Cerebral Oxygen Saturation Monitoring In Cardiac Surgery (COSMICS)

Overview

Neurological dysfunction continues to be one of the complications of considerable concern in patients undergoing cardiac surgery. It was previously reported in the literature, that cerebral oxygen desaturation during cardiac surgery was associated with an increased incidence of cognitive impairment. This study aims to determine whether continuous monitoring of cerebral oximetry improves the neurocognitive outcome in coronary artery bypass surgery when associated with predetermined intervention protocol to optimize cerebral oxygenation.

Despite all the progress over the last decades regarding the improvement of the perioperative care of patients with heart disease and the development of new surgical techniques, neurological dysfunction continues to be one of the complications of the greatest concern in patients undergoing cardiac surgery with cardiopulmonary bypass. Brain injury can manifest itself through permanent or temporary injury, contributing to the increase in-hospital mortality, in the length of stay in intensive care, in the length of hospital stay, to a higher incidence of motor dysfunction requiring rehabilitation, and consequently, to reduced quality of life. Even though the causes of brain injury are multifactorial, perioperative cerebral hypoperfusion, tissue hypoxia, and thromboembolic events are among the main factors related to neurological dysfunction. Several clinical studies have indicated an association between cerebral desaturation and the increase of neurological complications. Cerebral oximetry monitoring using near-infrared spectroscopy (NIRS) is a non-invasive technique used to estimate regional cerebral oxygen saturation (rSO2) and has been associated with diminishing the incidence of neurological complications. There is no consensus in the literature about its real benefit, mainly due to the absence of well-designed scientific studies that demonstrate that cerebral desaturation associated with intervention measures to improve rSO2, are related to the prevention of neurological dysfunction in adult cardiac surgery. The study hypothesis evaluates whether continuous monitoring of cerebral oximetry improves the neurocognitive outcome in coronary artery bypass surgery when associated with early interventions to optimize rSO2.