Treatment of Perioperative Neurocognitive Disorders With Olfactory Enrichment

Tongji University

Status: Enrolling

Conditions: Perioperative Neurocognitive Disorder

Treatments: Other: Sham; Other: Olfactory Enrichment

Study type: Interventional

Funder types: Other

Identifiers

NCT06488807

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Details and patient eligibility

About

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.

Full description

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.

Enrollment: 686 estimated patients

Sex: All

Ages: 65+ years old

Volunteers: No Healthy Volunteers

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.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Double Blind

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686 participants in 2 patient groups

Olfactory Enrichment Group

Experimental group

Description:

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.

Treatment:

Other: Olfactory Enrichment

Sham Group

Sham Comparator group

Description:

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.

Treatment:

Other: Sham