NCT06488807

Treatment of Perioperative Neurocognitive Disorders With Olfactory Enrichment

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

• Status: Recruiting
• Phase: N/A
• Study type: Interventional
• Enrollment: 686 (estimated)
• Sponsor: Shanghai 10th People's Hospital · Academic / Other
• Sex: All
• Age: 65 Years
• Healthy volunteers: Not accepted

Summary

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.

Conditions

• Perioperative Neurocognitive Disorder

Interventions

Type	Name	Description
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 the odor cartridge, (5) availability, and (6) inspiration from the previous studies.
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.

Timeline

• Start date: 2025-04-07
• Primary completion: 2027-12-31
• Completion: 2028-12-31
• First posted: 2024-07-05
• Last updated: 2025-05-14

Locations

1 site across 1 country: China