The aim of this study is to observe how the hemodynamic changes induced by spinal blockade affect cerebral oxygenation. Elderly patients are very frail. Hypotension is very frequent during spinal anaesthesia. Bradycardia is other side effect of regional anaesthesia affecting cardiac output and cerebral blood flow. These complications of spinal anaesthesia could decline cognitive function. In this way a non invasive monitoring technique as cerebral oximetry is useful for the safety of anesthetic procedure.

Patients aged 70 years old with hip fracture presenting for surgical repair under intrathecal anaesthesia performed with bupivacaine or L bupivacaine (dose 7 - 9 mg). Preoperative haemoglobin and drugs consumption are registered. All patients receive supplemental oxygen during surgery. Cerebral oximetry, blood pressure, heart rate and oxygen arterial saturation are measured. Level and duration of sensory and motor block are registered. The study observes if there is any correlation between cerebral oximetry and these hemodynamic parameters.

The investigators also observe if there is any correlation between cerebral oximetry and cognitive function evaluated pre and postoperatively by SPMSQ test.

Postoperative SPMSQ test will be performed on the 5th postoperative day and the complications registered.Patients will be followed for the duration of acute hospital stay.

Inclusion criteria:

• Patients aged >70 years old with hip fracture.
• No contraindication for spinal anaesthesia.

Exclusion Criteria:

• Allergic reaction to local anesthetics.
• Severe aortic stenosis.
• Local infection.
• SPMSQ test >7 errors.
• Patient refusal

Patients aged > 70 years old with hip fracture undergoing surgery under spinal anaesthesia.