Treatment of Perioperative Neurocognitive Disorders With Olfactory Enrichment
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- The protocol lists: Olfactory Enrichment, Sham.
- Who it may be relevant to
- Registry conditions: Perioperative Neurocognitive Disorder. Basic parameters: from 65 years · All.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- China
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
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Official title
Treatment of Perioperative Neurocognitive Disorders With Olfactory Enrichment: Study Protocol for a Randomized Controlled Trial
Overview
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
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.
Interventions
- Other 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 t - 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.
Primary outcome measures
- Incidence of postoperative delirium [Time frame: at baseline and postoperative day 1 to 3]
Secondary outcome measures (1)
- Incidence of delayed neurocognitive recovery and postoperative neurocognitive disorder [Time frame: at baseline, on 21 days and 6 months after anesthesia/surgery]
Eligibility criteria
Inclusion criteria
- Age ≥65 years old.
- 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).
- Being able to complete neuropsychological tests, 3D-CAM and CAM-S.
- Chinese Mandarin as their native language.
- Edmonton frailty scale (EFS) score ≥ 6.
Exclusion criteria
- Having delirium, assessed by 3D-CAM, before surgery.
- Having a brain tumour, stroke or mental disorders (eg, major depressive disorder or dementia).
- Participating in other clinical studies at the time of screening.
- Unwillingness to comply with the protocol or procedures.
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: No
Study design
- Allocation
- Randomized
- Model
- Parallel assignment
- Masking
- Double blind
- Primary purpose
- Treatment
Study locations
China · 1 center
- Shanghai Tenth People's Hospital — Shanghai
Publications
- 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. PMID 41013688
Identifiers
NCT: NCT06488807 · dsyy008