To solve the problem of the low rate recruitment, the authors of the Delphi scale were contacted, requesting the complete data of the original work. After careful study, it was concluded that a lower cut-off point could allow an increase in the recruitment rate. After performing the relevant calculations, it was determined that a value of five on the Delphi scale allows to discriminate patients at risk against patients without risk with a sensitivity of 85% (95% CI: 78.49-93.23), a specificity of 80% (95% CI: 76.16-83.75) and an accuracy of 81%, with an area under the calculated curve of 0.83 (95% CI: 0,79-0,87)so it is still excellent, in addition to allowing to considerably increase the chances of recruiting patients within the target population. Therefore the proposed and accepted changes by Agencia Española de Medicamento y Productos Sanitarios ( AEMPS) in the new version of the protocol were: 1) Inclusion criteria: Version 1.7: Patients over or equal to 65 years of age who are undergoing major non-cardiac surgery and who have a score equal to or greater than 7 on the Delphi scale. Version 2.0: Patients over or over 65 years of age who are undergoing major non-cardiac surgery and who have a score equal to or greater than 5 on the Delphi scale. 2) Exclusion criterion: Version 1.7: Patients at risk of developing delirium on admission. Version 2.0: Patients with a score of less than 5 on the Delphi scale -Extension of the total time of the clinical trial based on the extension in the recruitment period of 18 months, until expiration of the medication (June 30, 2020). Medication undergoes a process to guarantee the blind, one of the pillars of the study. It is not possible to generate new medication due to lack of financial funds.