Efficacy of unilateral continuous spinal anesthesia with hypobaric bupivacaine in elderly patients undergoing hip replacement

Abstract

Objective To evaluate the efficacy of unilateral continuous spinal anesthesia with hypobaric bupivacaine in the elderly patients undergoing hip replacement. Methods Sixty ASA Ⅱ or Ⅲ elderly patients of both sexes aged 69-98 yr weighing 46-81 kg scheduled for hip replacement were randomly divided into 2 groups (n = 30 each): hypobaric bupivacalne group (group HB) and isobaric bupivacaine group (group IB). Group HB and IB received intrathecal 0.5% hyperbaric bupivacaine 1.0 ml and 0.5% isobaric bupivacaine 1.0 ml both at a rate of 0.1 ml/s respectively. The level of sensory block and degree of motor block were measured every 5 min using a pinprick test and modified Bmmage scale respectively. 0.5% bupivacaine was given in 0.5 ml increments every time to maintain the block level at T8-T10 BP, MAP and HR were recorded before intrathecal injection and at the time when the block level reached T8-T10. Adverse effects, total amount of bupivacaine consumed, duration of analgesia and duration of motor block during operation were recorded. The complications were also recorded during 2 weeks after operation. Results Compared with group IB, SP at the time when the block level reached T8-T10 was significantly increased, the total amount of bupivacaine consumed was decreased, duration of analgesia and duration of motor block were shortened, and adverse effects were decreased in group IB (P < 0.01). No complications were observed after operation in both groups. Conclusion The unilateral continuous spinal anesthesia with hypobaric bupivacaine produces controlled sensory block level with stable hemodynamics and less adverse effects in the elderly patients undergoing hip replacement. Key words: Bupivacaine; Anesthesia, spinal; Aged; Arthroplasty, replacement, hip