10%, little is known about VS. We hope that, in future, tailored therapeutic protocols for VS will be developed.

[Pathophysiological mechanisms and treatment of septic shock-induced vasoplegia]

The hemodynamics of septic shock is characterized by a primary reduction of vascular tone, which defines vasoplegia. Septic vasoplegia is due to reduced endogenous production of vasopressin, as well as to the overproduction of vasodilating molecules (nitric oxide, prostacyclin, peroxynitrite and kynurenine) and the opening of ATP-sensitive potassium channels. Treatment is supportive and includes primarily alpha-adrenergic catecholamines. Vasopressin may also be useful, although its place is still controversial. Further agents can improve the vascular responsiveness to catecholamines, most notably low doses hydrocortisone, and, to a lesser extent, activated protein C. Further, innovative therapies, based on recent understanding of pathophysiological mechanisms, might become useful agents to treat septic vasoplegia in the future.