Comparison of Two Different Doses of Hyperbaric Bupivacaine with Fentanyl for Spinal Anaesthesia in Elderly Patients Undergoing Routine Endoscopic Urological Surgery: A Randomized Controlled Study

Background: The major drawback of spinal anesthesia in elderly patients is the per operative hypotension and its sequel. We compared two doses (7.5 mg or 10 mg) of hyperbaric bupivacaine 0.5% with 25 mu g fentanyl in 150 elderly patients undergoing routine urological surgery with respect to hemodynamic profile. Results: The time to onset of sensory block (min) was comparable amongst the two groups (2.41 +/- 0.86 and 2.25 +/- 0.79) in group A and B respectively. The mean time to regression of block to S2 level was at 3.56 +/- 0.53 hrs. in group A and 4.01 +/- 0.71 hrs in group B (p<0.0001). The maximum mean height of sensory block was at T8 level in 73.3% patients and T10 level in 18.6% patients of group A. In group B patients 58.6% had the sensory level at T6 level in 33% patients it was at T8 and in 8% it was at T4 level (p<0.0001). Onset of motor block was earlier in group B and was at 3.89 +/- 0.8 min over 4.23 +/- 1.01in group A. (p=0.026). The time to regression of motor block was earlier in group A (4.07 +/- o.54 hrs over 4.69 +/- 0.58 hrs in group B). (p<0.0001). The decrease in MAP from baseline values was more in group B over group A (0% vs. 4.7%, p<0.05) but the incidence of hypotension and bradycardia were statistically comparable amongst the groups (p>0.05). Conclusion: The use of 7.5mg bupivacaine with 25 mu g fentanyl intrathecally results in adequate anaesthesia and analgesia coupled with stable hemodynamic as required for transurethral surgery of around 2 hrs.duration.