NCT03441074

Olfactory Function and Delayed Neurocognitive Recovery

Effects of Odor Enrichment on Delayed Neurocognitive Recovery

• Status: Completed
• Phase: N/A
• Study type: Interventional
• Enrollment: 131 (actual)
• Sponsor: Shanghai 10th People's Hospital · Academic / Other
• Sex: All
• Age: 65 Years
• Healthy volunteers: Accepted

Summary

To explore whether odor enrichment can reduce the risk of delayed neurocognitive recovery as an intervention strategy.

Detailed description

Postoperative neurocognitive disorder, one of the most common postoperative complications in older adults, includes acute postoperative delirium, delayed neurocognitive recovery (within the 30 days recovery period, dNCR), and postoperative neurocognitive dysfunction (from expected recovery 30 days to 12 months). Previous studies showed that the incidence of dNCR ranged from 18% to 40% and is mainly characterized by cognitive impairment, which can develop into long-term cognitive impairment, even elevating the risk of Alzheimer's Disease (AD) related dementia and premature mortality. These symptoms can have significant adverse effects on quality of life and may increase the risk of other physical and psychological disorders, potentially impacting social stability. These statistics underscore the importance of early detection and timely intervention in mitigating the long-term effects of dNCR. Despite the significance of dNCR, effective treatment options remain elusive. Based on these insights, previous studies have explored the impact of olfactory enrichment in animal models. Zhang et al. demonstrated that surgery and anesthesia could cause olfactory impairment, which might contribute to dNCR, while suggesting that odor enrichment, a non-pharmacological intervention, could reduce postoperative cognitive impairment in animal models. Olfactory enrichment, also known as olfactory training, is a safe and affordable treatment and may have preventative or supportive effects on olfactory function or cognitive function. Evidence supports its effectiveness in treating olfactory function from various causes and in reducing cognitive impairment. Despite these findings, there is limited research on whether odor enrichment can serve as a mitigating strategy for dNCR among human populations. To address this gap, we conducted a clinical study to investigate whether odor enrichment could mitigate dNCR in geriatric patients and to explore the relationship between olfactory function and dNCR.

Conditions

• Delayed Neurocognitive Recovery

Interventions

Type	Name	Description
BEHAVIORAL	Odor Enrichment	Patients in intervention group will get odor enrichment during perioperative period (3 days before the surgery and 7 days after the surgery). Odor-enriched participants were exposed daily for 24 hours to different aromatic fragrances (phenyl ethyl alcohol - rose; eucalyptol - eucalyptus; citronellal - lemon; eugenol - cloves) referred to previous studies. Odors were changed for each subject after 24 hours. According to previous studies, 10 drops of the 100% essential oil (0.5 ml) were dropped on a fabric which was placed in tea bags hanging at the hospital bedside.

Timeline

• Start date: 2018-01-01
• Primary completion: 2021-12-31
• Completion: 2022-12-31
• First posted: 2018-02-22
• Last updated: 2025-07-31

Locations

1 site across 1 country: China