Effect of Preoperative Olfactory Training on Postoperative Delirium in the Elderly Undergoing Orthopedic Surgeries

Study Overview
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Brief Summary
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To observe whether preoperative olfactory training can reduces the incidence of postoperative delirium in elderly patients undergoing orthopedic surgeries, a prospective randomized controlled study method will be used in this study.

Detailed Description
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450 elderly patients undergoing orthopedic surgeries (hip or knee replacement and laminectomy) under general anesthesia or combined spinal epidural anesthesia will be selected. They will be randomly divided into control group and olfactory training group.The olfactory training group was performed 24-48h before surgery used phenylethyl alcohol (rose), phytol (press tree), citronella (lemon), eugenol (clove) 4 kinds of smell，twice a day for three days. The general condition, operation, anesthesia and hospitalization related data of the patients will be recorded. Outcome Measures： Incidence of postoperative delirium: The 3D-CAM scores of the control group and the olfactory training group were evaluated within 1-5 days after operation. Degree of delirium：The MDAS of the control group and the olfactory training group were evaluated within 1-5 days after operation. Pain：The VAS of the control group and the olfactory training group were evaluated within 1-5 days after operation. Olfactory function：The TDI scores of the control group and the olfactory training group were evaluated in 3 days before operation and 48h after operation. Cognitive function：The MoCA scores of the control group and the olfactory training group were evaluated in postoperative 5-7 days. Markers: Delirium related markers and inflammatory factors in bloods was detected before surgery and after anesthesia. Delirium related markers and inflammatory factors in cerebrospinal fluid was detected after spinal puncture. Subgroup analysis: patients were divided into delirium group and non-delirium group according to whether delirium occurred, and the data of the two groups were compared, including preoperative and postoperative olfactory function TDI scores, preoperative and postoperative VAS scores, nutritional scores, activity scores, and frailty index, Carlson comorbidity index, depression, anxiety state, sleep disturbance, etc., to screen risk factors.

Official Title
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Preoperative Olfactory Training Reduces the Incidence of Postoperative Delirium in Elderly Patients Undergoingorthopedic Surgeries: a Prospective Randomized Controlled Clinical Study

Conditions
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Preoperative Olfactory Training, Postoperative Delirium

Intervention / Treatment
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* Behavioral: olfactory training


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients undergoingorthopedic surgeries (hip or knee replacement and laminectomy) under general anesthesia or combined spinal-epidural anesthesia: 65 years old ≤ age ≤ 90 years old, gender is not limited, ASA classification ≤ class III: There is no recent history of surgery, and the operation time is ≥ 2 hours. Able to communicate normally, able to cooperate and complete the cognitive function test. MMSE score >17. Patients and their families are aware of and willing to participate. Exclusion Criteria: emergency surgery; People with brain diseases or history of brain diseases such as cerebral infarction, stroke, etc.: Have a history of neurological and psychological diseases, including Alzheimer's disease, Parkinson's, psychosis, etc.: Illiteracy, severe hearing or visual impairment; Those who have taken psychotropic drugs or abused psychotropic drugs within one month: Sinusitis, previous nasal surgery history, nasal congestion, upper respiratory tract infection in the past two weeks, previously diagnosed rhinitis and other diseases that may affect olfactory function. Patients who are allergic to pollen Patients who cannot cooperate or refuse to sign informed consent

Ages Eligible for Study
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Minimum Age: 60 Years
Maximum Age: 90 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: Recruited patients will be randomly divided into control group and olfactory training group.The olfactory training group was performed 24-48h before surgery used phenylethyl alcohol (rose), phytol (press tree), citronella (lemon), eugenol (clove) 4 kinds of smell，twice a day for three days.
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| No Intervention: Control group<br>The control group conducts standard preoperative preparation | |
| Experimental: olfactory training group<br>The olfactory training group was performed 24-48h before surgery used phenylethyl alcohol (rose), phytol (press tree), citronella (lemon), eugenol (clove) 4 kinds of smell，twice a day for three days. | Behavioral: olfactory training<br>* In this group, patients were performed 24-48h before surgery used phenylethyl alcohol (rose), phytol (press tree), citronella (lemon), eugenol (clove) 4 kinds of smell，twice a day for three days.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Incidence of postoperative delirium | The 3D-CAM scores | Postoperative 1-5 days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Degree of delirium | Memorial delirium assessment scale(MDSA) | Postoperative 1-5 days | 
| Olfactory function | The Sniffin' Sticks test involves testing odor for threshold and discrimination whilst blind folded and secondly odor identification. The sum of four odors responses ranges from 0-16. The sum of total score from odor Threshold, Discrimination and Identification (TDI) is a maximum of 48 points. The total score is graded as; normosmia equals or over 30.5 points, hyposmia 16.5-30 points and anosmia less than 16.5 points. | postoperative 48h compared to preoperative 72h | 
| Cognitive function | Total score of the Montreal Cognitive Assessment (MoCA). | postoperative 5-7 days | 
| Postoperative pain | Post-operative pain, measured in visual analogue scale (VAS),0:no pian, 10:worst pain. | Postoperative 1-5 days | 
| Delirium related markers and inflammatory factors in bloods | These markers include:IL-6, IL-8, IL-10, TNF-α, IL-1β, CRP, N-terminal BNP, albumin, NSE, S-100B, Aβ-42 and T-tau, P-tau, S-100β | immediate post-anesthesia compared to pre-operation | 
| Delirium related markers and inflammatory factors in cerebrospinal fluid | These markers include:IL-6, IL-8, IL-10, TNF-α, IL-1β, albumin, NSE, S-100B, Aβ-42 and T-tau, P-tau, S-100β | immediate post-anesthesia compared to pre-operation |