Study of The Analgesic Profile of Two Adjuvants Added to Low Dose Hyperbaric Bupivacaine Versus One Adjuvant in Patients Undergoing Anal Surgery Using Spinal Anesthesia

Group F (fentanyl group):will receive intrathecal 1.5 ml hyperbaric bupivacaine 0.5% and 0.5 ml (25 mcg) Fentanyl and 1 ml glucose 5% with total volume of 3ml.

Group D :Dexmedetomidine group: will receive intrathecal 1.5 ml hyperbaric bupivacaine 0.5% and 1 ml (4 mcg) Dexmedetomidine and 0.5 ml glucose 5% with total volume of 3ml.

Fentanyl and Dexmedetomidine group:will receive intrathecal 1.5 ml hyperbaric bupivacaine 0.5%, 0.5 ml (25 mcg) Fentanyl and 1 ml (4 mcg) Dexmedetomidine with total volume of 3ml.