Treatment of Perioperative Neurocognitive Disorders With Olfactory Enrichment

NCT ID: NCT06488807

Last Updated: 2025-05-14

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

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Recruitment Status

RECRUITING

Clinical Phase

NA

Total Enrollment

686 participants

Study Classification

INTERVENTIONAL

Study Start Date

2025-04-07

Study Completion Date

2028-12-31

Brief Summary

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Perioperative neurocognitive disorder (PND) is one of the most common postoperative complications among elderly patients. However, the mechanism and targeted intervention of PND remains unclear. Our previous clinical studies demonstrated the association between olfactory impairment and PND. Moreover, our translational studies showed that anesthesia/surgery induced olfactory impairment and caused cognitive impairment in mice and olfactory enrichment could prevent the anesthesia/surgery-induced cognitive impairment. However, there was no clinical investigation to determine whether olfactory enrichment can mitigate PND in elderly patients. Therefore, we propose determining whether olfactory enrichment can prevent and/or treat PND in elderly patients.

Detailed Description

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The study will be a double-blinded, randomized controlled trial. Participants (65 years old or older) undergoing scheduled orthopaedic surgery (≥2 hours, under general anesthesia) will be randomized to either olfactory enrichment group or sham group. Participants in olfactory enrichment group will receive olfactory enrichment with a dispenser twice sessions per day on preoperative day 1-3 and postoperative day 1-3 (30 min per session, 4 odors for each session) while participants in sham group will be equipped with the same pattern except that water will be used in the dispenser. Participants will be assessed twice daily by a research assistant blinded to allocation. The primary outcome will be the incidence of postoperative delirium measured by the Confusion Assessment Method on postoperative days 1, 2 and 3. The secondary outcomes will be the severity of postoperative delirium, cognitive function, plasma Tau-PT217 level, and olfactory function.

Conditions

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Perioperative Neurocognitive Disorder

Study Design

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Allocation Method

RANDOMIZED

Intervention Model

PARALLEL

Primary Study Purpose

TREATMENT

Blinding Strategy

DOUBLE

Caregivers Outcome Assessors

Study Groups

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Olfactory Enrichment Group

All participants enrolled in the olfactory enrichment group will receive twice sessions per day with an interval of at least 6 hours on preoperative day 1 and postoperative day 1-3. Each session will last 30 minutes. Each participant will be equipped with an electrical odor dispenser which allowed to distribute 8 odors (grapefruit, lavender, lemon, peppermint, tangerine, green tea, cloves and eucalyptus). When pushing a button, 4 odors will be released in turn and participants will sniff each odor (approximately 4 ml odorized air) for approximately 30 seconds by a nasal catheter. Considering of the adaption of odors, 4 odors will be used in the morning session and another 4 odors will be used in the afternoon session.

Group Type EXPERIMENTAL

Olfactory Enrichment

Intervention Type OTHER

Each participant will be equipped with an electrical odor dispenser which allowed to distribute 8 odors (grapefruit, lavender, lemon, peppermint, menthol, tangerine, green tea, and bergamot). The choice of odors was guided by (1) pleasantness of the odors, (2) presence of slight trigeminal activation in some of the odors, e.g., peppermint, (3) evaporation characteristics, so that the odors would last for the duration of the experiment, (4) technical issues mostly in terms of compatibility with the odor cartridge, (5) availability, and (6) inspiration from the previous studies.

Sham Group

The sham group will receive sham olfactory enrichment sessions, which is designed with the same pattern (twice a day, 30 min for each session, on preoperative day 1 and on postoperative day 1-3. However, the containers provided to the sham group will be odorless. The odor containers and labels will appear identical to those used in the olfactory enrichment group.

Group Type SHAM_COMPARATOR

Sham

Intervention Type OTHER

The containers provided to the sham group will be odorless. The odor containers and labels will appear identical to those used in the olfactory enrichment group.

Interventions

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Olfactory Enrichment

Each participant will be equipped with an electrical odor dispenser which allowed to distribute 8 odors (grapefruit, lavender, lemon, peppermint, menthol, tangerine, green tea, and bergamot). The choice of odors was guided by (1) pleasantness of the odors, (2) presence of slight trigeminal activation in some of the odors, e.g., peppermint, (3) evaporation characteristics, so that the odors would last for the duration of the experiment, (4) technical issues mostly in terms of compatibility with the odor cartridge, (5) availability, and (6) inspiration from the previous studies.

Intervention Type OTHER

Sham

The containers provided to the sham group will be odorless. The odor containers and labels will appear identical to those used in the olfactory enrichment group.

Intervention Type OTHER

Eligibility Criteria

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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.
Minimum Eligible Age

65 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

No

Sponsors

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National Natural Science Foundation of China

OTHER_GOV

Sponsor Role collaborator

Shanghai 10th People's Hospital

OTHER

Sponsor Role lead

Responsible Party

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Yuan Shen, MD, PhD

Director

Responsibility Role PRINCIPAL_INVESTIGATOR

Principal Investigators

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Yuan Shen

Role: PRINCIPAL_INVESTIGATOR

Shanghai Mental Health Center

Locations

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Shanghai Tenth People's Hospital

Shanghai, , China

Site Status RECRUITING

Countries

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China

Central Contacts

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Yuan Shen

Role: CONTACT

+8618602169932

Facility Contacts

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Yuan Shen

Role: primary

References

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Mei X, Wang J, Ni Z, Wang Y, Zhao B, Sessler DI, Xie Z, Shen Y. Effects of olfactory enrichment on perioperative neurocognitive disorders in elderly patients undergoing orthopedic surgery: a study protocol of a multi-center randomized controlled trial. Trials. 2025 Sep 26;26(1):363. doi: 10.1186/s13063-025-09109-w.

Reference Type DERIVED
PMID: 41013688 (View on PubMed)

Other Identifiers

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dsyy008

Identifier Type: -

Identifier Source: org_study_id

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