Low dose bupivacaine and bupivacaine with fentanyl for spinal anesthesia for transurethral resection of prostate

Background: Spinal anesthesia is most frequently used for transurethral prostatectomy (TURP), because it permits early recognition of transurethral resection of prostate (TURP) syndrome and bladder perforation. In this study, we compared the effects of low dose bupivacaine (5 mg) with fentanyl (25?g) and conventional dose of bupivacaine (7.5 mg) in elderly patients undergoing TURP. This comparative study was conducted to evaluate the efficacy of addition of fentanyl 25 ?g intra thecally to bupivacaine 5 mg and bupivacaine 7.5 mg alone for transurethral prostatectomy. Material and methods: The patients were randomly allocated into 2 groups, each having 30 patients. Group-A: Inj. Bupivacaine 5 mg (0.5%) (1ml) + Inj. Fentanyl 25 ?g (0.5 ml). Group-B: Inj. Bupivacaine 7.5 mg (0.5%) (1.5 ml). A standard subarachnoid block was performed in L2-L3 / L3-L4 Space in sitting / lateral position with 22G/23G BD spinal needle (Quinky type, 3.5 inch long) under all aseptic and antiseptic precautions after local infiltration of skin and subcutaneous tissue with 2 cc 2 % lignocaine. Drugs were injected after checking of free flow of CSF and according to group selected. All the observations were recorded and all the results were analyzed statistically. Results: The mean time of onset sensory blockade was significantly shorter in group A than group B. Group A took less time to reach the peak sensory level (3.57 min) as compared to group B (5.8 min). Onset of motor blockade was delayed in group B as compared to group-A, and the differences were statistically significant. Changes in pulse rate of all groups are statically not significant and comparable. The incidence of hypotension and shivering was significantly higher in group B as compared to group A. Conclusion: It was observed that intra thecal bupivacaine 5 mg combined with fentanyl 25 ?g provided adequate anesthesia for TURP in elderly patients and is associated with lower incidence of hypotension and shivering than a conventional dose of bupivacaine. The addition of fentanyl improves the quality of block, increases duration of sensory block and makes the blockade hemodynamically more stable than conventional dose of bupivacaine.