To study on the Postoperative Cognitive Dysfunction: Correlations With Olfactory Dysfunction and Related Gene Changes.To explore whether the olfactory dysfunction could be used as a predictor of POCD and to provide reference for POCD prevention, early detection and timely diagnosis and treatment.

Inclusion criteria:

• Between 60 to 85 years old;
• Undergoing non-cardiac and non-neurological surgery under general anesthesia;
• Expected hospital stay ≥5 days;
• American Society of Anesthesiologists class I or II.

Exclusion criteria:

• Mental or neurodegenerative diseases;
• History of severe trauma or surgery within one year;
• History of nasal or sinus illness or surgery;
• Cold or influenza within 3 weeks;
• Significant history of organ dysfunction;
• Previous neuropsychological testing;
• Difficulty to perform tests (including severe visual or auditory disorders);
• Mini-Mental State Examination (MMSE) <24 points, <20 points if the participant only attended elementary school, or <17 points if the participant did not go to school.

We included 300 male and female patients undergoing non-cardiac surgery at the Affiliated Hospital of Xuzhou Medical University and 30 healthy volunteers.

within six months after the trial complete