Cerebral Saturation Monitoring With Near Infrared Spectroscopy And Postoperative Neurologic Outcomes In Aortic Arch Surgery

Objective:To observe the variance of regional cerebral oxygen saturation during aortic arch surgery and to evaluate its correlation with postoperative neurologic outcome.Methods:We observed and collected data from patients who underwent aortic arch replacement surgery with deep hypothermic circulatory arrest (DHCA) and selective antegrade cerebral perfusion (SACP). Near-infrared spectroscopy (NIRS) INVOS 4100 was applied to monitor patients’ regional cerebral oxygen saturation (rSO2). The primary clinical endpoints were mortality, central neurologic outcome and major organ morbidity, length of stay in ICU and hospital.Results:Data from 101 patients were analyzed, in which 77(76.2%) were male. Mean age at operation was 50.41±11.57 years old.15(14.9%) patients died in hospital, average length of stay in ICU was 8.72±11.60 days, average length of stay in hospital was 23.50±23.29days.28(27.7%) patients experienced major organ morbidity and mortality (MOMM),43(42.6%) experienced various neurological complications, in which 13(12.9%) had permanent neurological dysfunction (PND), 15(14.9%) patients experienced motor or sensory disturbance,37(36.7%) patients experienced various disturbance of consciousness. Logistic regression suggested minimum relative rSO2 throughout the operation lower than 80% of baseline was an independent risk factor of death; minimum relative rSO2 during the hemostasis lower than 80%was an independent risk factor of length of stay in ICU over 3 days; mean relative rSO2 and minimum relative rSO2 during the hemostasis lower than respectively 85% and 80% were independent risk factors of postoperative acute kidney injury requiring dialysis; mean relative rSO2 throughout the operation lower than 80%, mean relative rSO2 during the hemostasis lower than 85% and minimum relative rSO2 during the hemostasis lower than 80% were independent risk factors of postoperative neurological dysfunction and MOMM. No significance correlation between variance of rSO2 and length of stay in hospital or postoperative ventilation time was found. Minimum relative rSO2 throughout the operation and age were independent risk factors of PND; minimum relative rSO2 lower than 79.5% had a sensitivity of 56.8% and a specificity of 84.6% in identifying individuals with PND (AUC=0.713,95%CI=0.564-0.863, p=0.013). Minimum and mean baseline rSO2were risk factors of postoperative coma. Age and preoperative hemoglobin were factors of baseline rSO2; MAP had a significant impact on variance of rSO2 at 10 minutes after the beginning of CPB. Preoperative SIRS resulted in lower rSO2 during hemostasis.Conclusions:Minimum relative rSO2 throughout the operation lower than 80% of baseline was an independent risk factor of death; mean relative rSO2 throughout the operation lower than 80%, mean relative rSO2 during the hemostasis lower than 85% and minimum relative rSO2 during the hemostasis lower than 80% were independent risk factors of postoperative neurological dysfunction and MOMM; baseline rSO2 were risk factors of postoperative coma; baseline rSO2 correlated with age, preoperative hemoglobin, MAP and preoperative SIRS.