Carotid Artery Corrected Flow Time and Inferior Vena Cava Collapsibility Index for Prediction of Hypotension After Induction of General Anesthesia in Geriatric Patients Undergoing Elective Surgery

Inclusion Criteria: * American Society of Anaesthesiologists Physical Status I to Ⅱ * receiving general anesthesia for elective surgery * fasted for at least 6 to 8 hours were recruited in this study Exclusion Criteria: * • patients who refused to participate in the study * American Society of Anaesthesiologists Physical Status Ⅲ or Ⅳ * Patients with a history of peripheral arterial diseases or atherosclerosis * Patients with body mass index of greater than 30 kg/m2 * Patients with arrhythmia or cardiomyopathy * Chronic obstructive pulmonary disease (COPD) * baseline systolic arterial pressure (SAP) ≥ 180 mmHg or \< 90mmHg * Any episode of desaturation or difficult intubation during general anasethia induction