Comparision of Dexmedetomidine and Clonidine as an adjuvant to intrathecal hyperbarik bupivacaine in patients undergoing lower limb orthopedic surgery: A prospective double blind randomised controlled trial.

After obtaining permission from the institutional ethical committee and written informed consent from patients, patients will be recruited in this prospective double blind randomized controlled trial. Patients will undergo routine pre-anaesthetic examination before considering for surgery. Patients who fulfil the above mentioned inclusion criteria will be enrolled in trial after obtaining a written consent.Patients will be kept nil-per-oral as per ASA( American Society of Anaesiologists )guidelines with oral Pantoprazole 40mg on previous day of surgery.

Participants will be familiarized with the recording of post-operative pain using a 10 point visual analogue scale anchored at one end by - no pain at all- and at the other end by - worst pain imaginable.

On day of surgery , after re-assessing the patient in pre operative room. Intravenous(iv) line secured and baseline vitals noted. Once patient is shifted to operation theater,  iv fluids started, all ASA monitors will be attached and initial readings are noted. Following patient positioning, local skin infiltration using 2ml of lidocaine 2%, 25 G spinal needle will be introduced through L3-L4 interspace under strict aseptic precautions.

One of the group will be receiving 3.0 ml volume of 0.5% hyperbaric bupivacaine and 30mcg clonidine intrathecally. Meanwhile, other group will receive 3.0 ml volume of 0.5% hyperbaric bupivacaine and dexmedetomidine 10mcg intrathecally. Drugs will be prepared by anesthesiologist who is not involved in the study so that both patient and investigator will be blinded . Intrathecally injection in both groups will be given over approximately 10 seconds. Immediately after completion of injection, patient will be made to lie  supine. The completion of injection will be taken as time zero of induction of anaesthesia. Sensory level will be monitored using pin prick method with 24 gauge hypodermic needle every minute till T10 is achieved. Time when sensory level of T10 is achieved will be noted. The highest sensory level achieved and time taken to achieve that would be noted from time zero. Motor blockade will be assessed every minute using Modified Bromage Scale. Time taken to achieve bromage 3 would be noted.

Heart rate, systolic blood pressure, diastolic blood pressure, oxygen saturation will be monitored every 2.5 minutes for initial 30 minutes and later every 15 minutes till end of surgery . Hypotension is defined as fall in blood pressure more than 20% from baseline value and will be treated with ephedrine 6mg. Number of hypotension episodes noted.

Post-operatively patient will be kept in recovery room for 2 hours and VAS score will be noted every half an hourly till 2 hours and every 4th hourly till next morning. VAS score more than 4 will be treated with injection tramadol 50mg iv. Total amount of analgesic required will be noted. Post operative nausea vomiting noted and treated with dexamethasone 8mg iv. Incidence of pruitus will be noted and treated with Tab Chlorpheniramine 40mg. Shivering will be noted and treated by applying warm blanket.