Introduction: Postoperative delirium is a complication that frequently occurs in post-operative patients, both in cardiac and non-cardiac surgery, with the most affected being the elderly. Diagnostic criteria for delirium or cognitive impairment are documented in the Diagnostic and Statistical Manual of Mental Disorders (DSM-V). The incidence reported on this entity varies between 25-80%, and its diagnosis will depend on its definitions, forms of presentation, type of surgery and time of its evaluation in the postoperative period. Considering that society is being demographically transformed by the increase of older adults in our population, the need to maintain the functionality and the cognitive state after the anesthetic-surgical procedure of this vulnerable age group has become more important. The incidence reported on this entity varies between 25-80%, and its diagnosis will depend on its definitions, forms of presentation, type of surgery and time of its evaluation in the postoperative period. Considering that society is being demographically transformed by the increase of older adults in our population, the need to maintain the functionality and the cognitive state after the anesthetic-surgical procedure of this vulnerable age group has become more important. Based on what has been reported in the medical literature of the specialty, a close association of postoperative cognitive deterioration has been demonstrated with the administration of anesthetic agents, among other risk factors. Objectives: It is to define if, through changes revealed through neuromonitoring with Near Infrared Spectroscopy (NIRS), factors that could be associated with the presentation of cognitive impairment in elderly patients undergoing a major surgical procedure can be detected early. Postoperative cognitive delirium is understood as: - condition characterized by alterations in memory, concentration, language comprehension and social integration, which in the short, medium or long term is reflected in the functional capacity of patients. Material and Methods: A sample of 60 patients older than 70 years, undergoing elective major surgery, who underwent NIRS neuromonitoring, were evaluated and the cognitive function was evaluated through the Montreal Cognitive Evaluation (MoCA) in the postoperative period. Measures of central tendency, distribution and dispersion were determined (Smirnov-Kolmogorov test). Frequencies and percentages were calculated, Whitney Mann's U-test / chi squared, Mommy Ratio with 95% CI. The Stata version 13 program was used. Statistical significance was taken with a p value of less than 0.05, with a 95% confidence interval. Results: Of the total sample obtained, 53.3% were women and 46.7% were men. The median age was 71 years. In relation to the service: General Surgery (30%), Orthopedics (28.3%) and Cardiology (20%). The type of anesthesia most frequently used was general anesthesia balanced 66.7%, followed by regional anesthesia (18.3%), and general intravenous anesthesia 15%. The surgical time had a median of 90 minutes, mean pulse oximetry saturation (SpO2) was 95%; In the NIRS, 68.3% had adequate cerebral saturation levels, that is, above 90% or no more than 20% of variation in their baseline. The 33.3% of the sample showed some type of postoperative cognitive delirium, through the evaluation of MoCA. There were no statistically significant differences in sex distribution, age and type of anesthesia between groups with and without cognitive deficit. Conclusions: In recent years there has been a special interest in the investigation of postoperative delirium, since there is currently no specific and sensitive assessment scale, applicable to the patient undergoing an anesthetic-surgical procedure, given the characteristics that a patient (Type of surgery, anesthetic time, hemodynamic changes, transperative cerebral hypoperfusion, perioperative haemorrhage, drugs used, to mention a few), such as the various risk factors that identify them.
