Comparison between Magnesium Sulphate and Ketorolac Intravenous Infusion on Characteristics of Spinal Anesthesia

Abstract
Background: Spinal anesthesia is used widely for many procedures, many adjuvants had been used to prolong duration of sensory and motor block and improve post-operative pain.
Aim of Study: The aim of this study is to compare the effect of magnesium sulphate and ketorolac intravenous infusion on sensory and motor blockage, hemodynamic pa-rameters, duration of analgesia and side effects during spinal anesthesia.
Patients and Methods: Patients were classified randomly into three groups (30 patients each) Group M (Magnesium sulphate Group), Group K (Ketorolac Group), Group C (Con-trol Group). Group M patients received a loading dose of magnesium sulphate 40mg/kg IV over 10min followed by 15mg/kg/h IV infusion, Group K patients received a loading dose of ketorolac (0.4mg/kg) (IV) over 10min followed by 0.8mg/kg/h IV infusion. Group C received 50ml of saline (IV) over 10min followed by saline infusion. After ensuring free flow of cerebrospinal fluid, 3mL of bupivacaine (0.5%) injected Pulse rate, electrocardiography, non-invasive blood pressure and SpO2 monitored continuously. Measurements: Demographic data (age, weight, BMI, ASA physical status). Hemodynamic (HR, MAP, SpO2) before giving study drugs, 10min after giving study drugs and after reaching the maximal level of spinal anesthesia and then every 30min till end of surgery. Onset of sensory blockade has been assessed by pinprick method. Onset of motor blockade has been assessed by modified Bromage Scale. Level of sensory and motor blockade has been checked at 3, 5, 10 and 15min after spinal anesthesia and then every 20min throughout the surgery. Time to achieve complete regression from sensory and motor blockade has been noted. All the durations were calculated considering the time of spinal injection as zero time. Post-operatively analgesia has been assessed by the Visual Analog Scale (VAS). The time at which analgesia was first received and total analgesic requirement in 24h was recorded. Patients observed for any adverse effects such as nausea, hypotension.
Results: There were insignificant changes between the three groups in HR and MAP but there was significant decrease in HR and MAP in each group at 10min, maximal level and 30min in comparison with base line.
There were insignificant changes in onset and duration of sensory and motor block in the three studied groups.
The total dose of analgesic consumption (pethidine (mg)) showed significant decrease in Group M in comparison with Group K & Group C with insignificant change between Group K & Group C.
The time of first rescue analgesia showed significant increase in Group M in comparison with Group K & Group C and insignificant changes in Group K in comparison with Group C.
Conclusion: Addition of intravenous magnesium sulphate with spinal anaesthesia provides significant decrease in post-operative analgesic requirements and prolongs the time of the first rescue analgesia as compared to intravenous ketorolac with spinal anaesthesia.