Using scent to prevent cognitive issues after surgery in older adults

Treatment of Perioperative Neurocognitive Disorders With Olfactory Enrichment: Study Protocol for a Randomized Controlled Trial

NA · Shanghai 10th People's Hospital · NCT06488807

This study tests if using pleasant scents can help older adults avoid memory and thinking problems after orthopedic surgery.

Quick facts

PhaseNA
Study typeInterventional
Enrollment686 (estimated)
Ages65 Years and up
SexAll
SponsorShanghai 10th People's Hospital (other)
Locations1 site (Shanghai)
Trial IDNCT06488807 on ClinicalTrials.gov

What this trial studies

This clinical trial investigates whether olfactory enrichment can prevent or treat perioperative neurocognitive disorder (PND) in elderly patients undergoing orthopedic surgery. Participants aged 65 and older will be randomly assigned to receive either olfactory enrichment or a sham treatment, with assessments conducted twice daily to evaluate the incidence and severity of postoperative delirium and cognitive function. The study aims to clarify the potential benefits of olfactory stimulation in mitigating cognitive decline associated with surgery.

Who should consider this trial

Good fit: Ideal candidates are elderly patients aged 65 and older scheduled for orthopedic surgery requiring general anesthesia.

Not a fit: Patients with pre-existing delirium, severe mental disorders, or those unable to comply with the study protocol may not benefit from this study.

Why it matters

Potential benefit: If successful, this approach could significantly reduce the incidence of cognitive impairment in elderly patients after surgery.

How similar studies have performed: While olfactory enrichment has shown promise in animal studies, this clinical investigation is novel and has not been previously tested in humans for this specific application.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

1. Age ≥65 years old.
2. Having a scheduled surgery (≥2 hours, general anesthesia) (e.g., total hip replacement, toal knee replacement, open reduction and internal fixation of hip and lumbar spine).
3. Being able to complete neuropsychological tests, 3D-CAM and CAM-S.
4. Chinese Mandarin as their native language.
5. Edmonton frailty scale (EFS) score ≥ 6.

Exclusion Criteria:

1. Having delirium, assessed by 3D-CAM, before surgery.
2. Having a brain tumour, stroke or mental disorders (eg, major depressive disorder or dementia).
3. Participating in other clinical studies at the time of screening.
4. Unwillingness to comply with the protocol or procedures.

Where this trial is running

Shanghai

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.

View on ClinicalTrials.gov →

Conditions: Perioperative Neurocognitive Disorder, Odor Enrichment

Last reviewed 2026-05-15 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.