Caval-aorta Index and Perfusion Index on Predict Hypotension After Spinal Anaesthesia in Elderly

Inclusion Criteria: * American Society of Anesthesiology(ASA) I-II-III score * Patients over 60 years * Elective surgeries * Surgeries in supine position Exclusion Criteria: * Patient refusal to participate in the study * The patient will undergo emergency surgery * Contraindication to spinal anaesthesia * Planning unilateral spinal anaesthesia * Failure of spinal anaesthesia * Body mass index above 35kg/m2 * Presence of preoperative hypotension (SBP\<90mmHg or MAP\<60mmHg) * The patient has valvular disease and arrhythmia impairing haemodynamics * Presence of neuropsychiatric disorders that make communication difficult * Presence of abdominal hernia