With the progression of population aging, the number of elderly patients undergoing surgery is increasing as well. However, as the condition of health differs greatly between individual elderly patients even of the same age, it is a necessity to evaluate elderly patients thoroughly and individually for better management of perioperative care.

Frailty is a condition in which patients are impaired at physical reserve and homeostatic control. Frail elderly people are at higher risk of morbidity and mortality after exposure to a stressor. Frail patients are at higher risk of perioperative complications and longer hospital stay. However, there has been no standard criteria or tool to evaluate frailty in the elderly. Neither has there been enough evidence explaining the mechanism between frailty and increased perioperative complications. Therefore, in this study we aim to discover the relationship between frailty and intraoperative hemodynamic instability, as well as perioperative complications in the elderly patients, hoping to find an adequate and practical model for preoperative assessment in the elderly hopefully for better perioperative outcome.

Inclusion Criteria:

• age≥65 years
• elective major non-cardiac surgery
• general anesthesia
• American Society of Anesthesiologists(ASA) grade I,II,III
• study protocol fully understood by the patients, written consent obtained

Exclusion Criteria:

• emergency surgery
• in active state of infection or inflammation
• chronic kidney disease(CKD) stage 5
• having conditions that would interfere accurate measurement of upper extremity blood pressure (e.g. subclavian artery stenosis)
• having conditions that would interfere assessment of frailty assessment (e.g. mental disorder, hearing disorder)
• study protocol not fully understood, no written consent obtained

This study intend to include elderly patients (≥65years) who undergoes elective major non-cardiac surgery who can cooperate with upper extremity blood pressure measurement and frailty assessment.