. Spinal needles (22 G) will be introduced in sitting position after skin disinfection with povidine iodine, iliac crest will be palpated and thumb extended to meet the midline, feeling the space between L4 and L5. spinal needle penetrates through the dura matter, a pop will be felt and then after the needle puncture into the subarachnoid space and the appearance of clear cerebrospinal fluid, the intrathecal local anesthetic will be injected. All patients will be receiving 2 ml heavy bupivacaine 0.5% plus 5 µg dexmedetomidine to total volume of 2.5 ml.

Spinal needles (22 G) introduced in sitting position . patients receiving1.7 to 2.2 ml heavy bupivacaine 0.5%( according to weight and height ) + 1 ml normal saline = total volume of 2.5 ml then at surgery end under sonographic guide transducer placed in transverse plane above iliac crest.A 90 mm 22 G short beveled block needle inserted in-plane with transducer, in anterior-posterior direction. needle connected to syringe contains20 ml of bupivacaine 0.25%+10 µg dexmedetomidine to deposit local anesthetic deep into the fascial layer between internal oblique & transversus abdominis muscles on each side.

Patients will be anesthetized only with spinal anesthesia using Bupivacaine Hcl( 10 mg).

60 Patients will be randomly divided into three equal groups:

Group A (n=20) : spinal anesthesia with Dexmedetomidine (5µg ) added to local anesthetic (bupivacaine Hcl ) (10 mg) given intrathecally .

Group B (n=20) : spinal anesthesia using local anesthetic( bupivacaine Hcl) (20 mg) combined with TAP block using Dexmedetomidine (20µg ) after the cesarean section

Group C (n=20) (controlled group ) : Spinal anesthesia using only local anesthetic (bupivacaine Hcl ) (10 mg) .

Demographic data (age, weight, and length), mean arterial blood pressure (MAP), and heart rate (HR) will be measured every 5 minutes intraoperatively and at 1, 2, 4, 6, 8,12,16,20 and 24 h postoperatively. Visual analog pain score (VAS) between 0 and 10 (0=no pain, 1-3=mild pain, 4-6=moderate pain, and 7-10=severe pain) will be recorded at 1, 2, 4, 6, 8,16,20 and 24 h postoperatively. First time of rescue analgesia: this is defined as the time from onset of sensory block till the time of first requirement of analgesia. The total amount of rescue analgesia consumption in the form of intravenous ketorolac→0.5 mg/kg if VAS greater than or equal to 4. Any undesirable postoperative side effects (as nausea, vomiting and pruritus) will be recorded and managed.

measuring BP , HR , oxygen saturation during operation every 5 minutes