Improving neurologic iutcome in cardiac surgery patients with a goal-oriented therapy protocol based on cerebral regional oxygen saturation

IMPROVING NEUROLOGIC OUTCOME IN CARDIAC SURGERY PATIENTS WITH A GOAL-ORIENTED THERAPY PROTOCOL BASED ON CEREBRAL REGIONAL OXYGEN SATURATION F. Franchi, B. Biagioli, A. Tabucchi, S. Scolletta University of Siena, Siena, Italy INTRODUCTION. NIRS (near infrared spectroscopy) is a neuro-monitoring tool that provides cerebral regional oxygen saturation (rSO2). OBJECTIVES. We hypothesized that a goal-directed therapy (GDT) protocol based on rSO2 values would be associated with reduced incidence of postoperative neurologic complications (PNC) in high-risk cardiac surgery (CS) patients. METHODS. 85 high-risk CS patients (mean age 71 ± 9) were monitored during CS with NIRS (cNIRS group). Intraoperative interventions were based on a GDT protocol aimed at improving cerebral rSO2 and blood flow (i.e., increasing arterial oxygen content with red blood cell transfusions and FiO2; increasing systemic blood flow and cerebral perfusion pressure with fluids, inotropic, and vasoactive drugs and increasing pump-flow during cardiopulmonary bypass). cNIRS group was compared with 100 patients (mean age 73 ± 6) (not monitored with cerebral NIRS, N-cNIRS group) who were selected from a historical database using a propensity-matching analysis. Neuron-specific enolase (NSE) and S-100B protein were collected at different times in the cNIRS group. RESULTS. PNC resulted 21 % in the cNIRS group and 35 % in N-cNIRS group (p\0.05). N-cNIRS group showed longer times of mechanical ventilation (MV) (150.3 ± 274.9 vs 29.9 ± 65 h, p = 0.02) and ICU stay (13.3 ± 14.7 vs 3.4 ± 3.9 days, p = 0.01) than cNIRS group. In the cNIRS group, preoperative rSO2 values were signifi- cantly lower in the patients who exhibited PNC than those who had good neurologic outcome (59.6 ± 7.6 vs 63.4 ± 7.8 %, p = 0.04). An inverse correlation was found between the lowest values of intraoperative cerebral rSO2 and the length of MV (r = -0.31, p = 0.04) and ICU stay (r = -0.43, p = 0.003). Only the peak of NSE, measured 6 h after CS, showed significant difference between patients who developed PNC and those who did not (p = 0.02). CONCLUSIONS. In our cohort of CS patients, NSE and S-100B protein were poor pre- dictors of PNC. Conversely, the lower the preoperative cerebral rSO2, the poorer the neurologic outcome. A GDT protocol based on NIRS values, aimed at improving cerebral rSO2 and blood flow, might reduce PNC in high-risk CS patients. REFERENCE(S). Murkin JM, Adams SJ, Novick RJ, et al. Monitoring brain oxygen saturation during coronary bypass surgery: a randomized, prospective study. Anesth Analg. 2007;104(1):51-8.