Inclusion Criteria:  Adult patients (>60 years) ASA I-II-III Patients scheduled for elective surgeries under spinal anesthesia.  Exclusion Criteria:  Operations which will last for less than 15 minutes. Deep vein thrombosis in the upper extremities. History of radiotherapy or neck surgery. Previous sonographic data show tricuspid or mitral regurgitation or a very distended right atrium and ventricle. Patients with history of valvular or carotid artery surgery, arrhythmia, heart failure. Being unable to lie in a supine position for the necessary measurements. Technical limitations to imaging of the IJV and carotid artery.