Ultrasonographic Assessment of Neck Vessels as Predictors of Spinal Anesthesia Induced Hypotension in Elderly

"Patient will be in supine position, The linear probe with frequency of 7- 12 M hz; depth of 3 cm. maximum IJV diameter (IJV-D) and area (IJV-A) will be recorded. M-mode will be used to obtain the distance between the 2 walls of the vein during inspiration and expiration.~Then, the patient will be positioned 10° Trendelenburg and similar ultrasonographic measurements will be again performed"

"US Probe is slided superiorly (toward the head) or inferiorly (toward the feet) until the bifurcation of the common carotid artery (CCA) appears on the left side of the screen. This is the ideal location for imaging and CIMT measurements.~IMT is assessed in longitudinal view from the arterial far wall, along a 10mm length. CIMT will appear as two parallel lines (leading edges of two anatomical boundaries) from it: lumen- intima and media- adventitia interfaces perpendicular to ultrasound beams."

Spinal anesthesia will be performed in the sitting position at level of L3-4 or L4- 5 interspaces with a 25-gauge spinal needle. Local infiltration of skin and subcutaneous tissue with 2% lignocaine will be applied. After confirming cerebrospinal fluid flow, 10 mg of 0.5% hyperbaric bupivacaine plus 25 mcg fentanyl will be injected. The degree of sensory block (cold test by alcohol gauze) will be assessed in the study with a goal of T8 dermatomal level block.