Evaluation of the Corrected Carotid Flow Time and the Inferior Vena Cava Collapsibility Index in Predicting Post-spinal Anesthesia Hypotension in Geriatric Patients

We include patient who will undergo elective surgeries such as orthopedic surgeries as fixator placement, lower extremity debridement, inguinal hernia, Urosurgery as bladder- prostate resection, hysterectomy, fibroid removal, ovarian cyct removal, plastic surgeries, and other types of surgery. The fasting durations of the included patients will be 8 hours for solids and 2 hours for clear liquids. There won't be any premedication given. The patient will be placed in a supine, neutral-head resting posture in the operating room as well as standard monitors such as a five-lead electrocardiography, pulse oximeter, and noninvasive blood pressure. An attending anesthesiologist will use a 25-gauge Quincke spinal needle to induce spinal anesthesia in the L3/4 or L4/5 vertebral interspace with the patient in the right lateral decubitus posture. Throughout the course of the trial, the attending anesthesiologist will choose the dosages of 0.5% hyperbaric bupivacaine (10 to 15 mg) and fentanyl (10 to 20 mg) 28. The patient will be placed back in the supine position without any lateral tilt once the spinal injection has been given over a period of 15 to 30 seconds. Three minutes following the spinal injection, the sensory block will be evaluated with a cold and pinprick test. The mean blood pressure will be taken every 3 minutes between the spinal injection and delivery, and every 5 minutes from the delivery until the end of the procedure. The lowest SBP measured between the spinal anesthesia injection and delivery will be determined, together with the percentage of the SBP drop from the pre-anesthetic SBP. The patient's head will be turned 308 degrees to the left. First, a 6.0 to 13.0MHz linear array transducer will be positioned vertically on the neck with the probe marker facing the patient's head. The lower edge of the thyroid cartilage will provide a long-axis B-mode picture of the right common carotid artery. The probe will then be positioned in the lumen's center, around 2