A study comparing two pain relieving medicines namely, butorphanol and fentanyl, added to 0.5 percent heavy bupivacaine, given into the fluid inside the backbone for pain relief after surgery in adults undergoing planned non obstetric surgeries below the navel.

INTERVENTION: Intervention1: Group BB: Intrathecally 15mg [3.0ml] Inj. Bupivacaine Hydrochloride (0.5 percent) (hyperbaric) with preservative free Inj. Butorphanol Tartrate 250mcg [0.25ml] and 0.25 ml 0.9 percent NS over 15 seconds Control Intervention1: Group BF: Intrathecally 15mg [3.0ml] Inj. Bupivacaine Hydrochloride (0.5 percent) (hyperbaric) with preservative free Inj. Fentanyl Citrate 25mcg [0.5ml] over 15 seconds CONDITION: Health Condition 1: K00‐K95‐ Diseases of the digestive system Health Condition 2: M00‐M99‐ Diseases of the musculoskeletal system and connective tissue Health Condition 3: N00‐N99‐ Diseases of the genitourinary system PRIMARY OUTCOME: Duration of postoperative analgesiaTimepoint: At the time of intrathecal injeciton, at VAS more than 4 INCLUSION CRITERIA: 1. 80 patients of ASA I & II, 2. Either se Xposted for non‐obstetric infraumbilical surgeries under spinal anaesthesia, 3. Patients aged between 18 years to 60 years, 4. Those who will give valid informed written consent for participation SECONDARY OUTCOME: Diastolic Blood PressureTimepoint: Intraoperatively every 5 min for first 30min, then every 10 min till the end of surgery. ; Postoperatively every 30 min till 3 hours, then hourly till 6 hours, then at 8th and 12th hour Heart RateTimepoint: Intraoperatively every 5 min for first 30min, then every 10 min till the end of surgery. ; Postoperatively every 30 min till 3 hours, then hourly till 6 hours, then at 8th and 12th hour Level of motor blockTimepoint: Intraoperatively every 5 min for first 30min, then every 10 min till the end of surgery. ; Postoperatively every 30 min till 3 hours, then hourly till 6 hours, then at 8th and 12th hour Level of sensory blockTimepoint: Intraoperatively every 5 min for first 30min, then every 10 min till the end of surgery. ; Postoperatively every 30 min till 3 hours, then hourly till 6 hours, then at 8th and 12th hour ; for 2 segment regression from maximum level & regression to S1 level Mean Arterial PresureTimepoint: Intraoperatively every 5 min for first 30min, then every 10 min till the end of surgery. ; Postoperatively every 30 min till 3 hours, then hourly till 6 hours, then at 8th and 12th hour NauseaTimepoint: From the time of intrathecal injection till 12 hours after surgery Oxygen SaturationTimepoint: Intraoperatively every 5 min for first 30min, then every 10 min till the end of surgery. ; Postoperatively every 30 min till 3 hours, then hourly till 6 hours, then at 8th and 12th hour PruritusTimepoint: From the time of intrathecal injection till 12 hours after surgery Ramsay Sedation ScoreTimepoint: Intraoperatively every 5 min for first 30min, then every 10 min till the end of surgery. ; Postoperatively every 30 min till 3 hours, then hourly till 6 hours, then at 8th and 12th hour Respiratory RateTimepoint: Intraoperatively every 5 min for first 30min, then every 10 min till the end of surgery. ; Postoperatively every 30 min till 3 hours, then hourly till 6 hours, then at 8th and 12th hour ShiveringTimepoint: From the time of intrathecal injection till 12 hours after surgery Systolic Blood PressureTimepoint: Intraoperatively every 5 min for first 30min, then every 10 min till the end of surgery. ; Postoperatively every 30 min till 3 hours, then hourly till 6 hours, then at 8th and 12th hour Total amount of vasopressor requiredTimepoint: From the time of intrathecal injection till 12 hours after surgery Total number of topup or rescue analgesic required till 12h postopTimepoint: From the time of intrathecal injection till 12 hours after surgery Visual Analogue ScoreTimepoint: Postoperatively every 30 min till 3 hours, then hourly till 6 hours, then at 8th and 12th hour VomitingTimepoint: From the time of intrathecal injection till 12 hours after surgery