Dobutacs: dobutamine after cardiac surgery

• Grant number: 15/20519-6
• Support Opportunities: Regular Research Grants
• Start date: September 01, 2016
• End date: August 31, 2018
• Field of knowledge: Health Sciences - Medicine - Medical Clinics
• Principal Investigator: Ludhmila Abrahão Hajjar
• Grantee: Ludhmila Abrahão Hajjar
• Host Institution: Instituto do Coração Professor Euryclides de Jesus Zerbini (INCOR). Hospital das Clínicas da Faculdade de Medicina da USP (HCFMUSP). Secretaria da Saúde (São Paulo - Estado). São Paulo , SP, Brazil
• Associated researchers: Filomena Regina Barbosa Gomes Galas ; Rafael Alves Franco ; Suely Pereira Zeferino

Abstract

Inotropic agents are often administered in the postoperative period after cardiac surgery Sometimes the need is evident, in the presence of cardiogenic shock or for termination of extracorporeal circulation. In other cases, inotropic agents are administered more routinely, for some myocardial dysfunciton after cardiopulmonary bypass or a low cardiac output with minimal evidence of altered tissue perfusion. Recent data show that inotropic agents are used in 35-52% of cardiac surgerys in the perioperative period. However, the use of inotropic agents may be associated with adverse events, including myocardial ischemia, by elevation in myocardial oxygen consumption and the imbalance between supply and consumption, and tachyarrhythmias (atrial fibrillation, sinus tachycardia, ventricular tachyarrhythmias), primarily due to the ²1-adrenergic effect. More recently Nielsen et al, found an independent association between the use of dobutamine in the perioperative period and a increase in mortality at 30 days and one year, as well as an increase in the incidence of myocardial infarction, stroke, arrhythmias and renal replacement therapy. In this context, the aim of the present study is to compare the use of dobutamine in a liberal strategy (in all patients at the time of withdrawal of CPB) with with restrictive strategy (based on clinical and hemodynamic evidence of low cardiac output syndrome associated with altered tissue perfusion). Our primary hypothesis is that the a restrictive strategy of dobutamine is as safe as a liberal strategy in patients undergoing cardiac surgery. OBJECTIVES: Combined endpoint of arrhythmias (ventricular and supraventricular), acute myocardial infarction, stroke or transient ischemic attack and death from all causes within 30 days after cardiac surgery. METHOD: prospective, randomized, controlled, single-center trial of non-inferiority. Will be eligible for inclusion in the study adult (> 18 years) patients undergoing coronary artery bypass grafting cardiac surgery with cardiopulmonary bypass. During surgery, all patients will undergo minimally invasive hemodynamic monitoring. Patients will be randomized for two strategies of dobutamine at the time of withdrawal of cardiopulmonary bypass: 1-Liberal strategy: all patients will receive dobutamine, with a minimal dose of 3 mcg/kg/min dose. 2-- Restrictive strategy: patients will receive dobutamine during the first 8 hours after withdrawal of CPB only if they have a cardiac index of d 2.5L/min and at least one other sign of tissue hypoperfusion: SvO2 d 70% and / or urine ourtput < 20 mL/h despite adequate fluid replacement, lactate e 27 mg/dL and / or CO2 Gap > 6. In each case, dose titration will be possible will occur based on clinical and hemodynamic condition of the patient, acording to clinical judgment of the anesthesiologist during surgery, and intensive care physician in the post operative. After the eighth hour, dobutamine will be tapered down and discontinued if possible.DV Nielsen, MK Hansen, Johnsen SP, Hansen M, Hindsholm K, Jakobsen CJ. Health Outcomes with and without Use of Inotropic Therapy in Cardiac Surgery: Results of the Propensity Score-Matched Analysis. Anesthesiology. 2014 May; 120 (5): 1098-108. (AU)