Blood pressure optimization has been considered as a crucial factor to avoid perioperative vital organ hypoperfusion, and perioperative hypotension has been addressed as a risk factor for complications and adverse clinical outcomes.

Hypotension prediction index (HPI) is an novel machine-learning derived parameters, and was developed to predict the risk of future hypotension.Series of clinical studies have verified its clinical efficacy in avoiding perioperative hypotension.

Major orthopedic surgeries, such as spine surgery, joint surgery, long bone fracture surgery, are quite common in elder people, who are vulnerable to perioperative adverse outcomes.Thus the investigator design this study to testify the clinical efficacy of implementing HPI in perioperative goal-directed hemodynamic therapy in elder patients receiving major orthopedic surgery.

Inclusion Criteria:

• adults elder or equal to 60 years old receiving scheduled orthopedic surgery

Exclusion Criteria:

• Patients with a history of arrhythmia, congestive heart failure, preoperative neurocognitive disorder, cerebrovascular event, chronic obstructive pulmonary disease, chronic kidney disease, ongoing infectious disease, will be excluded.