Intraoperative Anesthesiological Monitoring and Management

Abstract

Patients undergoing ventricular assist device (VAD) implantation are critically ill, usually receiving multiple inotropic drugs and/or an intra-aortic balloon pump, often showing a no more than 20% mean ejection fraction (EF) [1]. So that intraoperative management for VAD surgery may be challenging for cardiac anesthesiologists as this patient cohort is associated with significant comorbidities: pulmonary hypertension, peripheral vascular disease, kidney, hepatobiliary, and central nervous dysfunction. Even minor changes in hemodynamics may dramatically increase morbidity and mortality. In other words, the anesthesiologist should become familiar with the various assist devices; the anesthetic plan must take into account the severity of cardiac dysfunction and the degree of organ dysfunction. The use of diagnostic (transesophageal echocardiography), hemodynamic (MAPs, CVP, SvO2, PAPs), and therapeutic (vasopressors, inotropes) tools is mandatory. Particularly, the diagnosis of right-sided heart failure after implantation of left-ventricular assist devices should be intraoperatively investigated. Patients suffering from severe congestive heart failure (CHF) are typically chronically treated with ß-blockers, intensive diuretic therapy, ACE inhibitors, and/or angiotensin receptor blockers, the latter in order to reduce peripheral vascular resistances, but with the controversy of a theoretical increase in inotrope support requirement [2]. Patient that comes to theater has usually received premedication with benzodiazepine or opioids in order to reduce the sympathetic tone. However, an overtreatment with sedatives may cause hypoventilation and hypoxia, thus increasing pulmonary vascular resistances and acidosis [3].