• Ethical clearance will be obtained from the institution’s ethics committee. • The study will be conducted on ASA 1 and 2 patients of either sex, aged between 18 and 60 years who are willing to be a part of the study,undergoing elective lower limb surgeries at the tertiary care teaching hospital on ASA 1 and 2 patients of either sex, aged between 18 and 60 years who are willing to be a part of the study. • Patient and bystander of the patients will be explained about the procedure in the language understood by them and a written informed consent will be obtained in both English and local language. • Randomization will be done using computer generated random number series. The patients will be divided into 2 groups of 30 each. block will be performed using the following drugs. Group R: Intrathecal 3ml 0.75% Heavy Ropivacaine with 200mcg Morphine Group L: Intrathecal 3ml 0.5% Heavy Levobupivacaine with 200mcg Morphine • Principal investigator not involved in performing the block will be in charge in preparation of the study drug. An anaesthesiologist experienced in performing subarachnoid block who is blinded to the study group will be performing this block. Patient involved in the study will be blinded to the group to which they belong. Patients will undergo detailed pre-anaesthetic evaluation which will include physical examination and relevant laboratory investigations. Strict nil-per-oral according to standard guidelines will be followed. Premedication with Tab. Alprazolam 0.5mg HS and T. Pantoprazole 40mg HS and CMS. Patient will be shifted to OT and positioned supine, intravenous line will be secured with wide bore cannula and IV fluids will be started. Routine monitors like Electrocardiography, pulse oximeter and noninvasive blood pressure will be attached to the patient. Basal vital parameters like heart rate, blood pressure and SpO2 will be recorded. Technique: Under strict aseptic precaution Sub-arachnoid block is performed with patient placed in sitting position. The injection site will be cleansed with povidone iodine and covered with sterile drapes. Local anaesthesia at the injection site will be provided with 2ml of 2% plain lignocaine. Subarachnoid block is performed after identifying L3-L4 intervertebral space in the midline.4 Appropriate size Quincke’s needle is used and will be inserted with distal port facing upward. The preloaded sterile drug will be injected after confirmation of free flow of cerebrospinal fluid, over 10-15 seconds. Either 3ml of hyperbaric ropivacaine 0.75% with 200mcg morphine or 3ml of hyperbaric levobupivacaine 0.5% with 200mcg morphine as per group allotted randomly. Onset of sensory blockade will be calculated asthe time interval between injection of preloaded local anaesthetic and loss of prick sensation in lower limb. Onset of motor blockade will be calculated as the time interval from administration of the preloaded drug to loss of movements of lower limb. Duration of sensory block will be time interval between loss of prick sensations to its reappearance. Duration of motor block will be time interval between loss of movements of lower limb to reappearance of the movements. Duration of analgesia will be the time interval between onset of sensory blockade and the 1stdose of rescue analgesic given to the patient. Following the administration of the sub arachnoid block, patient will be turned to supine position immediately. Assessment Sensory block: Will be assessed by checking for loss of pin prick, using 22- gauge hypodermic needle sensation every 1 min till the onset of loss of sensation till highest level is achieved, then every 30min in the post operative period till regression of loss of sensation up to S2 Motor block: Will be assessed using Bromage score every 1 minute till loss of lower limb movements or modified Bromage 3, then every 30 minutes till lower limb movements regained or modified Bromage 0 is attained in the postoperative period. Motor block will be graded with modified Bromage Scale: 0 = No motor block 1 = Inability to raise extended leg, can bend knees and feet 2 = Inability to raise extended leg and move knee, able to move feet, 3 = complete motor block of the lower limbs.4 Saturation, non-invasive blood pressure and heart rate will be monitored at 3 minutes interval for first 15minutes post injection and at 5 minutes intervals thereafter till 1 hour after which assessment was performed every 10 min interval till end of surgery and then at 30 min intervals thereafter until complete recovery of sensations and motor blockade of grade 0 on Bromage scale will be observed. Hypotension, that is the decrease in mean arterial pressure >30% from baseline or if the mean arterial pressure <60 mm Hg will be treated with IV bolus of 5ml/kg ringer’s lactate and if needed incremented doses of ephedrine and other vasopressors. Fluids will be administered to replace intraoperative losses. Intravenous Atropine 0.6 mg will be administered if the heart rate <50 bpm. The incidence of any adverse effects will be noted. In case of block failure general anaesthesia will be administered to the patient and such case will be excluded from study. Intravenous injection of Diclofenac 75mg diluted in 100ml normal saline or injection Tramadol 50 mg diluted in 100 ml normal saline will be given as rescue analgesia if patient complains of pain in the post operative period. Injection ondansetron 4mg IV will be given at the end of surgery. All the patients will be monitored in post anaesthetic care unit (PACU) for two hours by the anaesthesia resident who is also blinded in this study. Post operatively, various haemodynamic variables, oxygen saturation and pain score will be monitored, until complete recovery of the patients from sub-arachnoid blockade. Postoperative analgesia will be assessed using visual analogue scale. |