A clinical prospective, randomized study to compare intrathecal isobaric bupivacaine – fentanyl and isobaric ropivacaine – fentanyl for lower abdominal and lower limb surgeries

Abstract

Introduction: Opioids have been used intrathecally as adjuvant to bupivacaine and ropivacaine for improvement in quality and extending the duration of spinal blockade. We hypothesized that intrathecal ropivacaine provides similar anaesthesia with lesser motor blockade as compared to bupivacaine. So, we conducted this prospective, randomized, double blind study with an aim of comparing theeffect of isobaric bupivacaine with fentanyl to isobaric ropivacaine with fentanyl with regards to sensory blockade, motor blockade and quality of analgesia in postoperative period.

Methodology: After ethical committee approval and consent, 100 patients, aged 18 to 60 years, undergoing lower abdomen and lower limb surgery were included in the study. The patients were randomly divided into two groups: Group I received 3 ml 0.5% isobaric bupivacaine plus 20 mg fentanyl. Group II received 3 ml 0.5% isobaric ropivacaine plus 20 mg fentanyl. The subarachnoid block was administered in sitting position in L3-L4 inter vertebral space and the study drugs were given at a rate of 0.2 ml/second. The patient was placed in supine position till maximum effect was achieved. The parameters observed included time of onset of sensory blockade, extent of sensory blockade, degree of motor blockade and duration of analgesia. The heart rate, blood pressure, oxygen saturation and respiratory rate were recorded.  All the parameters were recorded just after giving spinal anaesthesia, at 5 minute intervals till 15 minutes, then at 15 minute intervals till 180 minutes. Bradycardia and hypotension was treated with inj. atropine, crystalloid solutions and inj. ephedrine IV.  Inj. tramadol 1mg/kg was administered as a rescuer analgesic if the patient’s VAS score was >3. Any side effects were recorded.