The increase in the population over 60 years of age who could receive surgery due to changes in life expectancy and advances in surgical and anesthetic techniques.

Likewise, elderly people (EP) may have a higher risk of postoperative morbidity and mortality compared to young people, with frailty being one of the risk factors that increases adverse outcomes in this period and increases the probability of developing syndromes such as postoperative delirium (POD).

Assessment of frailty in EP prior to surgery is not routine, so it is unknown how many frail and/or pre-frail EP undergo surgery in health care systems. There is an association between being frail and developing greater delirium and/or postoperative cognitive deficit, which in summary translates into an increase in perioperative morbidity and mortality.

For the prevention of POD, there are pharmacological and non-pharmacological measures that seek to promote orientation with respect to their environment and make it as familiar as possible, stimulate early aspects of memory and thinking skills, as well as promote sleep using environmental hygiene measures.

In Chile, protocols of non-pharmacological measures have been proposed by occupational therapy teams, which have had positive results in reducing POD in frail elderly patients. These measures are temporal-spatial reorientation, physical mobilization, correction of sensory deficits, environmental management, sleep protocol, and reduction of anticholinergic drugs with statistically significant results in the reduction of POD.

In accordance with the above, the objective of this study is to evaluate the impact of non-pharmacological measures applied by the nursing team in reducing the incidence of POD during the post-surgical period in fragile and pre-fragile EP undergoing elective non-cardiac surgeries.

It is expected that in the end, frail and pre-frail EP who receive non-pharmacological interventions by the nursing team will present a lower incidence of POD at 24 hours compared to those who receive traditional care.

Participants will correspond to frail and pre-frail people over 65 years of age who undergo elective non-cardiac surgery that requires general anesthesia and who attend the UC-Christus Clinical Hospital.

Frailty instruments (FRAIL scale) and Clinical Frailty Scale (CFS) will be applied, together with a preoperative cognition test (MiniCog; in case of presenting an altered result, the Montreal Cognitive Assessment, MoCA instrument will be applied), the delirium screening test (Delirium Triage Screen, DTS; in case of presenting an altered result, the Confusion Assessment Method instrument will be applied. d, CAM). Then, the participants will be randomized into two groups:

1. A first group to which a protocol of non-pharmacological interventions implemented by the nursing team will be applied to prevent post-surgical delirium
2. A second control group that will only receive traditional care. The users of the first group who use glasses, hearing aids and/or removable dental prostheses will move from the pre-operative unit room to the surgical ward with these elements, which will be delivered to their caregiver or companion after the safety break and before starting anesthesia inside the ward room where they will be operated on.

Both groups will undergo standard monitoring (ECG, NIBP, SatO2) and anesthesia will be guided using frontal EEG (SedLine or bilateral BIS). During the intraoperative period, an effort will be made to maintain a Mean Blood Pressure ± 20% of baseline and to keep the patient normothermic.

In the postoperative stage, therapeutic activities of cognitive stimulation and socialization will be carried out where temporal-spatial information will be delivered, the visit of the companion will be coordinated, a protocolized mobilization routine will be carried out considering pain, state of consciousness, thromboembolic risk and risk of falls. In the event that she does not want or cannot carry out the protocolized mobilization routine, non-pharmacological sleep will be privileged.

One hour after the patient's admission to the recovery unit, a delirium evaluation will be performed using CAM by personnel other than the one who performed the non-pharmacological measures. Two hours later, the non-pharmacological measures will be reinforced and later a new evaluation of delirium will be applied using CAM.

An evaluation of delirium will be carried out during the morning by means of CAM 24 hours after the admission of the patient to the recovery unit by a person other than the nursing team, who has not applied the protocol of non-pharmacological measures.

If the elderly person is still hospitalized, a final delirium evaluation will be carried out by means of CAM during the afternoon (24 hours after admission to the recovery unit).

In the event that the person presents CAM (+), the application of non-pharmacological measures will be evaluated with the treating team and the respective interconsultation will be processed with the geriatric team of the study.

Inclusion Criteria:

• Patients older than 65 years
• Elective non-cardiac surgery
• General anesthesia with Bilateral BIS electroencephalographic monitoring or SedLine
• ASA I, II or III.

Exclusion Criteria:

• Neurosurgical patients
• History of alcohol and/or drug abuse
• History of recreational psychoactive drug use
• Allergy to anesthetic drugs.

After signed informed consent at the preoperative unit and during the post anesthesia unit care